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POP!!! gose the Stan's Arch rim and Maxxis Crossmark.

AnonymousAnonymous Posts: 79,667
edited July 2010 in MTB workshop & tech
Had a interesting failure this evening.

My rear tire popped (as in BANG) of it's rim.

First the setup:

Stan's Arch rim (few weeks old, straight and true),
Maxxiss Crossmark, 2.1 folding tire,
Pumped up to 40PSI (the max pressure for that size of tire).
Running tubeless with Stan's fluid.

What happened:

I was off for a quick 20 mile road ride before it got too dark. After a few miles feeling warmed up was going pretty fast 18-20mph, and feeling a bit cocky I pulled a little bunny hop off a drop curb (was at the end of a cycle path, wasn't riding on the pavement) and whipped the back round slightly to ride away straight down the road , when I landed - HUGE BANG. stopped pretty quick looked down and the tire had completely come off one side of the rim and sprayed sealant everywhere.

I was shocked, gutted I couldn't finish my ride and pleased I was still quite close to home.

So it seems that a heavy rider (I weigh about 100Kg, I'm very tall, not that chunky) with tires pumped up hard and landing a small jump at a slight angle was enough to pop the tire off the rim, I'm quite surprised by this and a little disappointed as when I do a road ride I like to pump the tires up quite hard.

As far as I can tell there's no damage to the rim or tire, so I'll remount and run at a lower pressure and see what happens.

Wondering if there was anything I could have done wrong in the set up? Or perhaps I should swap the folding tire for a wired on. the wire in the bead adding a bit more strength?

I set the tubeless system up 2-3 weeks ago and it's been great, not lost any pressure or anything.

Any thoughts?

Posts

  • AnonymousAnonymous Posts: 79,667
    I had my front tyre do this in Coed y Brenin, on a fast left hand bend.
    Hence my love/hate affair with tubeless.
  • AnonymousAnonymous Posts: 79,667
    Yeah, I know where your coming from.

    I'm currently struggling to get the bloody thing to re-inflate now. Gone try again tomorrow.

    These bloody wheels and all the tubeless kit has cost a small fortune, you'd have thought they could at least do me the courtesy of sodding well working.
  • NorthwindNorthwind Posts: 14,675
    Assuming you're not using a UST tyre, you don't have much grounds to complain really, you're asking the tyre to do something it's not designed to do. It won't be the rim, unless something's badly wrong with it. Still, most quality tyres won't pop off like that, very surprised a crossmark would.
    Uncompromising extremist
  • SplottboySplottboy Posts: 3,695
    Thanks guys, new wheels being made up as we speak, yeah, tubeless...
  • AnonymousAnonymous Posts: 79,667
    Northwind wrote:
    Assuming you're not using a UST tyre, you don't have much grounds to complain really, you're asking the tyre to do something it's not designed to do. It won't be the rim, unless something's badly wrong with it. Still, most quality tyres won't pop off like that, very surprised a crossmark would.

    That's a very fair point, don't think there's anything wrong with the rim. I think it's a case of a heavy rider running at the highest recommend pressure putting a side ways force on a system I was already pushing by running at high pressure.

    I'm thinking along the lines of trying a different tire (wired, instead of folding), or perhaps even tubless isn't for me.

    Seems great to run low pressures, but may be not if you like running a higher pressure set up.
  • NorthwindNorthwind Posts: 14,675
    You could try a LUST Crossmark maybe? 40psi shouldn't really give it any bother but if the tyre was a little loose it all adds up
    Uncompromising extremist
  • richg1979richg1979 Posts: 1,087
    i poped a lust maxxis tyre off the front rim with 30lb in by riding along some off camber roots.

    cant beat good old tubes.
  • NorthwindNorthwind Posts: 14,675
    If it can happen with tubeless, it can happen with tubes, the failure mode's identical. You can roll a tubed tyre off a rim, done it myself.
    Uncompromising extremist
  • AnonymousAnonymous Posts: 79,667
    Northwind wrote:
    You could try a LUST Crossmark maybe? 40psi shouldn't really give it any bother but if the tyre was a little loose it all adds up

    Think I'll try a wired Crossmark first. Trying to keep weight to a minimum, I have a XC hardtail bike so the thought of putting a 700g tire on it scares me. :oops:
  • NorthwindNorthwind Posts: 14,675
    The LUST is that heavy? Right, that was s**t advice then, ignore that, a 700 gram crossmark is an exercise in failure. Can I have another go? Get a Small Block 8. i've been running 3 of them tubeless for most of a year without a burp or a wobble, on a Flow and on a Traversee (which is basically a ripped off Arch i think) with yellow tape on each. Total balls to seal in the first place mind, but once on it's stayed on. And it'll be faster than your Crossmark, a reasonable weight and give better grip and volume.

