High Speed Long Distance Commuter Build

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).

Bad idea. If you are looking for high speed, a tiny chainring coupled with a high-powered mid-drive means you will be eating through chainrings and cogs. Assuming 27.5 x 2.2 tires, a 30T x 11T high gear only gets you to 22 mph at a cadence of 100 rpm.

I'd go with at least a 46T ring, so that you would not be relying on the 11T cog so much. Even larger would be better.
 
Your performance expectations and the engineering demands that will be placed on some of the proposed "solutions" are not necessarily aligned. Perhaps begin by looking at bikes like this one: https://www.bikesandbarbers.co.nz/product-page/stealth-h-52. Your specifications exceed those of a bicycle. At 70 kph you need a frame and front fork that will not break or bend when hitting a boulder or log. You need brakes that will stop, rims that can take the crashing offroad, and a motor up to the demands of torque, HP and water/mud. You need reliability to get you home.
 
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?
https://em3ev.com is run by an Englishman in Shanghai. Excellent support, makes his own batteries, backs his products, ships worldwide. I have no relationship with him except as a customer. I visited his operation, and organised a buying group of 27 BBS01/02 motors through him.
 
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.
It would get up to top speed quicker and with mor torque, but really wouldnt go any faster.
 
Your performance expectations and the engineering demands that will be placed on some of the proposed "solutions" are not necessarily aligned. Perhaps begin by looking at bikes like this one: https://www.bikesandbarbers.co.nz/product-page/stealth-h-52. Your specifications exceed those of a bicycle. At 70 kph you need a frame and front fork that will not break or bend when hitting a boulder or log. You need brakes that will stop, rims that can take the crashing offroad, and a motor up to the demands of torque, HP and water/mud. You need reliability to get you home.
Agreed! I rode the M2S FatBike full suspension. At 30mph on pavef roads (downhill) I felt like I was pretty close to the highest safe speed for that bike. Going 45mph would not be safe at all. The wind resistance would be a big problem, as would battery drain. The suspension on these chinese frames is not equipped to be traveling at that speed especially offroad
 
https://em3ev.com is run by an Englishman in Shanghai. Excellent support, makes his own batteries, backs his products, ships worldwide. I have no relationship with him except as a customer. I visited his operation, and organised a buying group of 27 BBS01/02 motors through him.
California eBike has EM3ev batteries and BBSxx motors with a real warranty. Doug the owner, I do online support and answer calls, insists on warranty support.

40mph is a tough demand for a bike. And hard on a motor regardless of what is posted. We sell a lot of parts to those guys. And not many, if any off the shelf bikes can efficiently stop at high speeds. Upgrade brake system that will make for sane braking distances will cost $300 minimum.
 
I think some of you are imagining baja desert racing with an ebike. In reality, I think the intent of the OP (and myself) is to build something more like what you'd use this to do.

https://www.juicedbikes.com/products/hyperfat-hf1100, at perhaps a little less than $4000.

Also, I'll add more clarity about my previous comment; I don't understand the immediate, extremely-negative assumptions that follow any mention of a bicycle capable of going faster than 28mph. It's like people immediately assume a guy with a 35mph ebike is going to do nothing but weave in and out of strollers on jogging paths, or break it in half racing along dirtbike trails. Maybe somebody really just wants to occasionally be able to keep up with 35+mph traffic on that mile-long stretch of narrow road with no sidewalk, but otherwise can perhaps be trusted to ride within relatively safe limits for the surroundings? Or, maybe somebody wants to go on casual dirt road rides, and has some flat pieces of smooth road in mind where it could be fun to open it up a bit?

For what it's worth, I have a physics background, I am a Mensan, I come from a family of doctors, lawyers, and engineers, I have 5 flying combat deployments, and am getting ready to start my second graduate degree. And as I said before, I also have tens of thousands of miles on 2 wheels of all types. I think there is a slim chance I could manage a modicum of judgment operating a bike that can do 7 or 10mph over the arbitrary bicycle speed limit.

