Hi all. I bought an Ari Fezzari, which is great, but I'm trying to swap out the 32t chainring to a 40t (maybe a 38t, I guess?). The only problem is I don't understand how to know if it will fit or not. I realize this is pretty basic but I'm confused.
Does the BCD and Offset have to be the same? Is it proprietary and has to be the same SRAM Eagle X-Sync 2 brand to work properly? Do I have to get a new, longer chain as well to go with it? Just to clarify, it's a SRAM SX Eagle 12 Speed (32T, 11-50T). Any advice would be helpful. Right now I feel like I may just have to order 3 and return whatever doesn't fit.
EDIT: Thanks for the clarification everyone, I reached out to Ari (Not, I now realize, Fezzari!) to see if there's even clearance for this. Didn't realize I was so far off.
by cgkygtuhjrivfcsz
12 Comments
Most frames from actual companies have a max chainring size. I’d check the specs on their website first!
You may or may not need a longer chain, but probably not. You may not have clearance for a 40t on that frame though.
Does the frame support a 40T?
I can tell you a 40t is not going to work.
Look at the chainstay where it is almost touching the chainring. It looks like it is barely clearing it.
The difference in the radius between a 40t and a 32t ring is 16.1mm. I doubt you got 16mm of space there.
You want to look at how the chainring mounts to the crankset.
You don’t have bolts on that crankset, so BCD doesn’t matter. You have to get SRAM direct mount rings.
Then you have to consider if the ring will clear your chainstay (which someone else has already pointed out is probably not likely).
And finally, as yet someone else has mentioned, you might need to add some links to your chain.
>Hi all. I bought an Ari Fezzari
“Fezzari” is just the retired brand name of what’s now known as “Ari”. So you basically said “I bought a Nissan Datsun”… which is nonsense. Providing the actual model name might be helpful to those trying to help.
>Does the BCD and Offset have to be the same
There’s no BCD involved in your case. What you have there is a SRAM direct-mount 3-bolt standard. Offset does indeed have to be the same.
>Is it proprietary and has to be the same SRAM Eagle X-Sync 2 brand to work properly
It is proprietary and another Eagle X-Sync 2 tooth design would work optimally, but generally something that is designed to work in 1x for 12-speed chains should work. There are exceptions (eg. Wolf Tooth) who optimize their designs for brands and series (eg. Shimano vs. SRAM, Eagle vs. T vs. Flattop), so go do your due dilligence.
>I’m trying to swap out the 32t chainring to a 40t (maybe a 38t, I guess?).
This is usually not going to work if your Ari is a contemporary mountain bike. Contemporary mountain bikes are built around the idea of minimal chainstay lengths + maximal tire clearances + best chainline, which makes the chainring clearance tight. Manufacturers will tell you what is the maximum your frame will accommodate without crazy hacks. You should talk to tech support and get that spec for your bike.
But in general, going from 32T to 40T on a contemporary mountain bike is no bueno. 40T is 1x gravel territory. Gravel frames can do that by compromising on tire clearance.
>Do I have to get a new, longer chain as well to go with it?
Yes, but I think this project is already fatally flawed for the prior explained reason.
I’m also confused – why would you want to do that?
That won’t fit. 34T maybe based on the image and is a common max chainring size on mtbs but doublecheck the product page or email the manufacturer. I’d be surprised if it took a 36T let alone anything bigger
3-bolt sram direct mount. There is no BCD. Get the same offset since that’s to get the right chainline.
You’ll likely need a longer chain. Big, big + 2 method is generally how I roll.
If you want more top speed you’ll need an xd freehub body for your wheel, assuming they make it, and a 10-whatever cassette (50 or 52) for said xd driver. Or get a new wheel that has an xd driver on it with the same rear spacing. Guessing either standard 142 or Boost 148… if they’re QR then -7 and a lot of times you can find QR endcaps to convert a wheelset from TA to QR.
Based on the square taper SX I’m guessing standard so that’s 142TA/135QR
Still, confirm my guess on rear spacing and search marketplace for something used. A lot of the time you can find good deals in perfectly fine takeoffs from someone who bought a new bike knowing they wanted nicer wheeled from the get go. Then of course slap a 10T Eagle cassette on it.
Just buy an old 3×9 bike. 44 tooth chainring baby. Cream past all the other mountain bikes on the flats pedaling like lunatics to go nowhere fast.
38t is ok on most hard tails mtb frame. I have 2 bikes both run 40t (off set 0mm), same SRAM cranks
While a 40t with the same offset will not fit, you might be able to cheat a little. What you are paying attention to is “chain line”. A boost chainring will sit 3mm farther out than a non-boost.
>SRAM SX Eagle 12 Speed (32T, 11-50T).
would be a pricy upgrade, but you could potentially upgrade to gx 10-50t cassette