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Thread: EPIC TACO time

  1. #1
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    EPIC TACO time

    So I went on my third ride on my new 2011 Specialized EPIC expert. 50ft or so from end of trail there is a small 3-4 inch branch..Which i normally bunny hop or manual on the way out. Well this time I landed off, and I was unable to recover. I either had too low of tire pressure (26psi, I way 146lb) or it just bent right away, tire caught the dirt,twisted I went over my bike and landed on my hip. Got up, picked up my bike and the front wheel was toast.

    I've wrecked several times on my dean but never had the rim just bend out of shape. So I limped my new bike over to the LBS too get a crash replacement on front rim. 185$ folks to replace the front rim.

    No pictures since I went straight to LBS after the incident.

    I'm still very happy with the bike, but not satisfied with the wheels. I'm not sure if It was user error , or just a different handling of the bike that I need to get use too I had gone over that small obstacle several times on this bike 5 laps as of this ride. If any body has Idea's, criticism of what I did.. please let me know.

  2. #2
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    It all depends on how the wheels lands and what pressure is put on it but I think 185 is pretty cheap to replace the front wheel so you should be happy about that.

  3. #3
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    185 for the front rim or for the whole wheel (hub/spoke/rim)? 185 is reasonable for a front wheel but for just the rim no way.

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    Most impt you are not hurt.

  5. #5
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    OUCH! That's no way to start a ride!!!

    Seriously though, glad to hear you're OK.

    I would guess (assume?) that $185 was for the rim, spokes, nips and labor to build it all up. At least I hope so. If so, that is a decent price.

  6. #6
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    I'm fine, I had a small bruise on my hip. 185 is a small price to pay for the complete front rim to be replaced. minus tire, latex and disk roter. But i'm still concerned that the rim gave the way it did. I'm going to take it slow on small bunny jumping over the next few weeks.

  7. #7
    Fat-tired Roadie
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    Check the tension on your wheels.

    I'd have expected that the Epic would get a pretty good build, but inexpensive bikes typically get machine-built wheels with inadequate spoke tension, and they don't last that long. Maybe that's true of Epics too.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  8. #8
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    It is always a good idea to check that spoke tension is correct and uniform. If you don't have a spoke tension gauge you can get a good idea on relative spoke tension just by plucking the spokes and listening for changes in tone. All the drive side spokes should be similar in tone to each other and likewise for the non-drive side spokes.Almost any decent shop tech should be able to check this for you also.

    As long as spoke tension is good I don't think you'll have any trouble with the new wheel.

  9. #9
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    I should be getting my bike back today. I will have the shop check the spokes just in case! Thanks for the advice erlau and andrwswitch.

  10. #10
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    PICTURES PICTURES PICTURES.. to bad there are NO PICTURES

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    I'd be the first one to say I love Specialized, but those DT Swiss wheels suck majorily. I toasted both of mine that came stock on my Stumpy 29er within a month. I'd say have your wheels looked over, and stress tested by a master wheel builder and you'd be fine. My guess is they don't tighten the spokes tight enough, just enough to make them straight.

    G

  12. #12
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    A properly built wheel will have uniform spoke tension (+/- 10% tension) that is approximately 15 to 20% of the rims yield point. For example, a good wheel builder will add about 10% tension to 4 spokes when he stress relieves them by squeezing 2 opposing pairs in each hand. If the rim looses alignment (i.e. starts to taco) when he squeezes the spokes then the tension is within 10% of the rims yield strength. If this happens the wheel builder will loosen all of the spoke nipples ľĒ of a turn and stress relieve all the spokes again. This fine tuning process is time consuming but will yield the most durable wheel for the given set of components. Light weight rims are more sanative to being over loaded by abrupt lateral impacts like the one you experienced with your crash because they do not have that much extra strength. The DT-Swiss rims that come on the Epicís are normally light weight and intended for XC riding only. If you plan on jumping and performing bunny hops on your Epic, I would invest in some heavier walled rims with a deeper and wider section laced with (36) DT-Swiss of Wheelsmith 14Ga. or 14/15/14Ga. spokes.
    With your front rim tacoed, it is almost imposable to determine if the factory builder and or machine over tensioned the spokes in your OEM front wheel and created a dangerous wheel to ride on. To be safe, I would strongly recommend that you bring your rear wheel and your new front wheel into a shop with an experienced wheel builder and have him check the tension of your spokes.

  13. #13
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    And after you've ridden them for a couple of months have your good wheel builder tension and true them again. They will last much longer.

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    Hmmm I guess the emphasis seems to be on good wheel builder. I think i might have to go up to San Antonio to find one of those guys. But I did not think that a minor bunny hop would cause the rim to go out. But I do agree these are cross country rim. But at 1800g you would think these guys are chunky enough. I thought 1500 and below would be the OMG be-careful range. However, i will look into heavier rim none the less but Have to wait a few months. I just bought this bike and my son a new bike as well. So better smarter half not happy!
    Last edited by moutainb1ker; 01-05-2011 at 12:18 PM.

  15. #15
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    The other weakness that your Epicís front wheel has built into it is that it is dished on the rotor side of the hub. This means that the spokes on the dished side of the hub will carry more of the load than the non-dished spokes because they need to be set at a higher tensioned to center the rim between the axle drop-out nuts. Your back wheel is dished on the drive-train side as well. So if your front OEM wheel was laced with 32 spokes (16 on the right flange and 16 on the left flange) than the majority of the pre-tensioned load is distributed around the 16 spokes on the disk side of the wheel. Since the spokes are laced into the rim in an alternating pattern (e.g. one spoke from the left flange and the next spoke from the right flange and so on), only one spoke on the rotor side will take the brunt of the load (your body weight along with any addition dynamic loads like a pot hole or a landing from a jump) when your wheel rolls over (or lands) on its contact patch. Without a picture itís a little hard to describe but I am only talking about radial loads (i.e. rolling loads) at this point no side or radial loads, which really wreak havoc on a wheel. With dished wheels it is better to use a deep sectioned rim with more spokes so that your rims load zone above your tires contact patch distributes the weight of the rider and any additional dynamic loads across as many spokes as possible. Light rims with shallow sections with spokes spaced far apart (i.e. 32 or less spokes) will not be that durable and are susceptible to catastrophic failure.
    If you performed this bunny hop on a 26er with cantilever rim brakes than that might explain why your old front wheel held up to the impact of the landing because many more spokes took brunt of the shock from the impact. Non-disc front wheels are not dished so both the left and right flange spokes are equally tensioned and equally share the load. Also the 32 spokes on a 26er wheel are spaced closer together than a 29er wheel 32 spokes because of its smaller diameter.

  16. #16
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    I actually don't think building wheels is all that hard, if you're patient and can follow directions.

    I followed these directions the first couple of times.

    http://www.sheldonbrown.com/wheelbuild.html

    IMO, building and maintaining wheels is a really good skill for a mountain biker to have, especially if you like lightweight equipment or race. This kind of riding is a lot harder on equipment than road. Unfortunately, a good truing stand is pretty expensive, but you don't really need one; same with a dish stick.

    Your LBS ought to be able to do any wheel construction and maintenance tasks too, if you ask them. They won't necessarily work on a new wheel because those theoretically come out of the box ready to ride. It's irritating that that's not always true.

    Anyway, driving someplace far shouldn't be necessarily to get your wheels worked on. Just ask how many wheels your mechanic's done if you're not sure about getting them worked on at your LBS, or do it yourself.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

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