Chainring what size ?

[Dano78]

Had anyone upsized the chainring on there trek rail? Does it help with battery performance thanks

 

[Philly G]

It won't have any effect on battery life, and due to the speed cut-off of the motor, is not really worth doing imo. My Rail came with a 34T ring, and due to lack of clearance with the chainstay I'm not sure I could fit a bigger one

 

[bluewater87]

36T should fit, as the Rail 9.7 I am waiting on says it comes with a Sram 36 tooth.
I’m replacing the sram with shimano, so I’ve purchased an e13 36T to install.

 

[Dano78]

36T should fit, as the Rail 9.7 I am waiting on says it comes with a Sram 36 tooth.
I’m replacing the sram with shimano, so I’ve purchased an e13 36T to install.

Thanks for the feed back may I ask why your swapping to shimano ? I'm thinking about doing the same maybe next year

 

[bluewater87]

Thanks for the feed back may I ask why your swapping to shimano ? I'm thinking about doing the same maybe next year

I really liked the shimano 12 speed slx on the rail 7s I tested. The ability to shift under slight load and multi gear shift is pretty handy. Prices for shimano are fairly decent as well.
Eagle is clunky and fussy, especially in sx or nx.I will probably be selling my takeoff nx drivetrain once I get the shimano swapped on.

 

[dixie600mhz]

Can you confirm the 36T front chainring fits? I'm thinking that will be my first mod.

 

[Philly G]

@dixie600mhz 34T is the max, unfortunately, specs confirm it Rail 9 | Trek Bikes (GB)

 

[bluewater87]

36t is too close. 34T max

 

[dixie600mhz]

Thanks guys!

 

[AME]

Anyone tried if a different crank or spider would be possible, so a 36 could be fitted?

 

[AME]

Anyone tried if a different crank or spider would be possible, so a 36 could be fitted?

I can find a FAA spider mase for gen4 motors. It schould be possible to use a different chai ring and maybe shim the chainribg out a mm or two. Yes, i understand it will change the chaine line but i will rearlu use the two largets cogs on the casette anyway

 

[Gyre]

Has anyone tried a 28 or 30t chainring? I'd prefer to keep my gearing in the neighborhood of my acoustic bike in case I need to pedal out of a bad situation or want to conserve juice on a long day.