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  1. #1
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    What happened to my cassette?

    Well to start off I am quite a Clydesdale at 6ft 3, 300lbs. I ride a brand new 2011 Trek 4300 Disc. Today while on the sinlgetrack I was going up a very steep hill I could never make it up before (super excited) in the granny gear and I was pumping quite hard and snap!!!! I stop moving, apply the brakes, come to a stop and flip onto my back. Upon further inspection my cassette has now become a freewheel. It functions exactly the same foward and backwards!

    I dropped it off at the LBS and they will have it covered under warrant. Any idea what actually went wrong?

  2. #2
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    busted PAWLs but im not a bicycle tech ... good luck hope its a cheap fix...

  3. #3
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    300 lb's and running granny up something steep with a Shimano hub will make things go snap, crackle, pop! At a minimum, you'll need to get a stronger,better built rear hub for a custom wheel build, by one of the heavy duty players like DT Swiss, Hadley, Chris King, etc. Do a search in this forum, or in the wheels and tires section, or even the 29'er section.

  4. #4
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    Well It was the first time I could make it up that hill actually riding the bike and not walking it. I bought the Trek 4300 becasue of all the bulletproof reviews. I know I am a large guy I thought that granny wouldnt be putting that much stress on the drivetrain since of the high mechanical advantage.

  5. #5
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    Quote Originally Posted by rmontgo21
    Well It was the first time I could make it up that hill actually riding the bike and not walking it. I bought the Trek 4300 becasue of all the bulletproof reviews. I know I am a large guy I thought that granny wouldnt be putting that much stress on the drivetrain since of the high mechanical advantage.
    The Shimano M475 hub is not known for it's durability. You can upgrade to the M756 freehub body which seems to be more durable, but at 300lbs you are pushing the limits of the Shimano hubs.

  6. #6
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    Sounds like what happened to my rear hub this past Sunday. Here is the video I made for Bikes Direct showing them the issue I'm having.
    http://www.youtube.com/watch?v=ZvlxjK_2FPs

    They shipped me a new freehub yesterday.

  7. #7
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    Beginners usually don't learn this math lesson first hand/right away, but. . . . .

    Short, very steep hills + the muscle to propel a 300lb human up said hill + Shimano freehub = "Pop!"

    Downer that you're already popping freehubs, especially if it's because you merely push too hard against too much force (ie; you @ 300lbs) rather than having poor technique hasten the freehub's demise. By 'poor technique', I mean a less than smooth application of power. Nevertheless, if you are strong and have some of those really steep 'grunt climbs' on your rides, it's usually only a matter of time until you will experience Shimano freehub failure.

    My advice: This is one place guys like us just have to 'buck up' if we want a freehub with reliability that has been tried and true. They make spare parts for all of them too, but it's much more rare to actually need them if you do even a minimum of maintenance.

    The good news is that it usually only hurts badly one time. That would be the day you have to pay for a quality rear hub. After that, it's normally smooth sailing. The most well known players are DT Swiss (with the star ratchet), Hadley, and Chris King.

  8. #8
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    Quote Originally Posted by rmontgo21
    I thought that granny wouldnt be putting that much stress on the drivetrain since of the high mechanical advantage.
    Nope, its just the opposite. The gearing increases torque at the hub. I had to cut apart one of my shimano hubs till I really understood what was happening. In order to allow your hub to freewheel in one direction and engage in the other, the internal has pawls or spring loaded fingers that catch on the inside of the hub in one direction but freehweel in the other. You basically just sheered the tips off the pawls so they don't engage anymore. More expensive hubs have either more pawls or different designs to handle more torque.

    Force yourself to only ride in your middle ring upfront and you will minimize failures. Drop to granny and your gamblin.

  9. #9
    @adelorenzo
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    IMHO replacing the entire wheel is overkill right out of the gate, if it happens again try upgrading the freehub on your existing wheel. LBS can order you a higher-end Shimano model that will fit on.

    Next step would be a new rear wheel if you have problems (or just want a nicer wheelset).