    But do bear in mind my first advice was s**t.
    Uncompromising extremist
  • AnonymousAnonymous Posts: 79,667
    Northwind wrote:
    The LUST is that heavy? Right, that was s**t advice then, ignore that, a 700 gram crossmark is an exercise in failure. Can I have another go? Get a Small Block 8. i've been running 3 of them tubeless for most of a year without a burp or a wobble, on a Flow and on a Traversee (which is basically a ripped off Arch i think) with yellow tape on each. Total balls to seal in the first place mind, but once on it's stayed on. And it'll be faster than your Crossmark, a reasonable weight and give better grip and volume.

    But do bear in mind my first advice was s**t.

    I have read good things about the 8 blocks, the reason I went for Crossmarks is because of the almost continuous centre ridge making them roll really quick on road and hard pack.

    Either way I think I need something a bit more manned up with a wire bead instead of folding.
  • AnonymousAnonymous Posts: 79,667
    I'm not sure if wire bead works well at all with tubeless. I certainly couldn't get a wire tyre to inflate at all.
  • NorthwindNorthwind Posts: 14,675
    I've always used folding bead for tubeless too.
    Uncompromising extremist
  • chedabobchedabob Posts: 1,133
    Glad I read this thread, because I was all ready to go tubeless, but now I've been seriously put off.
  • NorthwindNorthwind Posts: 14,675
    chedabob wrote:
    Glad I read this thread, because I was all ready to go tubeless, but now I've been seriously put off.

    If we start a thread "I use inner tubes and I got a puncture" would that help :wink: Yep, you can have some issues but it's the same with anything else, a loose fitting tyre can pull off the rim even with a tube. I gave up on "ghetto tubeless" as it was just hassle for me but proper tubeless with a rim designed for it, even with a standard tyre, has been fantastic for me, I could go back but I wouldn't choose to. Most people never have any serious issues.
    Uncompromising extremist
  • AnonymousAnonymous Posts: 79,667
    I'm not sure if wire bead works well at all with tubeless. I certainly couldn't get a wire tyre to inflate at all.

    Good point that was something I wanted to check, everyone/everywhere always says use a folding tyre, but no ones ever said *not* to use a wire bead. Just kinda thought a wire bead would be less likely to come off in the future.

    Maybe not such a good idea.
  • AnonymousAnonymous Posts: 79,667
    Unless you hear from someone who KNOWS a particular wire bead will work, I wouldn;t risk it. I tried using a High Roller, and it just wasn't going anywhere.

    A Kevlar bead will be just as strong, if not stronger (I was a cheapskate, so went wired).
  • AnonymousAnonymous Posts: 79,667
    Just trying to remount the old tyre now. Looks like a cut the side wall when it blew out somehow. Quite interesting, you can see the fluid trying to seal it and spitting fluid out, it just seems a little to big to seal.

    Was a pain to remount as well, real messy job.
    chedabob wrote:
    Glad I read this thread, because I was all ready to go tubeless, but now I've been seriously put off.

    I wouldn't be too put off, when it works it is really good. I'd heard people go on about the "tubeless feel" and had no idea what they were talking about, but really there is a diffrence, they even sound different, kind of 'pop and ping' over the rough stuff. It is worth a go.

    Also, I was running at the highest allowed pressure and I'm quite heavy. Most people quote one of the benefits of tubeless as being able to run lower pressures. If you do this I'm sure you won't see the problem I had.
  • AnonymousAnonymous Posts: 79,667
    Highest allowed pressure sounds like nonsense to me. I had to inflate my tyres to silly PSI to get them to seat properly.
  • AnonymousAnonymous Posts: 79,667
    I've been quite lucky in the sealing department, haven't even been using a inner tube first. I've just been pulling the bead tight to the edge best I can and pumping like mad for a few mins, then just spin them round/shake for 10-15 mins and they've been holding pressure very well.

    Had a nightmare last night trying to remount and reinflate, but that's cos it was so messy. Learnt you have to take the tyre off and clean out all the old muck and start again with everything clean.
  • AnonymousAnonymous Posts: 79,667
    I didn;t have any problems sealing them, really (apart from the wire bead which just didn;t work). I used a compressor with a large tank on it.
    But in order to get the tyre to "ping" into place properly, I usually had to go to about 80PSI or so.
  • AnonymousAnonymous Posts: 79,667
    Ahh, that's interesting, the crossmarks I was using were popping in around 20-30psi and maybe this is part of the reason the rear blew off - they just aren't sturdy enough and too elastic.

    If you were using more rigid tyres this would explain why you had to go to higher pressures and once on, were proably a lot stronger than mine. at 40psi the crossmarks really did look 'ballooned out'.
  • AnonymousAnonymous Posts: 79,667
    Ah, right.
    The front tyre did still blow off the rim on mine as well, mind!

    The reason it took such a high pressure to inflate could be because I was using the Stan's strips to adapt my ancient D321 rims. The tyre has to push really, REALLY hard against the rubber to seat fully with that particular setup.
    This is just conjecture, I've not used a proper tubeless rim, they might be the same, they might not.
  • chedabobchedabob Posts: 1,133
    What's the difference between a bog-standard rim and a UST one?
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