Showing posts with label ebike. Show all posts
Showing posts with label ebike. Show all posts

Saturday, February 3, 2024

Off-road Trails in Southern Nevada


 

I ride electric mountain bikes and a dual sport motorcycle in southern Nevada. Luckily, over 85% of Nevada is public lands, and there is lots of off road riding available for both motorized and non-motorized machines. I wanted to create this blog post to make others aware of some great resources to find all these available trails.  While many of these resources claim to have maps for both, coverage of motorized versus non motorized varies quite a bit within each of the apps/websites. Some have free access levels and others support both subscriptions free access levels.  I will say that none of these mapping tools has complete coverage.  Most are less than half the actual trails in most areas.  

I also use an old smartphone for navigation for both mountain biking and motorcycling. It is very important to keep your eyes on the trails to avoid an accident, like this one: https://jimroal.blogspot.com/2024/02/oops.html .  Stop to view the navigation.

Apps & Websites

Trailforks - This is my go to app for Electric Mountain biking, and any mountain biking. While it also supports motorized off road trails, it is not particularly good at that. For mountain biking, it is great because crowdsourced trails are available. I have found the coverage in my area to be better than any other apps I have found for mountain biking. It supports offline maps for navigation when out of cellular range.  Part of Outside+.


GAIA - This is a pretty decent app in general for finding trails. I have used it for both motorcycling and electric mountain biking, but I tend to find other apps a bit better and so it is not my go to app.  GAIA is more of a mapping utility and navigation tool than a way to find existing trails. It supports offline maps for navigation when out of cellular range.   Part of Outside+.


onX - There are several variants of onX. I use the off road version. It seems to be the best in my area for motorcycling. It is a subscription only app and website and has no access without a subscription. It supports offline maps for navigation when out of cellular range.  



AllTrails - The AllTrails app and website claim to support all kinds of off road trails and activities. It does but I have found the coverage to be not as good as trail forks for biking or for onX for motorcycling, at least in my area. It supports offline maps for navigation when out of cellular range.  



Kamoot - Supports hiking and biking.

Strava - This is more of a social networking app for bicyclers, but you can look up other people's ride segments and find some routes this way.

Garmin Explore - Garmin explore is an application used with many Garmin products. Garmin has other similar apps to Garmin Explore as well, depending on the product that you are using. It supports offline maps, navigation, and integration with several Garmin products such as InReach satellite messenger.  


Google Maps - Google Maps actually has features for navigating off-road too.  Well, somewhat anyway.  It has biking and walking modes that include trails.  While it is not a main feature it can work surprisingly well at times.  Often you will need to put it in biking or walking mode and also add some stops along the way to enforce your desired route.  Here is an example taking a Jeep trail over Wheeler Pass.



Google Earth - Google Earth has some great tools for searching the Earth for all kinds of detail. It also includes some great measurement tools that will show you the elevation profile. Another great feature is tilting the map to see a perspective from ground level or anywhere in between.  You can also import GPS data from Garmin Connect and other trip trackers. The satellite imagery is good enough to spot many trails that may not yet be mapped.  


RideWithGPS - created as a bicycle route planner it is generally a pretty good route planner.  

Local and national government sites

Each local area likely has its own resources for specific parks and places where there are trails. things like the U. S Forest Service and Bureau of Land Management cover many parks across the United States. Below are just a few that I use around Southern Nevada.






Related Resources

Backcountry Discovery Routes (BDR). Back country discovery routes are specific routes that have been created by the BDR community. They connect multiple trails together to make a long route, generally through part of or an entire state.


Once you find places to ride on the map, the next thing you wonder is how challenging and fun will it be. I generally search the trail name in YouTube where many people have posted some great videos of their rides/drives so you can actually ride the trail before you get there.  I contribute many ride segments on my YouTube Channel https://www.youtube.com/@jimroal .

Saturday, July 29, 2023

Use an old smartphone for bike navigation

 


I enjoy mountain biking off-road and often in areas with no cellular.  Sometimes I ride in areas with many established trails that cross each other and navigation would help.  I looked into bike navigation but they have small screens, are costly, and many of the features are redundant with my Garmin fenix 6x Pro Solar watch.  I also never trade in my old smartphones so I have several fairly recent ones laying around.  I decided to use my old Motorola Z4 smartphone as a biking navigation using.  First I needed a real robust mount.  I started on Amazon and found this one


It grabs all 4 corners and locks in place.  

