Tuesday, January 19, 2010

Double or Nothing?

Is the triple chainring mountain bike crank dead or dying? I think so. When I assembled my Leviathan a couple of years ago, I was coming off of a 1x9 Karate Monkey. And even though I knew I needed a granny ring on the Lev, I also knew that I really did not need a big ring either.

This was a real revelation for me since I had been running a triple crank for 20 some years. The big ring got used most of the time as a way to take up chain slack for rough sections and downhills, but of course it was used for faster sections of a ride. But I had found that the 1x9 Karate Monkey was pretty good with a 32T CR and 11T rear cog. Sure, it could have been taller, but it was 90% there, maybe more that that even.

2 years later I have little regret running a bash ring instead of a big ring. Every so often I lose the drag race if it comes to a flat, paved sprint to the parking lot with the boys but on trail I never miss it. It allows you to shorten your chain, run a shorter rear der, the shifting is either up or down...not up-up and down-down so it is dead simple to get the chain ring you want. You won't pit bull your calf on chain lube soaked teeth either. A bash ring is nice and smooth and the extra ground clearance is nice too. No more bent teeth on log crossing or shelf rolls.

And now I have been on the uber-gruppo XX 2x10 SRAM stuff mounted to the Epic Marathon. I will tell ya, except for the fact that I would like a slightly lower gear ( more on that later) it provides everything I need in gearing. A 39/11 is pretty darn tall. If you are spinning that out on the flats you are going really fast. A 39/36 is not very deep, but if you have momentum, it will get you over most trails. The 26/36 is deep enough gearing for most folks in most parts of the country and the better chainline that the 2x10 allows lets the 26T ring run the whole cassette in an efficient way.

And now, there is the news of the 2011 XTR/XT/SLX and XO groups being 2x10 as well. This is good as it means that dedicated 2x10 systems will be a bit better priced in the future. More on that here http://www.thecyclistsite.com/news/2010/1/19/hints-on-2011-xtr-and-sram-xo-pics.html and possible discussion here http://forums.mtbr.com/showthread.php?t=586753

But, I do not see it as perfect...yet. Why?

  • Gears are TOO BIG! I guy I ride with that is fit and darn fast (racer boy) has a carbon Trek FS with an FSA double crank. It has a 44T outer ring (maybe bigger...can't remember). Even he thinks it sucks and this guy is a greyhound. Who is that gear for? Kansas racers? Even the XX group I have is barely...barely deep enough for me. I would jazzed about a 24/36 option but the BCD may not support that OR the option may not be offered by the makers. That may open up room for the small guys to tool up and give us deeper gear options.
  • Whatever happened to a 9 speed version? Man that was just glossed over with the Shimano 12-36 cassette that was panned as too heavy by a lot of folks. Think you will see an XT level, lighter version of that gear cluster now that 10 speed is hitting the streets? Not likely. And that is too bad. With a 12-36 9 speed and a 36 tooth big ring, that 12/36 is a pretty tall gear. A 24/36 double with a 12-36 would be my choice but offer a BCD that supports a 22/34 double as well. Why not? Have pity on the fat old guys of the world, will ya?
  • For crying out loud....what ever happened to the 180mm crank arm? With all the buzz on 29ers and the new dawn that it provided the big and tall among us...rise up and shout, oh gangly ones!!!...there are less and less longer cranks out there. No Race Face except a low line crank (V Drive), no Truvativ other than the SS crank, no FSA, no SLX, but at least we have (or had...not sure about the new 10 spd stuff) 180mm options in XT and XTR, no SRAM either, what else...hmmm....except for oddball stuff like Middleburn or White Industries (god bless them for their options for us SS riders) crank lengths are getting reduced in choice.
  • PUUULLLLEEEZZZEEE SRAM....give us 10 speed Gripshift. Please. I beg you.
  • Chain wear and replacement cost? Remains to be seen. Finicky shifting in difficult conditions? Well, 9 speed was worse than 8 speed. 10 speed? Not sure but I doubt it will be better.
I really like the double crank. I am sold. I do not like the way that the combo of external BBs and proprietary BCDs combined with more speeds than most of us really were asking for are driving us into a sheep pen that allows for little chainline adjustment, gearing options, and crank length choices.

I don't think we have any choice. 9 speed will become the new 8 speed eventually and guys will be hoarding XT 9 speed cassettes and shifters and bragging about it on the 'Classic/Vintage' forums. I will likely be happily riding on a double chainring-ed, 10 speed driven mountain bicycle. I just hope I am not forced to go "baaah, baahh" as I am pedaling too tall a gear on too short a crank on too wide a stance.

1 comment:

Fonk said...

I'm with ya, in that I think 9-speed is sufficient, and probably even better, for mountain bike applications. I don't think we need 10 speeds. On the other hand, it does allow for more compatibility and parts swapping w/ road groups (setting up a drop-bar MTB w/ road shifters, using a MTB derailler for increased gearing on a road bike, etc.). Even so, I think I prefer to stick w/ the beefier 9-speed chain on the MTB.

I haven't used a double-chainring setup on an MTB yet, but you're right that the outer ring really isn't used that often for most of us on the triple setups. A 24/36 crankset would be perfect.