Looking at a new Orange, and very tempted by the option to upgrade to the Mavic XM819 UST rims. Not had tubeless before, but I've heard more about systems like Stans/No-Tubes (airtight rimstrip plus sealant) than UST. Is this because UST isn't so popular, for some reason? Or does non-UST tubeless generate more problems and therefore more feedback on STW?

And the XM819 rim- looks a bit heavier than some of Stans offerings- is it a decent strength rim, or just too heavy for an XC rim?!!

If you want to run UST tyres then UST rims are unbeatable. If you want to run non-UST tyres, converted to tubeless then a Stan's rim is the way forward, the bead will retreat into the well of a UST rim, so you end up having to 'fill' it with some draught excluder strip or sommat!

They're also a bugger to build on, but if you're not doing that, who cares! Heavier than Stan's too. They're meant to be pretty tough, but they're not that wide. Personally, Stan's all the way for me, Alpine or Crest rims if you're light, Flow or Arch if you're not/want to run wider tyres.

819s are tough – mine survived the Mega fine and I weigh 16 odd stone. I got Stan's rims since which are much easier to inflate tubelessly ime (with tubeless or non-tubeless tyres), but I've not tried them in anger yet.

I've a couple of sets of wheels with XM819's, and while not as light as the Stans rims (which TBH if I was buying a new set I'd go Hope Hoops on 355's), they are strong (enough) and less hassle than a Stans' kitted normal rim and I guess a bit less hassle than Stans' rims.

I've run them with UST, normal and tubeless ready tyres – all with sealant – and no problems at all. Just make sure you buy the Mavic 'removable' core valves, as they also make 'non-removable' core valves…

I would definitely dispute their being less hassle than a Stan's rim, unless you're running UST tyres.

For non-UST Stan's rims are unbeatable.

819 are a bit heavy I guess, but with a generic 20mm front and a hope xc rear I still managed to build a 1800g wheelset which if you're racing is loads but in the real world makes no real difference. Narrow? I can run 2.4 mountain kings on them happily which is as wide a xc tyre as you'd ever need. They are a bit of a PITA to build though as you can't use a driver, and you need the extra mavic tool. But like most mavic rims they're pretty round and straight from the factory so the build is straightforward. Can't make any comment on Stans as I've never built one, sorry

I would definitely dispute their being less hassle than a Stan's rim, unless you're running UST tyres.

I agree – and I own both. Any tyre I've tried so far inflates really easily on the Stan's rims – def easier than the 819s.

I've run both UST & non-UST on my 819's without a problem & they're still completely straight after 2 years of my ham-fisted approach to mtbing. Not the lightest out there but a decent strength to weight ratio.

IIRC 819s are 475gm + 75gm for ferrules – (latter "wasted weight") and its claimed that the lack of drliings in the inner wall adds strength.

So they are heavier but they seem pretty burly. I have both olympics and 819s, would probs echo njee20's comments on non ust tyres.

got both 819s and stans flows

819s stay straighter, and UST tyres go up like a dream.
Flows for choice of tyre and potential losing rag moment trying to get tyres to inflate

I also have a couple of sets of 823s and they are burly. Rode for a week in the alps once with 2 missing spokes in the rear and its still true. Heavy as though.

My 240s hubbed set are 1750g and the Hope Pro11 set are a bit heavier as when I went to see them he'd 'forgotten' to mention that by mistake he'd ordered V-brake rims on disc hubs… but I got the price so no probs.

Both bought s/h.

So 819s are nice and strong, maybe a bit heavy (nice of Mavic to quote the rim weight, but not the ferrules- as if you can do without them!), great with UST tyres, OK-ish with other tyres.

Stans good for width/tyre spread, and more general tyre compatability, maybe not so strong, or so round from the factory.

I'll have a word with the Orange dealer to see what they can do- I'm leaning towards some Stans Arch/355 at the moment. Tyre width and choice definitely important. Expensive UST tyres not that appealing. Can put up with inflation issues, I guess (famous last words…)

So, are 819s okay with 2.35 High Rollers? 2.25 Ralphs?

I've used 819s with 2.5 High Rollers ghetto tubeless and they were fine.

i have 2.35 high rollers on one bike and 2.25 NN/RR on another, both running 819 rims and been fine.

*cough* 819s you say? *cough*

Personally I wouldn't use 2.5s with 819s. The tyre profile is horrible, looks like a bubble and squirms around on the rim.
2.3s ok though

Personally I wouldn't use 2.5s with 819s. The tyre profile is horrible, looks like a bubble and squirms around on the rim.

I did the Mega on them, running ghetto tubeless, and they never burped at all, so they can't have squirmed around that much. 😛

2.5 Diesel on my 819.

I have two sets of 819 rimmed wheel and one with Stan's. Whilst the Stan's made for a lighter wheel set, I'd go for 819's if it were my choice. Absolutely bomb proof and much easier to inflate than the Stan's system, unless you happen to have easy access to a compressor.

i've had 819s for 4 years and Olympics for a year. 819s are very strong but they are heavy and really suited (IMO) for someone wanting a bomb proof xc wheel, something freeride lite or a fat ba$tard or a bit of all three. UST tyres easier to fit but cost more, weigh more and less choice. Thicker side walls have some advantage though.

Olympics are lovely and light with all the advantages that go with less rotating weight but harder to inflate, weaker (presumably but not bent yet but then I am a light jey).

Having had both I would choose Stans for wider choice of lighter tyres.

i got xt on 819's and just got some crest's on ztr.
Now i've not had the crest long enough to offer a solid comparison but initial impressions are good.
they are much lighter, infact with rotors and cassette they are still lighter than xt and 819.
819 stay very true though on comp spokes and are fairly bomb proof, they arnt as wide as the crest but the 819 sidewalls are considerbly thicker and i would have to say they appear stronger
no need to faf with tape on the 819' and you dont need draft excluder to fill the gap on the 819 though its recommended.

both sets work well with non ust tyres, currently monorails or ralphs

as I said. I wouldn't use 2.5s on an 819. I like a nice square edge profile to my tyre.

cheers

If you're gonna do a job do it properly.

So UST rims and UST tyres = better than any bodged up system

Pete
Proper tubeless since 2001

I've 2 sets of 819 and just got rid of some crossmax sx & 823's. The crossmax were great for getting normal, i.e. non-ust tyres to inflate and seat using a car foot pump initially, whereas I just can't normal tyres to inflate on 819's – ust/tubeless ready are a doddle.

I got rid of the burlier rims because 819's are so strong.

i've replaced mavic 819s with stan 355.

Mavic 819 is stronger and stiffer, but at 200g per wheel heavier its not really worth it for me. 355 is *slightly* flexy but much much lighter.

no problems inflating with either with proper tubeless tyres.

Just bought a pair of WTB rims cheaply and planning to do the yellow tape + valve thing to get a cheapo pair of tubeless wheels without the faff of the inner tube ghetto thing.