I cleared and reset the phone, removing all unnecessary apps to minimize battery consumption.  I also put it in airplane mode, and keep WiFi and Bluetooth off to save power.  The Moto Z4 I am using also supports MotoMod batteries, of which I have a few.  I am using the 2200mAh unit primarily and I can hot swap in others if it gets low on the trail (which is unlikely).  I could also connect the phone to the USB port in the bike display to keep it charged if I wanted.  I removed the SIM card as well so it would not search for cellular even out of airplane mode.  Then I installed Google Maps, Trailforks, Garmin Explore, and GAIA maps.  All of these offer offline maps of bike trails.  There are many others too.  So far I found GAIA to be the best for bike navigation as it can ever store satellite maps offline. 

Here is how I organized the home screen.   


Here is what GAIA maps looks like.

Here is a video showing the use of this riding some trails.

This first ride was on a pretty easy trail.  I have yet to test it on harsher rides but so far it seems solid.  I am of course by no means the first person to do this.  I wanted to use an old phone, and not my current phone, just in case that mount breaks or I crash the bike.  Also, I didn't want to drain the battery on the phone I use normally since I want to be able to make calls, or message through my Garmin satellite messenger in case of trouble.  









Saturday, March 25, 2023

Contrasting electric mountain bike hub-drive versus mid-drive

I enjoy real off-road mountain bike riding in places where full suspension is a must and fat tires are needed to get through the soft loam.  Much of my riding includes long steep hills, some in loamy terrain.  I often ride Jeep trails as well as dedicated bike trails.  

I started with a very inexpensive mountain bike with full suspension and 2-1/4" wire tires.  The narrow tires would sink in to the gravel and sand I often encounter.  Even on hard pack trails, the long steep climbs were exhausting.  I realized I needed a fat tire bike with full suspension.  Once you get that, you have a heavy bike so I decided to go electric as well (which of course add even more weight).

I have been riding my Rurui XT10 rear hub drive electric mountain bike over a year and over 1,100 miles. In that time I failed 2 controllers due to overloading them on long steep hills.  Since the motor must handle the wide speed range with no transmission, it is very poorly suited to low speed riding.  On PAS 1 it would go about 12mph where assist would then taper off.  Below about 10mph the motor was just turning too slow and was very inefficient. Electric motors may produce high torque at low speeds but they cannot sustain that very long.  The long steep hills were too much for the hub drive system.  The hub drive I have in this bike is geared which helps but it was not enough of a gear ratio for the riding I was doing.  Freewheeling the bike would reach 39mph top motor speed.  I never needed to motor to 39mph.  25mph would have been much more applicable to my riding.  A hub drive with much high gear ratio could really help.  


However, the other issue is how and when power is applied. The Rurui had what is called a "cadence" sensor which measures the crank speed.  In reality it seemed to only measure if there was crank speed or not.  If you were pedaling, it applied power assist based on your PAS level selected.  It makes for a strange riding experience since the motor power applied is independent of your pedaling force.  There is also a delay in reading pedaling speed (cadence) and applying power.  If you wanted to ride slow through some technical bits, you really had to cut the motor power.  I would often do this by just pulling a brake lever far enough to cut the motor.  There are now hub-drive bikes that use torque sensors.  

I think hub drives are a decent approach for road bikes or at least when riding on well developed hard trails with gentle slopes.  

I analyzed many approaches to augmenting the Rurui to better suit my riding.  I could add a front hub drive and I have seen some bike like that on the market.  However many of the downsides would still exist, now with the added weight of another motor and a whole bunch of added complexity.  

I could add a mid-drive.  This would give the benefit of mid-drive but also keep the hub drive.  It could more than double my power.  I could switch between as needed or use both.  Again, weight and complexity were concerns.  Another big concern was how low the add-on mid drive systems hang.  I already had problems smashing my pedals on rocks I did not want to smash a motor.  

It was time to just upgrade the bike.  I needed a powerful mid-drive bike with more speeds to handle tougher off-road situations.  I needed to be able to crawl along at lower speeds through the technical stuff.  I needed to be able to climb much steeper and longer off-road hills.  I needed better suspension to keep the pedals out of the rocks.  I needed a drive system that would work better at low speeds and higher loads for long periods.  I wanted less un-spring mass on the bike for improved suspension performance.  After many months of research, I decided on the Biktrix Juggernaut Ultra FS Pro 3.



