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729 or 721 ????

Discussion in 'Downhill & Freeride' started by Biffff, Oct 6, 2008.

  1. Biffff

    Biffff Monkey

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    I've been running 729's for the past 3 seasons, and just this year I've managed to to put some flat spots in them...
    They've been great hoops for sure. Here's the deal: Is it worth it to shave 200 grams (for 2 rims) to go with 721's ???? Are they as tough as 729's?
    I'll probably replace my old 729's this winter (unless I can pound the flat spots out), and I'm always up for dropping weight, but I don't want to loose much reliability.

    cheers
     
    #1 -   Oct 6, 2008

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  2. mccdh

    mccdh Monkey

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    The 721s look killer so there is a bonus reason to run them. Although I don't run either of the two rims I can bet they aren't as indestructible as your 729s. But since you have ridden 3 seasons on them and finally now have noticeable damage I think you could expect 2 seasons out of 721s (guessing) depending on your riding style/terrain. Question for you is, what is more important..the reliability and trust you have with the 729s or the 100gram savings of the 721s. I know some very talented guys who run 721s and go through one rim per season of mild racing mixed in with some resort riding. With that being said they do work in a shop, where parts and pieces come cheaper, and the work does not need to be paid for. I think it depends how hard you ride and how rough the riding is. Other than that I think they will both do well.
     
    #2 -   Oct 6, 2008
  3. big cal

    big cal Monkey

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    I run 721's and they are a super tough rim, they may cop a few more obvious dings because of the rim brake profile, but they are tough. My back wheel is 3 years old, has dings all over it but still spins straight and true enough for me. I should replace it but i just bend the dings back and keep rollin... It's the best place on your bike to save weight, just keep the pressure up to stop dings.

    Also the skinnier rim makes for more 'rounded' tire profile, which i like.
     
    #3 -   Oct 6, 2008
  4. dexter

    dexter Turbo Monkey

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    i have a set of d521's (old 721's) that are well over 4-5 years old and have been through 4-5 bikes and been laced up 2 different time that are still kicking. by far the best rims ever
     
    #4 -   Oct 7, 2008
  5. William42

    William42 fork ways

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    Fixed
     
    #5 -   Oct 7, 2008
  6. kuksul08

    kuksul08 Monkey

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    How did you manage to dent the 729's? Pretty much all I ride is rocks and mine are still perfectly true.

    Either way I'd say get the reliable ones again :)
     
    #6 -   Oct 7, 2008
  7. mccdh

    mccdh Monkey

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    ok so i dragged on. :clapping: thanks for pointing it out
     
    #7 -   Oct 7, 2008
  8. no skid marks

    no skid marks Monkey

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    Try running lower than 60psi and you might be able to go fast enough to bottom out the tyre.

    721s(521) are generally concidered more dent resistant due to the vertical side walls(canti breaking surface)than 729s(321).
    I'm not sure what makes for the stronger wheel, the 729s have double eyelets and possibly don't fracture as easy.
    721 gives a rounder profile, making turning slightly faster and more predictable, the squarer profile will give the 729 tyre a bit more cornering bite at a certain angle, but less feel for when it's going to let go. For Maxxis 2.5 tyres, a 721 is plenty wide enough, and weight , and side wall strength are the main gains. Also the wider the rim, the less roll the tyre will get as it has a better footing, but both these character differences are so small they'd not be noticeable to an average rider that they're virtually just theoretical. My pick is 721 out of those two for weight and tyre profile, but that's my second choice after 823s(tubless rim).
     
    #8 -   Oct 7, 2008
    Last edited: Oct 7, 2008
  9. Biffff

    Biffff Monkey

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    I put a good sized ding in my front rim last night. blind 5 foot drop into a steep chute/rock infested area, bad line choice put my front wheel right into a massive rock.......the bike stopped and I went flying. The only carnage between myself and the bike was the ding in the front rim. Yet the rim is perfectly true and my Minion DHF did not flat.......very impressive. I run about 22 PSI, I can't imagine running hard tires for DH.
    I'll try and get the dings out, and I might give the 721's a try.
     
    #9 -   Oct 7, 2008
  10. PepperJester

    PepperJester Monkey

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    What there was a ride last night? I must be off the call list :(

    I think you'd be fine with a 721 Dave.
     
  11. DirtBag

    DirtBag Monkey

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    Running 721 on my DJ and FR bikes. I really like the added feature of the way the tire sits in the rim. I never noticed it before until I said to myself that "the tires just seem to grab better" than my last set of rims. Then I noticed the profile compared to a friends 729 using the same tire.

    I have had zero problems with the rims. No dents or dings really. They stay true very well and I like the lighter weight.