Super Record Cage Size

markwb79

Hi,

A friend of mine has 10sp Super Record (might just be Record, not SR) (from googling, I guess its from around 2008, just before they changed to 11sp). The cassette was a 23, but he changed it to a 26 and now he cant use the 34/26. His LBS said that its because the cage on the rear deralier is too small. I am shocked that it isnt compatible.

Hence why I am here asking for confirmation etc?

Cheers

Wirral_paul

I think the short cage is 27T capacity.

Assuming he has a 34/50 chainset then thats 16T difference already. If his cassette was 13-23 then thats 10T so a total of 26T. To run a 13-26 cassette needs a capacity of 16T+13T = 29T - so a medium cage mech. Is that what the LBS recommended also?

markwb79

Wirral_Paul wrote:

I think the short cage is 27T capacity.

Assuming he has a 34/50 chainset then thats 16T difference already. If his cassette was 13-23 then thats 10T so a total of 26T. To run a 13-26 cassette needs a capacity of 16T+13T = 29T - so a medium cage mech. Is that what the LBS recommended also?

Really suprises me then!

yes he has a 50/34. Can you just buy the cage or do you need a whole new mech?

rolf_f

I have a Record short cage mech of that sort of age. Using 50-34 I can quite happily run either 12-27 or 13-29 cassettes.

I'm confused anyhow. 34 is the small chainring, 26 the big cassette sprocket. If he can't run 34-26, then what gears can't he run in the big chainring? The normal complaint would be that 50-26 doesn't work (which is usually immediately followed by a load of people telling you you shouldn't use that combination in the first place but never mind!)

Monty Dog

Record short cage will handle 29 sprocket and your mate needs to find a different bike shop!

napoleond

I can confirm the normal (short cage) SR mech will handle a 29T beautifully.

ugo.santalucia

I suspect this is the older Record 10, which was designed to take a sprocket up to 26. The last generation of Campag derailleurs go up to 30. Don't forget Record 10 has been around for 14 years

rafletcher

Markwb79 wrote:

Wirral_Paul wrote:

I think the short cage is 27T capacity.

Assuming he has a 34/50 chainset then thats 16T difference already. If his cassette was 13-23 then thats 10T so a total of 26T. To run a 13-26 cassette needs a capacity of 16T+13T = 29T - so a medium cage mech. Is that what the LBS recommended also?

Really suprises me then!

yes he has a 50/34. Can you just buy the cage or do you need a whole new mech?

Why surprised? Record is a racers group set, not some amateurs.

rolf_f

ugo.santalucia wrote:

I suspect this is the older Record 10, which was designed to take a sprocket up to 26. The last generation of Campag derailleurs go up to 30. Don't forget Record 10 has been around for 14 years

Yes, but it's 26 the OPs friend apparently has problems with and, of course, back then there weren't any 27s for them not to have the capacity for so there is no immediate reason to assume 26 was ever really the theoretical limit. And they can generally handle 29 anyway (as I said, my Record rear mech is also the previous generation) - put it this way, I don't recall anyone on here trying such a mech out with a 29 and finding it didn't work.

g00se

A mid 2000s short cage rear mech will take a 26 at the back (officially). It may go bigger (I have used one with a 29) but it could stress the spring if used too much.

What you also need to consider is the chain-wrap capacity of the short cage mech - how much it can suck up in links going from big-big to small small. For that vintage short cage mech, it's 30 - check out page 45: http://www.campagnolo.com/repository/do ... -07-09.pdf (it's for 2009 10 speed, but it'll be the same for the SR).

So a 50/34 with a 26/13 will have a capacity of (50-34)+(26-13) = 29 - which is fine. And to be honest, most will be able to take one or two more as these wrap capacities are worst-case calculations depending on how much lost slack is available on big-big. I've certainly run a 13/29 with a compact chainset on a short cage 10 speed from that era.