Campy 10 speed cassettes

[sjbraun]

Getting ready for the Moab Century Tour in a few weeks. I use a 13-29 cassette for this ride. If you've ever ridden the La Sal Mountain Loop, you understand the need for a 29. But the 13 robs me of too much downhill speed.
The 13-29 has these jumps: 13,14,15,16,17,19,21,23,26,29. Could I switch out the 13 and 14 for a 12-13 or even an 11-13 combination for the first two cogs?
I have an 11-25 and 12-26 cassette I could borrow from.

Will this work?

-Steve

[martinrjensen]

How about just changing the 13 to a 12? Yes there's more of a gear spread but when you are shifting up at the high end, you usually are not putting that much stress on the gears so I would think that the gear jump would be acceptable. Pretty easy to try and find out of it works for you also.

[Ralph]

Getting ready for the Moab Century Tour in a few weeks. I use a 13-29 cassette for this ride. If you've ever ridden the La Sal Mountain Loop, you understand the need for a 29. But the 13 robs me of too much downhill speed.
The 13-29 has these jumps: 13,14,15,16,17,19,21,23,26,29. Could I switch out the 13 and 14 for a 12-13 or even an 11-13 combination for the first two cogs?
I have an 11-25 and 12-26 cassette I could borrow from.

Will this work?

-Steve

Sure.....take a 12-25 and substitute in the cogs. Be sure to use the correct following cog. IE....use the 17 designed to follow a 15, not the one designed to follow a 16. Make a 12-13-14-15-17-19-21-23-26-29

[palincss]

Getting ready for the Moab Century Tour in a few weeks. I use a 13-29 cassette for this ride. If you've ever ridden the La Sal Mountain Loop, you understand the need for a 29. But the 13 robs me of too much downhill speed.


Really? Assuming you have a 700x23C wheel and a 53T chain ring, according to Sheldon's online gear calculator going at 90 RPM the 53x12 would give you a speed of 31.3 mph, the 53x13 giving you 28.7 mph. Ramp that up to 120 rpm and you get 41.4 vs 38.2. I'm not convinced the "penalty" for that 1 tooth is really all that great. In either case, wouldn't you be better off getting in an aero tuck and coasting?

[sjbraun]

Compact drive train, 50x34.
I don't care to aero tuck and coast for 20+ miles, nor do I care to spin at > 120 rpms for the long descent into the valley.

[prometheus20]

Have not tried them, but IRD makes a 12-30 cassette that is Campy compatible. It is just outside the recommendation of the rear derailleur, but you can usually get away with an extra tooth or two.
http://www.interlocracing.com/cassettes_steel.html

[thwart]

How about just changing the 13 to a 12? Yes there's more of a gear spread but when you are shifting up at the high end, you usually are not putting that much stress on the gears so I would think that the gear jump would be acceptable. Pretty easy to try and find out of it works for you also.
Tried this myself a couple of yrs ago. My experience was not positive in terms of shifting up from the 12 to the 14. More times than not I'd have to shift up one cog further and then back down to the 14. YMMV.

[DRietz]

Nobody's recommend the HTFU route?

I guess I've got the wrong forum... ;)

I've done the ride of which he speaks. To be honest, I rode it with a 34x26 low gear, but different strokes (literally) for different folks.

The best bet is a Miche or IRD. They won't shift nearly as nice as Campy cassettes, but they really take the guess work out of the equation.

Also, FWIW, my high gear was a 49x13. Never really felt too out of place...

[martinrjensen]

I did that on my 9 speed and didn't notice the issue you had. I did notice a difference before I changed from the 13 to the 12 though, so it's worth it to do something about it.Tried this myself a couple of yrs ago. My experience was not positive in terms of shifting up from the 12 to the 14. More times than not I'd have to shift up one cog further and then back down to the 14. YMMV.

[Ralph]

You can't expect a 14, that was designed to follow a 13, to shift properly following a 12.

[oldpotatoe]

Getting ready for the Moab Century Tour in a few weeks. I use a 13-29 cassette for this ride. If you've ever ridden the La Sal Mountain Loop, you understand the need for a 29. But the 13 robs me of too much downhill speed.
The 13-29 has these jumps: 13,14,15,16,17,19,21,23,26,29. Could I switch out the 13 and 14 for a 12-13 or even an 11-13 combination for the first two cogs?
I have an 11-25 and 12-26 cassette I could borrow from.

Will this work?

-Steve

yes, but read palincss note and also it 'may' not shift well going to lower gears at the beginning since the cogs are really 'matched' to be next to each other.

'May' have to shift twice and down once to get that 14, for instance.

But like palincss said, the differences between a 53/11 or 12 and 13 is really very small...stop pedaling, get aero, rest...

[chrisroph]

When I rode bicycle tour of colorado several years ago, I took a 13-29, removed the 13 and installed a 12 from another cassette. I didn't expect to need a 29 but I used it a fair bit because of the altitude. The 12 shifted fine and made an appreciable difference on descents.

[Birddog]

I have an older Miche cassette that I use in situations like this. Mine is an 11/28. You can order them configured however you like from 11 to 28. They come with individual gears and spacers. They aren't the smoothest quietest cassettes but they work. I did have the misfortune of having the 1st position 11 split and break a few years back and I replaced it. Others had the same problem but I have heard that Miche has addressed the issue. I also use Campy spacers where I can instead of the Miche supplied ones. I did this because on one wheel the Miche took up too much space and barely any threads caught on the lockring. It seemed to shift better too with the Campy spacers, but that could just be my imagination.