Hi all, I’ve got an FX Sport Carbon 4 which I love, but the factory gearing lacks oomph for flat road cycling. I’ve read about users changing the 40T chainring to 42 or 44T but when I asked at my local Trek dealer and they said they couldn’t. Tbh this sounds like rubbish to me given others having done so.

so I’m wondering if anyone out there has practical experience of doing so? I’ve been looking at a Wolf Tooth BCD chainring replacement (which claim to work on GRX cranks already on the bike). Would this work in practice and would a new chain be required? Any help would be most appreciated.

While I did not go with the FX 4 (because I'm an FX 6 Roadie* now), I did think long and hard about the gear range on the FX 4 when buying a bike last year. You definitely should be able to install a 42 or 44 Chainring, I think I saw some manage to fit a 46? You could also get a 10-42 cassette (or both).

If you're within your 30 day grace period with Trek, I would consider upgrading to the FX 5 or 6 if that's an option for you. The gear range on the FX 4 is perfect for gravel, but you'll find yourself spinning out frequently on the road.

I'm thinking about the FX Sport series now that the FX 3 is a 10-speed for 2022. The standover height of the Sports is also more than 2 inches less than the FX 3, which is important with my short legs (I would crunch on the FX 3).

I also read similar complaints to the OP about the FX 4 gearing, so I'm looking at the FX 5 or FX 6. You happy with yours?

Mark

I'm keeping up with the A Group a weekly rides riding 20+ mph. I've done some mods to get more aero and efficient to stay in the pace line.

See photo below. I flipped the stem, installed a longer stem (120 mm), SQLabs Grips and Innerbarends (my primary hand position), SPD Pedals and other minor changes for my fit.

https://www.facebook.com/photo/?fbid...34983863185180

Thanks for the info Darkskyhunter - your FX6 looks awesome. I've already put 4000km on the 4 so I'm not sure Trek will be swapping anything and in any event in Australia they don't stock the FX5 or 6.

I love bike I've got, I really do, it just needs a tiny bit more juice on the flat. Though at the moment you could ride it up a wall...

I got my wife on of these bikes earlier this year and she likes the 1x system, but agree with the stock gearing. We live in a very flat area and while she is not looking to be a speed demon, I did swap the cassette to a 14-28 as this helps her deal with the wind we have in the area and that allows her a much better gearing for our area. I looked into the Wolf Tooth and looked at getting a 44 or 46 and it is doable, but I just have not done it yet. She seems quite happy with the stock 40 and the change to the 14-28 cassette.

This is her bike:

Nice bike, the area looks for familiar, Raleigh NC, Falls Dam area? If not, it looks almost identical to an area local to me, lol.

It is! I enjoy cycling the Neuse River Trail on occasion. I mostly on the road these days.