Bosch Class III pedelecs cut out at 26.5 mph
- Thread starter rudymsmith
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dblhelix
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I was told Gen4 starts dropping at 26.4mph; assume it‘s the same after the recent update, but to be sure, ask your dealer or Bosch. I believe the update only changes the %assist, so at 26.4mph you will be getting more torque, but it starts its decline (to zero at 27.96 mph) at this point as well.
Ravi Kempaiah
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Now that is disappointing. Bosch could do so much better.
Any chance you can swap the motor to something that actually goes to 28 or slightly higher easier ?
Over50
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@Ravi Kempaiah is correct about my experience with Nuvinci (Enviolo) and the R&M Charger - it was a struggle to cruise at 25 mph. 23 mph was a more realistic cruising speed. When I upgraded to a Charger with Rohloff, hitting 28 mph was not a problem. I could cruise comfortably at 26 mph in Sport mode with a gear remaining (in 13th gear). 26 mph is about my comfort level for cruising. With the Allant 9.9s and the Gen 4 motor, I have no problem hitting the cutoff. I've been up over 28 mph and honestly I can't say that I even felt the motor cutoff - it is smooth. Here are a couple of recent Strava summaries. The 32 mph would have been on a flat aided by a tailwind. I have several recent summaries with max speeds around 27 and 28 with not much wind support. These speeds would have been in Tour and even with Eco as long as I have good pavement and not a headwind I can hit 25 mph. I pretty much never use Sport or Turbo.
Ravi Kempaiah
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Thanks for sharing your experience, @Over50 .
Sometimes the forum gets over-run by opinions rather than real-life experience.
My experience of Bosch Gen 2 mated to a Rohloff is similar and the attached data is my ride on a R-M delite. I was able to hit 33 mph top speed. I am pretty sure I can do better with a Gen 4.
I will release more range + speed data on Gen 4 system once I put few hundred miles on my prototypes.
onlineaddy
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Were you getting assistance from the motor beyond 26.5 mph?
Ravi Kempaiah
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Of course. All the way up to 28 mph.
I believe the gearing ratio and low resistance of Rohloff helped.
I have never had a problem of hitting 28mph on Bosch Gen 2 or Bosch Gen 4 motors. I have attached the Strava data above. Bosch motors are not over-powering nor are they under-powered and it would be difficult to maintain 23 mph average speed over 22+ miles if the motor did not assist properly.
onlineaddy
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That's good to hear. But, just to be clear, it's not a question of hitting 28 mph; it's a question of whether the motor is assisting you all the way there.
Based on the thread earlier, it is safe to say all Bosch assists cuts off at ~26mph.
rich c
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You must be incredibly miserable when buying a car if you insist on total and complete honesty in all marketing. You must go livid when they try to sell you that extended warranty. I have no idea how you could buy a new mattress if you believe that 10 year warranty is really a 10 year warranty and not a prorated small print contract that gives you about $100 off in 8 years. And that road hazard guarantee on your tires that will cost you $50 when you destroy the tire in a pot hole. Marketing and honesty are very distant cousins.
Ravi Kempaiah
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If you don't have personal experience on a bike, please refrain from making erroneous comments.
Making an informed comment is one thing but making a comment out of envy and jealousy to justify your Bafang purchase is another thing. If I wanted, I could write a 10 page article on Bafang's shady practices.
if you have a Bosch, post a picture of the bike and picture of your Strava rides. If you don't, may be it is better to stop spreading misinformation.
onlineaddy
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Why respond in kind, @Ravi Kempaiah ? pennybags and I are far from BFF, but why did you bring up Bafang and its "shady practices"?
If you tell me that the Bosch motor assists all the way up to 28 mph from your experience, I'm inclined to believe you. I don't need any proof from a picture of your bike, display, or Strava stats.
If you tell me that the Bosch motor assists all the way up to 28 mph from your experience, I'm inclined to believe you. I don't need any proof from a picture of your bike, display, or Strava stats.
