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Cassette Issues

by mancsi
Wed, May 25, 2016 08:37
9

Hello, I have a ribble gran fondo with 105. I changed the cassette to a 11 - 28 tooth, which has caused the mech hangar to snap and ruined my deraileur.

If I go back to an 11 - 25 tooth, and then replace all the chewed pieces should all be correct??

Having a nightmare at the minute!

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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9 comments

Avatar
huntswheelers | 8 years ago
1 like

11-28 works no problem with a Short Cage 105......   I did one yesterday on a Dolan....

there must have been some issue with your set up

Avatar
vonhelmet | 8 years ago
0 likes

There's no reason you shouldn't be able to fit an 11-28 cassette. I can't really imagine how changing a cassette could knacker everything as you've said.

Avatar
mancsi | 8 years ago
0 likes

AKH,

That was a big concern about the frame and wheel, somehow my wheel avoided any damage and frame has afew marks on but nothing major. I am just going to drop back down to 11 - 25 as that ran fine. My chain is bent, almost snapped in half! Also its ripped the cable from the bottom of the derailleur so its going to be cassette, derailleur chain and a cable! Adds up really looking at £110 for everything from wiggle!

Cheers for the help

Avatar
Carton replied to mancsi | 8 years ago
0 likes

mancsi wrote:

I am just going to drop back down to 11 - 25 as that ran fine.

Huh. Did you start out with an 11-23? 

Avatar
AKH | 8 years ago
0 likes

Hi mancsi,

 

I've been in exactly the same situation as you before. In my case, not only was the mech trashed, but also the rear wheel, and the frame was damaged.

 

As you're going to have to replace the rear derailleur, you might as well start from scratch with the cassette you prefer; you’re going to have to re-index the whole lot anyway.

 

GCN do videos on installing and indexing a rear derailleur. Well worth learning as it’s a simple task when you get the hang of it, and it’s something you’re likely to have to do if you change wheels or cassette.

 

How to Change Your Rear Derailleur - Replacing Your Bike's Rear Mech 

https://www.youtube.com/watch?v=CPLiW-0zLa4

 

How To Index Your Gears - Adjusting Your Rear Derailleur

https://www.youtube.com/watch?v=Bbk5RcH0bbQ

 

As the rear derailleur has likely collided with the rear wheel, check the spokes for damage and check the chain for any bent plates. If I were you, I’d replace the cable at the same time. I replaced the fancy teflon coated cable that came with my 105 groupset wth a basic stainless steel one and it’s been absolutely fine.

 

Good luck.

Avatar
mancsi | 8 years ago
0 likes

I didnt change my chain but wasn't shifting from big to small in wild ways. I presume that may have been the issue the as when I just ran through all the gears, big ring and small cog would jam slightly. Makes sense.

Cheers Phil

Avatar
TypeVertigo replied to mancsi | 8 years ago
0 likes

mancsi wrote:

I didnt change my chain but wasn't shifting from big to small in wild ways. I presume that may have been the issue the as when I just ran through all the gears, big ring and small cog would jam slightly. Makes sense.

Cheers Phil

You'll definitely need a longer chain when getting a larger cassette or chainrings. I've been there. Not changing means you're putting more tension in the chain, and stuff that's meant to withstand that tension will eventually snap.

While you're at it, do try to get Wheels Manufacturing rear derailleur hangers. They're machined 6061 aluminum and are usually stronger than the stock hangers.

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philhubbard | 8 years ago
0 likes

I presume you changed your chain as well and didn't just go from your big ring into the largest cog on your cassette? If so, your chain will have been too short...

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le Bidon | 8 years ago
0 likes

The only thing I can think of is that not loosening off your b-screw a little when increasing the size of your cassette has caused something to go a bit awry. But I'm not sure this would have caused your hangar to snap off.

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