High Speed Long Distance Commuter Build

MrLazy

New Member
#1
Looking for advice! I want to travel long distances on dirt roads and trails, pedal assisted 70+ km/hr max speed. I want a light weight setup with a derestricted middrive, belt drive and internally geared rear hub.

-Does anyone have experience with this kind of riding?
-Any off the shelf recommendations that could be tuned?

Thanks!
 
#3
I am looking for something similar. Everything I have found points to a full-suspension Fat bike for maximum stability (safety) and comfort.

The fastest completely-factory electric Fat bike I believe is the Juiced Bikes HF1100, a Hardtail, for about $4000.


The M2S Ultra Fat is a FS bike with a very good mid-drive motor for $3500, but would require reprogramming to reach those speeds (the motor is capable, but it is not "unlocked").

I have also been eyeballing a 72v plug-and-play BBSHD controller ($400), a 72v 20-40ah battery ($600-1000), and Bafang BBSHD mid-drive motor kits for about $800. However, that only leaves about $1800-2200 for a FS Fat bike which is going to be very entry-level. I have never owned a FS bike, but even with cushy fat tires, I think Id be a little nervous going those speeds with a hardtail.

I grew up on dirtbikes and commuted exclusively on bicycles, and then a motorcycle, for a number of years. I am now looking at something that I can enjoy on gravel and dirt roads and also commute without showing up to work drenched in sweat and while maintaining a safe speed relative to traffic instead of trying to hug the shoulder while I pray nobody breaks my arm with their mirror (I grew up in a town with nice sidewalks and bike paths--here, not so much). So, a single fat bike that kinda bridges the gap between bicycle and dirtbike actually is about perfect for me.
 

MrLazy

New Member
#4
Thanks for all the info. I'm a minimalist and pretty skeptical of most bells and whistles from bike manufacturers nowadays. I live in Canada and Mountain Equipment Coop have great deals on bikes. I'm thinking about adding a mid-drive kit to their Mixed Tape bike ($540 usd) and maybe swapping out some parts, like some cool Paul brakes. Add some fenders, rack, lights. This would be a lot cheaper than something similar from Europe (like Riese and Muller). I honestly think a lot of these bikes are overbuilt for dirt roads and bike trails.

Is there a source for mid-drive kits that you recommend?
 
#5
Only going by what I've read on blogs and various manufacturer's web pages, it seems like the Bafang BBSHD is the most affordable 40mph option out there (with non-factory programming).

Here are a couple links to the motor kit, with optional batteries:
https://lunacycle.com/bafang-bbshd-100

https://dillengerelectricbikes.com/...000-bafang-mid-drive-pre-order-by-bafang.html

Here is the controller I'd seen referenced in a blog and in a discussion post Id read somewhere:
https://electricrt.com/asi-bac-800-...ler-3000w-bafang-bbshd-upgrade-plug-and-play/

And here are a few articles Ive bookmarked regarding reprogramming these motors and their relative capabilities. Bottom line, it sounds like with careful programming, you can indeed get 40+ mph out of them with a fat bike, but carry some risk of damaging the internal gear if you throw too much current into it in the low end.

https://electricbike-blog.com/2015/...rying-your-controller-and-losing-your-sanity/

https://www.google.com/amp/s/electr...e-bafang-ultra-max-mid-drive-ebike-drive/amp/

https://www.google.com/amp/s/electr...t-s-72v-50amp-3000w-ext-bbshd-controller/amp/


Just to be clear, I have zero experience with ebikes. Granted, I have been offroad biking off and on for 25 years, and have lots of other experience tinkering with mechanics and electrics. But, everything I know about ebikes comes from the last month of reading.

Oh, the Biktrix bike linked in the 2nd blog post is here https://www.biktrix.com/collections/bikes/products/juggernaut-ultra-fs?variant=1134458667029 . Seems pretty similar in equipment to the M2S Ultra.
 
#6
I have a M2S R750 fat bike and can average 22 mph on a 23 mile commute each way to work with my 48 volt 16 ah battery. Looking to speed things up a bit and would like to add another moter and battery pack either to the front wheel or a mid drive motor. As the rear Bfang 750 watt motor is geared, would my top speed be limited by the motor that is already installed? I don't want to hack up the already installed system as this bike is working fine as is and I don't want to ruin it.
 
#7
I have a M2S R750 fat bike and can average 22 mph on a 23 mile commute each way to work with my 48 volt 16 ah battery. Looking to speed things up a bit and would like to add another moter and battery pack either to the front wheel or a mid drive motor. As the rear Bfang 750 watt motor is geared, would my top speed be limited by the motor that is already installed? I don't want to hack up the already installed system as this bike is working fine as is and I don't want to ruin it.
I also looked into dual-motor setups, like buying a simpler ebike with a rear hub motor and adding a front hub-motor wheel. Alternately, I considered going with a geared-hub rear wheel and a mid-drive crank system so I could get good power across all speed ranges.

However, I could never determine if the motors would be physically speed-limited (due to maxing out RPMs) in such a case.
 

