new cassette, chain now jammed

[fossyant]

105 won't do a 30 - 26/27 max especially if it's a short (standard) cage.....

What happens is that the length of the body and cage can't clear 30 sprockets, so the jockey wheels jam. Even lengthening the chain doesn't work, as the body is designed to ensure a close 'fit' to the sprockets, up to the max......30 is way too much !

My 8 speed Dura Ace and Ultegra rears are about 25/26 max from what I remember.

 

[chipmonster]

If I wanted a 10 speed on the bike, would I need to change all the gear and rear mechanism?

 

[RedBike]

The number of gears all depends on the gear shifters not the rear mech.

Although there are a few fudges; to correctly change from 8 speed to 10 speed( or vise versa) would mean buying and fitting a complete new groupset.

 

[chipmonster]

The number of gears all depends on the gear shifters not the rear mech.

Although there are a few fudges; to correctly change from 8 speed to 10 speed( or vise versa) would mean buying and fitting a complete new groupset.

Thanks, I will speak to the LBS.

I think I am going to get myself on a maintenance course to find how it all works.

 

[dodgy]

Look on the bright side, you've learned something and in all likelihood you now know more than your LBS on the subject. You've also rooted out the name of the local incompetent bike shop, so you know where not to go next time

 

[Tynan]

name and shame

 

[alecstilleyedye]

The number of gears all depends on the gear shifters not the rear mech.

Although there are a few fudges; to correctly change from 8 speed to 10 speed( or vise versa) would mean buying and fitting a complete new groupset.

when i went from double 8 to triple 9, it was cheaper to buy a whole new groupset than to buy just the bits i needed separately, so i got new brake calipers and all the cabling "free" so to speak.

 

[Randochap]

Definitely sounds like some major incompetance from the LBS. Unbelievable!

The difference between 8 & 9 -- besides shifters -- is chain width. The problem here is probably that you've made this big jump to a 30 and your original derailleur is short cage.

If your derraileur is a long-cage 105 (unlikely), you could actually squeeze a 30 in there, but the horizontal limit screw would have to be replaced with a longer one. It still wouldn't shift smoothly, though.

In any case, if the LBS was so out to lunch that they don't know you can't shoe horn a 30 tooth cassette into that system, they likely can't even tune a system. Did they replace the chain?

Pull your bike and demand a refund. You've wasted precious time.

 

[peanut]

I'm not sure you can get a 30tooth cassette. You can get 32/34 MTB cassettes but these will only be 8 or 9 speed.
The largest shimano 10speed cassette I know off 'only' has a 27tooth outer sprocket.

edit..........
Correction, I've just realised shimano do an Alivio (MTB) 11-30 cassette,

you can also get a Deore cassette 11t-32t 8 or 9 speed so they could have used a sprocket from a Deore

This weekend I split my 8 speed 12t-26t Campag cassette and replaced the 23t and 25t with a 24t and 28t
Cassette is now 12t-28t and works perfectly with a 10 speed short cage 105 rear mech and 8 speed Sora Sti

These componants are surprisingly tolerant of mixing and matching.

 

[jags]

take it easy there boy's,if you go into the bikeshop like a steaming bull your on a looser.so be nice smile to the muppet behind the counter and ask politly for some help,if that dosen't work well give him hell.

 

[Randochap]

take it easy there boy's,if you go into the bikeshop like a steaming bull your on a looser.so be nice smile to the muppet behind the counter and ask politly for some help,if that dosen't work well give him hell.

Yes, it can all be done civily, but, if things are as the OP says, he took the machine in to be modified and it came out dysfunctional.

Didn't the shop do a test-ride before releasing to customer? And, if it is what we suspect, they shouldn't be allowed to call themselves a bike shop.