To be clear, I am not talking about specific, related recommendations like "btw, make sure you have sufficient braking capability if you are going to be riding that fast." However, what gets me is the very apparent and dismissive attitude that us mere mortals are simply incapable of comprehending what it takes to build a faster ebike that won't explode at 29mph, or competently evaluating the risks of operating one.
 
However, what gets me is the very apparent and dismissive attitude that us mere mortals are simply incapable of comprehending what it takes to build a faster ebike that won't explode at 29mph, or competently evaluating the risks of operating one.
What you miss is no one here has or had ANY idea of your skill level. Next we see people new to eBike buy and build fast bike kits using $150 Walmart frames. Third, there are no brake systems, IME and testing, that will meet the sort of standard one would have braking with something like a 50CC gas scooter. No need to post a resume or become frustrated. Nothing written was intended as a personal affront.

That said I now understand you want to break all State and Federal laws and have a 40mph bicycle.

Seriously consider any number of electric motorcycles.

Here's an option. No legal but many choose to go that path... the fellas in this thread will help.

https://endless-sphere.com/forums/viewtopic.php?f=6&t=23996&hilit=voltaire&start=16325


Best of luck!
 

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Only going by what I've read on blogs and various manufacturer's web pages...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.

Based on these statements it seemed as if you were interested in getting some feedback for your ideas. My response was cautionary but you apparently took it as "negative" Were you just putting your recent conclusions out there for "attaboys" or were you seeking potentially useful, if not life saving, feedback before proceeding to make your ideas into reality and possibly learning the hard way?
 
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?
I just changed my 36t front chainring to a 48 and noticed a big difference in pedaling. I am changing it again next week when the 52 tooth chainring comes in. Top speed right now is about 30 on a flat with a 48 volt battery charged to 80%. If I get the 52 volt battery to add to the mix I will be pedaling at 32 or 33 mph on this fat tire 750 watt bang motor. Next build will be with a band or the cyclone on a 29er bike
 
What you miss is no one here has or had ANY idea of your skill level. Next we see people new to eBike buy and build fast bike kits using $150 Walmart frames. Third, there are no brake systems, IME and testing, that will meet the sort of standard one would have braking with something like a 50CC gas scooter. No need to post a resume or become frustrated. Nothing written was intended as a personal affront.
You take note of me posting my "resume," yet your own post also asserts that nobody should be allowed to receive any unapproved technical information until you have vetted their relative competence.

I certainly didn't take anything as a personal slight. I suppose I am simply used to most communities' interested in more academic discussions about pushing extremes, whether that be turbocharging a civic or somebody asking about free climbing. People usually respond with "here are some links to some good turbo kits," or "here are some training techniques to start free climbing," and then might rightfully add "also, make sure the vehicle is running well with good tires, and try to be safe on the road" or "and remember, always start small at gyms with padded floors, rather than a big rock face your first time out!"

Instead, almost all of the responses were either dismissive and deliberately-unhelpful links to motorcycles, or soapbox speeches about safety and legal obedience.

As a former high school physics teacher, I can confidently say if you are truly endeavoring to influence newcomers about safely ebiking, you will have a much bigger impact entertaining questions with thoughtful responses, rather than putting your head in the sand or dismissing newcomers' desires with holier-than-thou rhetoric. You'd be surprised how effectively you can sway wild desires with thoughtful, supported answers that make your desired conclusion clear. Also, see abstenance-only education.

That said I now understand you want to break all State and Federal laws and have a 40mph bicycle.
Okay, let's not act like we're dealing drugs. I'll go ahead and also assume nobody here has ever driven their car over the speed limit, because who are we to decide we are capable of safely operating outside the parameters established by our all-knowing lawmakers? Driving 45 in a 40 increases stopping distance of our 3500lb vehicles by 26%, which is tremendously more dangerous for everyone than me occasionally doing 35 or 40 on an open road (which is already easily attainable on a road bike with a little downslope).

Funny enough, if you are concerned about me owning a bike capable of exceeding all state and federal limitations, you should know that literally every car sold in America is capable of breaking dozens of state and federal traffic laws. Hell, every 5th commercial on TV is about another family sedan or SUV putting out 300+ HP. Of course, using any significant portion of that power on public streets is completely illegal; but they keep making them and we are continually allowed to buy them, and somehow we're not all dead yet ;) .


