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Crossmark and Larson on Mavic 819??


jpack's picture

By jpack - Posted on 20 May 2010

I want to mount a folding bead Crossmark 2.1 and a folding bead Larson 2.0 on my Mavic 819s WITHOUT tubes.

Has anyone tried this combo? Does it work with the non-UST tyres?

Obviously, i'll use a bit of stans.

thanks

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Rob's picture

I put a Monorail front and Larsen rear on the Yeti's 819 rims for the Rotorua trip. They go on but are really right so be patient. A good thing with the tightness was that they air up instantly even with a hand pump.

New Tyres

GAZZA's picture

they're ust! The question was about normal tires.

nh's picture

If have a larsen and crossmark on 819s at the moment but they are both UST. I tried to mount the original crossmark exceptions without tubes and destroyed then in one ride. I guess you are asking about the tyres in between these two so I am not sure. If it works let us know.

hawkeye's picture

... but you need Stan's or similar to seal, and plenty of concentrated soapy water + a source of compressed air to get them to bead up.

I've done both those tyres (folding bead non-UST) on Mavic Crossland rims. A bit of a hassle to bead up with a servo air pump, but I got it done. If you have your own or a mates compressor, it's a lot easier, as being limited ot 60psi on those horrible automated things they have at Coles Express and Wollies servos don't really give you the volume of air you need.

A home compressor at about 80psi works well. No issues with blowing off the rim to date with that pressure (it's only in the tyre for a few minutes), but I still wear safety glasses just in case.

Rob's picture

Talking of compressors, I've been toying with the idea of putting an air hose outlet and simple schrader valve input into the top of an old gas cylinder.

Reading around there are no safety concerns over the pressure these containers are good for easily 200psi of air and you'd only really ever need around 125PSI for tyre inflation. 4WD people seem to use them - they fill the gas tank with compressed air at a servo, go for a drive on the beach (where they let the tyres down for traction) then when done, use the tank to inflate their tyres.

For a bike rider with UST tyres, it's not the absolute volume that sometimes makes getting tubeless to seal a pain, but the very short period of time you need to stuff that air in. With an air tank one could pressurise it with standard foot pump (or even one of those dodgy automatic systems at most servos now) and then use this large reservoir of air to blast into your tyre at high volume.

Well - it's a theory - anyone tried this?

There's a couple of threads on Instructables about this, BTW:

http://www.instructables.com/id/In-line-portable...
http://www.instructables.com/id/Propane-Tank-int...

arghvee's picture

I've done the crossmark non-ust with stans. I had a large are bubble after about 9 months and 2 stans top ups. A bit of investigation showed that latex can get into a layer of the tyre and cause this bubbling (making the tyre unusable). Doesnt happen to all and if so takes some time, but you should be aware. Otherwise it was fine.

Glen's picture

I had the samething happen with a crossmark after 8mths, took it back to the shop and they replaced it under warranty, still doesn't help if the tyre bursts into a long ride though.

jpack's picture

just noticed my Larsen has a nice big gash in the sidewall.
Got to get a new tyre ASAP.

Am i better off going for a foldable bead or wire bead if i want to mount a NON-UST tyre with some sealant?

barney's picture

I always run a LUST Larsen on the rear and alternate between Ignitor and Crossmark (both LUST) on the front. In my opinion they are worth the investment for LUST as for me it has proven a reliable, low maintenance set up. I tried running non-UST for a while but they were unreliable (burping and loosing air fast). The extra weight saving from non-UST was not worth the extra maintenance.

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