Help me spend my $$

[melissam]

Ladies and gentlemen of TE,

The time has come for me to convert the gearing on one of my bikes to a mountain bike cassette and derailleur. I'd love to hear any suggestions for which components I should use -- cassette, rear derailleur, chain.

The rules are simple:

• The cassette should be in the 11-34 range
• All components should be compatible with Shimano STI 9 speed shifters
• Front setup will be a road triple - 53/39/30. I may change the big ring to a 52.

Thanks for any and all suggestions!

- Melissa

[Triskeliongirl]

I did it with a shimano XT RD, XT 11-34 casette and durace/XTR chain

Since then I started buying XTR casettes due to the lighter weight.

They work great with my 9spd ultegra short reach brifters and 50/34 compact double.

Ladies and gentlemen of TE,

The time has come for me to convert the gearing on one of my bikes to a mountain bike cassette and derailleur. I'd love to hear any suggestions for which components I should use -- cassette, rear derailleur, chain.

The rules are simple:

• The cassette should be in the 11-34 range
• All components should be compatible with Shimano STI 9 speed shifters
• Front setup will be a road triple - 53/39/30. I may change the big ring to a 52.

Thanks for any and all suggestions!

- Melissa

[maillotpois]

Nice! Have lots of cake and eating it, too!

[dachshund]

Nice! Have lots of cake and eating it, too!

That's exactly how I spec'd my gears to Chris: "I want my cake and eat it."

It seems that you're limited to a 22 tooth range on the Shimano front derailleurs, so for example 30-52 would meet that. Also it seems that 52 is as high as you can go for the large ring, just browsing some Shimano info. Most of the mountain rear ders. take a 34t sprocket, so that's good. Make sure you check the specs to be sure the derailleurs have enough capacity for what you want. Some of the front ders only take a max of 48 teeth on the large chainring, for example. Then watch the total capacity rating, which is the front capacity + rear capacity. So if you want a 30-52 in front and 11-34 in back, that's 22 + 23 = 45 as the total capacity.

This blurb explains it pretty well, http://sheldonbrown.com/gloss_ca-g.html#capacity

He says you can exceed the mfg's specs a bit, but that will get you into finicky shifting, which should be avoided since there are so many good options available in Shimano.

[melissam]

I do have a "cake & eat it too" setup on my other bike: a triple with a mtn. cassette. It's awesome! Low gears to help you over some of the steepest climbs, or if you've been out in the East Bay heat for too long during a permanent route designed by one particular TEer who should remain nameless.

I have an SRAM 11-34 cassette (PG-970), Shimano rear derailleur (RD-760), SRAM 9 speed chain.

I could duplicate this setup on my other bike, but I'm considering other parts. Criteria includes even better shifting, durability, bling factor, budget.

Questions I've been mulling over include:
* I'm pretty sure I need a long cage derailleur due to the # of teeth on the chainrings and cassette. Could I get away with a medium cage derailleur?
* Top normal or low normal? I don't think low normal will work with STI shifters, but if it will, is there an advantage to using low normal?
* Should I use one of Shimano's shadow derailleurs? It sticks out less, which is definitely an advantage for a mountain bike, since it won't snag on the obstacles you tend to encounter off road. Is it an advantage for a road bike?
* Is XTR worth the price difference over XT, performance-wise? (It has weight savings, and gets points for the bling factor.)
* Does SRAM have any derailleurs that would work with my STI shifters? If so, does it work better than a comparable Shimano derailleur?
* Is it worth it to go with a higher end cassette to save a bit of weight? (Common sense says no. But I could be wrong...)

And yes, in case you're wondering, I do obsess over the darndest things.

[dachshund]

Criteria includes even better shifting, durability, bling factor, budget.

Questions I've been mulling over include:
* I'm pretty sure I need a long cage derailleur due to the # of teeth on the chainrings and cassette. Could I get away with a medium cage derailleur?

I'm going to guess no, because of the capacity issue. A triple and 11-34 will add up to total capacity that will exceed the specs on a medium cage der., most likely. And it would stretch that "better shifting" criteria.

[Triskeliongirl]

MY XT RD stuff shifts smooth as butter. I did upgrade the casette to XTR to save weight at the last replacement, but no performance differences. I always use XTR/durace chains cuz there isn't much price diff on sale, but I do prefer the shimano chains to the sram. The calulations I ran on my 50/34 suggested I could get away with a medium cage RD, but only if I gave up my 11/34 to an 11/32 and I really wanted that 34 tooth ring paired with my compact double. But on your triple I think you must use the long cage RD. But it shifts very smoothly, no diff. from my ultegra RD did on an 11/27.