Nm Torque Comparison to BBSHD

geosped

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Mar 18, 2015
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So I'm reviewing all these youtube video's of e-bikes from Specialized, SantaCruz, Giant, on and on and they have roughly 250w and anywhere from 70 - 120Nw of Torque. How does this compare to a 52v 1000w BBSHD? How many Nm Torque does the BBSHD have? The bikes on the reviews look very powerful all be it they have no throttle but they seem to climb. I haven't tried one of these other LBS ebikes but just curious of those that have tried both. What is the main difference. 1000w compared to 250w seems like a HUGE difference why such a dramatic difference in numbers.
 
The thing is that a BBSHD will never be as well integrated with the bike which counts for a lot more than the raw power numbers.
Also most "250w" EMTBs peak around 1000w every pedal stroke.
 
Grantmac said:
The thing is that a BBSHD will never be as well integrated with the bike which counts for a lot more than the raw power numbers.
Also most "250w" EMTBs peak around 1000w every pedal stroke.
Just so were on the same page I'm comparing the BBSHD to those expensive as hell eMountain bikes motors that are on e-bikes made for Trek, Specialized, Santa Cruz, Canyon, Niner and the list goes on and on.

Of course the BBSHD was designed for an existing bike. All the LBS e-Bikes are designed from the ground up for an electric motor. I'm more interested in the how the numbers match up. This is not about comparing a BBSHD DIY kit to a Speaclized elevo or similar more interest in the power and how it relates to lets say performance like speed or hill climbing . I've had my BBSHD on the computer spike to over 1630w peak on some climbs in some gears. Also I think the other e-bikes mtn bikes are running on 36v batteries. I haven't really seen any comparisons on youtube of a Full Suspension e-mtn bike compared to a full suspension DIY BBSHD e-bike. in terms of performance.

There is a lot to be said about having a fully integrated bike it certainly looks nicer, more durable, better ergonomics etc.... I'm just curious from those that have ridden both how they compare in terms of performance. Also if there is a way to determine how many Nm Torque the BBSHD has compared to these other motors like the Bosch, Yamaha, Shimano, BrosBrothers. Bafang also makes one of these "integrated" motors but i think it's 120Nm and I've heard in some of the reviews that it doest seem to perform as well as some of the other brands in terms of performance but it's still a great option.
 
OP, I'm curious on that 70-120 Nm rating you mentioned for the factory emtb's. I'm no guru on ebikes, but I work part time as a mechanic at a shop that sells Trek, Specialized, and Santa Cruz. I've gotten to ride Trek and Specialized emtb's, and they are impressive. However, I thought their torque numbers were usually in the 65-85 Nm range at max. Grantmac is correct in that they can demand higher wattage than the normally rated 250 watts in certain situations, but I'm not sure how much...noticeably higher than the 250 they are generally rated at.

Now, on to your question about the torque of a BBSHD, from material on them from quite a few sources they supposedly have at least 125 Nm. That's a substantial overall increase at even the higher 85 Nm rating on some of the factory motors. Those factory torque sensing motors are super efficient, however, and seem to get all their power to the ground excellently. I would like to see a Bafang Ultra equipped emtb in a head-to-head comparison, however, as it is torque sensing motor also and is designed to be integrated into the bike frame.

Even working at a shop, I too thought the higher end factory emtb's were too expensive. I recently modded my '08 Santa Cruz Nomad with a BBSHD and am thoroughly enjoying it. My Nomad has high end suspension already along with other quality components. After reprogramming the software in the BBSHD, I'm pretty impressed with how it performs. You can get smooth power delivery with excellent acceleration and good motor shutdown so you don't get a bunch of overrun like it had with the stock setting. With a good hydraulic brake switch on the handlebar, a shift sensor, and a good display, this setup can deliver very good performance on a real trail with actual challenging terrain. I am not at all disappointed with the results, and it's regenerated my thrill for mountain biking. At some point, one of the guys I work with will take our shop's Trek Rail 7 demo bike out to the trail, and we will obviously do some drag racing and on-trail comparisons. On the drag race I don't have much doubt that my bike will prevail. On the trail it will be interesting to see the comparison as we will trade out occasionally. We'll see how it goes. So far I'm loving this BBSHD equipped Nomad.
 
I previously posted an Excel calculator for mid-drive gearing showing that these advertised torque numbers are.. creative, at best.

Taking the CYC X1 Pro Gen2 with an ASI BAC855, the actual rated motor torque is only 5Nm, and I calculated 5.73Nm peak. Depending on the secondary 219H gearing chosen, that multiplies to between 166-206Nm at the crank, but is reduced back down at the hub to, well, whatever you want it to be.

In short, torque is not relevant to compare on a mid-drive. Compare power (continuous and peak), integrated vs open, features, etc.
 
Modern wheel sizes run smaller chainrings so the torque is only reduced at the wheel on the higher side of the cassette. I spend most of my day on my non-ebike 29er in 1:1 or higher reduction part of the cassette.

I disagree with looking at raw numbers, look first at weight then at how the motor and battery integrate into the frame.

I think if the BBSHD bike didn't have a throttle then a factory EMTB would absolutely crush it in the technical stuff.
 
Grantmac said:
Modern wheel sizes run smaller chainrings so the torque is only reduced at the wheel on the higher side of the cassette. I spend most of my day on my non-ebike 29er in 1:1 or higher reduction part of the cassette.

I disagree with looking at raw numbers, look first at weight then at how the motor and battery integrate into the frame.

I think if the BBSHD bike didn't have a throttle then a factory EMTB would absolutely crush it in the technical stuff.

