Sunday, October 11, 2009

The frugal cyclist's guide to upgrading your mountain bike

The most common workers compensation claim for bike shops is hands cut on chainrings. The fact that pro mechanics do it makes me feel better about the hole I put in my knuckle Friday night when a chainring punctured my finger while I was removing a pedal.

A less frequent injury but one I can claim nonetheless is a blackened thumbnail. The thumbnail was smashed when I had my finger stuck in the gap in a brake rotor, didn't think about what I was doing, and spun the wheel. The thumb definitely looks worse (the cut was about three times as deep as it was long), but I don't know which one hurt worse.

In addition to the injuries, I managed to get all of two and a half hours of sleep that night. Fortunately, I have more to show for the sleepless night than just the injuries (notice it isn't completely clean; per Rick's rule, I had to get it dirty on Saturday before unveiling it):

This bike came about as a result of a massive cleaning of my garage wherein I sold a bunch of bike stuff I was no longer using. I know, when you're getting rid of stuff, you're supposed to end up with less stuff, not more. But in the process of selling stuff, I just happened to come across this frame. And it was my size. I've been wanting to swap my steel frame for something lighter for a while. This was perfect.

I also wanted to lighten up the fork a bit, as the Marzocchi I've been running, while functional, was heavy enough to use as ballast on an oil tanker. Fortunately, Elden prefers rigid forks, so he had a Reba literally sitting on the floor of his garage. He let it go for a song. And maybe some pie was involved. And perhaps a small sum of cash traded hands. The Reba rides great. I had always poo-pooed anything but Fox and Marzocchi, but Rockshox has got things pretty dialed with that fork.

Everything else, save the headset and seatpost, was swapped over from the other frameset.

The completed package is lighter than what I had before. Just not quite as light as I'd like it to eventually be. So I decided to do another dirtbag guide to upgrading a bicycle, this time the MTB version, to help me decide what to upgrade to as opportunities arise. Since I'm a bit obsessive, I weighed every part of my predominately XT drivetrain before putting it on the new frame. This serves as the baseline for my upgrade guide, with the formula being the same: most weight-reduction bang for the buck. Of course, assumptions are the same: you're working with a frame you like; you're not fat; and you don't care what brand a part is so long as it works.

One more assumption unique to MTB: I'm going to run a Thomson seatpost no matter what. One of my neighbors in Boise had a post break and badly cut the inside of his thigh. That's a really vascular area, and he's lucky he didn't bleed to death. Thomson posts are light enough for cross country use and strong enough for freeride. And they cost $100. I don't know why you'd use anything else. If you've got the post, may as well get a Thomson stem to match.
  • Wheels: I didn't even need to do the math to figure out the first place to start. Not coincidentally, it's the same as on the road bike. Unfortunately, since Revolution Wheelworks doesn't make a MTB wheelset, at least not yet, I can't recommend theirs. What I can recommend is the Stan's 355 wheelset with Stan's ZTR hubs. With the Stan's yellow rim tape, they'll be ready to run tubeless. These wheels would save me about a pound over my 29" Bontrager Race wheelset--400 grams, at a cost of $440, or $1.10/gram. With the yellow tape and valve stem rather than rim strips or tubes, they'll save even more weight.
  • Bars: The weight differences from one bar to another can be surprising. And when you can get a 140 gram bar for $70 or so, that might be the next best place to spend upgrade dollars. Unless you already have a 140 gram bar. My FSA bar is 180 grams, cost me $20, and it's staying put.
  • Brakes: With MTB brakes, the absolute lightest product presents the best value. SRAM XX brakes, at 576 grams (297 less than my Shimanos) for $746 for the pair end up costing $2.51 per gram saved. But since Hayes Stroker Gram and Avid Juicy Ultimate can presently be found at closeout prices, both of those could present a better value, albeit not as much weight savings--they weigh 130 and 100 grams more, respectively, than the XX.
  • Shifters: The next best value is in shifters, with SRAM X.9 being the winner here. Unless, that is, you prefer twist shifters, in which case X.0 twist shifters are the best upgrade value after wheels. Since some of us like triggers better, I didn't list them at the top, but it's worth noting. Another thing worth noting is that if you're running Shimano and you switch to SRAM shifters, you also have to switch your rear derailleur.
  • Rear derailleur: XTR shadow is the best value here, at $3.29 per gram saved. But if you're running SRAM shifters, X.9 or X.0 are the way to go. X.0 saves more weight but costs more. X.9 costs quite a bit less. Total difference between X.0 and X.9 is 34 grams--not a huge difference, though shifting on X.0 is a bit crisper.
  • Cassettes: XT cassettes present the best weight saving bang for the buck, but they're only 19 grams lighter than the SRAM PC980. If you're running SRAM everything else, I'd stick with the SRAM since it's designed to work together. Otherwise, XT is a lightweight and very durable choice.
Things I wouldn't worry too much about switching until they're worn out are chains, cranksets, and front derailleurs. Of note on front derailleurs and cranksets is that SRAM XX presents the best value, but, unlike the brakes, has to be done as a system of at a minimum front shifter, front derailleur, and crankset. And really, if you're doing that much, you may as well reap the full benefit of the 2x10 system.

