large cassette= chunky shifting?
 

i was thinking of switching from a 12/25 105 9spd to a 11-32 or 11-34 type cassette while running a single 42 up front on a long cage 105 derailleur and 105 brifter

will this give me some nasty shifts? i don't mind a slight difference but i don't want to switch if this is going to be cumbersome or slow

I tried an 11-32 and really didn't like all the chain slack but I was running a double not a single. I never found the shifting cumbersome or slow infact the spring action seemed a little more stout with the xt rd than my ultegra rd if I remember right. Mainly having that kind of range in houston was silly for me with a double don't know why I did that really.

I switched from a 12-25 to an 11-32 for some road rides this summer. It accomplished what I wanted, which was to get my sorry butt over some big climbs, but on the whole it slowed me down. The reason is that when you shift up, it drops you outside the efficient cadence range, and you have to work hard for a few seconds to get back up to a good spin. And it does that for every shift.

The questions you need to ask yourself are, (1) how often are you going to use a gear with more than 25 teeth, and (2) is it worth having to use a long cage derailleur to get that?

This is allmost the same teh same set up that I am using, only I am using a Sora rear no problems whatsoever.

i run an 11-34 with 48 chainring (1x9 speed); and i *love* it. no problems with cadence at all, from 34 all the way to 11. there might be some issue with terrain, but here in hilly mid-state NY i can cruise in the upper registers most of the time, but still maintain a more consistent cadence on the hills/little mountains. i see spandex road warriors grunting as they slowly snail their way up the big hills pedal-over-pedal (<60rpm), while i match their speed with about twice the cadence (which gives me the sensation of more stability and control at the slower speeds). and at the worst hill sections---that most rotten of 30-50ft---i am spinning at about 60rpm; i've not seen a road biker on those sections, ever (maybe just the super-dooper monster thigh bikers try it, i don't know).

Think I'd prefer an XT mid-cage RD. I haven't tried to shift anything larger than a 11-28 with a road double and it was temperamental. I'd heard it would be fine with up to an 11-30 and sometimes 11-32. However, when I adjusted the B-screw to shift the big cogs well, the small ones were sluggish. If I adjusted it for better shifting of the small cogs, the big ones ghost shifted. I went back to my 11-26 climbing cassette after the one sick climb I made the change for. With the mid-cage on the cross bike I've been able to swap between 11-28, 11-32, and 11-34 with no problems at all.

I use 11/32 on the MTB and this is standard gearing for most MTB's now. I have never had clunky changes- unless the derailler needs adjusting. Changes are instant and clean- even when the cassette and derailler are covered in mud.

But the annoying thing is- I can climb hills with 24/28 on the "OLD" so why do I need 22/32 with the newer bike on the same hills?

If you have lower gears- you will use them. Might not need them- but you will use them.

Let me explain what I think the issue is with the 11-32+ cassettes and the wider gear spacing. It isn't something that feels obviously wrong. It's a matter of efficiency.

My maximum efficiency is at a cadence of around 90-100. When I get to about 105, I shift up. If I'm using an 11-32 cassette, that upshift typically drops me down to a cadence of about 80. If I'm using a 12-25 cassette, it typically only drops me to about 90.

Now a cadence of 80 doesn't feel wierd. It's fairly normal. But it's not as efficient as 90, and so I have to work harder to get back into the sweet spot. With the tighter gear spacing, I stay in the sweet spot. The effect is, when my shift takes me to 80, it feels like the bike wants to stay at the current speed, and I have to work to make it do otherwise. When the shift takes me to 90, the bike feels like it wants to go faster.

Obviously in a 'cross race there are all kinds of things that tend to force your cadence down independent of gearing. On the road, the above argument is much more direct. Nevertheless, I think that the net effect of tighter gearing is more efficient acceleration through the range. The cost, of course, is a smaller range.

Mountain bikes use the wider range, because mountain bike riding requires it -- lots of ascents and descents. Road bikes use tighter spacing because the focus is one being able to accelerate efficiently through the range. I would argue that in this respect cyclocross is more like road than mountain.

I plan on doing a similar thing for my touring bike next summer. Which I plan on having one chain ring, have a lot of gear in my pannier and riding up some large mountains.

I think for a cross race bike 11-34 is unnecessary. If you are using a gear that big in the back you could probably run the bike faster.