Giant Fathom E+ 3 Chainring

[Bobexup]

Hi, Newby here, had my first e bike for a month, love it....but I run out of gears (36t chainring) beyond motor assist, so I'm pedalling like a nutter beyond about 20mph, any idea if I can fit chainring off Giant quick e+ (42t). The motor is the synchro sport. Cheers Bob

 

[RandallS]

Have a look at the chainstay - there may not be a lot of room for a bigger chainring.
There sure isn't much room on my 2021 E+1 Pro with it's 38T chainring - not sure if you could go any larger.

Drivetrain is sure messy with the winter riding in sloppy, slushy conditions.

I went over to the UK site and took a screen shot (as that model not available here). There MAY be some room there, but not a lot.

I did some googling - and still think it would likely be tight with a 42T.
This is from https://www.wolftoothcomponents.com/pages/chainring-diameter-by-tooth-count

Good luck - you might be best off talking to a local shop and see what they can offer rather than on-line shopping for a replacement.

 

[Stefan Mikes]

I did some googling - and still think it would likely be tight with a 42T.

Giant e-MTBs are good up to 38T chainring. These are not made for fast pavement riding. (The same remark pertains to all true MTBs).

Good luck - you might be best off talking to a local shop and see what they can offer rather than on-line shopping for a replacement.

It is worth trying. However, the chainguide (if any) will have to go even if the 42T chainring fits.

 

[Bobexup]

Thanks for feedback, I checked and pretty sure 42 would fit, with 1/4 inch or 6mm gap. Mine has the 36mm nut not the notched nut. I guess this was changed for regular hex. Noted point about not built for fast pavement, however I'm only needing to use top 4 gears, so I rev out. Does anyone know if splines are same on Giant quick e+?

 

[Bobexup]

Thanks for feedback, I checked and pretty sure 42 would fit, with 1/4 inch or 6mm gap. Mine has the 36mm nut not the notched nut. I guess this was changed for regular hex. Noted point about not built for fast pavement, however I'm only needing to use top 4 gears, so I rev out. Does anyone know if splines are same on Giant quick e+?

Apologies for poor photo, it's to show distance from frame to chain wheel

 

[PedalUma]

Hi Bob, Welcome to EBR.
You could work this from a number of fronts simultaneously. Chainring, Wheel size, and Cassette. It looks like you have clearance for 29'er wheels. There is no reason you cannot go with a 10-36 cassette, from the stock 11-36. And you should have room for a 38-T chainring. If you made these changes your top end at 90Rpm would be 44.8. Your current gearing and wheels puts you at 39.7 at 90Rpm. About 13% faster at the same cadence or a 13% lower cadence at the same speed. These changes can be done overtime incrementally. Just take your measurements before ordering anything. Cheers and happy riding.

 

[Bobexup]

Hi Bob, Welcome to EBR.
You could work this from a number of fronts simultaneously. Chainring, Wheel size, and Cassette. It looks like you have clearance for 29'er wheels. There is no reason you cannot go with a 10-36 cassette, from the stock 11-36. And you should have room for a 38-T chainring. If you made these changes your top end at 90Rpm would be 44.8. Your current gearing and wheels puts you at 39.7 at 90Rpm. About 13% faster at the same cadence or a 13% lower cadence at the same speed. These changes can be done overtime incrementally. Just take your measurements before ordering anything. Cheers and happy riding.

Hi,
Thanks for information, the wheels are 29 already, but the 10-36 cassette looks like a no brained, at least I will be using the top 4 gears rather than the top 3, that will spread usage and give me around 10% less cadence for a given speed in top.