What's my chances??
Peanutt
Posts: 229
of hitting 40mph on the flat?
Reason I ask is I've been trying to beat my top speed every time I go for a ride, currently 32.8 with a good tailwind, I'm 40 next march and would love to challenge myself to hitting 40mph before I'm 40yo even if only for a very short distance.
Reason I ask is I've been trying to beat my top speed every time I go for a ride, currently 32.8 with a good tailwind, I'm 40 next march and would love to challenge myself to hitting 40mph before I'm 40yo even if only for a very short distance.
No matter where you are, that's where you've been
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On a truely flat road, carrying no speed from a previous downhill, on your own and a normal road bike (i.e no tri bars) I would say accelerating to 40 mph (64 km/h) would be close to impossible.
Someone here http://forum.cyclingnews.com/showthread.php?t=2527 has counted Cav's pedal strokes and tried to estimate his speed based on 53x12 and 53x11 and it's not that much more that what you're aiming at (40-odd mph).
Without stating the obvious, he's the fastest guy in the world over the last few hundred metres and has a train of people protecting him whilst he builds his speed up to just before he hits top speed for a couple of seconds at most.0 -
Unlikely on a a stretch of road that really is flat - you'd need to be putting out over 1100W for several seconds. Not impossible for your regular amateur cyclist, but unlikely.More problems but still living....0
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I have done that speed in a road race in a bunch of 60 riders and a tailwind - but it blew the race apart because nobody could maintain the pace for long. For an amateur rider on their own, highly unlikely.Make mine an Italian, with Campagnolo on the side..0
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Also mathematically.
40 mph is 125% of 32 mph. A 25% increase in power output in 1 season would be impressive
However drag increases at the square of your speed so (1.25)^2 = 1.56
Therefore you would have to increase your peak power output by 56% to reach 40 mph
Happy training!0 -
I managed 38.7mph with gears to spare along a flat road recently (Garmin 800 GPS shows gradient - and it was along the promenade next to the sea). Another gear higher when I started to sprint and i recon the 40mph mark may have been on. Bit of a tail wind admittedly but i'd say its do-able if you have the fitness and strength.
Only one way to find out hey - try it and see
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Wirral_Paul wrote:I managed 38.7mph with gears to spare along a flat road recently
Really?, "gears to spare"?
53x11 is over 100rpm @ 38mph, so you've either got some serious "spin" in you, or you are running some kind of HUGE chainring.0 -
Over 100rpm is not that much to spin. I have done 48mph with 50 x 12 but dont claim for it to have been on the flat, it was on a slopedanowat wrote:Wirral_Paul wrote:I managed 38.7mph with gears to spare along a flat road recently
Really?, "gears to spare"?
53x11 is over 100rpm @ 38mph, so you've either got some serious "spin" in you, or you are running some kind of HUGE chainring. but I did not quite spin out but could not get faster on that slope. Any faster and better to freewheel anyway . 0 -
Forget the gearing; as has already been pointed out Cavendish gets up to speed behind the best lead-out men on the planet, then hits close to 50mph for just a few seconds.
I think 40mph on the flat, solo, without a tailwind would be pretty near impossible on a conventional bike.
Get yourself a recumbent with a fairing. And post a link to the YouTube clip when you do it.0 -
Thanks guys,
With the kind of power output I'd need and the amount of training I'd probably never reach 40yo let alone 40mph!!! might set 35 as a goal instead.No matter where you are, that's where you've been0 -
I'd say near on impossible mate. Don't fully understand the whole maths/science debate here but common sense tells me that you'd do very well to hit it on a snooker-table flat road whilst solo.The only disability in life is a poor attitude.0
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Not possible, I'd say, for an ordinary bloke on a flat road no tail wind. Rather than look at Cav with his lead out train, let's look at track cycling. Chris Hoy has done the kilometre standing start in just over a minute - that's 37mph and he's one of the fastest on the planet. Also the Olympic standard track sprinters like Hoy do the last 200m of a sprint absolutely balls out in about 11 secs (40.7mph) - the world record for the flying 200m time trial is 9.6 secs which is 46.6mph but I bet they are dropping down the camber of the track to get up to speed . These guys are producing well over 1200 watts for half a minute or so.