The differenced was stark and immediate.  The very first thing I noticed was the power delivery.  It is pretty much immediate assist when you start pedaling.  I can start off up a fairly steep hill with no problem.  It is like having bionic legs.  Since it is sensing the pedaling force to apply power, the response of very controlled and natural.  Here are some video clips from my first off-road ride on the bike. 



I have ridden this route before on the Rurui several times.  I normally have to get off and push the bike up the steep parts.  Not on the Biktrix.  I did push through a few very steep technical bits but that was not because the bike could not climb it.  This ride was a breeze on the Biktrix.  

The mid-drive system takes advantage of the narrower pedal cadence speeds versus wheel speeds.  The motor is geared to apply much more torque since it does not have to deal with very high pedal speeds.  It takes advantage of the bike gears to support a wide range of bike speeds.  

As with everything, there are of course some trade-offs.  When shifting gears motor power is interrupted to protect the gears from damage.  As with a non-electric bike, when shifting you should reduce pedal force until the sift is complete.  This of course does interrupt power delivery for a second.  Another trade-off is that this total power from pedaling plus the motor power now goes through your chain and gears.  This will be very hard on them.  Even if I have to change the chain, chainring, and cassette every year it will be totally worth it.  

If you enjoy real off-road riding, the mid drive with many speeds (11 in my case) and wide speed changes (42t-11t) is the way to go.  Hub drive could be fine in flatter and hard-packed terrain where you plan to be at speeds greater than 10mph at all times.  





Saturday, March 18, 2023

Biktrix Juggernaut Ultra FS Pro 3 - 30 mile review

 

I bought this bake based on my experiences with prior bikes given where I like to ride.  I go off-road much more than on pavement.  I put 1,200 miles on my Rurui XT10 and learned many things about the pros and cons of hub drive electric mountain bikes.  I realized that for my riding I needed a powerful mid-drive bike so after shopping around, I bough this.

The power delivery from this bike is much better suited to my riding.  It uses both crank torque and cadence sensors to determine how much motor power to add.  This is a much more controlled and natural way to add assist power.  It also takes advantage of all the gears, 11 on this bike, to provide high torque and a wide speed range.  The mid-drive is also all suspended weight which gives better suspension dynamics in rough terrain.  

It arrived in a box very similar to my Rurui bike did.


Like the Rurui, I had it assembled in about 30 minutes.  Pretty easy.


I took a couple short rides around the neighborhood and adjusted it to get everything working well and the best ergonomic feel.

My first off-road ride was out to a trail I had been building, less than 8 mile round trip.  Later that same day, I took it for a 23 mile loop which included paved bike path, long steep hills, loamy washes, rocky hard-pack, and everything else the desert has.  I had ridden most of this route before on the Rurui so this was a great ride to contrast them.  This bike is so much better suited to off-road riding.  With 11 speeds and the mid-drive, it can climb any hill with ease.  I shot a YouTube video with some clips from that ride.
I don't even have the range extended battery installed yet but so far the battery life is fantastic.  Surely this is at least partly due to the mid-drive motor being in a much more efficient operating range, especially in the off-road situations that require high power such as steep hills and loamy terrain.  The hub drive was just turning too slow and to close to stall where it become very inefficient and is hard on the controller too.  The mid-drive has a much narrower operating speed since it is based on crank speed and takes advantage of the gears to handle a wide wheel speed range.  

The Biktrix has a better suspension too.  It has air suspension front and rear.  The front rake has more angle which makes the wheelbase a bit longer, making the bike more stable at higher speeds.  This also angles the wheel more when turning.  



  


Sunday, March 5, 2023

New bike on the way

 I finally ordered a new electric mountain bike.  After long research I decided on the Biktrix Juggernaut Ultra FS Pro 3.


I have now put over 1,100 miles on my Rurui XT10 and I have learned much about what I needed for where I ride.  I chose the Biktrix bike because:
  • Bafang M620 ultra mid-drive is the best motor for serious off-road with steep hills and loamy terrain that I ride in.
  • 52V batteries are more efficient and powerful with the M620 motor than the typical 48V.
  • 11 speed cassette with 11-42 gears supports a wide range of riding conditions, including steep hills and loamy terrain. The bigger rear gears will work much better in the technical or real steep riding.  It is a proper cassette too, instead of the screw-on freewheel than has limits.
  • Fat-tire and full suspension for serious off-road riding.
  • It has an optional add-on battery for extra capacity when needed but easily removed to reduce weight when not needed.  Main battery alone is 126% capacity of the Rurui.  With the additional battery I will have 220% capacity of the Rurui.  I have only run the Rurui out of power one time so while this will be nice it is likely more than I will generally need. This will give the option of longer, steeper rides at higher speeds.
  • Air shock and forks.
  • Inverted fork has less un-sprung mass and is more rigid. 
The next best option I found in this price range was the Eunorau Specter S.  It was less expensive than the Biktrix.  It has the same motor and 11-speed cassette. It used 48V instead of 52V and lacked the air suspension.  Besides, it is hard to pronounce the name.  

