Anyone know what this is? I'm sure someone does :)

[Sophie777]

I just picked up a Trek Powerfly FS 7 2019.
In the "extras" bag that came with the bike, is this circular shaped thing (see attached photo).
"Bosch" and "20-25 Nm" are written on it.
What is this?

The lady at the cash said "it is just an extra" - but what it is it?

Thanks!!

(The bike's motor is Bosch).

 

[Beekeeper]

I just picked up a Trek Powerfly FS 7 2019.
In the "extras" bag that came with the bike, is this circular shaped thing (see attached photo).
"Bosch" and "20-25 Nm" are written on it.
What is this?

The lady at the cash said "it is just an extra" - but what it is it?

Thanks!!

(The bike's motor is Bosch).

View attachment 16922

I’d say it’s a Bosch lock ring which is part of the motor unit. Part number is BDU2XX
It is used to mount the chain ring I believe.

 

[Sophie777]

I’d say it’s a Bosch lock ring which is part of the motor unit. Part number is BDU2XX
It is used to mount the chain ring I believe.

Thanks so much for your answer.
I think you are right - it's a Bosch lock ring.

Why would I be given this as an extra?
The bike was already assembled when I picked it up.
Is it supposed to be for future use if I need to mount another chain ring?

(I apologize, I guess it would be easier to just ask the bike shop).

 

[Beekeeper]

I suspect without one of those lock rings in place the chain ring and chain would fall off when you started peddling so I would imagine there is one on your bike already. (I would hope so).
Why they have given you a spare is a very good question. Perhaps keep it as a souvenir ?

 

[33red]

You can email a manufacturer for info, bike, tire, etc... Online you will get correct info and other stuff. Also talk with your LBS a good relation is important.
Happy trails