See above, smaller wheels are faster. So, I'll stick to 26's. 29ers are like a steam roller.............
Guy Martin pedalling to 100mph
postierich - Member
Disappointed he never mentioned cracking one off in the back of a van at all!
Not your Royal Mail van I hope? !
*Glad to hear your op went OK... Look forward to seeing delivering some mail to WB !
Made me think though, what/who was in that video on the net building a bike to do similar, there was a part one, with another part to come I think? They had an old Ford Zephyr or something?
That was Donhou the guy who hand builds bike frames, he had a massive chainring made by Royce.
Think he only managed 80/90 mph though.
Yes i enjoyed that and i'm looking forward to seeing the other 3
Its good to to have some one on the box with some real talent
Not to self don't get my fitness tested at Lougbrough, I might be disappointed opening the envelope
It was shame they didn't look at the world record. I don't think it takes anything away from what they did
I was wondering what the speed rating on the tyres was? They looked like Contis but were they specials? with any bicycle tyre what speed are they tested up to, is it a case of just the best and taking a punt at the inner tube pressure. Pumping up the tyre recommended range, but that doesn't take into consideration the pressure/heat generated at a ton+
I was wondering about the tyres too.
I suspect that kevlar-banded 'tough' street tyres would cope with a short 100mph ride or two.
They might or might not cope with very many heat cycles. It wouldn't be difficult to do some testing, though.
It wouldn't be difficult to do some testing, though.
Test 1 would be touch your rear tyre after a turbo session, do they get hot? My memory is that my feeble power doesn't make the tyre hot. That's all your power out put into 1 tyre. On the road its spread over 2 so I think we can assume if you pass the turbo test then you are in the clear
Heat build up would be proportional to power, he's not putting out much power so I'd not imagine the tyres got much heat in them, not compared to repeated slowing down from 70mph+ on an alpine decent, or sitting on a turbo trainer.
I guess the more important consideration was not puncturing, hence commuter tyres rather than something like ultremo or even tubs?
I think I'm wrong
On a turbo trainer his say 400W isn't going into the tyre. Its being mainly used in the magnetic brake. On the slip streaming bike most of his power will go into heat in the tyre and surface he's rolling on
I think the short duration means heat won't build up. He said he did 1 mile at 100mph
I'd love to know what calculations or tests they did on that
A tyre is a big black radiator
my students can get 1kg of Aluminium pretty hot with a 35W heater, but it takes a while
The obvious test is a trailer of the correct weight with 2 of the tyres. Then towed at the appropriate speed
True, but then at 100mph most of his energy would still be going into wind resistance, truck or no truck, not the tyres.
They're surrounded by fast moving cool air.
The part doing work against the ground will be conducting heat into the sand, which was also damp so has both latent and sensible heat transfer.
And if there was any heat, compare it to a brake track on on a road bike after even a moderate decent. That's a lot of power going through very close to the tyre, with no ill effects (apart from melting patch or tub glue).
The tyre's not going to get hot - it's exposed to friction for approx 1/36th of a rotation the rest of the time it's moving through the cooling air at 100mph (It's actually 0-200mph as the bottom of the tyre is momentarily fixed to the ground and the top is going twice as fast but it averages at 100).
I would be more worried about it centrifuging itself off the rim more than anything.
anyone know where a non-UK resident like myself can watch this?
Darrell: Can you watch it on 4OD via the web?
nah. doesnt work if you're outside the UK
^^ Tunnelbear is your friend
Apparently Rourke's have be busy after the programme. Luckily I was fitted for mine 6 months ago and it should be shipped today
No speed records will be set on it though.
I agree that the tyres would dissipate lots of heat into he air
The principle means of heating would be side wall flex, or work deforming the sand. The friction wouldn't dissipate heat unless he is slipping
But he was working against the tyre. The programme was really clear that it was a turbo session. He was pedaling in still air. I think if he was pedaling through the air they'd have given him a less upright position?
Does anyone know if that's a ratified record? He hit a top speed of 112 but traditionally records are measured as average speed over a certain distance. For instance the video of Fred Rompelberg suggests his record was set over a measured mile.
Still, brilliant effort by all the team and especially Guy not being exactly a professional cyclist. I do enjoy watching him, whatever he does. I wonder how Tony Martin would do?
He was pedaling in still air.
from the aerodynamics guy's modelling he's riding with a tail wind, even at 100+mph.
Great programme though, the lack of weight of the bike and what looked like a fairly normal head angle must have made it pretty bloody twitchy. Ive done that speed on a 500lb motorbike (on a track, obviously...) but on a bicycle, on sand, staring at a wall on the back of a truck is a different matter. Noticed he had the presence of mind you use the truck's braking by riding "into" the tow bar rather than rely on his (sponsored) Hope brakes and risk locking up.
I do enjoy watching him, whatever he does.
I find him right on the cusp of entertaining and irritating, but give him the benefit of the doubt as despite (or because of) being a motorcyclist for 25years I cant watch on-bike TT footage without holding my breath.
thisisnotaspoon said » True, but then at 100mph most of his energy would still be going into wind resistance, truck or no truck, not the tyres.
What wind resistance ? He had an effective (small) tail wind.
. Noticed he had the presence of mind you use the truck's braking by riding "into" the tow bar rather than rely on his (sponsored) Hope brakes and risk locking up.
Not sure that was by choice. Shat me right up. As did the thought of clipping your bike to a truck that is going to tow you up to 60mph.
Noticed he had the presence of mind you use the truck's braking by riding "into" the tow bar rather than rely on his (sponsored) Hope brakes and risk locking up.
He said that his visibility was minimal. Brake too much and remove yourself from the truck slipstream == nasty.
Not sure that was by choice
I thought that first time, but he did it a couple of times (including the dry runs on tarmac) and it looked planned/expected ie. no reaction from him.
what was the guy called that had the big off trying to break the cycling speed record?
the footage was at a race track and he was carried off unconscious, then tried again a few months later
I am pretty sure he was french, but I don't think it was the guy on the autobahn
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