The Rurui was great for street riding and off-road in less steep areas.  The rear hub drive did not provide enough low speed power for climbing for where I like to ride.  It did great at speeds from 11mph and up but for lower speed technical stuff, or long steep hills it did not work well.  

I also looked into more aggressive off-road bikes that were closer to electric dirt bikes.  Here are some examples.

CAB Motorworks. They make bikes from 750W all the way to over 20kW.  These are based on motocross bikes more than bicycles.  They had some very appealing features such as proper motocross suspension, wheels, and tires and regenerative braking.  I also like the moto seat option.  However, these would not be welcome anywhere but off-road.  They would not pass as a bicycle to most people.  They are also much heavier that most ebikes and are single speed (pedal).  The one I was most interested in was the Falcon.

UltraTRX. They make a range of off-road ebikes that include bike that are based on the higher end of ebikes all the way to motocross bikes.  The Cheetah looked the most interesting to me.



I ordered the Biktrix but it has not shipped yet.  Once I get it and take it for a few rides, I will post about it here on this blog.  


Friday, December 30, 2022

Cheat-O-Cycle hits 1000 miles

 


My Rurui XT10 Electric Mountain Bike hit 1,000 miles today.  That took just over a year.  My first ride was December 11th, 2021 and today is December 30th, 2022.   I have had some great rides on this thing.  I made several upgrades along the way to make it better suited for heavy duty off-road riding.  I still get tons of exercise since it is a very heavy bike with fat tires and full suspension and I ride up long steep loamy hills mostly. I pedal the whole time.  A typical 2.5 hour 20 mile off-road ride burns around 1,300 calories and I can really feel it.  The big difference with the electric assist is the speed, especially up the hills and in soft terrain.  I mostly use power assist level (PAS) 1.  I would guess it is in PAS 1 about 70% of the time I am riding with assist. PAS 2 probably accounts for another 20%.  I don't use assist going downhill of course, which can be almost half of a typical ride.  

After my upgrades, this bike works well for my riding.  I am on my 3rd controller now.  They can't handle the power and fail.  Both were replaced by Rurui though and the latest one claims to be rated for 18A instead of 17A.  So far, so good.  If it fails again, I will be getting a higher power rated controller.  Other than that, it has been a good bike overall.  I also had to replace the rear tire and rear brake pads because I wore them out.  I bought this bike for $1,599 and I would say I got good value for the money.  That is quite inexpensive for a full-suspension 750W fat-tire electric mountain bike.  I have been looking casually at other bike like it since I bought this but have not really found a more compelling one in this price range, or even for more than tipple this price.  I have also considered building my own but decided I would be far better off just upgrading components on this one.  

Sunday, October 30, 2022

Biking Websites

 I enjoy mountain biking, especially off-road mountain biking.  Over the years I have found some handy websites for mountain biking.

First of all I use a Garmin smartwatch to track my rides.  I had a Vivoactive 3 first, then upgraded to a fenix 6X Pro Solar.  I use Garmin Connect and Garmin Explore website the most since they have the most detail for a Garmin user.  Since my rides take me outside of cellular coverage, I also have a Garmin InReach Messenger to track and stay connected.  Garmin has done a fantastic job with these devices.

Here are some other website I discovered and use:

  • Strava.  This is a social biking website.  It sync's with Garmin well so my rides tracked with Garmin Connect also post to Strava.
  • Trailforks.  This site is a place to find and share routes.  
  • PinBike.  This includes classified ads for bike stuff.

Friday, October 7, 2022

Rurui XT10 Gear upgrades

 


I ride mostly off road which includes steep hills, loamy sand and gravel, and technical trails.  The original gearing on this bike seemed more pavement focused and the gear ratios were too tight, and too geared for high speeds for me.  The original gearing had a 52 tooth chainring up front and a 28-24-22-20-18-16-14 freewheel. First gear was far too high for steep hills and technical stuff. 

