Rolled a tire

[sevencyclist]

I rolled a front tire (Panaracer Dart) and crashed today while riding mountainbike on a fast turn. I am sure several factors contributed to it, however, I want to check with you all regarding different factor that contributed to the crash.

1. Obviously, if I did not lean as much, the tire would not have rolled.

2. Too little pressure leads to rolling of the tire. True?

3. Tire with too much traction contributed to the rolling? If I had slid instead of tire hooking up and turned, I would probably not have rolled the tire. Is this true?

Any other contributing factors?

Thanks.

[shanerpvt]

is your rim wide enough for the width tire you are running?

[stevep]

how many psi in the tire?

[Dude]

it was or wasn't tubeless?

[toaster]

Too little pressure is the most likely cause. I'm assuming it had a tube in there, not running tubeless aka Stan's.

If it had the proper pressure it likely would have washed out resulting in a fall. So, crashing either way, rolled or washing out is a given.

[Volant]

Did you happen to inspect the tire before installing? I once rolled one that had a defect in the bead (running low pressure too which probably contributed). Fortunately, only a few scrapes with nothing major. I hope you're okay.

[markie]

Are you sure the tyre didn't roll as a result of your crashing?

Darts are a bit '95. Tyres have moved on a lot since then. Still too narrow a rim and too low tire pressure are the normal answers.

[sevencyclist]

Thanks. I just have a few scrapes.

I had the tube at about 35 psi, and the rim was DT Swiss XR 4.1 ceramic which should be wide enough for the 2.1 Dart. The wheel was built by Joe Young and it stayed true despite the crash. I got the Dart in August and rode it for the 24 hours of Adrenalin World Solo Championships for security of front specific directional control for the race when I would be too tired to focus on steering, and had no problem.

I am curious to see if the lateral traction actually could lead to rolling the tire whereas less traction would slide but not roll the tire. I was wondering whether I should pump up the tire a little more, sacrificing some lateral traction to prevent rolling the tire again. Amazingly, the tube did not flat, and I was able to use the same tube to pump up the tire.

[I Want Sachs?]

The lateral force on the tire has to be great in order for the tire to roll. Therefore, I think your tire had gobs of sideway traction at the moment when it decided to roll off the rim.

[DfCas]

Some combos or tires/rims result in a loose fit.Was the tire easy to mount?

There were many bad combos early on the 29mtb forum,but that seems to be resolved lately with tighter fits.

[Archibald]

It's 2007, why in the hell are you riding a Dart? 24 Hours of Time Warp? That tire sucked in 1997 though it was still pretty hot in what, 1990?

Assuming the bead of the tire & rim is sound (and properly sized), it rolled because it was under inflated.

[Too Tall]

Dittohead what Archibald said and ask if your innertube was properly sized and you checked for bead hook / fit? If the tyre did not flat and you rolled a clincher I'm leaning twords a poor installation over anything else.

[BURCH]

35psi seems really low to be running when you have a tube. But it got you thru a 24 hour race so I can't rip on it that much.

I was riding with a buddy who rolled a tire. He was running tubeless at the same pressure. His roll came because it was both a 1 foot drop with a sharp left turn. All that pressure coming down and forcing it left popped the tire off.

[zap]

Darts may not be at the top of the class today, but they are far from being the worst.

Also, 35 psi for the front Dart is not far of from ideal for most mtb conditions and riders. I used Darts for over 10 years @ 35-38 psi with no problems including some regional championship races. The only time I came close to rolling them was the last time I rode the old mtb for a quick spin on the road. The tires were under inflated @ around 20 psi.

Innertube size has little to do with this issue. The tube will keep expanding til it fills the space. It was common for xc racers to use smaller inner tubes due to their lighter weight. The risk is that smaller innertubes get thin and thus are more prone to punctures.

So whats the problem? Defective tire bead? Installation? A big hit at an awkward angle on the front tire prior to your crash? If something weird is going to happen on a bike, it's going to happen in the woods or on a tandem.

[Archibald]

Darts may not be at the top of the class today, but they are far from being the worst.

Also, 35 psi for the front Dart is not far of from ideal for most mtb conditions and riders. I used Darts for over 10 years @ 35-38 psi with no problems including some regional championship races. The only time I came close to rolling them was the last time I rode the old mtb for a quick spin on the road. The tires were under inflated @ around 20 psi.

Innertube size has little to do with this issue. The tube will keep expanding til it fills the space. It was common for xc racers to use smaller inner tubes due to their lighter weight. The risk is that smaller innertubes get thin and thus are more prone to punctures.

So whats the problem? Defective tire bead? Installation? A big hit at an awkward angle on the front tire prior to your crash? If something weird is going to happen on a bike, it's going to happen in the woods or on a tandem.
Anybody who can run 35psi on a 2.1 MTB 26" tire either weighs about a buck-ten, is riding smooth trails, or is slower than fog off a turd on a cold mountain morning. I can't run 35 psi in a 2.6 without burping a tubeless or pinch flatting but that's just the way I roll.

Nurture my pig.

http://gallery.mtbr.com/data/mtbr/500/big_d_knolly.jpg

[I Want Sachs?]

Dart is okay, but the Smokes in the rear is the digger. Too much rolling resistance though.

I think 35 for Dart is fine as well. You can run a little higher pressure, but will probably slide instead of digging in like you did.

[sevencyclist]

Thanks for all the feedback. I checked the tire, and the beads seem to be fine. It is average tightness. I have had looser tires that did not have any problem. I think I might just have overcooked a corner and the force popped it out because my speed was too fast.

As for Dart being out of date, anyone has a favorite front tire?

[zap]

Nurture my pig.

http://gallery.mtbr.com/data/mtbr/500/big_d_knolly.jpg

Cool rig.

But different discipline :D

On my newer xc rig I'm running Spec sworks 2 bliss 2.0 @ 28-30psi front and that seem to work well for the riding I do including rock gardens. But no big jumps/hits. I'm still tinkering with psi for different conditions but hesitate to go lower because of burbing/rolling potential.

Stealing Sandy's line...sort of.......Not so light and maybe not so fast ZAP

[Too Tall]

Archie where do I mail the Nurses? I'm stealing that line, dang....fogturd fawkinmoney.

[I Want Sachs?]

Nokian Gazzalodis are amazing up front. However, heavy and rolled slowly.