Faulty Maxxis Tyre or Crest Rim?

bobgfish
bobgfish Posts: 545
edited March 2012 in MTB workshop & tech
Hello

Brought some Hope hoops with Crest rims not so long ago and fitted a Maxis 2.1 Aspen with Stans no Tubes. I brought it out of the garage a few weeks ago and it was flat so added some air up to about 40 PSI. Put the tyre down and it went bang and tyre was sitting in one spot and wheel in another. I had not ridden the wheel and tyre at this point.

Checked the tyre and rIm and both looked fine. So refitted and predictably enough it went bang and blew off the rim in the first 50 metres of riding. Managed to graze up the rim on both edges on the road whislt I stopped.

I made sure that the tyre was seated properly on the rim and it had pinged into postion correctly.

So dodgy tyre? Send it back and get a replacement? or just a tyre that is not good for tubeless? Anyone else had issues with Maxxis on Crest rims (espically Aspen). Currently fitted a Monorail and a Crossmark but not ridden yet. Hoping the Aspen tyre is a one off becuase I don't fancy this happening at speed on or off road.
CyclingInTheLowMountainsOfSchweiz

CyclingInTheFlatlands

Comments

  • bobgfish
    bobgfish Posts: 545
    No one? Thought it would be a fairly common Tyre and Rim?
    CyclingInTheLowMountainsOfSchweiz

    CyclingInTheFlatlands
  • DHA987S
    DHA987S Posts: 284
    40psi tubless seems pretty high, more than likely the bead is faulty or it's not designed to be run tubeless. I use UST maxxis medusas on my crests in the winter and they run fine, tubeless ready schwalbes on there now.
  • bobgfish
    bobgfish Posts: 545
    The tyre says 35-65PSi on it. It's not the UST version but is an Exception series one.

    Not read any bad comments using Maxxis tyres with Crest Rims but getting nervous.

    I've got 7 weeks till a big race and can't afford the time loss if this happens...
    CyclingInTheLowMountainsOfSchweiz

    CyclingInTheFlatlands
  • DHA987S
    DHA987S Posts: 284
    Those pressures are for tubes, are you running tubes or tubeless on the crest rim?

    Stans rims have the recommendation of weight in pounds divided by 7, then take one off for the front and add two for the rear. You might need to play around a few psi either way to get the best from the tyre in question
  • bobgfish
    bobgfish Posts: 545
    That being the case I need about 25PSI. But that would be way to soft. I like them a bit firmer than that. Think I'll return the tyre and get a replacement and see what happens.
    CyclingInTheLowMountainsOfSchweiz

    CyclingInTheFlatlands
  • mherbie
    mherbie Posts: 16
    I run 40+ psi no problem with Maxxis and Crests tubeless, doubtful it's pressure issue, is the tyre new or used, if used the the bead could of stretched?
  • bobgfish
    bobgfish Posts: 545
    Went out for a 45 Km blast today with a Monorail on the front and a Crossmark on the back. Both 2.1 and both eXception series and are not UST specific tyres. Ran about 22 Psi on the front and 27 Psi on the back and also running tubeless. Both flawless and gave no issues. So either to much pressure in the Aspen or a faulty tyre I guess. Still going to send it back for a replacement...The Aspen was brand new and only done 50 Metres outside my house.
    CyclingInTheLowMountainsOfSchweiz

    CyclingInTheFlatlands
  • hoots
    hoots Posts: 134
    I had a Minion DHF blow off a Crest (26") rim when I was inflating it tubeless - I think it blew at about 30 to 35psi. I tried again (a bit more gingerly with the track pump) and it seated and inflated fine, although I only took it up to about 25-28psi. TBH, I was a bit apprehensive for the first ride, but have ridden the bike down some proper rocky & steppy routes in the Peak District and they've been OK.

    I also run Crest & Maxxis (Beavers!) on my 29er hardtail and they've been OK. The bike came with Aspens, but the trails have been too soggy to try 'em yet. I'll give you an update when I try 'em (I might be a bit careful with the track pump tho!).

    FWIW, I'm 90kg with full riding gear on and rarely find the need to run pressures of over 34psi tubeless, in fact most of the time in the Peak, I'm running 24-28psi rear and 20-24psi front. I think at 40+psi, you're not really going to get the full grip advantage of running tubeless.
  • jairaj
    jairaj Posts: 3,009
    Have a look at the documentation on the Stans website. They don't recommend pressures above 40 psi.

    I've had good experiences using Maxis folding bead tyres with Stans crest rims (ie on UST tyres).

    Although I too have blown a tyre off the rim when fitting because I pumped it up to 60+ psi. But that was only to help get it seated correctly.

    In normal operation I use pressures around 30 psi give or take a few psi and have never had any problems during a ride as yet. Been riding tubeless for almost 2 years now.

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