How does the Bosch motor freewheel?

[HikerDave]

When you back-pedal your Bosch motor does it tick or is it smooth. When you start pedaling does it engage instantly?

I’m trying to find out which, if any motors use a sprag or roller clutch for instant engagement.

A drawback of my Yamaha PW-SE motor is that it has only 18 points of engagement in the motor’s ratchet mechanism. This has been increased to 24 in the PW-X.

With a freewheel in both the wheel and the motor, my bike gets sloppy ratcheting over rocks when the going gets rough.

 

[Bearing Man]

The Bosch Performance Line motors use a large clutch roller bearing that is smooth, quiet, instant and very strong. Brose use a sprag bearing which is quick to lock but has proved troublesome for some. The Bosch Gen 3 motor has gone back to a ratchet system, but with quite fine action, so there is very little slack.

Hope this helps.

 

[HikerDave]

The Bosch Performance Line motors use a large clutch roller bearing that is smooth, quiet, instant and very strong. Brose use a sprag bearing which is quick to lock but has proved troublesome for some. The Bosch Gen 3 motor has gone back to a ratchet system, but with quite fine action, so there is very little slack.

Hope this helps.

Yes, thanks!

Does anyone know how Shimano does this? If I had a guess I’d say fishing-reel style.

 

[R120]

Not sure, but from my prior investigations there is daintily Fishing Reel developed elements in there, much the same as the Brose and Bosch owe a lot to windscreen wiper motors

 

[Sijmes]

The Bosch Performance Line motors use a large clutch roller bearing that is smooth, quiet, instant and very strong. Brose use a sprag bearing which is quick to lock but has proved troublesome for some. The Bosch Gen 3 motor has gone back to a ratchet system, but with quite fine action, so there is very little slack.

Hope this helps.

Apparently, that's what's rattling on the gen 3. Some say it's unbearable, no pun ?

 

[Bearing Man]

Apparently, that's what's rattling on the gen 3. Some say it's unbearable, no pun ?

The Gen 3 that rattles is the Active Line Gen 3 and this has a clutch bearing but "clunks" through the gearing each time the clutch bearing activates.
The Performance Line Gen 3 has only just been released so no complaints yet, but this motor uses a ratchet and pawl system, so should just drive you nuts with the clicking and not clunking