Chain rubbing on front derailleur in highest gear since new

[DuncanM]

Hello,

I bought a Specialized Allez in May, and it has always had a slight bit of chain rub in the highest gear, only on the right pedal downstroke if that makes sense.

Hanging the bike up and watching it closely as I slowly pedal, I can see that the chain gets closer to the derailleur as the right pedal is at the top of its travel, and then lightly touches it for a bit on the way down.

I'm a little disappointed with this tbh, and it didn't get picked up in the free 6 week service - bought from Evans-. I have emailed them saying I want it sorted properly.


Question is, how bad is this? Should I still be riding it whilst waiting to book it in?

[lufbramatt]

Probably just a case of the cable stretching a little bit, so the tension in the deraillieur spring is pulling the cage too close to the chain.

[jesusbuiltmycar]

lufbramatt said:

Probably just a case of the cable stretching a little bit, so the tension in the deraillieur spring is pulling the cage too close to the chain.

Sounds like good advice. I had the same problem after replacing my cables, should just be a case of using the barrel adjusters.

[anonymous-user]

Sounds like the chainring could be slightly bent if it only happens at certain points of the pedal rotation or one bolt is tighter than the other and causing the deflection. The cable may stretch a little over time but they are not under that much tension.

[RicksAlfas]

Can't you just undo the high screw half a turn?

[pembo]

From my experience the service from Evans is great but they are rubbish at indexing gears. We had to get a new mech hanger, rear derailleur and chain the other day from them, figured they might as well fit it for us to make sure it was right... All day today I've had to listen to clicky chain and the gears changing up and down at random. I'll have to fix that in the morning, it's winding me up and I'm not even riding it!

[DuncanM]

Checking again the chain moves considerably from on side of thr derailleur to the other in any gear, surely something ain't right there?

Around 3mm.

[Stugots]

As above reply from your description it sounds like the front ring is bent, causing chain rub only at certain crank positions ?? Straight back to Evans would hope they'll sort this out.

Edited by Stugots on Thursday 30th July 22:38

[Wilmslowboy]

Drop the chain onto the smallest ring and slowly turn the pedals, looking directly down on the large chain ring (as mentioned above it looks like it's either bent or not on square)

If it appears to be bent, it is worth, checking the tightness of the screws that hold it on (again as mentioned above) if they are all tight, next step undue them, take the large ring off (you should be able to take it off without the need to remove the crank) and then lay it flat on a hard very flat surface (office desk etc) it should be obvious if it's bent.

[shouldbworking]

Also check to ensure that your chainring bolts haven't worked loose.

[Dixie]

i have a similar problem on my cross bike only on the non drive side (left). When on the top chainring and the lower 3 or 4 gears of the cassette it rubs quite badly. I adjusted the front mech as it was getting on my wick only to find the chain now throws completely if the mech isn't there to stop it.

It's only when i press heavily on the non drive side in the higher gears. Never had the problem before and not really sure ho to fix it.

I've checked the bolts on the chainset, everything is as tight as it should be. I'd take it back to the shop but i bought it online from Pedal On.

Any suggestions?

[Magic919]

Any BB play? I'm sure Pedal On would advise by phone too. They are decent chaps.

[RicksAlfas]

Could be a wonky bottom bracket; cranks not seated squarely; or cracked frame!

[murray]

I had to replace sram red crankset on mine this week because the spider was bent. No idea how it happened.

[nagsheadwarrior]

My wet weather/winter Hybrid did that for Bearley a year til I got it serviced,I'd just give the derailleur a kick while on the move and that's sort it for a bit!

[DuncanM]

Stugots said:

As above reply from your description it sounds like the front ring is bent, causing chain rub only at certain crank positions ?? Straight back to Evans would hope they'll sort this out.

Edited by Stugots on Thursday 30th July 22:38

A quick update.

Evans were okay but not great as they didn't want to contact Specialized for me.

I ended up sending Specialized an email and they agreed to pay for a repair, an upgrade to a 105 chainset.

So super service from Specialized, mixed feelings about Evans if I'm honest.