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Discussion Starter · #1 ·
I was riding up a little uphill section today and started to shift my rear derailleur when i heard it get caught up in my spokes and crunkle crunch break it ripped it right off. i didn't break the drop out i just bent it. I figure that when i shifted i pulled the derailleur too close to the spokes and the rest is histoy. But the real reason was because i jinxed myself the night before by telling all my buddies i wanted to buy a new rear derailleur because the one i have is a SHimano Deore XT and silver and i want the new black Shimano SLX because its black and it will match my bike.

My question......can i just swap out the hanger and derailleur fairly easily? Or do i need to replace the shifter etc. I was looking on ebay and saw a Shimano SLX for 40$ (i had read a review of the SLX on Bikeradar.com and it was a good one. I would also consider going XTR or XT if i need to but i though the review sold me on the SLX.

I also need a new chain because i murdered mine by trying to turn my bike into a single speed on the trail by shortening the chain and going without a rear deraileur. I ended up removing a ton of links and loosing some of the pins.....so i may have to also get a new cassete but have replaced chains with out replacing any of the cassettes or front rings.


Any advice would be much appreciated. Im sure im not the only one who ha to do this.


My bike setup

Motobecane Phantom DS 2008
with Shimano Deore XT rear derailleur and shifters.
front is Shimano LX.
 

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As far as I know the derailleurs (to use a computer term) are plug compatible, so your existing controls should be fine. If I'm wrong someone will correct me within a short while. The cassette is probably OK, so you're out a derailleur, hanger tab, and chain, not bad for a days work.

When you set up the new stuff and get the bike on the trail, be sure that you make sure the inner "L" limit is correctly to avoid a recurrance. You aren't the first nor will you be the last to put an RD into the spokes. Feeling a bit lazy so here's a cop of a post I put up fro the last gut who had this happen.
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....On a decent derailleur a properly adjusted inner (low gear) limit will provide near bulletproof protection from overshifting. Moreover on modern ATB bikes the clearance between the RD at it's innermost position and the spokes is larger than it used to be not too long ago.

As I said a properly adjusted limit is key. Besides the problem of poor mechanics at some LBSs they can also be messed up in use. What happens is that bikes get banged around, and the derailleur hanger gets bent inward slightly. The owner notices that the derailleur is no longer trimming perfectly and adjusts it with the cable adjuster. Now you have that problem situation of a correctly indexing derailleur no longer protected by the dead stop of the upper limit.

Warning to all who read this, If you find yourself adjusting the cable so the RD, indexes and trims correctly, do not assume that the cable stretched, re-check that the inner limit is correctly set. From a functional standpoint a slightly bent tab mimics a cable tension problem, and you need to check for both.
 

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Discussion Starter · #4 ·
thanks.

Thanks for the response and advice

awesome.... thats what i wanted to hear... i figured it was the L adjustment or the fact that i had just applied a small dab of lube to the mech parts on the RD (something that i read to do in one of my bike maintenance books) causing it to move a little more freely thus over shifting into the spokes....but its over now and i just want to fix it and prevent it from happening again..

i had posted another thread about the Shimano SLX reviews and what others thought and have decided on purchasing a Shimano SLX M662 Long Cage and replacement hanger. as well as a new chain...i looked at the teeth on my rear cassette and the front rings and they dont look too chain worn so i think i can swap the chain pretty cleanly.

Again i thank you for all your advice
 

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klembasek said:
i had just applied a small dab of lube to the mech parts on the RD (something that i read to do in one of my bike maintenance books) causing it to move a little more freely thus over shifting into the spokes
That didn't cause your problem. An incorrectly adjusted low gear stop caused the problem. When you get the parts replaced and you're adjusting the derailer (use the Shimano website for the fine details) do this -

With the derailer shifted into the low gear, push with the thumb as hard as you can to try to get the derailer to shift over the top of the big cog. If it will go, adjust the stop so that it won't go. That way, unless you bend the derailer hanger, it will never shift into the spokes.
 
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