  10. #10
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    Quote Originally Posted by rmontgo21
    Well It was the first time I could make it up that hill actually riding the bike and not walking it. I bought the Trek 4300 becasue of all the bulletproof reviews. I know I am a large guy I thought that granny wouldnt be putting that much stress on the drivetrain since of the high mechanical advantage.
    You just found the weak spot in the bike. As others said, the shimano pawls aren't very strong and because you are a big boy, you create a lot of torque on the freehub when climbing. If you are interested in new wheels, you should take a look at the Easton Havocs on sale at pricepoint. They are lighter than what you have now, much stronger (designed for freeride) and are a good quality product that would not be out of place on a $4000 bike.

    http://www.pricepoint.com/detail/167...elset-2010.htm
    Riding slowly since 1977.

  11. #11
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    If you really like riding, plan to do a lot riding in the future, and don't like replacing your freewheel every 1-2 months......UPGRADE!!!! You will be saving yourself money and hardship in the long run. The only certain thing is that you will break more freehubs, its just how many before you realize there's no fixing it.

    I replaced 4 before I gave up and bit the bullet. I've got a DT Swiss 440 FR out back now with no issues for a year.

  12. #12
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    Thanks for all the info guys. The bike is in the shop right now getting it replaced under warranty. I understand the concept of the problem and hopefully it does not happen again. I was applying power smoothly sitting down so that was not the problem. If it continues I suppose I will upgrade.

    The first upgrade I would like is a better set of hyrdo's. The stock promax hornets are trashhhhh. I was thinking Hayes Stroker Ace's as they have a large 4 piston caliper and have pretty good reveiws.

  13. #13
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    Hi,

    I am a repeat offender for breaking hub pawls.

    I think I am up to 6 hubs but i stopped counting.

    The engagement mechanism for most hubs is a pawl/ratchet system.

    There is a ratchet of fixed teeth with spring loaded pawls. as you spin the hub, the pawls get pushed back then lock in to the next ratchet 'tooth'.
    simple design and very effective.

    The issue happens if you are a powerful guy. The hub shell flexes under torque and the pawls get restricted. Some will part engage and some will miss. This means instead of the force being shared between 4-6 pawls; it will be massively concentrated on a few and the pawls will shatter. Once one goes, it starts a vicious cycle of increasing peak pressure until they all snap and you get thrown over your bars.

    The ultimate panacea to this issue is the Chris King design. This uses a star ratchet system. instead of 4-6 pawls engaging, you have 72 points. the 72 points are linked, they all lock in or they all miss. Absolutely indestructible. After a year of use, it still looked brand new inside.

    do not confuse this with the DT Swiss ratchet, that was a lousy copy that is more fashionable than well designed. Do not waste your time on it.

    When somone stole my CK wheel I tried to find a cheaper alternative.

    The rear hub I am currently using is the NEW DESIGN Saint (shimano). Must be the newest design.

    It engages fast and is very very stiff and very fast.

    Not a cheap hub, but 1/4 the price of a CK.

    For brakes, you seem to have the right idea, you cannot have a brake too powerful. Shimano Saint or Formula the one (mine) are the more common choices, but the Aces are erm ACE.
    Why would I care about 150g of bike weight, I just ate 400g of cookies while reading this?

  14. #14
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    Quote Originally Posted by rmontgo21
    The first upgrade I would like is a better set of hyrdo's. The stock promax hornets are trashhhhh. I was thinking Hayes Stroker Ace's as they have a large 4 piston caliper and have pretty good reveiws.
    I don't know what size rotors you have, but at 300 lbs I would recommend 203's front and rear. That will help a lot. Make sure your fork is rated for a 203 though.

  15. #15
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    Quote Originally Posted by CaveGiant
    Hi,


    The ultimate panacea to this issue is the Chris King design. This uses a star ratchet system. instead of 4-6 pawls engaging, you have 72 points. the 72 points are linked, they all lock in or they all miss. Absolutely indestructible. After a year of use, it still looked brand new inside.

    do not confuse this with the DT Swiss ratchet, that was a lousy copy that is more fashionable than well designed. Do not waste your time on it.
    Wow, I guess I and all the others that have been running the DT Swiss hubs should replace them before they blow up. I have run the 240s hubs for 6 years with far less issues and maintenance than my chris kings. The kings have a faster engagement, but the design in the DT swiss works with the same principal. The Hope hubs are also very strong and reliable and not nearly as costly.
    Riding slowly since 1977.

  16. #16
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    nice

    you look at this at the wrong way . You made it to the top at the first time.. the glass half full..) i recommend strongly to upgrade this bike , i have the same one and the only thing i kept was the frame and the rims..i went with X0 crank, cassette, shifters, etc...i'm 240 and works fine..love this bike...

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