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Riding a punctured tire


Justify

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Hi guys

 

I've been having the worst luck possible with my tubeless setup. I have Bontrager tubeless tires, and a conversion kit on my rims.

 

Long story short, I've gone through two inner seal kits (thanks to not being told that one shouldn't use a hand pump on the presta valves, by my LBS. And replacing the system costs about R400 per tire), having torn at the valve head, and this weekend, I got a small cut in my rear tire, causing it to vent most of the sealant.

 

Thankfully I had a traditional inner tube with me and have been riding with that since the weekend.

 

My question is this. The cut is in the centre of the tire sidewall, and approx. 1cm long. Can I continue riding like this for an extended period, or will the cut deteriorate further? Logic tells me the cut shouldn't deteriorate as fast as if it was in it's tubeless setup... but perhaps that logic is faulty?

 

What do you guys think?

 

Either way, I'm pretty 'gatvol' of the whole tubeless system and the epically-nasty expenses when it does go wrong.

 

Justify2009-05-05 13:59:44

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(thanks to not being told that one shouldn't use a hand pump on the presta valves, by my LBS

 

Sorry im new to the whole cycling thing and just done the whole tubeless conversion. Can you please explain why you shouldn't use a hand pump?
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(thanks to not being told that one shouldn't use a hand pump on the presta valves' date=' by my LBS

 

Sorry im new to the whole cycling thing and just done the whole tubeless conversion. Can you please explain why you shouldn't use a hand pump?
[/quote']

 

Well, what I've found out is that there are two "no-no's" with regards to tubeless conversion setups (please correct me if I'm wrong).

 

1) Don't tighten the screw against the rim, on the presta valve, as it pulls the rubber section of the inner lining towards the metal valve hole. With friction it can cut through the liner.

 

2) Use the gas cyclinders ("bombs"), or pump with a tethered valve (like a car pump), as the rocking motion from pumping has the same effect... basically chewing away at the rubber.

 

When you hear the dreaded hiss, you can pretty much see Rands and Cents in the white goo coming out.

Justify2009-05-05 14:15:07

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Tubeless can be scary. It happened at the Barberton Classic. You can imagine the scene. About 10 km's up the climb, you are quietly suffering to yourself, not hearing anything, not aware of anyone near you, mindless to everything but the pain, grinding slowly, ever upwards, occasionally cursing for ever having gotten off the road bike. Everything is happening in a kind of cloudy slow motion, not because you're doped, but because you are in a haze..... and oh, it also happened to be misty.

 

Then, an almighty explosion rips through your numb senses. You get splattered by white goo straight out of the Men in Black- or another movie. You quickly realize that you have a sphincter to control, and your brain works out that there's a guy next to you and his tyre has just blown.

 

Lemme tell you, that was enough to tell me that tubeless is not for me.

 

Having said that, what about inner tubes with sealant??
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I've had my fair share of bad luck in races with tubeless, but mostly due to experimenting with ultralight tyres. I've also trained 1000's of km's on ultra light tyres with not one problem in months.

 

I've pulled my valves from my Stans strips long ago... I just inserted them again and tightened the screw and they were fine...

 

You can get a small 3x4mm O-Ring and slip it over the valve and it will seal even better (remember to not screw the locknut too tightly else the O-Ring will pop off)

 

Today... I use road bike valves, ripped from a trashed road bike tube, with my stans strips... I tighten the screw all the way and they seal. I pump hard with a hand pump and they don't come loose or rip out or leak...

 

What rim strips are you using? Stans has a nice thick area at the valve hole.... hope the bike shop didn't take your ripped out strips... you can still use them...

 

As for the cut... 1cm is a big but not fatal... I've plugged a 8mm cut on a 410g tyre with a normal automotive rope type plug and went ahead to ride over 400km in a 24hr solo with the same tyre (I plugged it the day before the race for the second time as the original plug were worn down, so the day before the 24hr I pulled the old plug and inserted a new one... ) I kept riding it for another 500km before the side knobs started falling off the tyre and I had to trash it...

 

I would first stitch the tyre....use a needle and linen thread. 6 loops per cm should be fine... make double loops. clean the area to be joined before stitching and put some super glue on after the stitching. Then put a 30mm heavy duty patch on the inside and clamp it for a day to vulcanise properly... 

 

You would be surprised... :)

 

Light tyres cut easier and when using them tubeless, ride them softer. A hard tyre cut much easier. I inflate a 2.0 Python Air Light to 1.9 bar at the back and I'm 67kg. On the full suspension I would ride it 1.8 bar.  Just get used to riding rocky sections with a little finesse.

 

PS: I've seen some Bontrager Tubeless Ready tires with snapped beads... :(  I have a habit of never inflating a tyre over 2.5 bar when seating it for tubeless... that way there's not a chance of damaging or stretching the bead...  

 

Brighter-Lights2009-05-05 16:21:10
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Hi guys

 

Long story short' date=' I've gone through two inner seal kits (thanks to not being told that one shouldn't use a hand pump on the presta valves, by my LBS. And replacing the system costs about R400 per tire), having torn at the valve head, and this weekend, I got a small cut in my rear tire, causing it to vent most of the sealant.

 

 

 

[/quote']

 

don't buy the conversion kit, just buy bmx tubes stretch it onto your rims, cut it down the middle, so that there is a flap on both sides, mount the tyre, inflate and cut of the excess rubber flap. I rode Sani2C with a setup like this with no issues at all. Total costs R50 for the tubes.

 

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Justify, I think your'e just having seriously bad luck!

 

Go to YouTube and search for "tubeless"....there will be several video clips showing how to do them etc.

 

The best one for me is the video clip (forgot the link...it was posted here on the Hub sometime ago)...from Stan's (or Joe's) tubeless website....

where this dude sticks a screwdrivere several times through the sidewall of a tubeless tyre...and it instantly seals up again!! That impressed me big time....

 

Good luck

 
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