Hi

I currently have a set of mavic 521 rims with hope pro evo 2 hubs. I’d like to give tubeless a go, not to avoid punctures (not an issue for me as I have heavy duty tubes), but as I understand the grip is better and I like the idea of a lighter setup.

My plan is to buy a set of mavic crossmax XLs, I like the look of the new ones. The one thing that’s putting me off is all this burping that I hear of. Are people who run tubeless doing drops and jumps or is it only suitable for XC? I really don’t like the idea of doing a big drop then getting a sudden loss of pressure as I land, causing a face to ground moment.

The other thing that’s concerning me is that l like running 2.35 minions, which I see is not available in ust. I see from this forum that non ust minions are fine. But to people who run them tubeless, again do you get issues with burping on drops etc with a non-ust tyre?

Cheers

Been running tubeless for a couple of years now. I’ve never had them burping and I use regular Maxxis tyres, not UST. Not even Tubeless Ready. Plenty of sealant required to inflate and the stuff sticks around the bead which should help against burping.

I think it depends a lot on rim profile, tyre compatibility, weight of the rider and/or aggressiveness.

Those I’ve seen burping tyres have done it more with big tyres on skinny XC rims, but then also see it with people who are heavier than me and/or land big drops heavily, slam into corners hard, etc.

Tubeless is by no means just for xc.

Jump, drop, skid, wheelie, and even riding with no hands are all fine with tubeless. No different from a tube wheeled, assuming you’ve got a tubeless set up that works…!

There is a chance with some non-tubeless tyres they will burb. I found hi-rollers on my Flow EXs burped all the time so I had to put tubes back in. I took some minions to the alps this year and ran them tubeless, no problems at all!

I run non tubeless kore something or other on my DH bike. Set up with gorilla tape and stans valves, doing jumps and drops of a decent size with no worries.

I gave up tubeless on any of my bikes i hit proper jumps and stuff on, burped, and got ejected over the bars too many times.

I tried a whole host of tyre/rim/pressure combos, had to run 30+psi to avoid burping.

My xc bike is tubeless.

What worked best for me was actually wire bead minions. The size of stuff burping would occur is ~ 5ft+ drops to off camber landings or jumps you go in with a good bit of speed and again land off camber.

I have been running tubeless for 5 or 6 years on stans flow rims without a problem. However got some easton haven wheels this year and have had problems with burping, and am having to run at higher pressures than I normally would to prevent it.

I think it is partly the internal width of the rim, and partly the depth of the central channel, being a bit narrower it is a bit less stable then when the tyre does get moved because of the deep channel it just all lets go and totally deflates.

Personally I wouldn’t go for a mavic/easton ust wheel until they catch up with more modern designs and get wider and shallower.

Thanks for the help. I guess I could change the rims/get new wheels then always go back to tubes if I get problems.

MSP thanks for the warning re Easton/mavic. Out of interest has anyone tried a tubeless setup on the new crossmax XLs that I’m looking at?

On a related question, are new bikes coming tubeless these days? It’s really hard to tell from the reviews in some bike mags. Eg in Dirt they’ve reviewed several bikes recently that come with the Crossmax Enduro, but they make no mention of whether or not they’re running it tubeless for the review.

Personally I wouldn’t go for a mavic/easton ust wheel until they catch up with more modern designs and get wider and shallower.

This. Even speaking as a long time Mavic fan, the rims are too narrow and too deep to support wide tyres without tubes. Everyone else is way ahead of the game.

This is the best article I have read on the subject.

http://www.pinkbike.com/news/Tech-Tuesday–Wider-Rims-Are-Better-and-Why-Tubeless-Tires-Burp-.html

There is potential to burp any combination if you put enough force in the wrong direction ie side load the tyre, I’ve had a few issues around landing sideways and dropping into ruts on the sidewall. What I can’t tell you is what would have happened in that situation with a tube. On balance it’s a very good system.

Mavic x21 rims are 21mm internal width, same as a Crest/Arch with the Flow only being 22.5mm.

There are a bunch of other wide options out there though heading up to 30mm.

As for out the box tubeless it really depends but if you order something with Tubeless Ready it should be easy enough to set up, it may come with tape/valves/sealant etc. It depends on the supplier though.

Mavic x21 rims are 21mm internal width, same as a Crest/Arch with the Flow only being 22.5mm.

