Worrying News...

[hellymedic]

http://www.bbc.co.uk/news/uk-wales-south-west-wales-22835865

[LittleWheelsandBig]

Possibly connected with
https://yacf.co.uk/forum/index.php?topic=10.msg1500291#msg1500291

[hellymedic]

Well spotted LWaB! Could well be.

[Rhys W]

The incident I read about on the BBC site was on the descent of the Bwlch heading towards Port Talbot, not the Black Mountain. I also recognised the name of the rider who stopped to help... so is that Nuncio? I'd also heard there were several crashes yesterday.

The most worrying thing is the way the BBC reports refers to a "race", although I think it's been heavily edited since I read it earlier.

Fuller report.

[Hot Flatus]

I don't think that's Nuncio

[mcshroom]

I don't think so, the stories don't quite tie up. There were coments on the road.cc article about there being a number of incidents so I'd guess Nuncio's was one of the others. I hope both cyclists are ok.

I do worry about Sportives with multiple incidents like this (I would about audaxes too if it happened) and what response the local police might decide on for cycle events in general.

[Rhys W]

I didn't think it was Nuncio tbh, but the two incidents sound remarkably the same.

I also heard that the two first riders back were DQed because they were seen running red lights.

[caerau]

I do worry about Sportives with multiple incidents like this (I would about audaxes too if it happened) and what response the local police might decide on for cycle events in general.

The Dragon Ride had 6000 entries - two incidents (if that was the extent of it) is hardly something to get ones knickers in a twist about.  It must be nigh on impossible to hold an event of that scale and have zero incidents of people having blowouts or otherwise falling off.

[Nuncio]

Different incident.  Mine was less serious.  Bloke never lost consciousness and possibly the only break was to his nose (didn't check the bike other than to see which tyre had blown).  I suspect he's going to come out of the incident uglier than he went in.  I wish I'd had a camera to take a photo of his bloodied face, but perhaps that would have been less than sensitive.  The military medic chappy said that his face hadn't been that bad when he'd been IED'd.

Here's a link to the updated version of that story: http://www.bbc.co.uk/news/uk-wales-south-west-wales-22839283

And here's a curious postcript to my story.  That was the first time ever I've phoned 999 - I've lived a sheltered 51 years.  But at 3:20 this morning the Spooner Minor household was awoken by a rapping at the front door and the flashing of a light into our bedroom window.  It was a policeman who said that a 999 call at 2:55 had been cut off but had been traced - with BTs help - to our number and from that to our address/name.  He looked around to check everything was OK but I imagine from our demeanour and my wife's hair that he could tell we'd just been woken by him.  I asked him to check the number and it turned out that the third digit was different from ours. 

[mattc]

I do worry about Sportives with multiple incidents like this (I would about audaxes too if it happened) and what response the local police might decide on for cycle events in general.

The Dragon Ride had 6000 entries - two incidents (if that was the extent of it) is hardly something to get ones knickers in a twist about.  It must be nigh on impossible to hold an event of that scale and have zero incidents of people having blowouts or otherwise falling off.

Yes exactly - that's about 600,000 rider-miles. I'll be glad to cover that distance without incident!

I also heard that the two first riders back were DQed because they were seen running red lights.

If true, that's good news.
(as it happens, we had a new traffic light stuffed on our club TT course on Thursday - the only rider to RLJ was DQed. Shame, as he would have probably won anyway ... )

[sojournermike]

I do worry about Sportives with multiple incidents like this (I would about audaxes too if it happened) and what response the local police might decide on for cycle events in general.

The Dragon Ride had 6000 entries - two incidents (if that was the extent of it) is hardly something to get ones knickers in a twist about.  It must be nigh on impossible to hold an event of that scale and have zero incidents of people having blowouts or otherwise falling off.

Yes exactly - that's about 600,000 rider-miles. I'll be glad to cover that distance without incident!

Well yes, but I've heard about too many blowouts recently. A mate came off at about 25mph halfway through a downhill lefthand bend when his front tyre blew, plus various incidents reported on the fora. They make me nervous.

I broke my collarbone through self inflicted and inappropriate speed/misjudgement. That I can do something about, but apparently random blowouts are a bit worrying.

[giropaul]

One issue is possibly the Darwinian MAMIL's strange and overwhelming desire for carbon wheels (probably because they look good and make a nice noise).

1) In side winds these take very experienced handling - most MAMILs have little or no real experience of bike handling
2) Full carbon pressures heat up dangerously on descents - to the extent that they are banned in some sportives abroad. The heat leads to blow-outs.

[mattc]

2) Full carbon pressures heat up dangerously on descents - to the extent that they are banned in some sportives abroad. The heat leads to blow-outs.

I didn't know that.

The only Sportive I've been near was on the Galibier - a rider in the lead group had a blow-out approaching a hairpin. Bit of a small sample I know, but it did make me think.

[caerau]

Well my budget/wallet is not expecting enough cashflow to afford full carbon wheels for few years yet but I'll bear it in mind if the desire starts entering my brain. 

