Horizons Unlimited - The HUBB

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-   -   How to cope with a puncture at speed? (https://www.horizonsunlimited.com/hubb/travellers-questions-dont-fit-anywhere/how-to-cope-puncture-speed-21855)

Ian 13 Jun 2006 12:43

How to cope with a puncture at speed?
 
A few weeks ago, for whatever reason (still not investigated it), my front tyre deflated very quickly whilst I was riding at some speed (don't recall exactly how fast but I guess 50 to 60 mph) along a dual carriageway. I only just managed to hang on and somehow maintained control and steered the bike onto the grass verge (I think off-road experience helped here), although at the time it felt like the handlebars were no longer connected to the front wheel.

Fortunately the road wasn't very busy, but nonetheless the whole incident left me very shaken up, with thoughts of 'what if that had happened at 70mph in the middle lane of a motorway?' and similar.

Anyway, are there any recognised riding techniques for safely dealing with this type of incident?

Do tubeless tyre deflate slower in the event of a puncture? If so why?

Thanks.

brclarke 13 Jun 2006 14:14

I've read some claims that tubeless are a bit less likely to deflate so rapidly, but I can't say if that's true or not.

I've had a rear puncture a couple of times while at speed. I've found that I've instinctively hugged down lower to the bike and eased off on the gas while pulling over to the shoulder.

It would interesting to know if there is some type of "recommended technique" for handling a rapid puncture. I imagine the best advice would be to not panic and try to get out of the flow of traffic while losing speed smoothly...

Maverick Bubble 13 Jun 2006 17:33

I have had two rear blow outs/rapid deflation at speed, 70mph plus both last year and i have never had a flat before. I checked the tyres and there were no signs of punctures. I was leaving for a 6000mile trip and i was worried as i could not find an obvious problem with the tyres.

It turns out that the motorbike which i had purchese from a dealer the month before had been fitted with the wrong size inner tube in the rear tyre, ie they were smaller than they should have been. When the tube was pumped up to the correct air pressure for the tyre, it would cause the tube to stretch thus making the rubber thinner, this coupled with a high speed blat on the motorway and the rest is history.

I had the first puncture on the way to Manchester from last year Horizons meeting, in the middle of Derbyshire. Funny enough i had had Ultraseal put in the tyres at the Horizons meeting from the Ultraseal stand. I fixed the puncture with some pucture seal and had the tube changed in Manchester. The guy in the tyre shop took the tube out looked at the size and replaced it with the same size. It was only after my second blow out,when i called the breakdown recovery guy out that the problem came to light. he was changing the tube in the back of the van and he said 'You have the wrong size tube in this tyre mate' it all made sense then. I have not had a problem since.

I don't know if the Ultraseal helped by making it a a controlled deflation, but i did get a warning because i felt the bike twitch on both occasions whilst i was riding. There was more of a slight tear in the tube than a small puncture.

So if you run tubes on your bike check your tube sizes, it may be the cause of your rapid deflation.

Getting back to your original question, i agree with Bruce's answer and let bike come to a halt under its own steam........and then change your underpants.

London Bubble

lee5500 13 Jun 2006 18:33

The best way is Ultraseal or an equivalent brand - I swear by it. I have a number of first hand experiences of changing tyres (road to knobbly and v/v not for punctures) and finding punctures that had already been fixed by the ultraseal without me ever knowing I had sustained a puncture in the first place. It isn't particularly cheap but in does do what it says on the tin - and that is for tubed and tubeless.

a1arn 13 Jun 2006 19:47

Puncture at speed
 
For rear wheel punctures, hit the front brake HARD as soon as you get the wobble under control and the bike is in a straight line. It unloads the rear wheel and prevents it from getting off the rim, which can only lead to more excitement. There is also better control as the front wheel takes most of the weight.

I've done this (totally unplanned at 45mph) and it works.

Tyre sealants help, and so do tubeless tyres, in PREVENTING this sort of thing.

Ian 13 Jun 2006 20:17

Lots of good info so far - metaphorically I can identify with the change of underpants - it really was quite scary.

Maverick - when you say the wrong size tube was in, do you mean the wrong diameter (e.g a 17 inch in an 18 inch tyre) or a 3.00 x 18 in a 4.00 x 18 tyre? I can understand the former being a big problem - it'd be a struggle to fit it in the first place.

Thinking back to the incident, I do recall experience taking over and avoiding braking, to help prevent transfer of weight to the front. I also recall lurching from side to side, mentally preparing myself for the pain which thankfully never happened. It was rather like trying to get out of trouble in a trials section (I'm a trials rider in my other motorcycling life), except you can't foot above a certain speed.

Still wondering if there's any definitive technique.

hook 13 Jun 2006 21:13

A motorcycle guide I once had, had these suggestions for coping with a flat: Roll off the throttle. Once you know which tire is flat, apply gentle braking to the good tire- avoid braking on the flat tire. Carefully exit the road. Sounds so easy! I was cruising along Interstate-25 in Colorado last year, traffic flying past me at 85mph...I was doing around 70mph. Suddenly it felt like I was riding on grooved pavement- exactly like that. I began to slow- got down to 60-65 when the back tire went flat. The back end of the bike swung to the left and I thought I was going down but didn't. I did exactly what the guide said and it was fine. This was just instinct, I wasn't thinking about the guide-book. I was lucky to be in the right-hand lane. A friendly motorcycle cop waited with me until my local shop rescued me. Pretty scary though!

Maverick Bubble 14 Jun 2006 06:46

Ian, come to think of it he didn't say? I would assume its 3.00 x 18 in a 4.00 x18. I guess if it had been the diameter it would be obvious at the time of fitting. I have learnt to fit my own now.

I hear people complaining about the price of Ultraseal and the related products, but i don't think its that expensive if its gonna help you be safe, what price safety? If i know in my mind i have taken every concievable precaution for my own safety and piece of mind, then i have done my best and the rest is in the lap of the gods.

Maverick Bubble

parkie 14 Jun 2006 10:51

Quote:

Originally Posted by brclarke
I've read some claims that tubeless are a bit less likely to deflate so rapidly, but I can't say if that's true or not.

I've had a rear puncture a couple of times while at speed. I've found that I've instinctively hugged down lower to the bike and eased off on the gas while pulling over to the shoulder.

It would interesting to know if there is some type of "recommended technique" for handling a rapid puncture. I imagine the best advice would be to not panic and try to get out of the flow of traffic while losing speed smoothly...

Best technique - rapid and strenuous sphincter tightening. Followed by consumption of large amounts of alcohol.

Works for me. :w00t:

Had it happen several times at 100+ mph - tubeless valves seperating, motors seizing, etc - jolly exciting.


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