Cassette change - should this work?

dabber

I'm currently running a Veloce short cage RD. The current cassette is a Veloce 13-29. Previously I'd been running a 12-27.
When I changed to the 13-29 I never needed to change the chain length and the 13-29 runs well with no problems.
I've been debating putting on a Miche 12-29 when I need to change the cassette.
Given that the RD and chain length have worked OK with both extremes of sprockets it seems to me the 12-29 should be fine.
On the front I'm running a 50/34.
I realise that I'd be far exceeding the theoretical short cage RD capacity but it seems to me that in reality it would be OK. Am I missing something?

keef66

I'm sure it will be fine as you've already run it at both extremes already

dabber

Thanks... that was my reasoning. I was just concerned that there was some vital bit of logic that I was missing. :?

rolf_f

Or you could just take have of your 12-27 and half of your 13-29 and make a 12-29 out of those and not bother with the Miche cassette (and I get the impression Miche cassettes aren't so great though I have no personal experience of them). I've done this myself and it worked fine. There was no issue with the cage length but I do use a longer chain with the 13-29; possibly it doesn't need it but it's no bad idea to base the chain length on the derailleur position at small, small - better a very tight clearance between the chain and itself on the return from the lower sprocket than having things too tight at the big big end.

Most of the time you should be fine with the 12-27 anyway; I'd get another 12-27 and keep the 13-29 for the occasional more extreme rides - it works for me in hilly West Yorkshire. There's also not so many seconds in a ride where the 12 is missed against the 13.

dabber

Thanks Rolf... an interesting suggestion.
The reason I'm tempted towards the 29 is that I spend about a third of the year riding in France and the area that I'm in means lots of Cat 3 and 4 climbs, sort of one after the other... and to get home from any direction means a Cat 4 climb so if it's been a long day a "get out of jail" option is always very useful.
The 12 end appeals because I seem to have a pretty low cadence ... now I know the answer might be to work on raising my cadence, which I have been doing.