Anyone gone tubeless on their trials bikes?

[Ben Davies]

Apologies if this has already been covered...

I'm running an Alex DX32 rear and a Mavic EX721 front on my Hex and I run my tyres around 40-50 psi, I've been riding on and off since the late 90s but I haven't ridden properly for ages - maybe 5-6 years so I'm 'learning' some of the stuff I used to be able to do again/building up my confidence etc and was wondering... would tubeless be a good idea? No pinch flats, no annoying punctures... or would the sheer leaping around on a bike and having the odd dodgy landing cause the tyre to 'burp' and spill the sealant all over the place?

Obviously my rims don't have massive weight saving holes all the way round   as for tyre choice, at the mo I'm running Larsens, 2.35 DP rear and 2.0 SP front

thoughts/opinions/experiences?

Ta

From an old skool 'novice' 

[forteh]

Fatmike tried ghetto tubeless some 12 years ago on his trials bike, the front worked fine but the rear burped a lot of air; this was with non-tubeless ready tyres and home brew sealant at low trials pressures though.

With a decent sealant (I use oko magicmilk on my intense) and modern more airtight tyres I reckon it would work pretty well at the pressures you're looking at.  The biggest issue you might have is sealing the bead onto the rim, you're going to need an airline to blow them up and it might take a good while to get a solid seal.  If trials rims could be made with a ust compliant rim bead it would potentially make true tubeless wheelbuilds a possibility as the rim holes would be pretty easy to seal with correct width tape.

Build a tape cutting jig*, buy a roll of gorrilla tape, cut it to the external width of your rim and layer it up till you get a tight bead seal.  Blow the f**ker up and see if you can get it to hold air.  With ust bead it is super quick and easy, doing it ghetto can be very messy and can take a while to get right.  The intention with the tape is to have the edges just snug to the inside of the sidewall and build up the vertical height till the bead is wedged against the bead hook.

 

*I use a plank of wood with a stanley knife screwed onto it with the blade parallel to the plank and packers between the two to give the correct cut width.  Place the side of the roll onto the plank and simply rotate it round against the blade cutting to the right width as you go.

[ooo]

I bought a fourplay of a guy that ran it tubeless, the tyre pressure had to be quite high though. He said it worked for him, I ended up just running tubeless on the front and that worked pretty well. The main problem is it is difficult to run low pressures and fix on a ride. Not much benefit for all the hassle though. If you want to save weight drilled / lighter rims are probably easier.

[thinkdougie]

I've tried going tubeless but these try all k2 rims just let air out. No idea why... 

Edited March 10, 2016 by thinkdougie

[forteh]

I reckon you could run a holed rim tubeless with a bit of clever sealing strip and carefull application of the right adhesive

[CC12345678910]

I got it to work on my inspired using 4 rounds of quality, plyable ducttape (3m I think) to seal the rim, a halo combat, a 20inch tube cut down the central seam like you're filleting a fish (when stretched over the rim this is both a gasket and your tubeless valve) & the aforementioned OKO sealent thinned down with water. I built up the central section using hard foam between the rim and tubegasket and then fitted the tyre on top. At no point did I need a compressor, just used my donkeys old track pump. The only reason it didn't work is that is wasn't a tubeless ready tyre (a Schwalbe table top) and the air leaked through the weave of the sidewall, but aside from that I'd say I've got it down pat - the actual conversion/bead didn't leak a drop.

If I was on a hex I'd be getting some TLR tyres on there as fast as I could. If you've the skills/inclination I would say f**kin do it, for the few rides my tubeless worked the extra compliance and suppleness felt bloody mint. It took away the harshness of a 45psi+ front tyre, like letting pressure out would, but without any (more) tyre roll when it came to spins. And the increase on grip was nuts - I started doing 180 endos on curbs again trying to make it slip - didn't happen.

Edited March 11, 2016 by CC12345678910

[AndyT]

Four rolls of duck tape, foam, glue, whatever else you need to seal the rim weighs as much as a tube 

 

from  what I remember is tubeless doesn't exactly workout in the range of 16-23psi , what many trials people run. A high psi front tire for street could probably work

Edited March 12, 2016 by AndyT

[CC12345678910]

1 hour ago, AndyT said:

Four rolls of duck tape, foam, glue, whatever else you need to seal the rim weighs as much as a tube 

 

from  what I remember is tubeless doesn't exactly workout in the range of 16-23psi , what many trials people run. A high psi front tire for street could probably work

ROUNDS, as in you go round the rim from the valve back to the valve, then repeat 3 more times, not 4 full rolls of duct tape...

Yes, it did/does weigh the same as the tube that the conversion replaced, so no, there isn't any weight advantage, but you gain a 'feel' that probably can't quite be conveyed over the internet - it's kind of like the conforming and wrap-around-an-object feel of a Der Kaiser but without the harsh and jarring deadness. At the same time it's got the 'pop' of a soft rear mod tyre, but without the uncontrolled fast rebound that can fling you all over the place, it's just slightly slower, i'd describe it as 'bouncy but not scary'

I also see no reason lower pressures would burb either, as I said above my install on the inspired failed because of a not at all tubeless tyre w/ porous sidewalls, low TPI count and inconsisioncies in the plys, not my conversion leaking at the bead join.

Also worth noting that with tubeless I find that the pressure has to be increased to account for the sidewall now bearing all the weight, not having the thickness of the tube as a crutch. Surely this would only decrease the chance of burbing further? The OKO sealent also dries the a sticky glue like consistiency around the bead/rim/tubegasket.

I'm confident enough that I reckon I'll try it again when I get new tyres for the mod.

[AndyT]

Sounds like a mess for nothing, my kaiser isn't dead feelin. :dunno:

 

have fun fun with your experiments, maybe it will work out.