How to fit a bigger chainring on MTB?

I run a 34t 1x11 drivetrain on my mtb. I need to run a 36t chainring but it would grind against the frame if I did that. Is there any way to push my chainring further away from my frame for me to be able to fit a bigger ring? I have a 2017 Trek Procal 9.7 if that helps at all.

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I don’t think that’s possible. You might be better splashing out on one of the bespoke cassettes that has a 9 or 10T sprocket?

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You may be able to fit an oval 34 which I’ve heard “feels” like a 36, but clearance is what it is.

Sounds like it’s time for a new bike

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My friend told me about bb spacers. Has anyone tried these?

Depends what bottom bracket you are running. There are spacers designed to take up the space on different width bottom brackets. Does your bike currently have any spacers on either side? I’d be surprised if it’s not press fit being a Trek?

Yea its pressfit gxp. I cant change the bb because my powermeter only fits a gxp bb. It doesnt have any spacers on either side.

You can probably run a direct-mount chainring with a smaller offset, but it will make the chainline worse. Depending how far you’ll move from the ideal chainline, that might make shifting to and riding in the low gears (big sprockets) difficult.

The other thing is, if you often ride in muddy conditions, you probably want a bit more clearance between chainring and frame, or you could damage your frame.

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A 34T oval chainring is roughly the same diameter as a 36T in the long axis and a 32T in the short axis so it will have the same problem as a 36T round chainring.

Pressfit and GXP? You have my deepest sympathies.

Depending on your crankset you may be able to fit a boost chainring (no idea if the Procal is already Boost) which moves the chainline out by a couple of mm but as @splash says the shifting in the low gears might be compromised.

Probably easiest to fit a freehub and cassette with a 10T smallest cog. Won’t be the cheapest option though.

I have a 36t Sram Eagle (round) on my 2017 Procaliber (aluminum frame).

I’m using a Sram road crankset with Stages DUB spindle and direct-mount ring. It took some trial and error to get it set up. I have a “magic” number of thin metal washer shims on either side so that the chainring barely clears and the crank arm does the same on the opposite side. The chainring has still touched the chainstay at some point, as there is a bit of paint scraped off.

Let me know if you want some pics?

Is your crankset and chainring a direct mount or bolt on?

If it’s bolt on, I assume you already have the chainring bolted to the outside of the crank arm?

Wheels Manufacturing should have something available. They make a thread together bb92 that works with GXP and have loads of different spacers available.

I just want to thank all of you for your help! It looks like I am running out of options though, my crankset only allows bolt on chainring and might try some spacers. The chain line is going to be garbage but I mostly train on the road so it should not be too bad.

Direct mount ring on sram road crank.

I meant the OP

I realized I do not have a boost chainring yet I have a boost frame and crankset. Can I fit a 36t chainring if I have a boost chainring?

34t non boost chainring pictured.

Can you take a picture of your current chain line. I’m far from an expert, but that does look very close to the frame/more in board than usual.

What gear do you want it in?

I was also confused why my frame could not fit a 36t

Nevermind, I ordered a boost chainring which should clear with the extra 3mm room.