Based on these statements it seemed as if you were interested in getting some feedback for your ideas. My response was cautionary but you apparently took it as "negative" Were you just putting your recent conclusions out there for "attaboys" or were you seeking potentially useful, if not life saving, feedback before proceeding to make your ideas into reality and possibly learning the hard way?
See above points about relevant responses.


I just changed my 36t front chainring to a 48 and noticed a big difference in pedaling. I am changing it again next week when the 52 tooth chainring comes in. Top speed right now is about 30 on a flat with a 48 volt battery charged to 80%. If I get the 52 volt battery to add to the mix I will be pedaling at 32 or 33 mph on this fat tire 750 watt bang motor. Next build will be with a band or the cyclone on a 29er bike
Thanks for the anecdote! I had also largely decided to go with the 52v/50A route.
 
30t chainring.



Any chainring smaller than 42T may present serious problems with chainline. 42t is as small a chainwheel possible and still have offset similar to the OEM.

PMost often the result of less than 42T is a loss of available gears with a derailleur. ebikes.ca has a controller, Baserunner and Phaserunner along with cables to use an external controller. All dealers I know will not support any motor warranty with extermnal controllers.

IF I wanted a fast bike I'd look to the frame I posted above and go to Barent Hoffman at
West Coast Electric Cycles
[email protected]
https://west-coast-electric-cycles.myshopify.com/collections

He is currently running a group buy on a powerful hub motor that could meet your goals and not be a cobbled BBSHD.
 
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Bad idea. If you are looking for high speed, a tiny chainring coupled with a high-powered mid-drive means you will be eating through chainrings and cogs. Assuming 27.5 x 2.2 tires, a 30T x 11T high gear only gets you to 22 mph at a cadence of 100 rpm.

I'd go with at least a 46T ring, so that you would not be relying on the 11T cog so much. Even larger would be better.
Sorry, to be clear, I am running 26x4.9 tires. But, I see what you mean about the extra force applied through the chain from the smaller ring could cause a bit of extra wear!

In any case, the 46t ring actually really does get me where I'd like. At ~2500w with my factory 11-36 cassette, its highest cadence at max power output would still only be about 100rpm or so, which is pretty reasonable

However, my bike has a pretty intrusive chainstay, which means in order to fit anything beyond maybe a 36t chainring, I would actually have to space the ring further out from centerline than the 75mm it already is (120mm BB). By my measurements, a 46t ring would require roughly 10-12mm greater spacing (85-87mm offset. To avoid extreme "cross-chaining," I'd have to lock out the 3 inner cogs, giving me a 1x7 drivetrain.

Now, while I don't love the idea of neutering my 1x drivetrain, it is certainly not the end of the world. Really, if my only options are a 1x10 that becomes a moped after 25mph, or a 1x7 with reasonable cadences at all speeds, I'll take the latter. I would customize the cassette to get the range I need, especially knowing I'll have extra power helping me through the larger cadence changes. Id have to buy the three largest cogs, but something like an 11, 13, 17, 25, 32, 40, 49 would be a pretty sweet range for a 1x7, and get me close to my factory bottom ratio.
 
Sorry, to be clear, I am running 26x4.9 tires. But, I see what you mean about the extra force applied through the chain from the smaller ring could cause a bit of extra wear!

In any case, the 46t ring actually really does get me where I'd like. At ~2500w with my factory 11-36 cassette, its highest cadence at max power output would still only be about 100rpm or so, which is pretty reasonable

However, my bike has a pretty intrusive chainstay, which means in order to fit anything beyond maybe a 36t chainring, I would actually have to space the ring further out from centerline than the 75mm it already is (120mm BB). By my measurements, a 46t ring would require roughly 10-12mm greater spacing (85-87mm offset. To avoid extreme "cross-chaining," I'd have to lock out the 3 inner cogs, giving me a 1x7 drivetrain.

