Chain hits the frame

6220

I just bought a 2013 CAAD 8 2300.

I heard some noise when front outer, rear top. I thought it would be like the chain is hitting the front derailleur. I checked it at home and found actually the chain is hitting the frame.

I don't know if it's the frame or wheel. Please let me know if there's anything I should check before taking it back to the store.

6220

I don't know if the frame is unsized.


or is it like I can adjust this by loosening the nut on the wheel?

Ride hard

It's nothing major. Your rear derailleuer limit screw need adjusting. Search on t'internet for guides and videos on how to do it as its pretty simple.

Secondly, by front outer/rear top I assume you mean big big combo. I wouldn't cross chain like this personally as you're putting the chain at an angle which can reduce its life, but hey its your steed

Barbarossa

It shouldn't do that. Check that you had the wheel sitting in the dropouts properly, if that doesn't sort it, get the shop to have a look at it.

It could be a fault with the frame or it could be that the cassette or hub hasn't been put together properly - a spacer missing from the axle or a spacer fitted behind the cassette where it shouldn't be.

It isn't deraileur adjustment because it is on the drive side of the chain. Neither is it using the wrong gear combination.

rolf_f

Ride hard wrote:

It's nothing major. Your rear derailleuer limit screw need adjusting. Search on t'internet for guides and videos on how to do it as its pretty simple.

Secondly, by front outer/rear top I assume you mean big big combo. I wouldn't cross chain like this personally as you're putting the chain at an angle which can reduce its life, but hey its your steed

Why would you assume front out/rear top means big big? Rear top is the smallest sprocket and he'd hardly have the chain hit the chain stay if the chain was in the biggest sprocket anyway.

Also, I can't see how adjusting the limit screw will help here. The chain is fouling the chainstay - it has to pass round the smallest sprocket before it reaches the derailleur so it's hard to see how any adjustment to the rear mech is going to do anything here. There are three points of contact here - the chainstay, the small sprocket and the large chainring. The latter should be aligned in such a way that the chainstay isn't a point of contact. Effectively, either the chainstay is too far in or the cogs are too far out (assuming that the wheel is ok). Or, if it is only a tiny contact, a narrower chain might help.

I had this issue converting a touring bike from freehub to cassette. In that case the only thing I could do was place the spacer between the sprockets and the lockring (it was meant to go behind the cassette) - which actually worked perfectly well. But this is a new bike and should work without botching. I agree with what Barbarossa said.

desweller

Some frames have this problem as a result of the design. I believe Planet X have form in this area, with the Kaffenback frame not able to accept top sprockets bigger than 12 teeth or so, and one of their plastic frames not being able to use Campag for the same reason.

However, this is a new bike with the stock cassette, so it shouldn't do it. Take it back.

6220

Thank you guys for your opinions.

Yes, I meant front big rear small cuz I felt the fastest gear is called top gear. I think the wheel sitting in the dropouts properly

I wonder if there is a way to make sure that the rear wheel is set in the centre of the frame as well as the front wheel. This may be solved by putting a spacer between the frame and the wheel but it won't be good if there is some offset against the front wheel even if it's 1-2mm?

It's far but I'll take it to the shop I bought.

desweller

The position of the cassette and hub is fixed. If you had an old-fashioned solid axle then you might have been able to put a washer in to spread the rear triangle a bit; as it stands, with the short hollow axle that you get on a quick-release hub you can't really move the frame out as it means the dropout is supported on too short a land.

The only thing I can think of that might work is fitting a MTB axle (which is 5mm longer), but that solution relies on the axle being a straightforward hollow stud, which most aren't.

6220

Thank you,

could it be the cassette is not inserted to the free hub properly?

I can see splines about 2-3mm.

6220

I took it to the store. The mechanic took off the cassette and assemble again but it didn't fix the problem. I checked the wheel of other CAAD 8 at the store but it looked like visible spline is normal.

He said they'll fix if I leave the bike so I left it. I was wondering what else they can do tho.

Ride hard

Rolf F wrote:

Ride hard wrote:

It's nothing major. Your rear derailleuer limit screw need adjusting. Search on t'internet for guides and videos on how to do it as its pretty simple.

Secondly, by front outer/rear top I assume you mean big big combo. I wouldn't cross chain like this personally as you're putting the chain at an angle which can reduce its life, but hey its your steed

Why would you assume front out/rear top means big big? Rear top is the smallest sprocket and he'd hardly have the chain hit the chain stay if the chain was in the biggest sprocket anyway.

Also, I can't see how adjusting the limit screw will help here. The chain is fouling the chainstay - it has to pass round the smallest sprocket before it reaches the derailleur so it's hard to see how any adjustment to the rear mech is going to do anything here. There are three points of contact here - the chainstay, the small sprocket and the large chainring. The latter should be aligned in such a way that the chainstay isn't a point of contact. Effectively, either the chainstay is too far in or the cogs are too far out (assuming that the wheel is ok). Or, if it is only a tiny contact, a narrower chain might help.

I had this issue converting a touring bike from freehub to cassette. In that case the only thing I could do was place the spacer between the sprockets and the lockring (it was meant to go behind the cassette) - which actually worked perfectly well. But this is a new bike and should work without botching. I agree with what Barbarossa said.

My bad.

I only skim read it before setting off an 80 mile puncture fest. I mis read the bit about it hitting the chainstay.

6220

I got my bike back. The receipt says "moved rear axle towards non-drive side."

I wonder if this is a proper solution tho. I'm not sure this was just the rear wheel was not assembled properly. Is "axle" something adjustable? How do you know the rear tyre is located at the centre of the frame? Is there any guidelines like the length from the axle end to the center of wheel should be xxx mm?

keef66

If it's fixed the problem, there's the same amount of axle protruding at each end, and the wheel sits centrally between the stays i'd say there was something wrong with the wheel to start with.