Chain too long?
04-27-14, 10:49 AM
#1
Road Runner
Thread Starter
Chain too long?
Over the winter I changed my drivetrain over to use a wide-ratio cassette using a Deore rear derailleur and SRAM 12-32 cassette and also installed a new chain. Unfortunately that was 3 months ago (long winter!) and I don't remember if I sized the chain by calculation or direct fit, but when I had it up on the stand today to tweak the shifting it seemed like there's a bit too much slack in it.
Before I just open it up to recheck it, can anyone tell if the photos below would indicate that? I'd never normally ride cross-chained this much, but one photo is of the gears in the large-large position and the other extreme is the small-small combo. Any comments?
Before I just open it up to recheck it, can anyone tell if the photos below would indicate that? I'd never normally ride cross-chained this much, but one photo is of the gears in the large-large position and the other extreme is the small-small combo. Any comments?
04-27-14, 11:00 AM
#2
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Your chain is not too long.
The chain MUST be long enough to loop the big/big combination with an inch or so to spare.
The chain MAY be longer than that with no consequences unless it's so long that that the RD cannot take up the slack in the small/small combo, and even that is OK since you won't use those combinations.
Consider that regardless of it's length the chain will be running in combinations for which it's too long, with the RD taking up the slack. If it can run, for example, on a mid-range sprocket, why shouldn't it run on that same sprocket if it happens to be the largest?
Simple rule, size the chain according to the largest cassette you plan to mount, and all smaller ones will work fine too.
The chain MUST be long enough to loop the big/big combination with an inch or so to spare.
The chain MAY be longer than that with no consequences unless it's so long that that the RD cannot take up the slack in the small/small combo, and even that is OK since you won't use those combinations.
Consider that regardless of it's length the chain will be running in combinations for which it's too long, with the RD taking up the slack. If it can run, for example, on a mid-range sprocket, why shouldn't it run on that same sprocket if it happens to be the largest?
Simple rule, size the chain according to the largest cassette you plan to mount, and all smaller ones will work fine too.
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
04-27-14, 12:23 PM
#4
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If it isn't slack (and it isn't) on the small/small combo, you're fine. If it doesn't pull banjo string tight just before (or upon) shifting to big/big, again you'bs fine. You have a couple inches. I'd run it.
04-27-14, 12:35 PM
#5
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From the photo's it looks ok to me. If you had a master link ( quick release ) you could disconnect the chain. When It is on the largest chain ring and largest cog, you should have a couple of links extra. There are videos on youtube providing a good explanation .
04-27-14, 02:34 PM
#6
Road Runner
Thread Starter
Thanks all. After looking at the photos myself, it does seem to be less of an issue and I'm pretty sure I was careful in sizing it the first time.
On the other hand, how many grams am I adding if I keep a whole extra link in there??
On the other hand, how many grams am I adding if I keep a whole extra link in there??
04-27-14, 02:48 PM
#7
Really Old Senior Member
How much reserve do you have if you damage a link and need to shorten?