Now, while I don't love the idea of neutering my 1x drivetrain, it is certainly not the end of the world. Really, if my only options are a 1x10 that becomes a moped after 25mph, or a 1x7 with reasonable cadences at all speeds, I'll take the latter. I would customize the cassette to get the range I need, especially knowing I'll have extra power helping me through the larger cadence changes. Id have to buy the three largest cogs, but something like an 11, 13, 17, 25, 32, 40, 49 would be a pretty sweet range for a 1x7, and get me close to my factory bottom ratio.


I have added a 48tooth to the front chainring and have an 8 speed on the back, with the motor and battery at full charge I am pedaling at a reasonable cadence at 30 or 31 mph. Once the battery drops voltage a bit it will only go to 28mph, so I want to run a 52volt 20 ah battery and a 52 tooth front chainring so I can pedal and go 32 or 33 for a good bit of distance say 20 miles.
 
Any chainring smaller than 42T may present serious problems with chainline. 42t is as small a chainwheel possible and still have offset similar to the OEM.

PMost often the result of less than 42T is a loss of available gears with a derailleur. ebikes.ca has a controller, Baserunner and Phaserunner along with cables to use an external controller. All dealers I know will not support any motor warranty with extermnal controllers.

IF I wanted a fast bike I'd look to the frame I posted above and go to Barent Hoffman at
West Coast Electric Cycles
[email protected]
https://west-coast-electric-cycles.myshopify.com/collections

He is currently running a group buy on a powerful hub motor that could meet your goals and not be a cobbled BBSHD.
Any chainring smaller than 42T may present serious problems with chainline. 42t is as small a chainwheel possible and still have offset similar to the OEM.

PMost often the result of less than 42T is a loss of available gears with a derailleur. ebikes.ca has a controller, Baserunner and Phaserunner along with cables to use an external controller. All dealers I know will not support any motor warranty with extermnal controllers.

IF I wanted a fast bike I'd look to the frame I posted above and go to Barent Hoffman at
West Coast Electric Cycles
[email protected]
https://west-coast-electric-cycles.myshopify.com/collections

He is currently running a group buy on a powerful hub motor that could meet your goals and not be a cobbled BBSHD.
Thanks for the info! I hadnt mentioned it above, but I am running a fat bike with a 120mm BB and 75mm chainline. The factory BBSHD chainline on its 120mm variant should also be 75mm, if I am reading the Bafang diagrams right. Of note, the center of my cassette is chainlije is something like 71mm, and goes down to about 52mm and up to 90mm. Unfortunately, as mentioned above, my issue is chainstay interference, so I'll have to end up with an ~87mm front chainline (using four 3mm spacers, I think) and will lock out inner cassette cogs until I get back to that ~23-24mm max factory chainline offset. Dropping 3 cogs would do it, and give me a ~65 to 90mm rear chainline. 87 to 65mm would actually be even easier on the chain than stock.
 
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I want to run a 52volt 20 ah battery and a 52 tooth front chainring so I can pedal and go 32 or 33 for a good bit of distance say 20 miles.
In my experience, my 52V pack got those speeds on my BBSHD. But, like the 48V battery, it loses speed as the battery depletes. Confirmed by scores of sales and customers. A 20Ah or larger triangle battery will give the longest 32MPH ride. I gave up riding mine simply because I found cages were misjudging my speeds. They see bicycles, 12MPH the norm, and I was coming at them at 32MPH. Cages daily making a dangerously close left turns across my path. Or at a stop sign pulling out in front of me thinking they had plenty of space and time. As always, YMMV!
 
In my experience, my 52V pack got those speeds on my BBSHD. But, like the 48V battery, it loses speed as the battery depletes. Confirmed by scores of sales and customers. A 20Ah or larger triangle battery will give the longest 32MPH ride. I gave up riding mine simply because I found cages were misjudging my speeds. They see bicycles, 12MPH the norm, and I was coming at them at 32MPH. Cages daily making a dangerously close left turns across my path. Or at a stop sign pulling out in front of me thinking they had plenty of space and time. As always, YMMV!
Ive had and read these the exact thoughts regarding fast ebikes, and even several motorcycle and bicycle experiences to match.
 
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