chain slipping while peddling

Hurricane151

I have just been on my first commute on my new Allez Sport and after about 2 miles in by chain appeared to slip on occasion. So when I was putting power on it felt as though there was no reesistence for a split second and then it would grip again and keep going. It wasn't slipping out of gear just slipping forward. (hope I have explained that well enough)

This only appeard to happen when using the centre 3 or 4 cogs on the rear set but on both the front cogs.

Any ideas what this is, I've had this before on an older bike but that was because the teeth were worn down but this is brand new so I'm stuggling for an explanation.

Any ideas please!!!!!!!!!!!!!!!!!!!!!!!

schweiz

Probably just a bit of cable stretch in the new cable since everything was first set up.

Where the cable enters the rear derailleur is a black/grey plastic collar. Rotate it towards you 1/4 or 1/2 a turn and see if that helps.

Hurricane151

might sound like a daft question but is it clockwise or anti-clockwise?

schweiz

looking side on at the bike, then rotate the top of the collar towards you.

looking from the rear towards the front of the bike, turn it clockwise.

The way I always think of it is to rotate the collar in the direction I want the chain to move to get it to stay on the selected cog. If the chain is trying to jump up onto a bigger cog, rotate the collar towards you/clockwise. If the chain is trying to jump onto a smaller cog then rotate away from you/anti-clockwise. I hope that makes sense.

don't overdo it and remember how far you rotated it so you can always put it back to where it was if it doesn't solve your problem.

if you can get the bike in a stand or get someone to hold the saddle so that the rear wheel is in the air you can turn the cranks at the same time to make sure that the skipping stops.

biondino

Was it wet, and were you riding over metal or painted lines?

Hurricane151

schweiz wrote:

looking side on at the bike, then rotate the top of the collar towards you.

looking from the rear towards the front of the bike, turn it clockwise.

The way I always think of it is to rotate the collar in the direction I want the chain to move to get it to stay on the selected cog. If the chain is trying to jump up onto a bigger cog, rotate the collar towards you/clockwise. If the chain is trying to jump onto a smaller cog then rotate away from you/anti-clockwise. I hope that makes sense.

don't overdo it and remember how far you rotated it so you can always put it back to where it was if it doesn't solve your problem.

if you can get the bike in a stand or get someone to hold the saddle so that the rear wheel is in the air you can turn the cranks at the same time to make sure that the skipping stops.

Thanks for that but the chain isn't trying to jump cogs it is just slipping forward as if the teeth aren't in the chain properly or the chain is loose but only in certain gears.

hope that is clearer. It is wet but I wouldn't expect this to happen on this bike as it is brand new.

Any other ideas?

el_presidente

stiff link in chain? dodgy freehub?

otherwise sounds like symptoms of a worn chain / cassette / chainring but that shouldn't happen on a new bike

MrChuck

Another vote for freehub or worn parts, if it wasn't brand new. Take it back to the shop and see what they say.

Hurricane151

Right, I had made a slight adjust as suggested and all was fine, then it happened again and I had it down to the LBS who said that they have checked it over and re-set everything but this morning I go out and after less than a mile it is happening again.

The cahin is definatly now jumping from cog to cog and no matter how much I adjust the rear derailleur as suggested by schweiz it doesn't seem to improve.

It is really starting to get me down now. £700 on a new bike and nothing but bother, think i might just try and return it and give this whole commuting on a bike thing a miss and stick to my trusty car.

biondino

Dude, you seem to have dropped your toys. Shall I put them back in the pram for you?

crankycrank

Did your lbs check the derailleur hanger alignment?

adrianpugh

If I were Hurricane I would be unhappy. It seems to be a strange problem and sometimes that happens with cars as well as bikes

I would ask the shop to investigate the Freehub and whether the chain has been lubed properly.

dilemna

Hurricane151 wrote:

Right, I had made a slight adjust as suggested and all was fine, then it happened again and I had it down to the LBS who said that they have checked it over and re-set everything but this morning I go out and after less than a mile it is happening again.

The cahin is definatly now jumping from cog to cog and no matter how much I adjust the rear derailleur as suggested by schweiz it doesn't seem to improve.

It is really starting to get me down now. £700 on a new bike and nothing but bother, think i might just try and return it and give this whole commuting on a bike thing a miss and stick to my trusty car.

I would go back to your LBS and tell them that the problem still persists. Ask them what they have done to try to identify and rectify it. Also ask them to explain how to use the gears. These are your stautory rights. If they fail to do so ask for an alternative bike or failing this a refund. It beggars belief that an LBS would not resove a problem with your bike in this current economic climate however well bike sales are holding up.

TCBLUE

I had the same thing lbs could not find a reason turned out it was the chain it had stretched and one link had split the shimano chain that come on the sport is not the most hardy, but as it is new check for a stiff link check out your chain it could be that

the_hundredth_idiot

I'm having a similar problem at the moment and it is frustrating (but still better than getting the train )

I had a minor spill and the chain then started falling off into the gap between the cassette and the wheel whenever I used the lowest gear (so not often, of course D) ) - not good fun. I adjusted the max and min settings to stop the chain falling off and took it back to the bike shop (Condor) to get them to straighten the rear derailleur hanger - hangers are a bit exposed so reasonably easy to bump them out of alignment.

The bike shop straightened the hanger and readjusted the derailleur but I'm still having the same problem that you mention. It jerks me forward enough to make my feet pop out of the SPD clips. :oops: It does sound like the same problem as you have - it sounds as if the chain isn't quite correctly seated on the cog.

I've tried fiddling with the adjuster (quick plug for Cycling Plus - there was an article about exactly these adjustments a month or two ago) but that doesn't seem to do any good. For me, it's usually when I'm changing to a lower gear - so when I'm slowing down for red lights, say. When I then pull away, with a bit of force on the pedals, the chain slips as if it hadn't quite seated on the teeth.

I just need to get around to taking my bike back to the bike shop and asking them to look at it. It's hard to tell by sight if the hanger is bent (unless it is really bent) but could be another problem, I guess.

Just do the same - take it back to the bike shop. They should be able to fix it - perhaps they just tried to do it a little too quickly last time. Maybe the rear hanger got knocked when the bike was in storage or being prepped when you bought it or something (just guessing - no idea how likely that is).

THI