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Rear derailleur advice.

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 Tonybhoy 07 Sep 2020

Currently I have an 11-28 cassette with a short cage. With some big climbs planned for next year I’m looking to swap to a 32 which will require a long cage.

Can I just change the cage or do I need to completely replace the rear derailleur?

many thanks.

Post edited at 10:16
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 LastBoyScout 07 Sep 2020
In reply to Tonybhoy:

I have run a 32 cassette with a short-cage mech for one-offs by adjusting the B-screw, but probably not the best idea if you're going to do it regularly/long term.

Because of that, I "suspect" you will need to change the whole mech because of the increased size of the rings, but someone will know better than me.

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 a crap climber 07 Sep 2020
In reply to Tonybhoy:

What derailleur do you currently have? The specs for it will include a maximum cassette size. Assuming this is on a road bike you might need to switch to a mtb derailleur.  Are replacement cages available for it?

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 Sans-Plan 07 Sep 2020
In reply to Tonybhoy:

You will need to replace the whole derailleur, but as above it depends on the make and model, for instance if its Shimano 105 then a medium cage will do up to 32

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 ffati 07 Sep 2020
In reply to LastBoyScout

A wolf tooth road link would work for occasional use(a longer mech hanger) use your current mech and just put in a new cassette 

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 Sans-Plan 07 Sep 2020
In reply to ffati:

> In reply to LastBoyScout

> A wolf tooth road link would work for occasional use(a longer mech hanger) use your current mech and just put in a new cassette 

Trouble is they are more expensive than a lot or rear mechs !

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 GrahamD 07 Sep 2020
In reply to Tonybhoy:

Not very helpful to you, but when I last looked at this, I used it as the perfect excuse for a new bike 😁

Seriously, I think you need a new cassette, deraileur and chain.  Depending how many gears your cassette has,, and how much of a gear freak you are, certainly don't dismiss groupsets like Tiagra.  They are pretty impressive these days.

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 beardy mike 07 Sep 2020
In reply to Sans-Plan:

You can get them for non shadow style mechs for a few quid on fleabay. Obvs not Wolftooth...

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In reply to Tonybhoy:

I've had short cage 105, Ultegra and Dura Ace all play (just) with a 32t cassette. If you're set on a 32t cassette why not try it first before getting a new mech? Nothing really to lose. Chain length might need considering too. 

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 DaveHK 07 Sep 2020
In reply to Sans-Plan:

> Trouble is they are more expensive than a lot or rear mechs !

Cheaper versions are available from St John St Cycles. I've got a mid cage mech running with one on a 40 tooth cassette. 

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 Sans-Plan 07 Sep 2020
In reply to Stuart (aka brt):

Agreed, its worth a shot, in my case the rear mech cage fouled the cassette so had to swap to medium cage to get a 32 on the CX bike, but it does all depend what mech he has, no word on that yet...

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 jack92 07 Sep 2020
In reply to Tonybhoy:

Shimano has compatibility chart online for their cassettes and deraileurs:

https://productinfo.shimano.com/#/com?cid=C-453&acid=C-454

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 ianstevens 07 Sep 2020
In reply to Tonybhoy:

You'll need to replace. There are longer cages available but these are more expensive in most cases, so not really worth it. Keep in mind you'll need a new, longer chain.

Worth consideration if you haven't already is an 11-30 cassette. Only changes the three largest sprockets (assuming 11 speed) so you still have access to all you favourite ratios on the flat/downhill with a bit of extra climbing capacity. Worth nothing too that for this you can get away with a short cage and a bit of b-screw adjustment (and again, a slightly longer chain). 

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In reply to Sans-Plan:

clone off ebay, fiver!

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 munkins 07 Sep 2020
In reply to Tonybhoy:

A rear mech extender might work? I'm using a rear mech designed up to 34t on an 11-40t with an extender.

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 Lord_ash2000 08 Sep 2020
In reply to Tonybhoy:

I have a medium cage ultegra derailleur which was used with an 11-28 originally but soon swapped out the cassette for an 11-32, I had to adjust the B screw a bit and get a new chain so I could have 1 extra link but it all works fine now.

For me it was worth the cost of a new cassette and chain for that 1 extra gear because 95% of my riding is in the Lakes and Whinlatter, Newlands and Honister passes are all within evening ride loop range of my house. Not sure I'd have bothered if it was just for an occasional trip to somewhere hilly though as it does add up and you could argue I just need stronger legs, but I'm a climber after all, leg power is not my thing.

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 Dave Cundy 08 Sep 2020
In reply to Tonybhoy:

As a slight deviation, i built my own rear cassette using Miche parts, from LordGun in Italy.

I started with a 13-30 10sp cassette and modified it to a 14-32.  Dead useful for hills, bike touring and ageing legs. The 32 sprocket is for 11sp but works just fine in the 10sp cassette, it just needed a few spacers made out of plastic card (about 0.2mm thick).

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 Timy2 09 Sep 2020
In reply to Tonybhoy:

Hi, what size is small front ring? Im guessing your running a compact so probably 36?  I changed to a compact 36(small) and put a 32 cassette on back.  Kept the same Tiagra small cage deraillier with no probs, Id try it before you buy another.  

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 GrahamD 09 Sep 2020
In reply to Timy2:

I thought Compact was 50/34 ?

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 LastBoyScout 09 Sep 2020
In reply to ffati:

> A wolf tooth road link would work for occasional use(a longer mech hanger) use your current mech and just put in a new cassette 

Don't think those were around/I didn't know about them at the time.

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 GrahamD 09 Sep 2020
In reply to LastBoyScout:

I think I've seen a GCN video where they fitted a hanger extension 

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 Tonybhoy 09 Sep 2020
In reply to a crap climber:

Hi. I have an Ultegra R8000 groupset.

Post edited at 22:12
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 Tonybhoy 09 Sep 2020
In reply to jack92:

Thanks for the link. I’ll have a look 👍

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 Tonybhoy 09 Sep 2020
In reply to Tonybhoy:

Thanks for all the advice. A bigger cassette is for long term planned rides and next year the plan is to do the C2C. I’ve got plenty time to sort something out. Thanks again 👍

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 GrahamD 10 Sep 2020
In reply to Tonybhoy:

From a personal perspective,  I can say that the hills are far more enjoyable for me on a bike with Compact and 11-32 as opposed to what I used to use, Compact and 11-28

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 Sans-Plan 10 Sep 2020
In reply to Tonybhoy:

In that case i would try it as the short rear mech will do up to 30, so depending on the bike and hanger geometry it might go, it will be obvious if it isn't going to work if not its £60 at Merlin for the mech and £25 for a chain on top of your £70 for cassette (assuming you are sticking with Ultegra for the cassette)

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