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#1
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Is my chain too long?
I just dusted off my old road bike (a 14 year old Raleigh Technium) and
started riding again. Last week the chain broke so I replace it with one of the same size recommended by the LBS. I took it for a 15 miler over lunch today and the chain came off the front sprocket no less than 3 times! This doesn't seem right, so how do I fix it? I've got a chain tool so I could remove a link or two, but it looks like there's no going back if that doesn't help. I'm not even sure that's the problem since it is the same length as the original one. I realize that this is a pretty general question and not knowing the details of the parts involved it might be tough to answer my question exactly. But is there some general principle that guides these things that I could follow? TIA, Bob M |
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#2
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Tue, 24 Aug 2004 16:30:59 -0400, ,
"Bob Marchese" wrote: But is there some general principle that guides these things that I could follow? The length of the chain is determined by wrapping the chain around both of the largest sprockets, without going through the derailleur pulleys, and adding one complete link. http://www.sheldonbrown.com/derailer-adjustment.html Could it be the front derailleur over shifting or a bent chain ring? -- zk |
#3
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"Zoot Katz" wrote in message ... The length of the chain is determined by wrapping the chain around both of the largest sprockets, without going through the derailleur pulleys, and adding one complete link. No, wrap the chain around both the smallest sprockets and cut it where it just starts to take up the derailleur tension. |
#4
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On Tue, 24 Aug 2004 16:30:59 -0400, Bob Marchese wrote:
I just dusted off my old road bike (a 14 year old Raleigh Technium) and started riding again. Last week the chain broke so I replace it with one of the same size recommended by the LBS. I took it for a 15 miler over lunch today and the chain came off the front sprocket no less than 3 times! This doesn't seem right, so how do I fix it? I've got a chain tool so I could remove a link or two, but it looks like there's no going back if that doesn't help. I'm not even sure that's the problem since it is the same length as the original one. I realize that this is a pretty general question and not knowing the details of the parts involved it might be tough to answer my question exactly. But is there some general principle that guides these things that I could follow? Is there reason to suspect that the chain you replaced was installed properly? Or not? The chain dropping off the front chainring can be caused by several things. The first thing to check is front derailleur adjustment. The next thing is to check for wear on the chainrings themselves. If the teeth are very sharp, and very thin, probably the inter-tooth distance has been stretched due to chain wear. Since this is a new chain on old rings, that would tend to support my guess. An extra link is the least likely cause of shifting trouble (OK, 3-4 extra links might be a problem, but one, no). Misadjusted shifters are the most likely, and chainring wear is next. -- David L. Johnson __o | "Business!" cried the Ghost. "Mankind was my business. The _`\(,_ | common welfare was my business; charity, mercy, forbearance, (_)/ (_) | and benevolence, were, all, my business. The dealings of my trade were but a drop of water in the comprehensive ocean of my business!" --Dickens, "A Christmas Carol" |
#5
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Tue, 24 Aug 2004 23:12:08 GMT, cXPWc.199717$M95.178734@pd7tw1no,
Euro-Pro "Fabrizio Mazzoleni" corrected: No, wrap the chain around both the smallest sprockets and cut it where it just starts to take up the derailleur tension. That may be the way you pros do it with modern equipment. Obviously the OP was seeking a more traditionally recognised method by speaking of their '90's era Raleigh in other than a "retro" context. Besides, just on the off chance they were a cyclist of your category, the pictures provided by the link would be most helpful demonstrating what is meant by the accompanying polysyllabic words. -- zk |
#6
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Though I generally encourage watching the road ahead when riding; have a
glance down at that chain and see if it's jumping around at all...if it should go slack momentarily and then "jump" forward, your freewheel is sticking a bit, probably needs some lube after all that storage time... |
#7
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"Brian" wrote; Though I generally encourage watching the road ahead when riding; have a glance down at that chain and see if it's jumping around at all (clip) ^^^^^^^^^^^^^ Better yet, have a friend ride behind and to your right and watch it for you. |
#8
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"Brian" wrote in message
... Though I generally encourage watching the road ahead when riding; have a glance down at that chain and see if it's jumping around at all...if it should go slack momentarily and then "jump" forward, your freewheel is sticking a bit, probably needs some lube after all that storage time... I think an easier way to see this is to turn the crank backwards manually while off the bike. If the freewheel(hub) is sticking, or if there are any stiff chain links, you'll see the chain slack or jump in the rear derailer respectively. You can also look for front derailer rubbing, chairing wobble (bent or bolts loose), and bent teeth. It was the last problem that was causing my son's bike to drop a chain while shifting last weekend. |
#9
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Bob Marchese wrote:
answer my question exactly. But is there some general principle that guides these things that I could follow? Thanks for all the replies and especially the links to sheldonbrown.com (now bookmarked). It looks like it could be a combination of several things: worn sprockets, mis-adjusted front derailer, bent/broken teeth on both sprockets. I hope I can find replacement parts. |
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