Tubes or tubeless?

tsalway

Might sound like a stupid question, but i've got a 2006 Kona dawg Supreme with Nokian nbx 2.3's on, cant find anything to say whether i'm running tubeless or with tubes?
Is there an obvious way to tell?

BikerDan

No real obv way. Just take the tyre off and see what happens.

justrideallday

should say on the tries.

it will have somehting like 'ust tubless' on them if they are. If you do take them off and they are tubless you will need a track pump to put them back on and maybe more sealant.

Hope this helps.

dixonpj

Won't the valves be a give away? If they're screwed to the rims, you're running tubeless.

Splasher

dixonpj wrote:

Won't the valves be a give away? If they're screwed to the rims, you're running tubeless.

All presta valves are "screwed to the rims".

It's highly unlikely you are tubeless on stock Kona equipment.

prophet_1000

Not All Presta are screwed to the rims, some are free floating if they are after market cheapo's, But you are right Splasher, from the factory bikes come with Screwed presta valves!
The presta valves on my Mavic XM819's are held tight to the rim via a knurled threaded lockring and have only a small portion of thread (1/16") protruding out of the lockring then its smooth for about 5/8" of the rest of the valve, where as the Presta vales on tubes are usually a bit longer and threaded there entire length.

However, The presta valves on the 2006 Dawg supreme do look like tubed valves and as Splasher says do screw to the rim, I've tried to look on the net for a side view of the UST version of a Nokian NBX tyre but they all show a tread pattern view!!!

Looking at a zoomed view of the tyres fitted to the Dawg and there is no sign of Tubeless or UST which most Tyre manufacturers usually wanna show off in a BLING kinda way.

Hope this helps?

Chaka Ping

Have you had the bike from new or is it secondhand?

If it's new, I think the manufacturer would be unlikely to supply the bike new with tubeless already set up.

For example, my Anthem came with UST tyres and rims - but with inner tubes in place.

daniel_b

Dumbass question:

What is the theory behind tubeless tyres - how does it help?

Am I correct in thinking you seal the typre to the rim, and as you make it airtight, there is no longer the need for a tube?

What is the advantage though, will a thorn going through the tyre still give you a puncture?

Dan

cjw

From here http://www.xcracer.com/content.php?pid=2249

You don't really need to 'do' anything to seal the syre to the rim. Tubeless rim and the tyre bead should seal themselves. And you are correct, there is no longer need for a tube.

1. Less punctures.
You're not going to win the race if you puncture. Running tubeless tyres means you eliminate pinch flats where the inner tube gets pinched between the tyre and the rim under a big impact, cutting a hole in the tube. You can still get punctures from thorns and nails but a dash of latex sealant will solve that easily. The one type of puncture tubeless tyres don't handle well is cuts from sharp rocks, especially in the sidewall which is why it's important to choose tyres carefully. You need a tough, preferably rubbery sidewall; stay away from the sub-400g Continental Supersonics even though it's tempting.

2. More grip.
Getting rid of the inner tube means a more flexible tyre. When the tyre and tube are in contact, especially if you haven't coated them in talcum powder, they act as one big thickness of rubber and as any engineer will tell you, stiffness is very strongly affected by thickness - so a small increase in thickness makes a big difference to how flexible the tyre is. In the real world this means that losing the tube makes a very noticeable increase in grip both from traction and even more importantly, cornering.

3. Lower rolling resistance.
Rolling resistance is affected by many factors but luckily going tubeless improves them all. The extra suppleness from having no inner tube means the tyre can deform more easily over small bumps, rocks and roots. Less fear of punctures means you can run lower pressures which, you have probably heard, increases rolling resistance but that only applies to roadies. Off road, the majority of rolling resistance comes from bumping over a continuous procession of small divots, rocks, roots, bumps and mammals. Lower pressure means the tyre can deform around the obstacle rather than having to lift the entire weight of the rider and bike over it. It might not sound like a lot but if you are riding over many small bumps several times a second it soon adds up to a lot of energy wasted.

4. More comfort
Again related to the lower pressures and greater suppleness, you get less of a pounding from a tubeless tyre. The ride of a tubeless tyre (like a road tubular) is noticeably smoother than an inner tube/tyre combination. More comfort means you feel fresher at the end of a hard ride or race.

5. Less weight
Well, sometimes. A carefully selected tubeless setup is slightly lighter than a tube, but weight is not the main reason for going tubeless. The other factors are far more important.

daniel_b

Comprehensive reply!

Thankyou cjw

JWYATT-18

Wow learnt more there than is a school week think i mite be going tubeless after that ! nice one !

Splasher

JWYATT-18 wrote:

Wow learnt more there than is a school week think i mite be going tubeless after that ! nice one !

Wow! I learned more there than in a school week. I think I may be going tubeless after that. Nice one!

Write it out 10 times and you've learned a bit more

prophet_1000

It is important to point out that you should not run LOWER pressures than req'd just because you read in a mag that tubeless tyres can be ran at lower pressures,

What this actually means is that you can run them at a lower pressure than a tubed tyre if you were riding the same piece of rocky/rooty terrain, as you would not need to inflate them harder to resist pinch flats like you would with a tubed tyre!

I recently saw a post on another forum warning other riders of the Dangers of tubeless tyres! the guy went on to say that he had great grip due to the larger foot print of the under inflated tyre, But he came a cropper when going around a corner at speed as the tyre rolled on the rim and lost all its air suddenly! Doh :oops: