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  1. #1
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    06 Stumpjumper HT Max Rotor Size?

    I just picked up a used 06 SJ with BB7's and 160mm rotors. I have a bad squeal on one set and I don't feel as though I have enough stopping power. To add to the problem, the guy before me had them set up horribly and I just want to start from scratch. One of the rotors is also slightly bent so I think I need to replace it.

    So, I see online I can get new 09 BB7's for like $45 bucks. That's less than buying new pads and a new rotor. I figure I might as well buy new breaks for front and back while I'm at it and then I can put one of the old ones on my 07 Rockhopper.

    Anyways, I'm a Clyde. 6'7" and about 240 with gear. I'd like to go bigger on the rotor size. What is the biggest I can go on rotors? I don't care about the weight so much, I just want super stopping power.

    Here's a link to the bike. The only upgrades worth mentioning are Velocity rims with Hope Pro II hubs and Salsa skewers.

    http://www.specialized.com/us/en/bc/...006&spid=21818

    Thanks,

    Bob

  2. #2
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    Let's see....

    The maximum rotor size for the 06 F series of forks is 203mm so you should be good to go there for anything from 160mm to 203mm. The problem may be the frame. Very few XC Hardtails like the Stumpy will accept a 203 in the back. It will likely make contact with the chain stay. Usually a 185mm will fit (185 if you stick with Avid brakes that is). But that's not a big deal really. Many riders prefer to go a size smaller on the rear rotor. The reason being is it tends to balance out the brakes. You usually don't need as much omph in the rear as the front brake should be doing most of the stopping anyway. A size smaller rotor in the rear evens out the pull on the brakes, you get less power out of the smaller rotor for the same amount of lever pull, so you're less likely to lock up the rear. What I would do is take a look at the position of your current 160 and see how close to the stays you are. Then take a thin ruler and lay it flat against the outside surface of the rotor while the wheel is installed on the bike, then meausre out an additional 12mm and see how close to the stays you are. If the ruler just is clear of the stay you'll have no problems with a larger rotor. Or you could use a semi ridged pice of plastic or what ever. The idea is to give you a parallel visual indicator for the larger diameter, but it will need to be as thin as possible. My best guess is a 185 will likely be fine, but a 203 could be pushing it in the rear. Just depends on the design of the chain stay.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  3. #3
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    I did a rough estimate like you suggested on the rear and I think a 185 will be fine. It will definetely have clearance but not a lot. I guess as long as it doesn't hit it should be fine right?

    How big a difference would I get going with a 203 in front and a 185 rear over the stock 160's? I'm thinking I'd have plenty of stopping power right?

    Is the 203 overkill? I live in pretty much the flattest area on Earth I just like to have a lot of stopping power and I also like to be able to hold myself when going down short technical downhill sections. I figure too much is better than not enough.

    Are there other concerns with going to a 203? I'm hoping there isn't some downside that I haven't considered.

    Thanks

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