Now this is a great post, thank you. Ties so many loose ends together. Ravi, if I'm understanding you correctly.. it's the 17% or so efficiency loss on the Enviolo that is causing the low cut out? That would mean that Bosch cut outs are based on some parameter of torque/revolutions? I guess actual RPM's at the wheel are not being measured. Interested in your view..
First, I am not complaining - this is a thread about Bosch motor performance, not your bike. Second, I am not singing praises of any brand here. This is not a competition. Bafang isnt a shining star, and evidently Bosch isnt either.
Just taking everyting else out of it, logically, if assist has to stop by 28mph, then the assist ramp-down should start before 28mph. There is nothing wrong in that. As tRump says "it is what it is"....
Since it has to be a number lower than 28. We are trying to get your (or whoever is riding Gen4) as to when it starts to drops off.
Ravi Kempaiah
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Because these days, the forum is over-run by a few people who think it's their playground and use it wantonly.
There are a lot of very smart, sensible people here on the forum but a few people make all the noise without contributing to the overall benefit of others. They just comment on one particular product and never help any other posts and many times it is just a marketing ploy or done out of envy. I have started ignoring those kind of people.
This particular guy, I don't know his name started inciting unnecessary negative narratives here. It makes me pissed if I see someone talking about something and spreading misinformation without any personal experience. I just posted picture of the bike ride and explained why I think some of the concerns expressed here are unwarranted but somehow he had to thumb his nose and make some comment.
Most of the forum users here are smart and they can smell good stuff from BS miles away.
onlineaddy
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Yes, we help when we’re able and learn from others when the opportunity presents itself. That’s all we can do, here on the forums and generally in life as well.
Ravi Kempaiah
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Not really.
The issue was with Enviolo or Nuvinci over-drive setting. Some of the older Nuvinci's hub interface had a 2-lever mechanism to set over-drive limits and when set correctly, you could enable high gear ratio (~28mph)
But, over a period of time, it would get loose and will need to be re-set. On my bike, I tried to re-set it many times but the interface had worn out. So, I just got a new hub and it worked fine.
Enviolo certainly doesn't have the gear ratio of Rohloff but for most purposes it works fine. There is one guy who has done 45,000 kms on a R-M traveling all over the world. He had to replace his motor but still using the original Enviolo hub and belt. So, it clearly works but if someone needs a larger gear ratio, Rohloff is a better option.
Very interesting, sorry to see this is an issue with their hubs. In that case, the Bosch cannot apply its torque properly without access to the high ratio. I wonder why there isn't firmware to compensate with higher RPM's in the case of overdrive slip? Most motors (although I know the CX is specialized for higher torque, lower RPM) have no issue with a few hundred higher RPM's. There must be an engineering reason.
Over50
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I went for a short 15 mile ride tonight on my Allant. I was really trying to pay attention to the behavior of the assist as I approached 28. It definitely does not cut out at 26 but I was working to get to 28 - particularly because the wind speed shown below was headwind (Tour mode). If the assist was decreasing from 26 to 28 I could not detect it. I rode perhaps a quarter of a mile right around 27 to 28 in Tour and I was pedaling hard with a fast cadence. But I still had Sport and Turbo mode which I did not use. I tend to think therefore that a cruising speed close to 28 mph with a comfortable cadence would be possible relying on the upper assist levels. Unfortunately, absent my commute at 6am, I don't really have a long stretch where I can cruise for several miles at a high speed. I'm not commuting now due to Covid so all my rides are residential and urban and during times of more traffic - hence less ability to test out high speed cruising over a long distance.
I also went farther back in my Strava history and found a 35 mph max speed. It was back in April and I honestly don't recall the ride but I'm sure tailwind and perhaps Sport mode were involved. I really don't have hills where I live - most of my rides show minimal elevation gain - so it definitely wasn't a downhill run.
Today's ride and April 28
I also went farther back in my Strava history and found a 35 mph max speed. It was back in April and I honestly don't recall the ride but I'm sure tailwind and perhaps Sport mode were involved. I really don't have hills where I live - most of my rides show minimal elevation gain - so it definitely wasn't a downhill run.
Today's ride and April 28
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