Pinch flats are killing my racing-any suggestions?

[kookstick]

I startes mtb racing this year and have done 6 now averaging 20-27 miles each, ever since I got new tires I have been getting alot of flats and it really sucks to have to change a rear tire when all the people you passed are passing you back. I wondered what techniques you guys do to make sure the tube isn't being pinched when you inflate it. I have tried working the bead area with it slightly inflated,using different pressures, different tubes ect.. Any suggestions are appreciated

[HELLTACO]

Tubless

[Merwin5_10]

sacrifice the weight and go for tuffy strips or self-sealing tubes (slime tubes.)

Yes they're heavy but I put self-sealing tubes in my tires last summer.

Number of flats in the last year= 1.

Or learn to change a tube in record time. (I'm at 1 minute 12 seconds, drop to drop.)

[B-Loco]

kookstick -

Have to agree with HT - go tubeless.

If you can wait Mavic is going to release a rim-only version of the Crossmax in 2002. So you should be able to pick a pair of those up and build them up with whatever lightweight hub you want - Hugi 240 or Chris King and spokes. That should bring the weight down quite a bit.

Or you could go with what merwin suggested and try to seal up your current rims and run either tubless tires of normal tires sealed up.

Read up on stan's system for more info on this:
Stan's system (http//www.notubes.com)
He's some guy that does a tubeless system. Mtbr.com has a bunch of people on it that use his system with good results. But from what i've read some tires/rim combos don't seal up very well. I've never tired it, so your milage may vary.

hope that helps!

[RideMonkey]

I have had excellent luck with tubeless tires over that last 18 months. I have the Mavic UST with Hutchinson Pythons, an expensive setup.

The Stans system is only $25 and will make your current wheelset tubeless. Can't go wrong trying it out for only 25! Let us know how it goes! :)

[SK6]

Originally posted by ridemonkey
I have had excellent luck with tubeless tires over that last 18 months. I have the Mavic UST with Hutchinson Pythons, an expensive setup.

The Stans system is only $25 and will make your current wheelset tubeless. Can't go wrong trying it out for only 25! Let us know how it goes! :)

Can ya get me more info on this?

Thanks!!!!

No of flats this past month = 3

[Heidi]

Have you checked your tire pressure??????

[RideMonkey]

Originally posted by sirknight6


Can ya get me more info on this?

Thanks!!!!

No of flats this past month = 3


www.notubes.com

[SK6]

Had a dang flat last night...........

I ordered the Stan stuff, so when it get's here, I'll give ya all a report............

In the mean time...........HELP!!!!!!!!!!!:eek:

[chunk]

Originally posted by kookstick
I startes mtb racing this year and have done 6 now averaging 20-27 miles each, ever since I got new tires I have been getting alot of flats and it really sucks to have to change a rear tire when all the people you passed are passing you back. I wondered what techniques you guys do to make sure the tube isn't being pinched when you inflate it. I have tried working the bead area with it slightly inflated,using different pressures, different tubes ect.. Any suggestions are appreciated

Yea, put more air in you tires. :D

[KMan]

Pinched flats are caused by running lower tire pressure, going tubeless (if still running low pressure) will not "eliminate" pinched flats as tubless tires are still prone to pinched/thorne flats. Unfortunately you cannot fix a tubless pinched flat.

Several things you need to look at: What tires are you running as many lightweigt tires have thin sidewalls, TIRE PRESSURE, Pinched flats or thorns?, makes sure the inside of the tire is clean, rim tape in in good condition.

[Merwin5_10]

Kman is correct in that is is POSSIBLE topinch flat a tubeless tire however, it is unlikely unless you are running a very low tire pressure AND have a thin sidewall. The rubber in a tire is MUCH more resistant to being pinched. That's why tubeless tires were created. To allow riders to run lower tire pressures without the constant flats. Also, if you do flat a tubeless tire be prepared for a ROYAL pain in the arse when you change it.

