Australian Cycling Forums - Bicycles Network Australia

G'day

Does anyone know of any problems I may encounter if I use a mid cage Campag rear derailleur with an 11-25 rear? I am ordering a Centaur groupset with 13-29 so will get a mid cage derailleur with it. If in future I decide to go 13-26 or 11-25 I can't see any problems but thought I would ask before I buy it, incase I am overlooking something.

Also does anyone feel strongly that I am better off with a CT front set up rather than the big rear?

NB: Getting out of the saddle at 70kph and sprinting doesn't interest me. This is about climbing the back side of Mt Mee or Mt Gorious with 160km or more already in the legs.

Thanks in advance.

You should be fine if you set your chain length for the largest cog you are likely to use. Otherwise you may need to lengthen the chain if you suddenly decide to move to a cassette with a greater range.

Sorry if I did not make it clear enough, but my concern is with going from the 13-29 to the smaller cluster, not the other way around. I understand the chain issue but am more interested with any issues related to excessive clearence between a mid cage derailleur and an inner cog of less than 29, particularly if it is significantly less.

I don't quite understand the problem. With a longer arm, it would be able to handle the range of cogs all the way down to 11. Don't quite see where the clearance comes in. Worse comes to worse, a small tweak of the appropriate screw will sort it all out.

Does anyone think a compact front is a better choice than a larger rear. My main reason for the 29 rear rather than a 34 front is the perceived wear factor of smaller rings and cogs. Plus I think 39-29 would surely get me up anything even when I'm tired.

Hi, I've just been through some similar thinking in my very recent post and early on I came to the conclusion that changing the rear was the way to go. Really all I wanted was a couple of low gears to get up the steep climbs, changing the front instead would reduce the usability of the mid-section of the cassette on the small front - a group of gears that are frequently used on the lesser climbs. I've bought a 12-27 to go with the 53-39 on the front, I'll know how well it's worked after this weekend.

One web page I found very useful for playing around with 'what ifs' is Sheldons gear ratio page which I'm sure you've already got book marked

Problem with large cog at the rear would mean that you have bigger gaps b/n some of the cogs. If that doesn't bother you, then no problem. CT or triple would permit you to run tighter cassettes without sacrificing spacing, or at least less sacrifice.

I use a 13-26 cassette with a short cage rear derailleur without any drama. There's only one three-tooth gap on the cluster and it's a smooth change unless I'm standing. Going to a 13-29 cassette would only mean two three tooth changes and a medium cage derailleur should change just as well. If you have 53/39 cranks now, then I'd expect that the bigger cassette and medium cage derailleur (you might even be able to just change the cage) would be significantly cheaper than compact cranks.

I would have thought the angle of travel or B screw limits on the mid cage would have been different. Otherwise, providing you had enough chain, there would be no need for it. Anyway, I've decided I will buy Centaur with 13-29 and if I like it will also pick up a Chorus before the dreaded 11 speed comes in and Campg go broke.

Oh...kay, why would 11x send Campag broke?

Shaun

Do people want it? That's the question. The reading I've done suggests people think they don't use the ten they've got. It does seem a bit silly. To me anyway.

Fair call, first time I heard of 11x, first impression was marketroids at work.
How far does it go?
Won't be long before you have to replace the 2.8mm, 18x, $250 chain every 500kms

Meanwhile, work on Shimpagnolos new 36x gruppo hits a snag...

Hiya MountGower,

I was in a silmilar boat (although with Shimano and already a short cage RD). I am looking at going the Compact front to enable me to climb hills.

The rear cassette is 12-25, so will spin out down steep descents, but meh ? Can easily put on a smaller cassette as the fitness improves or go to larger rings on the front as well.

For me, a much cheaper option and easy to boot.

A 12-27 cassette didn't quite give me the bailout gears I wanted.

Lotsa work to be done on the engine as well ....

MountGower wrote:Do people want it? That's the question. The reading I've done suggests people think they don't use the ten they've got. It does seem a bit silly. To me anyway.

I would have been happy to stop at 9.

I mean 10 lets you run 11-21 with single tooth gaps, or 11-25 with mostly single tooth gaps. I don't see the benefit of turning one more 2 tooth shift into a single tooth shift.

Bnej wrote: ... I would have been happy to stop at 9 ...

+1
In fact, I have chosen to stop at 9 - now I just hope that I have spares / service coverage for the next upmty (unless something nasty happens to me) years.
I realise that I face having more 'multi-tooth' changes than 'single-tooth' ones on just about every cassette I use, and that those changes aren't quite as smooth.
I haven't ridden enough to be able to comment on the relative life-span of 9- vs 10-speed components.
It must be the 'old phart' in me - I just like the idea of an odd number of gears and polished alloy.

9 speed cassettes and chains will be around for a while unless they come up with a way to flog 10 speed to mountain bikers.

10 is a nice round number and I'm sure people go for it because it's a logical number of gears to have.

11 isn't, I don't think they'll be able to sell the benefit of one more gear.

Bnej wrote: 10 is a nice round number and I'm sure people go for it because it's a logical number of gears to have.

Or there are no alternatives. If you want Campagnolo 9-speed these days its a trawl for NOS.

Bnej wrote: 11 isn't, I don't think they'll be able to sell the benefit of one more gear.

They don't have to really. Sure you can stick with your 9-10 speed if you want to, but if you want new gruppo to go on your new frame (or some such) you're going to have to go 11-speed. Rumours/reports are that all three top-end Campagnolo groups (Record, Chorus & Centaur) are going to be 11 speed.