Another case of chain riding on tips of teeth

[j beede]

I've been a way from biking for a while and am seeing something on 10-speed road bikes that I have not seen before. On the bike I have, the chain will occasionally ride on the tips of the teeth of the small chain ring after shifting from the middle ring. Odd. On the bike that I looked at last night the chain was riding on the tips of the teeth of the cassette gears regularly after upshifting or downshifting. Both bikes have 10-speed cassettes. One has FSA triple crank with Dura Ace chain. Other has Shimano 105 double crank with no-name chain. Is this something that you guys are living with? I have not seen this behavior before. I hesitate to get off the seat with a bike that exhibits this behavior.
...j

[DaveM]

First guess would be a stretched chain

[j beede]

DaveM,
Yes, that was my thinking as well. As it happens, the Dura Ace chain measures exactly 12" for 12 links and the second bike with the no-name chain was virtually new and I didn't measure it. Have you seen chains riding on the tips of the teeth this way?
...j

[DaveM]

I've seen this on older bikes, but I don't have much experience with 10 sp drive trains. Maybe they are 9 sp chains?

[ATX760]

It sounds like the chain has stretched. start looking for shark toothing of the small chain rings

[Bill]

(01-26-2010, 08:00 PM)DaveM Wrote:  I've seen this on older bikes, but I don't have much experience with 10 sp drive trains. Maybe they are 9 sp chains?

On Dave's note here I would like to add I recently , by accident, purchased a KMC 5-6speed (meaning the number of cogs on the back) chain for a 7 speed (7 cogs on the freewheel) and guess what! When I was measuring the chain, by doing Alex's method in the video, to figure out how many links I needed it wrapped all the way from the top of the large cog on the crank back on through to the large cog on the freewheel around it back to the bottom of the large cog on the crank the teeth would not line up with the link! The links were on top of the teeth even after stretching them a bit! Although both are 1/2" x 3/32" there must be some other factor, which I believe is the design of the link walls or a 3rd measurement that is not mentioned by chain companies. i.e. Slim, Ultra Slim, etc. To be honest after that I decided to study in depth of chains which I am currently doing.

[j beede]

The 10-speed Ultegra RD with Dura Ace chain shifts so smoothly... if that truly is a 9-speed chain on there I will probably leave it alone! On this setup the chain occasionally rides on the tips of the small ring up front. The other bike is full 105, <100 miles, and it shows the problem regularly, but in the rear. I'd rather not buy another 10-speed chain ($$$) only to find that the problem lies elsewhere. Anyone know how to identify a 10-speed v 9-speed Via chain?
...j

[cyclerUK]

Usually chains have a number stamped on them (ie: HG73 or IG71 etc.)
I'm don't know about the the newer 10 speed ones though.
If there is a number then Google it and you should come up with the spec.
It's not stamped on every link though!
As far as I understand 10 speed and 9 speed chains are not compatible?
10 speed chain is definitely narrower than 9 speed.

[j beede]

cUK,
I'll get out my magnifying glass and look for a number on the chain. I have only seen VIA and Dura Ace on it when I have looked before--but I wasn't specifically looking for numbers. It shifts through the 10 cogs beautifully so I will be shocked if it turns out to be a 9-speed chain. Overall, the whole drive train works very well--no comparison to the "old days" with Huret, Suntour, Velox derailleurs with down tube friction shifters. Maybe my expectation levels are higher given today's $80 chains and $500 shifters. Back in 1975 I think I paid $375 for a complete Reynolds 531/Campy Record Falcon San Remo 76! Of course a Honda Civic was $3750 then.

[j beede]

It's an HG 7801. 10-speed Dura Ace chain. Brand new, measures exactly 12".
...j