Or learn to change a tubeless in record time. ( My best so far 30 lousy, frustrating minutes.):D

[oldfart]

It sounds to me like no one told you what a pinch flat is. Its when the tube gets pinched between the rim and a rock. The cure as mentionned is more air. Or not hitting rocks or other sharp edged obstacles. If your tube is getting pinched between the tire bead and the rim that's an installation problem. You should air up the tube a little before installing it. It will prevent this installation pinch. Race tires tend to have thinner more supple, lighter casings which are more prone to pinch flats than a stiffer heavier casing. Put in more air. Spin skins and other tire liners do little if anything for pinch flat resistance but do help thron puncture problems. Slime will help plug up small punctures. I'd suggest that if you hit something hard enough to pinch flat a tubeless tire you have a mighty big ding in the rim too. What size tires did you get? What make and model?What do you weigh and how much air are you putting in?

[Merwin5_10]

Originally posted by oldfart
I'd suggest that if you hit something hard enough to pinch flat a tubeless tire you have a mighty big ding in the rim too.

True Dat. Completely ruined a Mavic 517. That's what happens when you forget your cape on a ride and try to bunny hop a planter box at about 18 miles an hour.:eek: :eek:

[kookstick]

Guys, thanks for the responses, haven't been on my computer for days since moving and the fact it was in a box. I bought the intense wedge cc with kevlar bead off Jensonusa.com , i'm currently running 50 psi already but most likely it the way i'm installing the tube, talked to some guys today and bought some of the cloth tape that goes around the rim to cover nipples, they said the same thing you guys said except to mark with a pen the tube,rim and tire and if I get another one to take it apart and see if I can tell whats causing it, well the only problem with that is that i'm in a race and don't want to dick around with that while wood ticks are crawling up my legs :). anyways, I might just go tubeless but I would rather just figure out what the prob is. I rode a long time with no flats but since I got the new tires I took the tuffies out to try and save on a little weight, probably not worth it. Well I'm doing alot or riding this weekend but I really want to work out the bugs before the 2500 person chequamegon fat tire race in 2 weeks. thanks for all your help.

[TwoWheelinTim]

I agree with all those that told you to go tubeless! You WILL go faster. There is less internal friction associated with having a tube. You WILL go faster.

[MuDHoG]

!!Tip 'o the day!!
Take one of your old tubes and cut it down the middle, insert your new tube into the cut tube and seat it in the tire..inflate and ride...you'll end up sacrificing a little in the wieght category but I can almost gaurentee you won't see another pinch falt for quite some time!!! ~MuDHoG

[Target]

I ride the wider mavic (321 i think) rims and rarely have a pinch flat with tire pressures of 25-35 (and I weigh 190). I have noticed running narrower with same tires (El Gatos on the back and Cujo on the front) leads to more pinch flats. Narrow rims lead to a more curved side wall which buckles easier I think. Just speculation on my part.:)

[RedMonkey]

Originally posted by MuDHoG
!!Tip 'o the day!!
Take one of your old tubes and cut it down the middle, insert your new tube into the cut tube and seat it in the tire..inflate and ride...you'll end up sacrificing a little in the wieght category but I can almost gaurentee you won't see another pinch falt for quite some time!!! ~MuDHoG

Hey, I was gonna say that!

[Yankee Tim]

Just something that I do.

When installing the tubes, I cover them in baby powder. This really helps when installing them. Allows them to slide around inside of the tire when inflating.

[Merwin5_10]

Damn it quit giving away trade secrets!;)

[Target]

Okay, I take back the thing about the wider rims helping. On our night ride last night I had one rear flat and my friend had two!!. We both have 321 mavics and el gato rear tires. Mine flatted as i was standing there with my bike shining a light on his so he could fix his tire - sheesh. I started looking for stick figures on the trees.........

[DHG]

Originally posted by sirknight6
Had a dang flat last night...........

I ordered the Stan stuff, so when it get's here, I'll give ya all a report............

In the mean time...........HELP!!!!!!!!!!!:eek:
Before you use Stan's Tubeless system be sure to watch the two Quicktime videos on his website www.notubes.com

Also, the prep work is KEY to everything working good so make sure to take your time and follow the directions and watch the videos mentioned above. Just a caution....different tires are easier or more difficult to mount than others. It may take you a few tries to get the tire aired up the first time......its a little tricky. You may want to practice airing the tire and getting it to seat on the rim before using the latex mixture. Once you get a handle on seating the tire go ahead and deflate it and use the latex. The reason I suggest this is because if you do have trouble seating the tire you will end up with the latex liquid everywhere......you NEED to use an air compressor to get the tire to seat. ** Once you get it to work it is an awesome system!