WilliamT

Active Member
#9
I have a M2S R750 fat bike and can average 22 mph on a 23 mile commute each way to work with my 48 volt 16 ah battery. Looking to speed things up a bit and would like to add another moter and battery pack either to the front wheel or a mid drive motor. As the rear Bfang 750 watt motor is geared, would my top speed be limited by the motor that is already installed? I don't want to hack up the already installed system as this bike is working fine as is and I don't want to ruin it.
I used to have a dual motor setup on my cargo bike (front geared hub, rear direct drive). Both had similar top speed limits so in the end, I didn't go any faster. Acceleration definitely improved. It went from "casual increase" (rear only) to "hold on to the bars" pick up speeds. Climbing hills was easier. With all that power, you really don't need to put any effort in pedaling. Your just there for the ride.
 
#10
I used to have a dual motor setup on my cargo bike (front geared hub, rear direct drive). Both had similar top speed limits so in the end, I didn't go any faster. Acceleration definitely improved. It went from "casual increase" (rear only) to "hold on to the bars" pick up speeds. Climbing hills was easier. With all that power, you really don't need to put any effort in pedaling. Your just there for the ride.
thanks for the info, I believe I am going to leave that bike as it, and start a new project with a mid power setup
 
#12
I ended up getting a 4.9" fat tire rigid. Now I am deciding how to drive it! Above all, I want to ensure I am always able to provide meaningful pedal effort at the top end (for the exercise), which makes me worry that an overdriven BBSHD would basically have me clown-pedaling.
 

Alaskan

Well-Known Member
#13
I would recommend some caution cobbling together a high speed ebike to go over 40 mph in wilderness or remote areas. This is your life at stake here. Risking it on a bike that has not been engineered from the ground up to handle that kind of speed does not sound at all prudent. I admit, even on a bike that has a purpose built robust frame, superior brake specs, a heavy duty single speed chain with a Rohloff hub I would still not be riding out in wilderness conditions, far from any medical help at those kind of speeds. However doing so on a bike that really is not designed and built for the kind of forces a bike encounters at those speeds is beyond risky.
 

Nova Haibike

Well-Known Member
#14
I would recommend some caution cobbling together a high speed ebike to go over 40 mph in wilderness or remote areas. This is your life at stake here. Risking it on a bike that has not been engineered from the ground up to handle that kind of speed does not sound at all prudent.
Plus, anything you add a motor to will void the warranty that came with the bike.
 
#15
Other than knowing I want to start with a BBSHD, I am having a hard time deciding what I want to do.

On the one hand is a 72v+ controller and 30t chainring. The benefit is a relatively quiet motor, arguably less stress on the components (due to reduced amperage and thus reduced torque). The downside is I would be pretty limited to maybe 25mph or so before the cadence because too fast. Not that my 200w would really make a difference with 2000w+ coming from the motor, but I still want the exercise.

On the other hand is a 52v controller, driven at 50+ amps, with a 46t chainring. The benefits are a slower cadence that I can realistically push to 40+ mph, and possibly functioning pedal-assist (a nicety, but I am not opposed to simply dialing in throttle as required to "supplement" my pedal power). The downside is lower overall power potential, and greater load on the motor and internal gears.

Thoughts?
 
#16
I would recommend some caution cobbling together a high speed ebike to go over 40 mph in wilderness or remote areas. This is your life at stake here. Risking it on a bike that has not been engineered from the ground up to handle that kind of speed does not sound at all prudent. I admit, even on a bike that has a purpose built robust frame, superior brake specs, a heavy duty single speed chain with a Rohloff hub I would still not be riding out in wilderness conditions, far from any medical help at those kind of speeds. However doing so on a bike that really is not designed and built for the kind of forces a bike encounters at those speeds is beyond risky.
Great point, Alaskan. In total agreement. Those speeds are not wise, especially on a “Frank-en-Bike”.
 

Alaskan

Well-Known Member
#17
I took my Riese & Muller Delight Mountain down a long steep hill with no other cars in sight on pavement that was in good shape. I let it roll up to almost 41mph. This is a bike with Fox front and rear suspension, 27.5 x 2.4 Super Moto X tires and a frame built to carry two 500 watt batteries. The force of air resistance at that speed was impressive. I really felt vulnerable sitting in a moderate upright position. In crouching down closer to the handlebars, I experienced a real loss of leverage on the handlebars and awkwardness with hand/arm angle. I could not even imagine doing this speed regularly on a home-built bike and feeling anything other than kamikaze foolhardy.
 

Alaskan

Well-Known Member
#19
Talk all you want. Others are free to do the same. If you don't want your ideas challenged, don't post them on a forum. It is a dialectic and hopefully a learning process. Nothing quite so effective for growth and change than having to defend one's ideas.
 
#20
I learned a long time ago little comes from trying to justify one's desires on the internet while simply searching for information--as opposed to advocatoring for it--and will simply accept this just may be the wrong crowd for such discussion :) . That's totally fine; I wouldn't expect to go to a hypermiling forum and expect anyone to entertain questions about how to add a turbocharger. But, now we know!