1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
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2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
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  1. #1
    mtbr member
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    How to adjust air pressure in Marzocchi Dirt Jumper...

    I have a 2009 Kona Hoss with a Marzocchi Dirt Jumper fork, want to properly set the air pressure for my weight (200 lbs) I know how to do it, just need help determining the psi for my weight. Looking at the owners manual online I am confused on the psi, this is what it states...

    Air pressure - Rider’s weight
    > 90 Kg > 90 Kg
    > 200 lbs > 200 lbs

    bar psi
    2,5 ÷ 3,5 37 ÷ 52

    How do I turn this into what psi I need to set the fork to??? HELP!

    Thanks in advance!
    Last edited by harm; 04-08-2010 at 10:28 PM.
    Rueben

  2. #2
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    i'm reading that as between 37 and 52 PSI for someone over 200 lbs.. I'd start in the middle, If it feels too squishy, add more air. Too Firm, take some air out.

    There's no magic number, just what feels right and doesn't bottom out.

  3. #3
    mtbr member
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    Quote Originally Posted by jay80424
    i'm reading that as between 37 and 52 PSI for someone over 200 lbs.. I'd start in the middle, If it feels too squishy, add more air. Too Firm, take some air out.

    There's no magic number, just what feels right and doesn't bottom out.
    I dont know how to read their instructions, I thought 37 ÷ 52 meant to divide these numbers to come up with the number for my weight
    Rueben

  4. #4
    Underskilled
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    Just try and get sag right, the suggested numbers are rarely good as different frames have different weight distribution.

  5. #5
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    Quote Originally Posted by harm
    I have a 2009 Kona Hoss with a Marzocchi Dirt Jumper fork, want to properly set the air pressure for my weight (200 lbs) I know how to do it, just need help determining the psi for my weight. Looking at the owners manual online I am confused on the psi, this is what it states...

    Air pressure - Rider’s weight
    > 90 Kg > 90 Kg
    > 200 lbs > 200 lbs

    bar psi
    2,5 ÷ 3,5 37 ÷ 52

    How do I turn this into what psi I need to set the fork to??? HELP!

    Thanks in advance!
    Hey im trying to do this to my Dirt Jumper fork 2 as well but im not sure how to pump it up.. Any ideas?

  6. #6
    Fat-tired Roadie
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    Do you have a shock pump? If you don't, this task will be difficult or impossible.

    "Don't buy upgrades; ride up grades." -Eddy Merckx

  7. #7
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    No i do not so any pump really?

  8. #8
    Fat-tired Roadie
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    No. You need a shock pump. Your LBS can hook you up. It should have a hose with a threaded metal thing on the end and a gauge.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  9. #9
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    I just used the air compressor at the local garage shocks are much more stiff which i wanted and can handle my weight when i jump. Cheers. How much PSI is recommend tho?

    Thanks for answering my questions.

  10. #10
    Fat-tired Roadie
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    I've got no idea what the recommended PSI numbers are for that fork, although you might find it on the web site.

    Most riders do it by setting sag. When you sit on the bike, the suspension fork sags some. Most riders and suspension companies recommend 15-25% sag depending on what you want out of the fork - more sag for DH, less for XC. I think people use less for dirt jumping too, but it's not really my thing.

    If the fork has any kind of compression damper or lockout, set it on fully open and let the pressure out. Push the fork all the way into its travel. That's how much travel your fork has. It's probably within a few mm of what it's rated as having; if it's drastically different, you may have a problem. That's how much travel you have. Now pump it up some of the way, put a zip tie on the stanchion right next to the seal, and sit on the bike. Get off the bike. If the zip tie traveled up by more than 25% of your fork's travel, the pressure's too low. If it didn't sag much, it's too high. Once you've got it roughed in, set your dampers back to how you like them and take your shock pump with you on a few rides. If the ride's too harsh, you can try letting out some air. If it bottoms out a lot, try adding some air.

    I like my fork at the lowest pressure that doesn't bottom out or nosedive. It's totally a preference thing, though.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  11. #11
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    Hmmm yes I got my pretty stiff which is what i want when i do my jumps. Thing is it's 100mm fork and it goes over half way just doing 3 Foot Drop.

    Thanks.

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