I'm generally going to agree with you for the moment. The torque sensing quality of the factory bikes is amazing. I've only recently built up my '08 SC Nomad with the BBSHD, but every time I ride it after a small programming tweak here and there, the more "civilized" the bike becomes in technical terrain. In the weeks ahead my fellow shop worker and I will try that side-by-side comparison I mentioned with the Trek Rail and my Nomad.

I'm used to somewhat explosive acceleration and trying to corral momentum, weight, and speed at the braking points because of dirt motorcycle riding, so the BBSHD hasn't seemed out of control. And again, the programming really changes up how the bike behaves coming out of corners, picking through technical terrain, etc. I agree that the BBSHD will probably never achieve the pure, predictable smoothness of the better factory torque sensing motors, but frankly I'm shocked at how well the BBSHD can be tuned to alleviate the lack of torque sensing. On a side note, I tried riding the bike without the hydro brake sensors at first...just to see...it doesn't work if you're really trying to "get it" on a trail...LOL!

I will say this also that I don't think having a throttle can be beat but maybe not for the reason many think. One PITA has always been the situation where you stall out in a technical situation, have to unclip, and have a hard time regaining momentum to get started again in rough or rocky approach. Having that throttle really solves that because you can smooth into the throttle lever, getting rolling, clip in, and haul butt again. Factory emtb's should have something like that where they can limit the duration or whatever to meet legal requirements but still have that little short boost to get control in those situation. It would be kind of like a "walking mode" that most factory bikes have but reserved for restarting in a precarious situation. I still like to pedal, so I haven't wanted or needed to resort to throttle only for anything except that restart in a hard position.
 
Having a the capability to gain momentum without pedaling is the biggest difference between motorcycling and mountain biking. I say that as someone who has done a lot of the former but only recently gotten heavily into the latter. That difference really impacts trail design and difficulty which also makes comparison between a bike with throttle and one without almost impossible.
 
I have both bikes with throttles and no throttles set up for riding in similar situations. in my opinion, its never apples to apples. Torque sensors work great for off roading and in my opinion, a throttle generally isnt a necessity but if its an option its nice. if you don't have it, you can still have a great riding bike

cadence based PAS is generally not great on the trail, but it can be tweaked to be ok with a bit of work depending on the setup. a throttle definitely more a necessity with cadence based IMO, in fact i usually disable the PAS on that bike when i ride tight trails

Throttle only, definitely was better than i expected except i felt like i was going to get carpal tunnel after a half hour. could be rectified with a better setup. Better for high powered builds though. also, for snow, less than optimal terrain etc

Factory vs DIY, definitely feel like factory numbers are tricky with how they correlate with build your own setups: 250w of shimano/bosch/brose feels nothing like 250w of BBS01. im not really sure how they are rating these...take your typical BBS02 rated for 750w peaking around 1100, bbshd people saying 1500ish? I hear a lot of the factory motors are peaking closer to 700 W. close to 3x rated power seems deceptive, but riding one i would guess that sounds about right. The battery life always seems crazy though, right in line with what a 250w bike would draw. im curious how they are tuning these things but i guess they have a shitload of $$$ to pour into all the best developers.

I will probably stir up a hornets nest here but i was android/windows until a few years back. i am not a power user, though i was really into android devlopment back in the day. always hated apple, thought they were overpriced for the spec and just hated them in general. well, for certain uses and at the extreme end of the spectrum i can't compare what windows can do or what the latest android phone may be capable of. All i can say is spec for spec my apple stuff now beats the crap out of anything similar, runs cooler, gets better battery life etc. its boring and unmodifiable but it works and does what it does well

so getting back into what i was saying in another thread, some of these factory bikes are likely more efficient than what we have and well integrated. they will work well until they don't. like a macbook. when they eventually break, you will need to go to an authorized service center and spend more than a new BBS/tsdz2 on a service for some BS like a pinion gear or whatever. you will need proprietary cable and software to attempt DIY which nobody will have so not really user serviceable. what do you do at the point? i have a QBP account so i see what the parts cost and its not a pretty picture, plus a TON of parts not in stock and eta of 2022, so somehow our chinese clunkers are winning at this moment
 
I'm actually really looking forward to factory ebikes with bricked controllers/bms/etc becoming available for cheap but even though I live in a MTB hotbed it's just not happening.
I may eventually just buy a 3-4 year old EMTB to compliment my "acoustic" bike even though my original intent was to do an ultralight removable power system and keep it under 20kg. Honestly though the more time I spend riding without the motor the less I miss it.
 
Grantmac said:
I'm actually really looking forward to factory ebikes with bricked controllers/bms/etc becoming available for cheap but even though I live in a MTB hotbed it's just not happening.
I may eventually just buy a 3-4 year old EMTB to compliment my "acoustic" bike even though my original intent was to do an ultralight removable power system and keep it under 20kg. Honestly though the more time I spend riding without the motor the less I miss it.

I ran into a guy the other day after I had gotten my 2nd pinch flat of the day lol. He was riding his Wife's Specialized LEVO he mentioned his levo had been in the shop for three months waiting on parts. He mentioned it was an issue with a controller. One of the good things I've heard about Specialized is they transfer the warranty on the e-bikes and it's pretty long.
 
Speed,
I would imagine you must test ride those brands to judge for yourself if they have thrust you can trust and durability, maybe ask if it breaks what spare parts support you'll get and when.
 
Torque alone is irelevant. Peak and continuous power are relevant.

Factory 250w bikes (bosch, brose, shimano itd) have ~250-500w continuous power and max 800w peak. I tested them against my BBSHD and they cant climb very steep mountalin trails. BBSHD delivers 1600W peak (for 5 minutes or so).
 
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