Chain Length??
- Thread starter 8_wood
- Start date
If everything worked well with the old chain just make it the same length. If starting from scratch I just like to make the chain one pair longer than required to get it into the largest front and rear ring without ripping the rear derailleur off.
Yupp.8_wood said:
I strongly recommend using "LARGEST COG-to-LARGEST CHAINRING method" (http://www.parktool.com/repair_help/FAQchainlength.shtml).
After advising friends and newbies on how to do repairs and builds, I have learned that recommending shortcuts could cause serious problems because an inexperienced mechanic might follow the shortcut exactly without realizing something is wrong.
For example, lets say you used the "sizing to the old chain" method, but it was the wrong length to start or stretched out. Or you have changed your chainring or cog sizes. Or your new rear derailleur has a different cage length, or the old chain was fitted for a different frame. You could either have a badly shifting bike or potentially rip the rear derailleur off your frame.
The largest chainring to largest cog method is the most time consuming (next to the "Calculation" method which I have never seen), but you are guaranteed the perfect chain length if done correctly. This picture is what you should see when you have the correct length:
I usually have the chain a little looser than that (typically a 45 degree angle), but I would look over the Park Tool page for good directions.
After advising friends and newbies on how to do repairs and builds, I have learned that recommending shortcuts could cause serious problems because an inexperienced mechanic might follow the shortcut exactly without realizing something is wrong.
For example, lets say you used the "sizing to the old chain" method, but it was the wrong length to start or stretched out. Or you have changed your chainring or cog sizes. Or your new rear derailleur has a different cage length, or the old chain was fitted for a different frame. You could either have a badly shifting bike or potentially rip the rear derailleur off your frame.
The largest chainring to largest cog method is the most time consuming (next to the "Calculation" method which I have never seen), but you are guaranteed the perfect chain length if done correctly. This picture is what you should see when you have the correct length:
I usually have the chain a little looser than that (typically a 45 degree angle), but I would look over the Park Tool page for good directions.
Sram says to set your chain length so that it's just long enough to wrap around the largest ring and the largest cog with no derailleur installed. Then add 2 links and install the derailleur.
Not sure about shimano, but I would think it would be similar.
Not sure about shimano, but I would think it would be similar.
I read that bit from the Park Tools site last night, installed the chain today and it worked perfectly. SRAM PC-59 chain, XT 11-32 cassette, XTR 952 series F&R der.'s, Bontarger Race-Lite 44-32-22 cranks.
the method jackson stated is actually shimano's official chain sizing rule: wrap chain around big cog, big ring, (no derailleur), draw tight and add ONE link. (a link is defined as a set of inner and outer plates.