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Discussion Starter · #1 ·
How do I check to see if my rear derailer hanger (solid ti) is bent?

I had a nasty crash on the 'expensive side' (right side) of the bike. Now I'm trying to determine if I have a bent hanger or just a damaged right STI. Chain is shifting fine between cogs, just won't go down to the smallest cog (the shifter thinks it's bottomed out and with derailer cable removed, chain still runs in the next to smallest cog...for this reason, I suspect a bent hanger). Chain will go to the largest rear cog, but shifter thinks I can make one more 'easy' shift onto an even bigger rear cog, which would put the rear derailer into the spokes.

I've done a search of 'bent derailer hanger' and found mention of having a shop determine if the hanger is bent, but wanted to know if i could do this on my own. If it's not bent, that could mean my rear derailer is damaged from the crash. Either way, guess it may be time to upgrade to 10 speed. Thanks.

mike
 

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Eyeball it

morkm said:
How do I check to see if my rear derailer hanger (solid ti) is bent?
While there are tools for this, you should be able to just sight down the derailleur cage (the two idler pulleys) and see if it's vertical. If you want to get anal about it, you could put a level along side the cage, but that's probably not worth the trouble. If the derailleur cage is not vertical, then it could be either a bent derailleur or a bent hanger, and you would have to swap derailleurs with a known good one to check. In either case, shifting would not be good. If the cage is vertical, then you have some other problem, like the need to adjust the lower limit screw.
 

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Discussion Starter · #3 ·
Thanks. The fact that the shifting is still pretty good, just off by one cog, makes me think that it's less the derailleur hanger and more that the derailleur itself got bent and/or the crash somehow altered the limit screws...probably some damage to the derailleur, so now the limit screws are out of whack.

I'll play with the lower limit screw and see if that doesn't resolve it. Still may have to convert to 10 speed.....then the question is do I go for Chorus 10 or stick with Ultegra. I know better than to ask opinions here, as there are already millions of posts on that topic!

Thanks again for the help.

mike
 

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Checking derailleur hanger alignment is so fast and easy to do that I'd take it to a shop and have it done just to rule misalignment out as the cause of your problem. As manufacturers continue to cram more rear cogs into the same amount of space, derailleur alignment is becoming more and more critical. It's also more difficult to check accurately enough just by eyeballing.
 

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A wreck isn't going to move the limit screws...your hanger is bent. Go to the LBS and get it re-aligned. I haven't wrecked and my hanger was bent. Reset it today and it's all good. I would have this check every 6 months just to rule out any issues....

Flash
 
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