How do I check how big chainring my bike can fit??

[Reinardt van Heerden]

How do I check whats the maximum chainring my bike can fit. I ride a mtb, but now and then do road races, but no enough to go and buy a road bike. I want to get a bigger chainring fir road races, but dont know if it will fit my bike

Edited Wednesday at 03:15 PM by Reinardt van Heerden
People requesting photos

[RobynE 🚵‍♀️]

Show us a pic of what you’ve got. 

Bigger ring will also need longer chain and your gears will need to be tweaked so it’s not quite plug n play. 

[guidodg]

I think he is asking about the clearance on the chain stay...take a pic and maybe we can help you

[Bub Marley]

Nothing bigger than a 38T that’s for sure. 

[Lynskey]

2 hours ago, Reinardt van Heerden said:

How do I check whats the maximum chainring my bike can fit. I ride a mtb, but now and then do road races, but no enough to go and buy a road bike. I want to get a bigger chainring fir road races, but dont know if it will fit my bike

How long is a piece of string! Without the knowledge of what bike and maybe a few pictures no really possible to say. Not being rude. You will probably also have to use a longer chain. 

[DieselnDust]

if the cassette is smaller the chain ring can be bigger without changing the chain. Although, the cassette and chain would need to be compatible.

Most mtb's only accept up to a 38T without a chainline adjustment. So if the cassette is smaller the chainline can be combobulated a wheee bit to allow for maybe a 40T

[Dexter-morgan]

I have converted a Silverback Sola and I fitted a 42t on it but nothing bigger will fit

[Reinardt van Heerden]

3 hours ago, RobynE 🚵‍♀️ said:

Show us a pic of what you’ve got. 

Bigger ring will also need longer chain and your gears will need to be tweaked so it’s not quite plug n play. 

Done ✅ 

[Reinardt van Heerden]

3 hours ago, RobynE 🚵‍♀️ said:

Show us a pic of what you’ve got. 

Bigger ring will also need longer chain and your gears will need to be tweaked so it’s not quite plug n play. 

No problem, its about the clearance with the frame

[JoeMerida]

Trial and Error is the Only Way. There is no Formula available.

[thebob]

What bike is it? The manufacturer should specify the maximum chainring size

Edited Wednesday at 04:44 PM by thebob

[RobertWhitehead]

I think a 40-42 will fit

[Dexter-morgan]

PS: I got mine from Rapide.

[Bub Marley]

What is your current size chainring? From those pics, it would seem like you have quite a bit of room there. 

[DieselnDust]

There's room for a 38T provided you don't have any chain suck. Larger chain rings may rub when you're cranking on the power as the stays and down tube flex. A 40 may fit if you reduce the chainring offset by 3mm and reduce the cassette sprocket size

[Reinardt van Heerden]

3 hours ago, Bub Marley said:

What is your current size chainring? From those pics, it would seem like you have quite a bit of room there. 

I have a 36 tooth, but it was touching slightly, but I've put in a bottom bracket spacer