Mountain Biking - Chain guide and rear deraileur?

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View Full Version : Chain guide and rear deraileur?


PA28Scuderia
04-23-06, 04:19 PM
I recently put on an E13 SRS on my Kona Coiler with only a 32 tooth ring. I used the same chain length as i had with the original 22/32 tooth because i figured the largest gear combination was going to be the same. The guide tightened the chain a bit, but I thought it would be fine. I'm now having problems adjusting the rear deraileur: I can not get it to shift and stay on the innermost cog even though the limit screw has been backed off quite a bit and the cable is as tight as it will go. I noticed that the cage is bent a little and I'm afraid that the poor chainline mixed with the tighter chain (caused by the guide) has bent it. Should I have used a longer chain and is my deraileur messed up beyond help? I'm pretty frustrated and would appreciate some help. Thanks.


PA28Scuderia
04-24-06, 09:46 PM
Bueller..........

cryptid01
04-25-06, 06:18 AM
There's no reason your chainline should be any better or worse with a properly installed SRS.
WRT chain length, your reasoning was correct - there's no reason to lengthen it.

If your derailleur is bent, you should fix that problem first, then reevaluate.


dirtyamerican
04-25-06, 06:43 AM
Ya, if your derailleur is adjusted all the way in it makes no different if it's bent because that screws it all up. e.13's are awesome.

nodnerb
04-25-06, 09:02 AM
I'm by no means an expert here. But, I am contemplating a chainguide myself. If a chain is already the correct length to just get into the longest chain combo and run smooth, wouldn't adding the chainguide (which takes up at least a few links of chain slack) cause problems with the length for the longest combos? I could see a potential for bending a deraileur there. But again, I'm new to chainguides so maybe I'm missing something.

cryptid01
04-25-06, 09:21 AM
If a chain is already the correct length to just get into the longest chain combo and run smooth, wouldn't adding the chainguide (which takes up at least a few links of chain slack) cause problems with the length for the longest combos?

I have found that the chain deflection caused by the lower jockey wheel/roller takes up less chain length than you may think - maybe one link, but certainly not two.

http://img.photobucket.com/albums/v246/pinit/3412c702.jpg

edit: although a short cage derailleur will certainly be less forgiving, as will a larger chainring in the front. 32T shouldn't be a problem.

nodnerb
04-25-06, 10:56 AM
I have found that the chain deflection caused by the lower jockey wheel/roller takes up less chain length than you may think - maybe one link, but certainly not two.


edit: although a short cage derailleur will certainly be less forgiving, as will a larger chainring in the front. 32T shouldn't be a problem.

Good to know. I'll take your word for it. Just looks like it would be at least a few links. But I guess "looks like" isn't an acurate measurement. :o

cryptid01
04-25-06, 11:15 AM
I'll take your word for it.

Whatever you do, don't do that! :eek:

Just give it a test fit before you add any links, and it may save you the trouble.

PA28Scuderia
04-25-06, 11:25 AM
hey thanks for the replies, i was getting worried i wasn't going to hear anything.

PA28Scuderia
04-25-06, 11:34 AM
hey thanks for the replies, i was getting worried i wasn't going to hear anything. i probably should deal with the deraileur and go from there. i brought it up though because since installation i have been in my lower gears for most of the time and when i am on these cogs, the cage is bent perfectly in line with the chainline from the deraileur to the chainring.