Chainring Replacements - What am I missing?

[gilbertdave]

Hi all,

Apologies if this has been asked before, but a search didn't yield the answer.

I'm jsut going through my first round of drivetrain updates... new cassette, chain and chainring (all 12spd).

Firstly, its blown my mind how many different tools are needed... So, the £200 of parts needs £100's worth of specific tools to install (yikes).

The cassette was a bastard to install and as the 11th and 12th gears didn't perfectly stack the first time I've pulled the thread off of the aluminium lockring.... It calls for 40Nm, but I guess I wasn't fully engage and off she popped... Fitted a replacement. Lucky.

The chainring though is baffling me. I ordered an e thirteen chainring to match the spec of my Trek Rail, whcih clearly shows the Bosch Gen 4 as compatible. Upon arrival, the spline teeth are much finer that my bosch motor (which I guess means its a shimano part?)

So, now I've set about tring to buy a suitable part and I can't get there...

It looks like I can get a spider for next to no money (anyone know if these are any good?)

Meaning then that all I need is a chain ring with 104 PCD (no probs) that is compatible with 12 spd...

These are rare as rocking horse shit?

I can't get my head round how few products are on the market given the quantity of ebikes running Bosch motors and how frequently these parts need changing... AM i missing something or am I really going to NOT ride for 2 months whilst some dingbat builds some stock?

HELP, please

 

[Oxon]

11 speed chainrings work with 12 speed chains and cassettes. That's what I run on two of my non-ebikes.

 

[Geedog]

Hello, I've recently fitted the hope bosch gen 4 chainring, very nice quality, and went on a treat.

 

[Doomanic]

I bought one of these from Ridewill in Italy when I couldn't find anything in the UK.

Dal 2013 il negozio online dedicato al ciclismo | Entra su Ridewill.it

Vendita on line delle migliori marche sul mercato di accessori e ricambi per ciclismo

www.ridewill.it

Currently out of stock so I wish I'd ordered two.

Chainrings for that spider from here;

Uberbike Made In Sheffield UK MTB - E-Bike Steel Chainrings

www.uberbikecomponents.com

 

[Doomanic]

Have you got a link to that spider? I seem to recall they do boost and non-boost so you need to be sure to order the correct one.

 

[gilbertdave]

Have you got a link to that spider? I seem to recall they do boost and non-boost so you need to be sure to order the correct one.

FSA W0134 Spider Bosch Gen4 Ø104mm black | Bikester.co.uk

The FSA W0134 Spider Bosch Gen4 Ø104mm black at Bikester.co.uk ✓ Biking specialists in the UK ✓ Buy online with free returns ✓ Easy shipping ✓ Great prices with the best service ✓ Find what you need with Bikester.co.uk ✓

www.bikester.co.uk

I think I've managed to get my hands on a direct replacement for the stock part, but it seems so easy to make a mistake or to simply not find the thing you need... It's bizarre.... Perhaps I should start manufacturing chain rings!

 

[Richiefromboston]

Hi all,

Apologies if this has been asked before, but a search didn't yield the answer.

I'm jsut going through my first round of drivetrain updates... new cassette, chain and chainring (all 12spd).

Firstly, its blown my mind how many different tools are needed... So, the £200 of parts needs £100's worth of specific tools to install (yikes).

The cassette was a bastard to install and as the 11th and 12th gears didn't perfectly stack the first time I've pulled the thread off of the aluminium lockring.... It calls for 40Nm, but I guess I wasn't fully engage and off she popped... Fitted a replacement. Lucky.

The chainring though is baffling me. I ordered an e thirteen chainring to match the spec of my Trek Rail, whcih clearly shows the Bosch Gen 4 as compatible. Upon arrival, the spline teeth are much finer that my bosch motor (which I guess means its a shimano part?)

View attachment 65610

So, now I've set about tring to buy a suitable part and I can't get there...

It looks like I can get a spider for next to no money (anyone know if these are any good?)

View attachment 65611

Meaning then that all I need is a chain ring with 104 PCD (no probs) that is compatible with 12 spd...

These are rare as rocking horse shit?

I can't get my head round how few products are on the market given the quantity of ebikes running Bosch motors and how frequently these parts need changing... AM i missing something or am I really going to NOT ride for 2 months whilst some dingbat builds some stock?

HELP, please

I ordered 4 chainrings after nuking mine, get the ethirteen steel 34t chainring direct form E13 and you will be good. aluminium would worry me steel bent like a pretzel as it was.