[DHG]

Originally posted by Yankee Tim
Just something that I do.

When installing the tubes, I cover them in baby powder. This really helps when installing them. Allows them to slide around inside of the tire when inflating.
Definitely the best tip for installing tubes :thumb: Also sprinkle some in the tire. Don't be afraid of using too much powder.
Also, if you carry a spare tube on your rides go ahead and coat it with powder and keep it in a baggy......it will be all ready if you need to replace a tube when riding. Not a bad idea to keep a little powder in a baggy as well.

If you don't like using powder you can check out a spray on liquid product made by Rock 'n' Roll lubricants. It is a liquid you spray on the tube and dries to a powdery texture.

[DHRacer]

I ride michelin wildgrippers, nice string wire bead side... in 8 years of riding and 2 years of racing, I have only pinch flatted once and that was in the nast rock garden at Deer Valley... that's all I got.

[Shibby]

If you're not running good ol' regular butyl tubes (Specialized 26x1.5-2.2 are my fave, but they all come from the same factory in Asia), you should be (at least in the rear). None of that ultralight tube shiznit. And if you are running the cheapies-but-goodies and still PFing, you can...

1. Take one of your old tubes (or a new one if you're feeling spendy), slit it down the middle all the way around, and wrap it around your good tube. Twice the thickness means less pinchflats.

2. Buy some thornproof innertubes... $2 more than the regular puppies, 2-3 times as heavy, but durable as hell. Some are also extra thick on top to resist punctures, but they're much thicker all the way around, too. I run them for DH racing, and so far this season, I have flatted zero times during both racing and practice. This is running 25-35psi front and rear, and I'm ~150lbs. If you can swing the weight, go thornproof, and never worry again.

3. I've heard that using Talcum powder between the tire and tube can help to avoid PFs, since the tube can slide freely inside the tire, thus lowering the chances of the tube "sticking" to the inside of the tire and getting dragged into the pinched area. Sounds like myth, but the BMX foolios at my LBS swear by it.

4. Run 10-15psi more than you are right now. Not advisable. Starts feeling like riding a road bike. Not good if your course has more than 3 or 4 rocks per mile :)

5. Avoid obstacles.

6. Buy a bike with rear suspension, or, if you are pinchflatting while seated, a suspension seatpost (assuming you are riding a hardtail right now; I don't know). The forgiveness in the rear of the bike will help to absorb some of the impact that is currently biting your tube.

Good luck

-shibbbbbbbbbby-

[kookstick]

Well I think I have it taken care of, since my last post I did what people have suggested but also bought some of the sticky cloth stuff that covers the spoke nipples on inside of rim, coated tube with baby powder, inflated slightly and was very careful while inflating. Well since then I have finished the chequamegon 40 mile fat tire race and a few others to finish out a series where I live and not one flat. I am running 50 psi. One thing I didn't realize is that the compressed air I was using while racing, to try to quickly get back into the race is just a temporary fix cayse the next day your tire will be flat. Anyways thanks for all the tips!

[MuDHoG]

Originally posted by Shibby
1. Take one of your old tubes (or a new one if you're feeling spendy), slit it down the middle all the way around, and wrap it around your good tube. Twice the thickness means less pinchflats.


Didn't I already say that at the top of the page? I think I did? hmmmm....maybe not. :)

[Shibby]

well, using rimtape is a good start. you kinda have to if you don't want your spokes/nipples to puncture your tube...

glad to hear that it worked out for ya.

[Clark Kent]

Are ya runin those "low resistance"? that may be the prob...I run 'em thick...2.25's 2.5's whatever and keep em pumped up. If your meat is big enough you still hook up nice like, but ya wont be gettin al those pinchies.....I've had 2 in the last three years...( on the same day!)...arrrgh!