tendency

My chain jumped off the large cog of my rear cluster and immediately got sucked between my wheel and cassette (due to a space from running a 9 speed cassette on 10 speed free hub) shredding the j-bend part of 4 spokes which will need to be replaced. Is there concern for future wheel integrity having to replace this many spokes? It's a 28 spoke wheel. Let me know if more deets about wheel are needed & thanks!

Andrew R Stewart 

I might replace all the spokes on the flange's outside, all 7. This way all will be of the same age/condition/spec and there might be less need to revisit the wheel's tension and true in the future. The quickie way is to just install the spokes and tension them up to about the same level as the other 7 spokes on the same flange. Then true and final tension the wheel. The slow but in my mind better way is to loosen all the spokes and equal, no tension, amount so the rim is not being pulled on by the spokes but is still "held in place". Spin the wheel and ascertain the rim's condition with no spoke help to make it true. It should look very straight and without wobbles. If not expect more future issues sooner. If the rim looks good then go ahead and replace those 7 outside spokes and do the usual tension/true/dish thing. Either way do expect to need to do a follow up after a few hundred miles has gone under the wheel. Andy

maddog34

8 9 and almost ALL 10 speed freehubs are the same overall mounting width... How old is the wheel? i'd do as the other response said and replace all of the spokes that pass to the outside of the hub on the drive side, and if the wheel is high miles or old, you might consider replacing ALL the spokes at this time.

And i advise installing a Spoke guard disc, AKA: dork guard, to prevent damage.... And Have your Rear Derailleur and Derailleur Hanger checked for trueness too. 9 times out of ten a bent Derailleur Hanger is the Cause of this problem.... the other 10% is from someone fiddling with the derailleur stop screw settings.

pdlamb

Agree with changing all 7 outside spokes. If you only change the four that are obviously shredded, you'll want to very carefully (microscopically?) inspect the remaining spokes. There's a good chance some more have been nicked; these spokes won't fail immediately, but the nicks will be stress risers that will lead to those spokes failing sometime down the road. You'll find them later, when you look at a broken spoke and scratch your head thinking, "How did this break two inches from the hub?"

Kontact

Spokes are generally the toughest part of the wheel. If this was my bike, I would just replace the 4 damaged spokes. Replace them one at a time, making sure to seat the elbows before threading into the nipple. By doing them one at a time you can simply re-tension them by bringing them into true. Use a light oil like Triflow on the threads. As a shop mechanic, I did this exact job countless times without any problems down the road.

Your 9 speed cassette didn't cause this to happen. You didn't adjust your low limit stop on the RD, which should be checked anytime you install a new cassette or wheel.

tendency

Thanks I'll just do the 4 damaged spokes and see how it goes.

Not sure what caused this - I rode the bike fine last summer/fall without any shifting issues. The bike then sat for the past 4.5 months in very cold garage (un insulated) then, my first ride of this year, shifting onto largest cog this happens. So, the bike - at least at the end of last year - was setup correctly. I can only assume something about sitting in a cold garage caused some funkiness.

Mr. 66

It could be that your derailleur hanger has gotten banged out of alignment. Check the alignment of the hanger and your limit screw setting in that order.

Andrew R Stewart 

Independent of damaged spokes and the often claim of a der hanger align is this from the OP- "My chain jumped off the large cog of my rear cluster and immediately got sucked between my wheel and cassette (due to a space from running a 9 speed cassette on 10 speed free hub"- The overshifting of a chain past the large rear cog, and onto those spoke ends, is not from any 9 VS 10 speed dimension thing. Chains have been able to derail to the spoke side of the larger cog and jam down onto the spokes for many decades. As the cog count has increased the gap between the large cog and the spokes has lessened and the chains have gotten narrower, but the chain will still fit well enough between to get really wedged in there. Especially when the pedal forces are not stopped quickly enough. This can happen due to a bent der hanger, poor limit screw adjustment, objects caught up in the chain, large enough shocks to the system to cause the chain to jump and bounce about while still pedaling and likely more that I am not thinking of right now. That there's a gap between the spokes and cog big enough to allow the der cage to reasonably clear the spokes will also allow a chain to fit down in and... is a basic aspect of our current bikes. Andy

maddog34

OR.. something smacked the Rear Derailleur while the bike was being stored then removed from Storage........