Flow are 25.5 internal, crest/arch are xc rims I wouldn’t run them with 2.35 minions as in the op.

my mistake it’s in tiny writing on the drawing on the website. I know heaps of people running 2.35 tyres on 21mm rims with no issues.

if you’re just looking for a reason to buy new wheels it’s not a bad one. otherwise just do the ghetto thing. schwalbe tubes, whatever tyres you want, stans spaff.
a lot of people run very low pressures with tubeless. some run in to bother and others don’t. i just run my normal pressures and enjoy lighter wheels. is grip better? maybe. rather subjective though.

The pro DHers use tubes. Read into that what you will.

I run Spesh Purgatory on Flow EX rims and I burp air from time to time. I’m no mincer but I’m nearer the mince end of the spectrum than the gnar.

Flow ex on 2.3 TR minions. No burps and ride pretty hard. 15ft gaps etc. run 20 in each tyre as well for extra extra grip…

tubeless is a game changer…

The pro DHers use tubes. Read into that what you will.

and the Pro EWS guys are tubeless?
http://www.bikemag.com/blog/feature-jared-graves-ews-3-rider-journal/
I thought there was a mix, especially with the dual chamber thing coming along.

tubeless is a game changer…

Of all the technological improvements I’ve adopted since I began mountain biking – indexed gears, geometry, (decent) suspension, disc brakes, dropper posts – tubeless tyres is the one that has left me the most underwhelmed. Granted where I ride I never really suffer badly from punctures with tubes.

no punctures
better grip
much lighter rotating mass
don’t need a backpack on most rides because no need to carry tube and pump.

game changer for me..I run all 3 bikes tubeless

Tubeless all the way for XC/AM riding.

Still on tubes for my 180mm shred sled though. Tried riding it fast with Exo tubeless tyres last week and burped the front quite bad, then holed the rear.

Intrigued by the possibility of running 2-ply tyres tubeless, might give it a go soon.

chapa, I ran 2ply 2.5 minions in the alps for 2 weeks this summer. no problems at 17 psi! amazing grip on my Mega AM fully coiled up.

It’s all a matter of luck with your tyre/rim combo.

Took a while , but for me it’s Geax/Dt Swiss , bullet proof for a 16 stone rider!

Have to agree tubeless has been a game changer in terms of ride quality , grip & reliability , best thing since hydraulic disk brakes for me !

chapa, I ran 2ply 2.5 minions in the alps for 2 weeks this summer. no problems at 17 psi! amazing grip on my Mega AM fully coiled up.

OK I’m sold, will give it a whirl.

Interesting how for some tubeless is a game changer. I only went tubeless when I got a new bike, so I suppose I didn’t have a very fair before/after comparison. Maybe it is a game changer and I’ve always assumed it was the new bike that was ace 😆

I find it most amazing holding lines on rooty off camber lines sections. just seems easier to keep the line..almost like it molds to the ground!

There’s a fair few DH pros tubeless now isn’t there? I didn’t see a tube getting wrapped up in Gwinns back tyre. That said I didn’t see any sealant either, guess that’s the joy of proper UST.

much lighter rotating mass

no cos the tyre is heavier for a decent non-flexi sidewall.

no punctures

nope. still get them. just i get covered in white jizz trying to fix the basterd things. also see above to stop cuts you need a heavy tyre. yes a tube will puncture if you get a cut but there is no mess.

better grip

hmmmm… not sure on this one. are you just running a better tyre?

still – nearly getting one out of three isnt too bad i guess. i like the idea of tubless and when its working i feel smug and happy but when it goes wrong or i need to put a new tyre on i **** hate it.

still – nearly getting one out of three isnt too bad i guess. i like the idea of tubless and when its working i feel smug and happy but when it goes wrong or i need to put a new tyre on i **** hate it.

Yeah but the number of flats has dropped so far that it’s not really an issue for me at least. Running the same tyres as if I had tubes and the rest is really the whatever.

MSP – Member

Flow are 25.5 internal, crest/arch are xc rims I wouldn’t run them with 2.35 minions as in the op.

I would- the Crest and Arch are still wide for XC rims, Mavic rate their much narrower 717 for up to a 2.3 tyre. And the 2.35 Minion isn’t a 2.35, it’s more like 2.15.

Wrong Van Halen

I use Minion TR 2.3 exo DHF and DHR 2 which is the same weight as the old 2.35 at 820 grams..take the tube out of the equation and its much lighter…

They are bigger volume tyres for the same weight

never punctured…tyre once went down overnight but the sealant had dried out so just put in some more…

they go up with track pump and no soapy water …

your doing something wrong..

For me I’m fine to put up with the odd loss of pressure/burping. What I don’t want to happen is to cause myself a nasty injury whilst doing a gap or drop! That said I think a 15 foot gap is a bit beyond me…