Changing the chainring was simple.  I bought a 44 tooth chainring.  I swapped that out and it immediately helped but I did of course loose top speed.


I chose a Drift Maniac 11-34 freewheel with wider gear ratios than original 14-28.

Changing the freewheel on this bike is a challenge.  The axle nut is too big for even this special tool: https://www.area13ebikes.com/products/bafang-750-watt-freewheel-removal-tool-made-in-usa-by-bolton-labs, which I did buy for this job.
The connector is too big for the nut to go over and the nut is too big for the tool to go over.  I had the motor apart to see of there was an easy way to remove the wiring but no, it is all soldered in.  I did not want to hack the wiring up so I needed a better way.  I finally decided to get a larger fitting to replace the nut and slot it so the nut can be installed without having to go over the electrical connector.  Having a slotted nut is not great as it is much weaker this way so I found an item made for something different and modified it for my needs.  Here is what I used: https://www.amazon.com/dp/B07T18ZKH1?psc=1&ref=ppx_yo2ov_dt_b_product_details.  


Not ideal as stainless is softer than I wanted, and it needed significant modification to work for what I needed here.  I had to drill out the unthreaded end, reduce its diameter a bit (grinding), and slot it to fit over the wire.  Having a slot in a nut like this weakens it substantially but this is far thicker and longer than the nut it had.  Just to make it stronger, I bought a 7/8" shaft collar from Tractor Supply that goes over the special slotted nut to clamp it down which both locks it to the axle and eliminates the weakness caused by the slot.  I also had to grind flats on the new nut so I could tighten it on the axle.  The result, crude as it is, looks like this.





I was able to get plenty of torque on it, similar to the original nut.  The collar then locks it in place and strengthens the nut.  Now I can easily remove these to swap out freewheels.  Here is what the gear ratio comparison looks like, Opt1 being the new gearing.

Torque in this chart is just the ratio from original, 1st gear having 144% of original 1st gear torque for instance.  The speeds are derived from my "typical" pedaling cadence (estimated).  The lower 3 gears give more torque and less speed than original.  The upper 3 gears give higher speeds than the original.  This give a much wider ratio between the low and high gears.

My first ride with this new setup was much better at climbing hills.  In the more difficult stuff, I could power through in first gear now where I could not before.  At times I started having traction problems now where I would spin the real wheel.  I ordered a more aggressive rear tire as mine was worn and had a damaged sidewall as well.  After searching through all the options, I ended up with a Zol Montagna (available on Amazon: https://www.amazon.com/dp/B08KFMHLHJ).  




I have been on many rides since these modifications and the bike is much better suited to my off-road focused riding now.  Since this freewheel has wider ratios, it still works great for higher speeds on pavement too (actually can go a bit faster than before).   I have considered other mods like switching to a cassette style rear gear, going to a 9-speed, etc., but for now I am pretty happy with it.  I use that low first gear quite often off-road when climbing hills or in real loamy conditions and it makes a world of difference.  In super tight situations I can ride it in 1st without motor power and it is so much more useful than before.  




  






Sunday, December 26, 2021

Rurui XT10 Electric Mountain Bike 150 mile review

 


I like bike riding for exercise and fun.  I have began riding much more off-road where a fat-tire full-suspension bike is really needed.  I started shopping for one and ended up with this Rurui XT10.  It was on sale through Amazon for $1899 with a $300 coupon making the price $1599.  Given all the features this bike has, that seems like a good price for what you get.  I call this my Cheat-O-Cycle since the electric power on a bike is sort of cheating.

The bike came shipped in one box.






It took me about 30 minutes to complete the assembly.  It was pretty intuitive which is good given there was no documentation, manuals, or instructions at all.  I later emailed Rurui and got the manual for the display.  I also found out later that one of the videos in the Amazon listing is an assembly video.  

The bike feels very solid and inspires confidence.  The hydraulic disc brakes are fantastic.  This is my first disc brake bike and this has been a huge upgrade.  The improvement is comparable with the difference between my 1968 Ford Mustang with 4-wheel no-assist drum brakes and my 2006 Porsche Cayman S.  The rear suspension is a bit too soft for me when you are off-road in rough terrain at speed.  The front can be adjusted so I set the preload to the maximum, and the damping about half which works well.  I plan to upgrade the rear shock soon. The headlight as great, although I have not ridden much at all in the dark.  I wish they would have included a wired taillight as well.  They included a battery powered taillight but that is a bit inconvenient.  The controller does have outputs for brake and tail lights and I may add that in the future. I really like the clamp-on grips as they feel great and stay put.  All my previous bikes had slip-on grips and they were always moving around.  The seat is really great too.  This is the best bike seat I have ever had, by far.  The shifter is great.  Button click upshifts, and you can downshift multiple gears at once.  

