AM/Enduro rear tyre solution for my Reign...

[Headshot]

I have a front wheel solution - its a HD Super Gravity - wide, stiff and grippy. The back tyre is still a problem. I am currently running a Purgatory 2.3 tubless at the back on DT E540 rims.

 

Its a lot better than the Nobby Nic but not really up to being pushed really hard into corners and off drops. I pumped it pretty hard before descending on my ride yesterday but it ended up trying to burp off my rim and eventually lost 50% of its air with sealant everywhere.

 

Seems to me that it cant stay on the rim properly when landing drops on the back wheel or pushed hard through berms or on off camber fast descents like Vasbyt at Tokai. Its as if the tyre grips the ground better than the rim and tries to come off the wheel.

 

I never had this kind of problem with my XT UST rims and Maxxis UST tyres which seated in the rim groove with a pop.

 

So, is it the rim not holding the tyre on properly or the flimsy bead or sidewall of the Purgatory?

 

I have been advised to try the Purgatory on the front and the HD at the back, but I love the HD where it is.

 

I have also read that the Minion DHF works a treat as a back tyre - anyone know where to get one and which model would be best as a tubeless set up - UST presumably?

[Captain Fastbastard Mayhem]

Minion DHF UST Super Tacky - http://www.chainreactioncycles.com/Models.aspx?ModelID=9413

[Capricorn]

I'll bet its due to a non-UST rim. Technically, if the sidewall is stiff enough, you can have a beadless rim and the tyre will hold. Look at car wheels and tyres.

 

But since we dont have ultra stiff sidewalls, the rim bead needs to do the job of holding the tyre on under serious loads. Pumping it hard is not always the best solution as it introduces handling issues.

 

Checked on the web quix, and from what i've managed to squizz through, these rims are not UST compatible. They can be made tubeless compatible with the DT Swiss TL kit, but that's not UST bead compliant when it comes to not ripping the tyre from the rim.

[Hairy]

Headshot, just take that Purgatory off and give it to me

[Headshot]

Cap, thats interesting - could well be the case, then again, the Purgatory is not a proper UST tyre so the fact that it burps does not really prove its the rim, no? I see a Maxxis UST tyre at the back as a test in the near furture... or maybe some second hand Easton UST rims...

[Capricorn]

Cap, thats interesting - could well be the case, then again, the Purgatory is not a proper UST tyre so the fact that it burps does not really prove its the rim, no? I see a Maxxis UST tyre at the back as a test in the near furture... or maybe some second hand Easton UST rims...

 

I have a Hans D EVO SS pacestar on my trail bike that uses Giant rims (non-UST), which i've converted to TL. I burped that sucker to flat spraying stans like an exploded geyser. I've never done that with other Schwalbe tyres on my Deemax or Crossmax rims, and those are fully UST compatible. It's definitely because of the rim.

 

So what I'm saying is, that a non UST rim + non UST/TLR tyre is a burpfest waiting to happen. UST was designed not only to prevent the use of tubes, but also to ensure the bead stays on the rim.

Edited July 15, 2013 by Capricorn

[Headshot]

An interesting summary of the Tl/R v UST tech out there...

 

http://www.bicycling.com/mountainbikecom/bikes-gear/pssssst