[hellymedic]

I thought all wheels with rim brakes would get hot on a long descent, though carbon might get hotter.
The lady who suffered explosive deflation on the approach to High Wycombe did not have carbon wheels.

[Wowbagger]

I'm sure that's true. The less material that goes in to make the rims, the greater the problem. A good solid touring rim will probably have more metal in its construction and will therefore not reach such high temperatures, or at least not so easily. Increased surface area will also help dissipate the heat and I wonder if that's part of the thinking behind deep-section rims, which also seem to act as a sound-box to amplify tyre noise.

[tiermat]

I think the problem is (and a real engineer will, no doubt, be along in a minute to explain better than I can) not that carbon heats up more or less for a given amount of heat input, but that it holds onto the heat better than metal rims.  This leads to greater heat build up as the heat from a previous braking session might not be fully disappated by the time you come to brake again.

[ferret]

I too had several hundred cyclists heading towards me last Sunday as the ride also intruded into my little bit of Wales, The few things I noticed were
no mudguards. no carradice baggage, very red faces and very very few smiles, They all looked so serious, the odd one or two actually acknowledge my presence and they were all over the road, leaving me very little room to wobble up the hill. There also appeared to be a total lack of banter in the larger groups of riders. I'm so glad I decided to take up audax, it really does seem to have the right attitude to riding.

[Nuncio]

I had a front wheel blow-out, caused mainly by rim failure though, on the descent of the Devil's Elbow once.  On the steeper side between the two bends.  I was going cautiously enough, though, that I was able to come to a halt, upright, without overshooting the bend too much. 

I think I saw pretty much the whole field for the 210km version between the turn off to Llanddeusant and the turn into Ystradgynlais.  It was fairly obvious that the ones nearer the front were serious because they were racing.  The nearer the back the more frequent the hellos, nods, waves and even 'lovely day's; the less there was of crossing the white line to overtake; and the more there was of groups of friends riding and chatting together and enjoying the day and the scenery.  To be expected, I suppose.  And it's all bums on saddles,  isn't it.

One surprise was the number of Radioshack jerseys.

[sojournermike]

I think the problem is (and a real engineer will, no doubt, be along in a minute to explain better than I can) not that carbon heats up more or less for a given amount of heat input, but that it holds onto the heat better than metal rims.  This leads to greater heat build up as the heat from a previous braking session might not be fully disappated by the time you come to brake again.

Funny, I've just had a chat with a colleague who ridse with a club locally and he said that a lot of their lads have had blowouts on carbon rims. The policeman who was killed on Greenhow Hill recently is also thought to have had a blowout - not sure what his wheels were made of though.

It's possible that carbon has a low specific heat capacity and so suffers a greater increase in temperature for a given amount of energy input - i.e. slowing a 100kg rider and bike from 40 to 20 mph always dissapates the same amuont of energy, but carbon may get hotter because it gains more temperature for a given energy input. Don't know the numbers though, so that's just surmise.

Another friend had a blowout or two, then found his back rim was cracked lengthways at the inner edge of the brake track.
 
Mike

[mattc]

Being a beardy luddite I would LOVE to blame this dodgy new tech, but  it doesn't really make sense so far ...

The temperature of the rim isn't really the issue - it's the temperature of the tyre. As Mike says, same energy required to slow the rider, irrespective of the rim material.

There must be more to this - or it's pure coincidence; high-end bikes having more carbon rims, being ridden faster downhill by 'keen' riders? Or something.

[giropaul]

The problems with carbon pressures (especially those without aluminium braking tracks) are well known. Mavic have pro-actively dealt with it, as have Zipp.


http://www.cyclingweekly.co.uk/news/latest/537358/mavic-cosmic-carbone-40c-carbon-clincher-wheels.html

However, many riders now buy "Chinese" or unbranded deep full carbon clinchers. Unfortunately many of these riders may be less experienced riders as well - and therefore brake more on descents. It's a bad combination.

Sportives in, in particular, South Africa, but also elsewhere, have banned full carbon clinchers for safety reasons.

The pros of course use tubs, and therefore there isn't any issue.

[mattc]

Thanks for that.

Although I've always thought 'pressures' meant ... you know, pressures of gases, liquids etc.

I can deal with "clinchers", and "high pressures" [tyres, surely?!]; please don't introduce any more jargon!

[LittleWheelsandBig]

Tubs are tyres too

/pedant

[Pedal Castro]

It's possible that carbon has a low specific heat capacity and so suffers a greater increase in temperature for a given amount of energy input - i.e. slowing a 100kg rider and bike from 40 to 20 mph always dissapates the same amuont of energy, but carbon may get hotter because it gains more temperature for a given energy input. Don't know the numbers though, so that's just surmise.

Carbon fibre has a larger specific heat capacity than aluminium, so it's not that. I can remember descending Wrynose pass, stopping halfway down and the Al rims were too hot to touch. Maybe with a tyre initially at a very high pressure, the pressure increases with temp sufficiently to cause a carcass failure? The extra strain on the tyre on a fast corner creates a weak point and BANG! If the carbon rim is stiffer than All then is it more likely to create a weak point in the tyre/run interface?