I wanted electric assist as a heavy, fat-tire- full-suspension bike like this takes more pedal power to ride.  The electric assist is fantastic to help with that.  I pedal pretty much all the time and let the electric power assist.  I still get plenty of exercise but my range is at least triple what I would have without electric assist, probably even more. So far my longest ride has been 30 miles and that used about half the battery.  Only having 7 speeds means you don't have the lower gears you would with a mountain bike that has a front derailleur.  The electric assist fills most of this gap but in very tight technical bits, I do miss the lower gears.  The electric assist does not work as well at speeds below about 5mph. I have considered changing the gear set to have a lower first gear to help with low speed riding.  You tend to ride much faster off-road than you would without electric assist.  I found myself going up loamy grades at over 15mph where I would be going more like 5mph without electric assist.  I also noticed my rides work my arms much more than before because I am riding much faster off-road.  

Fat tires make a huge difference in soft loamy conditions.  My other mountain bike has 2.2" tires and they just sink in and you stop.  The 4" wide fat tires float over most of that.  You also retain steering control much better in soft conditions.  It enables riding in places I just would not with narrow tires.    

I had some strange issues with the display.  It would only read speed when the motor was engaged, and even then it was way off, only reading about one third actual speed.  I emailed them back and forth for a while until finally fixing one of the parameters.  The display has settings you can change in a programming mode.  My parameter P07 was somehow set to 255 when it should have been 1.  I have heard others having parameters being off on bikes like this.  If you get one, and you have issues, check these settings.  My speedometer now works correctly.  You can also calibrate it to ensure accurate speed.  They have a wheel size setting as well as a fine tuning speed adjustment.

The color display is very hard to read in the sunlight, especially when wearing sunglasses.  It is very important to make sure your sunglasses are not polarized!  Even with non-polarized sunglasses, and on the brightest display setting, it is very hard to read.  


I would prefer a high-contrast black and white display that is focused on easy reading in direct sunlight.  Color is really just a gimmick.  Sure it looks pretty but it is much less functional.

The rear shock is not properly mounted to allow for proper rotation in the joints.  I noticed creaking when riding.  When I removed one end of the mounting, I found the other end to be clamped very tight.  



I replaced the front bolt with a longer 8mm shoulder bolt that I cut and added a locking nut.  I also greased the inside of the shock mounting hole and the bolt as this surface will be moving.  I was able to file down the rear shock enough to prevent the binding.  I also lubricated this.  Now the suspension moves freely with no binding or creaking.  

My first off-road ride was great, but I did have issues with how low the crank is to the ground, especially when the suspension is compressed over bumps.  My pedals took a beating.  I adjusted the front preload to the maximum and that helped.  The rear could really use a preload adjustment, and a longer shock.  See the "upgrades" section below.

When riding fast over very bumpy terrain the chain sometimes comes off.  This is a common problem with mountain bikes when you ride them aggressively off-road.  See "upgrades" section below. Mountain bikes with a front derailleur don't tend to have as much of a problem with this as the derailleur guides the chain back on the sprocket. 

The motor power is great from about 8mph to over 27mph.  However, when running full power for long periods sometimes the motor cuts out.  I suspect this is either the controller overheating or battery voltage at the controller dropping intermittently below the 39V cut-out.  The first time it happened I was going up a soft loamy grade that was at least 6% and very long.  After about 20 minutes on assist level 2, and moving fairly slow, the power assist surged a few times and then dropped out.  I felt the motor temperature and it was not that warm.  I was tired anyway so I rested for a few minutes.  After that the assist was fine again.  I have found on very long steep hills you need to use assist level 1.  I had the power drop out like that one other time.  This time it was at the end of a 30 mile ride where I had been using full power for a long time and the battery was about 1/2.  This was all in December so it was cool out.  In all my riding so far this issue has been rare and temporary.  If you are wanting a off-road bike that you don't have to pedal, just get a dirt bike.  This bike is great for my use case though.