In case you're wondering, a complete XX group costs about $2300 and would save me about 650 grams, or a pound and a half. That works out to about $3.54 per gram saved, at least on my bike. It's sexy, it's super functional, it's all anyone can talk about on mountain bikes right now, but it's more than I'm willing to spend.

If I were buying a complete gruppo, however, and wanted the most weight-saving bang for the buck, regardless of the number of bucks, XX is the way to go. X.0 is nearly as good a value, but only costs about half as much (and only saves about half as much weight). XTR 970 weighs about the same as X.0, but costs about 80% more (almost as much as XX). XT weighs about the same as X.9, but costs about 60% more. If you want value and weight savings, SRAM is the way to go. And you don't have to have the top-shelf group to get it, either.

What I've just said notwithstanding, the reality is that on the mountain bike (and truth be told I do the same on the road bike), I wouldn't switch anything besides wheels unless it was a break/fix situation or I found a deal that was just too good to pass up. The weight savings from enthusiast-level parts to pro-level parts just aren't that great. Aside from brakes, there's not a single upgrade that will save you more than about 100 grams. Moreover, there's so much more to a mountain bike race than just power to weight that minor component upgrades are unlikely to make or break a race for you.

Think of it this way--Elden's bike that I rode at Leadville was about five pounds lighter than my bike at the time. I figured it saved me about seven minutes (and I gave most of that seven minutes back in an unscheduled pit stop at the Pipeline feed zone). That's three times the weight savings of a XX upgrade on a course that's five times as long as a typical XC race. So upgrading to XX might net you 20 seconds or so in a XC race, if that. Only you can decide if those 20 seconds and the extra $5 on your gift certificate if you're one step higher on the podium as a result are worth north of two grand.


  1. "What I've just said notwithstanding, the reality is that on the mountain bike (and truth be told I do the same on the road bike), I wouldn't switch anything besides wheels unless it was a break/fix situation or I found a deal that was just too good to pass up."

    i'm so glad you finally said this. i was going to reconsider our relationship. stop the madness.

  2. Interesting way to look at upgrades.

    Did your friend break a metal or carbon fiber seat post? If metal, that's unusual. If carbon, I've seen too many broken ones. And a good metal seat post (I like Thompson too) is no significant weight penalty. Seriously people, don't do carbon fiber seat posts on mountain bikes!

    I prefer to think of my non-light-weight bikes as a way to pack more training benefit into each precious hour of ride time.

  3. Number one rule when removing pedals (mainly drivetrain side) - leather work gloves. It took a few chainring knuckle gouges to learn this lesson.

  4. I'm now seatpostbreakaphobic. Thanks.

  5. Dude put down the scale and admit you have a problem.

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