Whats happening here??? Jumping chain
lackofgrip
Posts: 851
I recently bought a new bike and every so often when pedaling hard the chain jumps off the big ring at the front.
The derailleur's are set correctly and I had it back to the shop to have them both checked.
This seems to be one of those "can't get it to do it in front of the bike mechanic" type problems.
I have taken some photos of what happens to chain just before it slips.
Is the chain too long???
http://www.flickr.com/photos/95736461@N ... /lightbox/
The derailleur's are set correctly and I had it back to the shop to have them both checked.
This seems to be one of those "can't get it to do it in front of the bike mechanic" type problems.
I have taken some photos of what happens to chain just before it slips.
Is the chain too long???
http://www.flickr.com/photos/95736461@N ... /lightbox/
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Comments
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looks like something is old and something is new.
new bike? new to you but old to someone else.
check your chain for wear."Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown0 -
No brand new mate. Only 150 miles on the clock! :-/0
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How on earth have you managed to get the chainrings looking like that in 150 miles?! They look like they have 20 times that mileage.......Faster than a tent.......0
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What do you mean? Wear? Or dirt?0
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for me it look like the front gear cable is to tight and maybe the limiter screws are mest up0
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SpiderNdc wrote:for me it look like the front gear cable is to tight and maybe the limiter screws are mest up
it's already been back to the shop for gear adjustment. :-/0 -
what shop ?0
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hmmm so in this case I cant relay blame the mechanics :P but from a pix it looks like over tensioned cable to me .Try different bike shop maybe0
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SpiderNdc wrote:hmmm so in this case I cant relay blame the mechanics :P but from a pix it looks like over tensioned cable to me .Try different bike shop maybe
I'm not paying when it's only a week old. It doesn't happen when shifting, it's just when I'm hammering in top gear. :-/0 -
Must admit the photo makes it look like a worn chain on a new cahinring. Since that seems unlikely on a new bike, do you have any sideways play in the cranks if you heave on them?0
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No play side to side on cranks that's first thing I thought of lol0
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keef66 wrote:Must admit the photo makes it look like a worn chain on a new cahinring. Since that seems unlikely on a new bike, do you have any sideways play in the cranks if you heave on them?
It does doesn't it ...
Has the chain been measured?
It could be just one or two links that are duff rather than all of them.0 -
Slowbike wrote:keef66 wrote:Must admit the photo makes it look like a worn chain on a new cahinring. Since that seems unlikely on a new bike, do you have any sideways play in the cranks if you heave on them?
It does doesn't it ...
Has the chain been measured?
It could be just one or two links that are duff rather than all of them.
No idea I'm no bike mechanic.0 -
Could well be a duff chain. It's happened to me on a new bike where they've inexplicably fitted an obviously worn chain; if I were you I'd get it swapped.- - - - - - - - - -
On Strava.{/url}0 -
Planet X just called me back, they are swapping chain set and chain tomorrow. :-D0
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Right, an update, the bike went back to Planet X, chain and rear wheel were swapped.
Been out for first time today, seemed OK for most of ride then jumped off twice towards end of ride.
Any further ideas??????????0 -
Ask them to face the bottom bracket? I was wondering if its ever so slightly off, and so under the extra force of cranking it in the big ring, the angle causes it to jump?
Not even sure if its possible.0 -
Nairnster wrote:Ask them to face the bottom bracket? I was wondering if its ever so slightly off, and so under the extra force of cranking it in the big ring, the angle causes it to jump?
Not even sure if its possible.
Thanks for reply I've emailed them. They must hate me by now :twisted:0 -
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DesWeller wrote:What's the front derailleur alignment like?
Spot on. They checked that last time it went back to shop. Also it doesn't happen when shifting. It's when I'm applying force. Always in the highest gear/s0 -
try a different chainring ...0
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Slowbike wrote:try a different chainring ...
Will see what they say in email, surely thats all it can be0 -
If they already swapped chainset and chain how could it be either?
For me it has to be either front mech or bottom bracket related0 -
Only swapped the chain.0
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Why didn't they swap the chainset? Thought they said they were going to?0
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Yes that's what they said but just ended up swapping chain and rear wheel because of play in freehub0
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I just thought on the off chance I'd check the BB tightness. The non-drive side was tight but the drive side was fractionally loose by at least half a turn could this have been the problem?????
I could move the drive side with my fingers.0 -
Could be I suppose. Next thing is to make sure cranks are on correctly and BB bearings preloaded, and then I suppose take it for a spin0
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Nairnster wrote:Could be I suppose. Next thing is to make sure cranks are on correctly and BB bearings preloaded, and then I suppose take it for a spin
Preload the bearings? Forgive my ignorance0
