Thursday, February 18, 2010

SRAM XX thoughts

I know, I know, I'm about a year late with this. But I am finally getting serious interest from customers in putting XX on their new bikes, so when Craig asked for my take, I thought I'd type it up and use it as a blog post.

My take is that if the goal is to move away from making lots of front derailleur shifts (which suck) then it's good - with a 26 or 28 or whatever as your smallest ring, it should be easier to shift up and down, as well as harder to suck the chain, all things being equal, as compared to a 3x drivetrain.

On the other hand, if the goal is to save weight, it's stupid - replacing a 22t aluminum chainring and 4 bolts (assuming you're being a weight weenie about it) only saves you maybe 30g. Adding a big fat 36t cog adds at least that much, especially when you consider that you could get the same gear ratio with a 22t in the front and a 28t in the rear. A fancy 11-28 road cassette would be way, way lighter than an 11-36 (especially if you used all the silly machining tricks they're doing on the XX cassette). Couple that with a 22/32/42 or whatever, and you've got a huge range of gears at a very light weight. But you have to shift the front end a lot, which is a bummer.

The direction they're going, though, which I think is a good one, is eliminating the front derailleur altogether. Lots of racers (and other folks) already run 1x9 with 32t or 34t cassettes - 36t will allow more people to ride without a front derailleur (or shifter) which is a pretty huge weight and performance (no front shifting!) advantage.

Of course, only some folks are fit and/or masochistic enough to want to run a 1x whatever. 36t is not *that* much less gear than the 34t that we've got now (about 6%) so it's not going to convert every weekend warrior to a single front chainring. But it will somewhat increase the capability of the single ring setup, which is great. The price, though...whew! I'm not about to drop 300 clams on a cassette!

I have no particular feedback about the brakes, since I have yet to even see them, and as far as I know, they're just really nice light standard Avid disc setups. I'm guessing they're great, but nothing really exciting. Likewise the XX fork lineup.

So bottom line: good stuff and a step forward, but not worth buying until the ideas trickle down to cheaper stuff, unless you're loaded and have to have the newest thing. I think you'll see 10speed XX-like versions of XO and X9 next year, that's what I'd probably get.

7 comments:

Andrew Brautigam said...

I think that q-factor/chainline is a factor for reformed roadies - people who are used to road bikes are used to having a relatively narrow q factor, and if you're training on the roadie to "win" (i.e. not suck) mtb races, you want maximum transference of fearsome wattage.

Also, it's cool, and expensive, and kinda light. All Sram has to do (or Shimano, for that matter) to make me happy is have XT level pricing on a quality 2x9/10 setup.

grannygear said...

I have been on the XX suite for a few months now and it spoils ya. I think lower overall gearing will be needed for it to trickle down to the 'masses' in XT/X9 level stuff.

It is costly stuff, but it shifts crazy good and the 2x crank is really all I need (I have not had a big ring on a bike in a couple of years...just 2x9).

Loving the narrower Q factor thing, something I never cared about before...non-roadie here.

Walt said...

Hey GG, Andrew - Agreed that the narrower Qfactor (which is officially called "stance width", btw. SRAM is using the wrong term) is nice to have. Of course, we *had* that back in the day of square taper, so we're really just getting back what we lost.

On the shifting front, I've never understood the comments about shift quality - I find that any <10 year old parts in good condition (SRAM, Shimano, Campy, whatever) shift so quickly and precisely if they're set up well that I can't imagine needing them to shift any better. Maybe I just need to experience it to see for sure.

One more gripe: I want gripshift!

Anonymous said...

This seems like much ado about not much. Is shifting into the granny ring every once in a while so taxing? Heck, most of the time most folks run in the middle ring and only get to the big ring for downhills or the small ring for heinous uphills. The current setups shift amazingly well and the XX stuff has yet to offer any compelling reason to sacrifice range. Is it that hard to shift? Maybe if you live in fire road country it makes sense . . . but I don't get it.

Anonymous said...

Nice run down on XX. You can still build really solid 2X9 set ups nearly as light. I wonder how durable 10 speed is in the dirt and I assume a $300 cassette turns into a nice piece of table art after a couple months in the grime. My Waltworks runs best as a single. I've gone back and forth from 3X9, 2X9 and 1X9. For some reason the bike seems faster as a single. Think of all the rear cogs I can buy for $300! Keep your no-nonesense product reviews coming!

--Jon

MikeQ said...

Having run 3x9 with 12-27 all last year's races i didn't find it necessary to make all that many front shifts; perhaps a function of the Colorado-style races (UP-UP-UP-DOOOWN), could be argued rolling courses would be far worse. But a close ratio block feels SO much nicer than those awful massive gaps.

If you live in a gentle climate (=Boulder), and have time to keep your gears dialed (/=me), good. But I agree that in the UK, in the mud, 10sp alignment would be hard to maintain; it is tough enough on the winter road machines.

Good race equipment, pointless extra$$ for recreational riding?

steve-o said...

im using a fsa afterburner "mtn compact" crank in a 2x9 setup. Its awesome. My only gripe with a 22t chainring is unintentionally bouncing the front wheel in too small a gear. 42-27 is perfect, not too big, not too small. The xx parts sure do look sweet though.