See my 700 mile update for how the motor performance problems were fixed: https://jimroal.blogspot.com/2022/10/rurui-xt10-700-mile-update.html 

One thing you will notice when shopping for bikes like this is that many of the components can be found on competitors bikes.  Most of these bikes are a collection of components assembled into a complete bike.  This is of course true with many things today but it seems even more so with these ebikes.  Some are so similar you may not be able to tell them apart except for the labels.  I found other bikes which appear to even have the same frame.  

Overall I am very happy with my purchase especially given what I paid for this bike compared to the alternatives.  The bike is a blast to ride and I ride more often, and go places I never did before.  The first 150 miles have been great.  Sure, there are a few things I will change but even making those changes I am well under $2,000 for a well featured electric mountain bike.  The 150 miles I have ridden so far has been a mix of pavement and off-road but mostly off-road.  It has enabled rides I would just not be able to do on my other mountain bikes.  

Upgrades

As I mentioned above, there were a few things that I wanted to improve.  I made the following modifications to the bike at 150 miles.

Rear Shock Upgrade

In order to keep the pedals from hitting the ground so much I needed to raise the bike.  While I was at it, I also wanted more aggressive damping and preload.  The original shock on this bike was 165mm (mount-to-mount) and most of these shocks have 35mm travel (at the shock).  I wanted a 190mm shock at least.  Given the space in this frame, I needed an air shock rather than a coil spring type.  The front fork has a lockout so when you are riding on pavement you can reduce your energy consumption that is absorbed into the suspension when pedaling.  It is even more important on the rear.  You can easily spend $400 or much more on a rear shock with these features.  I found a DNM AO-38RL-190 that looked like it would work well and was only $99 on Amazon. It is 190mm long and has 55mm travel.  

It was tricky getting the remote cable routed.  I was not able to use the routing they intended because the cable would interfere with the suspension.  If I rotated the shock 180 degrees, then the air port was not accessible.  Instead I routed the cable the opposite direction and added a cable clamp I made from a simple screw, nut, and washer that I drilled a hole through.

Now the cable housing is what locks the shock.  Leave the original cable set screw loose in this orientation.  It actually works quite well like this.  The cable has a nice long loop to prevent fatigue with suspension movement.

I took it for a good hard run off-road over very bumpy, rocky, rutted trails and it works great.  Much more controlled overall.  It no longer sacked the suspension even over the very rough stuff.  My pedals never hit anything either.  Before this was a common issue and an issue I had on this same trail.  I found myself riding faster and with more confidence.  The feel of the bike really improved. 

I tried the shock lock on the road while I was pedaling hard.  It worked well.  The suspension did not move while pedaling when locked.  The lock is not a full lock but it makes it enough stiffer that the suspension acts pretty solid.  Over real hard bumps it may move some though.  Perfect actually.   I like having the remote cable instead of having to stop and fiddle with a shock valve.


Front Sprocket/Chain Guard

A problem with mountain bikes is that the chain will come off when traveling fast over very rough terrain.  Not having a front derailleur makes it much worse.  The problem generally happens when going downhill where you don't have tension on the chain.  Riding in 3rd gear really helps as the chain is straight between the sprockets in that gear.  Also, make sure you don't rotate the crank backwards at all on rough terrain.  I had this issue pretty bad.  First I tried this chain guide, after significant modification.

It really helps.  I had it come of once or twice but far less than before.  I noticed that I tended to roll the pedals back at time while riding downhill over rough terrain and that would cause the issues too.  I was careful to stop doing that and it worked pretty well.   I was not thrilled with this approach though.

I noticed another electric mountain bike that solved this by adding an inner sprocket guard such as the Cyrusher XF900. I decided this was a better approach to solve this issue.  I bought this one from Amazon. It is made of plastic which is what I wanted so it would not get bent or wear with chain contact.  It was intended to be used on the outside but I just bolted it to the inside.


It worked fantastic!  I took the bike on a good rough off-road ride and never had an issue.  It retains the chain on the sprocket great.  In first gear the chain actually touches it a bit but it is silent.  Even if you pedal back a bit the chain stays on the sprocket.  Since installing this the chain has never come off again. 

Here is a short video discussing these upgrades








Sunday, December 12, 2021

Mountain Bikes

 My favorite form of exercise is biking.  I really prefer to ride on designated bike paths or off-road versus on the street.  I currently have 3 bikes.  