So anyone who thinks they can do 40mph on a road bike on a flat road unpaced should get in touch with British Cycling because an Olympic berth awaits you.0 -
schweiz wrote:Also mathematically.
40 mph is 125% of 32 mph. A 25% increase in power output in 1 season would be impressive
However drag increases at the square of your speed so (1.25)^2 = 1.56
Therefore you would have to increase your peak power output by 56% to reach 40 mph
Happy training!
Its even worse than that. Aerodynamic drag increases with the square of speed but power increases with the cube of speed because power = force x distance moved. You're really looking at twice the power to get to 40mph vs 30 mph and that doesn't even include resistance due to bearing friction etc.0 -
Your chances are zero.0
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I did it today actually, but it was on a brand new road (it was chippings on tuesday), but there was a hill just before it, then coasted a car - but it was flat road!
Without the above it's iffy, it depends on you and your bike and if you do try and reach that speed it will be seconds at best (with a full-on effort your muscles will deplete their energy stores in about 15 seconds), the only other option is to use a kick arse tailwind.0 -
RoadyForever wrote:it depends on you and your bike
I think this challenge is really very little to do with the bike and almost everything to do with the engine driving it!
I think the difference between attempting it on an old bone shaker and the latest and greatest carbon bling is the difference between no chance and not a chance at all!0 -
borrow a friend and a van, cycle behind said van... then it is do-able.0
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Surprising how hard 40 is even on a slope. eg on my way home from work there is a longish (1km) straight descent. Not sure what the gradient is (steepest bit might be 10%)but it is enough that it is hard work to go up! Without a tailwind, even with that length 40 is just about as much as I can do with 34-12.Faster than a tent.......0
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danowat wrote:Wirral_Paul wrote:I managed 38.7mph with gears to spare along a flat road recently
Really?, "gears to spare"?
53x11 is over 100rpm @ 38mph, so you've either got some serious "spin" in you, or you are running some kind of HUGE chainring.
Most people cruise all day at 95-100rpm!! My Garmin 800 shows i've hit 160rpm cadence on more than one occassion so I dont see why i'd need a huge chainring to hit 38mph. I run a 53/39 and 11-25 and was probably on the 14 sprocket if you fancy a go at the maths Danowat
The Garmin 800 runs a GSC-10 sensor - so i'm not sure which actually takes preference for speed when both it and GPS are active?? The speed was confirmed using the standard Cateye that I had running off the front wheel magnet - correlation on distance was very close over a 120 mile ride to the GPS so suspect it was set pretty accurate.
It surprises me how many are willing to dismiss anyone being able to hit 40mph without a leadout. Watching the Vuelta yesterday and they were talking about 60-65kph (37-40mph) speeds several kilometers out from the finish and the riders were doing sustained turns on the front. How accurate that was we've no idea as they didnt do the TdF thing and pan down to the motorbike speedo. The pro's do those sorts of speeds all the time over the closing stages and what we're talking about here is a one off sprint of a few seconds at maximum effort. Its hardly a rarity for an amateur to do a 22min 10mile TT and thats over 27mph average (i've gone under 22mins plenty of times in the past). Safe to say for much of that you're riding at 30mph.
For the OP though - as said if the best is 32mph to date and that was an all out effort, its a massive increase of power to put your top speed up to 40mph.0 -
First sprint prime at Goodwood a few weeks back - there was a little bit of tailwind and 53x12 gear used.
Close, but no cigar..... :shock:
http://connect.garmin.com/activity/99435307
Didn't even get in the first 5 over the line either!0 -
Mike67 wrote:Rolf F wrote:, even with that length 40 is just about as much as I can do with 34-12.
Blimey, sure you meant 34-12. At that speed I make it about 180rpm. Your feet would be a blur
I should be grateful I didn't get a load of posts telling me off for crossing my chain
50-12 of course. As it happens, I barely made 35 today with a headwind on that hill.Faster than a tent.......0
