Rear Derailleur Tension Estimates
03-27-07, 07:54 AM
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Rear Derailleur Tension Estimates
Hi,
I was hoping someone could help me out. I need a quantitative estimate of the maximum tension that the rear derailleur cable on a typical bike would be under. If anyone has ever measured this, or knows where I could find this number, I would be very appreciative. I used the word "typical" on purpose. I need only a very rough estimate, so for example, this could be for a recent ShimanioTiagra 8spd. Any numbers would be very helpful.
I am also interested in the total cable travel. i.e. Between shifting from gears 1-8 (or 9 or 10) how much cable is wound up in the shifter? 5 inches? 10 inches?
Your help is very much appreciated
I was hoping someone could help me out. I need a quantitative estimate of the maximum tension that the rear derailleur cable on a typical bike would be under. If anyone has ever measured this, or knows where I could find this number, I would be very appreciative. I used the word "typical" on purpose. I need only a very rough estimate, so for example, this could be for a recent ShimanioTiagra 8spd. Any numbers would be very helpful.
I am also interested in the total cable travel. i.e. Between shifting from gears 1-8 (or 9 or 10) how much cable is wound up in the shifter? 5 inches? 10 inches?
Your help is very much appreciated
03-27-07, 08:04 AM
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The tension changes some as the derailleur is shifted to different cogs. In the smallest cog position there is not a lot of tension on the cable. As the derailleur is shifted to larger cogs the derailleur spring is being compressed.
Al
Al
03-27-07, 08:26 AM
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Originally Posted by AndrewP
The travel is in the order of 1/2 in and the tension about 3 lb.
1/2 inch per gear? Or over the whole set of 8 or so?