Hybrid Mountain Bike

My oldest is a 2013 Specialized Crossroads Sport hybrid (mountain/road) rigid frame, no suspension. I bought this bike in 2014.  At the time of this post my Garmin watch recorded 830 miles but I did not get the watch until 5 years after I bought the bike.  I would guess I have closer to 4,500 miles on this bike.



Full-Suspension Mountain Bike

In December 2020 bikes were scarce.  Most bike shops had very little available and even used bikes were hard to find.  I found myself looking for a full-suspension mountain bike at a very bad time.  I happened to be shopping at Walmart one day and they had a Kent Flexor in stock for $148 so I bought it.  



I was surprised how inexpensive this bike was, but it is also cheap.  I call it my Cheap-O-Cycle.  At the time of this post I have accumulated 676 miles.  I would say about half the hours I have put on this bike have been off-road.  I did have trouble with the freewheeling hub.  It fell apart on one of the early rides. 


Kent sent me a set of replacement wheels (which included the freewheeling hub).  The new one did it as well and I learned how to tighten it.  It appears they do not seat the bearings or torque the unit properly when assembling it.  I tightened it very tight and the issue seems to have been corrected now.  I did buy a replacement on Amazon for $16 and that was much better.  Overall though I did get my $148 worth.  


Electric Fat-Tire Mountain Bike

Riding the Kent Flexor made me realize that I needed a fat tire bike for off-road.  The narrow tires on the Flexor would sink it too much.  A fat-tire full suspension bike takes more energy to ride.  I also found steep or long hills to be not fun on the Flexor.  When riding downhill on rough terrain, the Flexor did not feel substantial enough either.  It does not have actual shocks, just springs.  The brakes are just rim brakes and I wanted hydraulic disc.  These things led to to wanting to upgrade to an electric assisted mountain bike.  

I ended up with a Rurui XT10.  Since it has electric assist, I call it my Cheat-O-Cycle.  This bike has a much more substantial frame, full suspension with real shocks, hydraulic brakes, and 4" wide fat tires.  


My first ride on this bike was great. I was able to ride a trail that previously took about 2 hours in 20 minutes.  This particular ride has about 1000' elevation gain and is mostly loamy sand and gravel.  I made about a 14 mile loop which also included some paved bike path.  Most of that 14 miles was rugged off-road riding.  I was in PAS mode 1 for most of the ride.  PAS mode 1 provides electric assist up to about 10mph.  I took it on a paved bike path for a bit as well and tested the top speed in mode 5.  I was able to get over 27mph which is plenty fast for me on a bike. The maximum assist speed in user configurable through the display. In high gear the pedaling cadence is the limiting factor.

It took a bit to get used to how the electric drive worked.  This bike uses a rear hub-motor.  Some other electric bikes used a motor at the crank.  Each have pros and cons.  The hub motor is simple and does not impact the chain or gears.  However, it lacks the multiple gear ratios of the gears too.  This limits the speed range where it is most efficient.  I am happy with my choice of bike having a hub motor.  One upgrade I may consider it going with wider gear ratios, mostly for first gear.

I am happy with the battery range versus weight.  My first ride was not many miles for the effort as it was mostly off-road with many hills and loamy terrain.  Since these bikes don't have regenerative braking, that really consumes battery.  Garmin reported the ride at 13.9 miles and I used less than half the battery. This will really vary based on the specific ride and how much the rider puts into it.  I ride for enjoyment but a main goal is also exercise. I plan to always pedal. The first ride was much more intense than off-road rides on the Flexor since the speed was so much higher going up in elevation, and through loamy terrain.  

The hydraulic brakes and actual shocks were big upgrades from the Flexor.  One issue I did have is the pedals hit the ground when riding in ruts or when there are rocks.  I measured the distance from the bottom of the pedals to the ground on this and the Flexor and found the Flexor had at least 1" more ground clearance.  I may look into raising the back suspension on this bike a bit.  The fat tire made a huge difference off-road.  I was able to easily go through stuff I would have to get off and walk the Flexor through.  Same with hills.  The fat tires also soak up some of the bumpiness.  

I had dirt bikes back in the day.  My favorite was  KTM 500MX.  Riding the Rurui was somewhere between a mountain bike and a dirt bike, but more towards the mountain bike.  Obviously the 1HP this Rurui generates is tiny compared to my KTM that had 55HP.  Of course the KTM was also at least 100lbs heavier.  I was able to push the Rurui up super steep hills which was not really possible with dirt bikes.