Fandomii

Hi all,
I just moved from a Bosch Gen2 Performance Speed + Gates CDX (24T front / 24T back) + Nuvinci N380 to a Bosch Gen4 Performance Speed + Gates CDX (55T front / 22T back) + Enviolo TR. Unfortunately the new Gen4 setup is noisier than the Gen3 setup! I thought the Gen4 was supposed to be quieter.

During pedaling, the Gen3 setup would quiet down as I shifted up to a higher gear. The Gen4 setup behaves somewhat similarly but does not quiet down enough, it retains a high whiny pitch. Do you know if that's expected and if there's anything I can do about it - or ask my bike shop to do?

One more thing - there is noticeably more effort required to pedal at the maximum gear using the Gen4 setup, than with the Gen3 setup. Looking at the Nuvinci and Enviolo hubs, I can see they offer the same gear ratio (380% - 0.5 to 1.9). Why does the Gen4 require more effort to pedal at max gear (at the same riding conditions), is it because of the many more teeth in the front compared to the Gen 3?

veganbikes

Just FYI it would be Gen2 technically the Gen3 stuff was entry level performance line (cruise and sport 60nm stuff) and all of the active line stuff.

Not sue why you would be getting more noise. I had never experienced the problem but something could be off in belt tension or something. I know that Bosch in generally noisier but it shouldn't be exceptionally louder than the old stuff unless there is something wrong with it.

The hubs are the same I believe just Nuvinci sort of rebranded to Enviolo and have been slowly converting everything over. So there shouldn't be a difference there but belt tension could have varied.

I would take it to the shop and have them look at it. It is hard to diagnose online. I know for my Gen4 speed and Rohloff the 7th gear is the noisiest but that makes sense and truthfully I don't really notice the motor noise other noises sure when something sounds off but that is a rare occurrence.

Fandomii

Thank you veganbikes - corrected the Gen3 to Gen2

The Gen2 would start with a loud whine at low gears and would quiet down while gearing up. At max gear it was pretty quiet.
The Gen4 starts with an equal amount of whine as Gen2, but does not quiet down as much as the Gen2 did while gearing up.

Any idea why that is?

veganbikes

Like I said I am unsure. I am assuming same assist level usage on both? The motor does have more torque but I don't think the noise really has changed from that. I guess it is possible. I would still take it to your local Bosch dealer and see if they can take a look but I doubt anything is really awry unless you are hearing a strange noise.

MarcusT

Just switched Gen 3 to 4 and have noticed the noise, but when I think back to when the Gen 3 was new, I thought it was quite loud. I even recorded it and showed the LBS, and they said that was normal.
My opinion is, we are much more sensitive to noises on a new bike. I also hear a noise coming from the new forks, but all the tests show it's working fine.
One more possible reason, is the gen 3 had internal gearing, where the gen 4 does not (the 14T chainring vs 36T)
All the motor comparisons I've watched say the Bosch is the quietest, but still makes noise.

Fandomii

Is it supposed to get quieter after 300km-ish? I've read that reply from Bosch somewhere, but it sounds weird - why would it quiet down with use? If anything I would expect it to get louder with time.

Darth Lefty 

What specifically is the noise? Is it the switching frequency of the speed control? The gearbox?

Fandomii

It is the whiny, high pitch noise when the motor operates. It's constant under load/pedaling.

fooferdoggie 

the gen 4 is noise coming from the Gen 2 speed. new chain noise is still there. but tire size makes a huge difference my bulls with 1.5" 70 psi tires to my trek gen 4 with 2.5" ties its a huge difference. I had to crank up assist on the lower speeds to try to get some of that acceleration. but still I tend to be 3mph shower on the trek. it can out climb the bulls on steep hills though.

veganbikes

Agreed with everything else said but what comparisons are that??? Brose is probably the quietest it is internally belt driven and so long as you don't break the belt or sprague clutch it is pretty darn quiet and there could be some others but Bosch would not be that. It is a great motor and certainly one of if not the highest reliability wise but noise it is average to louder end. Maybe down the road it will quiet down and maybe the new Smart System stuff is quieter but my rides have been less focused on noise and usually on any issues from a new bike build or just having some fun because it is a cool new bike.

MarcusT

Just simple, non scientific reviews on YT.
While shopping for my new Emtb, I searched exhaustively for user opinions. I was undecided with the Bosch CX Gen 4 and the Shimano EP8. In the end, the Bosch pulled ahead.
However, I can say, not a fan of the Tour+ so far. Maybe needs getting used to.

Kabuki12

My wife has a Bosch mid drive set up on her Townie Go. It has a Shimano internal 5 speed geared hub and it is about two years old. We just rode yesterday ( I ride a vintage steel road bike) and I couldn’t hear anything coming from her bike. She cruises about 15 mph on the flats , sometimes faster at 18mph . On the hills she leaves me behind so I can’t say but she has never complained about noise. When she bought it I tried it out without the motor on just to see how it was and I was surprised that it actually could be ridden even if the battery was not charged up. The range, the way she rides it, far exceeds her requirements.

veganbikes

Weird, I guess they missed the Brose motor. I haven't had a good chance to try the EP8 motor so maybe it is louder than Bosch.

Bosch is a great motor, I would say you did well. Though Shimano does have decent support I think the Bosch support is higher. Sometimes frustrating to folks who know what they are doing because you have to go through a lot of doing the basic stuff and intermediate stuff we did on day one but it is good they have a solid process and go through it for everyone.

I haven't had much chance to try the Tour+ because it is not available on the Speed motor but I suspect it takes some getting used to as you said. Anytime you take away control it is tough. I know trying the Enviolo Automatiq system the first time it was terrible now it is passable but I still don't love the lack of control.