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Help! Need info on highest speed on bicycle(32 posts)

Help! Need info on highest speed on bicycleelviento
Jun 20, 2002 6:56 AM
My couch potato friend doesn't believe it's possible to go downhill at 50mph on a bike. Anyone knows any official information on downhill high speeds in bike races? Thanks!
he's rightmr_spin
Jun 20, 2002 7:02 AM
Last Saturday I could only get 48.6 mph on a descent. Based on this highly scientific evidence, I'd have to conclude that it is impossible to get 50 mph.
I have hit over 60 I think on descents. Just need a long-steep.refusenick
Jun 20, 2002 7:04 AM
Find a bigger hill ... Just a thought nmPhatMatt
Jun 17, 2002 4:35 PM
Jun 20, 2002 7:28 AM
It only takes someone 3% faster than you to hit 50mph, right? Maybe a skin suit, a tighter tuck, a steeper downhill, a stronger rider, or even smaller ears, will do that.
Aerodynamic pear shape...klay
Jun 20, 2002 8:09 AM
...should get you past the 50 mph barrier.

Worked for me :-)

Guiness Book, flat ground I think someone hit over 100mph.refusenick
Jun 20, 2002 7:02 AM
Not without drafting...jose_Tex_mex
Jun 20, 2002 11:37 AM
Check your source and constraints. I doubt if a lone cyclist went over 70mph without drafting.
Check out Cyco Boy Drafting a rocket car at 152mph!!!jose_Tex_mex
Jun 20, 2002 11:46 AM
The question was 50mphrefusenick
Jun 20, 2002 12:51 PM
I was merely showing that 167 had been hit on a bike. There was no mention of constraints or drafting, so I dont have to check my "source or constraints." I suggest you check the thread before you point nonsensical things out.
You Are Still Just a Nasty Bitter Troll - AND WRONG TOOjose_Tex_mex
Jun 20, 2002 1:38 PM
Notice that the child thread I started was under your parent thread stating obliviously "Guiness Book, flat ground I think someone hit over 100mph." This means that I was replying to your wild ramblings.
If you do not know what you are talking about - fine. Just don't waste the board's time with your ramblings. You blindly throw out a quote with no supporting data. Was the person drafting, being towed, or riding in a hurricane? You have to lay down some constraints and initial conditions. If you had been listening in high school science class rather than contemplating your next bitter troll hex you might have learned this.
Read the first message - the guy is talking about cycling NOT motor pacing. You reply to this by stating the previous. Since you FAILED to throw down any new constraints the old ones are inherited. This is NOT NONSENCIAL - it's just what those of us who have an ounce of formal training do in order to ensure we are still on the same page.
Since we were talking about cyclists it is IMPOSSIBLE TO GO OVER 100mph on a normal bicycle, with a human being cycling it, on a calm day, on a level field, and not drafting. YOUR POST IS JUST WRONG - you have nothing else to say which is why you always fill out only the Topic field. I AM DONE WITH YOU - YOU BITTER LITTLE TROLL.
50 is routine in pro races; I've seen 60+ on a friend's computercory
Jun 20, 2002 7:12 AM
My record is 50.5--I looked at the computer when it said 48, and gave it a couple of pedal strokes so I could say I'd gone 50. When the pros used to race in Reno, they came down the hill from Virginia City at 60+, and Lance talks in his book about 70mph packs descending in the TdF. I've been passed many times descending the mountain passes around here at 45 or so. I could easily have gone faster, but when I get above that, I start to remember that my bike was assembled and maintained by me, with parts I bought as cheaply as possible.... So, yeah, 50 is no big deal.
re: Help! Need info on highest speed on bicyclecomedy-tragedy
Jun 20, 2002 7:15 AM
I've personally been at 55mph on a 9% downhill, but I'm old and fat, so I get a little extra momentum.


The world land speed record on a bicycle is around 150 mph. This was set on the Bonneville Salt Flats a few years back by a Dutchman who was about 45 at the time. He was riding a specially designed bike and following a specially designed draft car. They towed him to about 90 mph and he did the rest from there.

By the way, the first time he tried he lost it at about 140. They said he rolled for over a quarter of a mile. As best I recall the injuries were relatively minor. Something like a broken leg, arm, 6-8 ribs, and some head trauma. Then he cam back a couple of years later and broke the old record.

I'm getting nervous just thinking about it.
I hit 48.4 mph record high!komatiite
Jun 20, 2002 8:08 AM
Guiness Book-167 mph-10/3/1995-F. Rompelberg-Salt Flatsrefusenick
Jun 20, 2002 7:16 AM
re: Help! Need info on highest speed on bicycleJBurton
Jun 20, 2002 7:24 AM
Man, I have friends that do 60 mph down hills every week! Look at rides like 6-gap in North Georgia, or similar hilly rides across the country. Regular old people are hitting 50 and above coming down the back side of the climbs. In races during mountain stages, the pros routinely hit 60-70mph. Hell, even some finish sprints on the flats can reach 50 mph, or so I've heard. Personally, I've been up to and over 50 mph more than a few times on my road bike, and even hit 50 once on my MTB (on the road) though that was a bit hairy for my tastes. Your friend must have never, ever been down a hill of any substance riding anything other that his Ford. However, I don't know why he would believe us if he won't believe you. I say you prove it to him. Get out your beater and set him on top of it. Find a large hill and let loose.
At his weight, he might end up faster than me:-)elviento
Jun 20, 2002 7:46 AM
At his weight, he might end up faster than me:-)PhatMatt
Jun 20, 2002 8:31 AM
Hell just have him pace you in a car. If you trust him enough.
But what gears are used to go so fast ????????PeterRider
Jun 20, 2002 9:49 AM
When I am at 45mph, I pedal crazy fast on my 53/12 max gear. I would never reach 55 or 60 by pedaling more, to me this speed has to come from slope and aerodynamism. What gears do people use to reach 70 ?? maybe if I had an 11teeth I could reach 55...

Also, that supposed 150+ mph must have been with a motor, I don't believe even one minute that somebody can go as fast just with legs...

At that speed, you are typically going downhill,elviento
Jun 20, 2002 9:57 AM
and a tight tuck without pedaling is faster.
But what gears are used to go so fast ????????Romani
Jun 20, 2002 9:57 AM
The guys who set the land speed records, like John Howard in the 70's and the Dutchman mentioned previously, have specially modified bikes that have a huge chainring. That's why they are towed up to 90 mph first. They have to be going that fast in order to turn the cranks properly. As I recall, they do these record attempts at places like the Bonneville Salt Flats.

Also, they are drafting the car because there is no way you could go 150mph against wind resistance.
Here's A Picture of the Gears and the two Cranksets!!!jose_Tex_mex
Jun 20, 2002 11:57 AM
Here's the link for the guy who did 152mph while motor pacing.
Also, check out the other link I posted in another thread about cyco boy.
Believe it Pete, it's in the book (nm)comedy-tragedy
Jun 20, 2002 12:08 PM
I think I saw a pic of the bike used for the land speed recd.Lone Gunman
Jun 20, 2002 1:56 PM
The bike was a single speed and the chainring barely cleared the ground, something like 144 tooth with big holes drilled out of it and an 11 tooth on the rear.
Even my cruiser can break 60 ...Humma Hah
Jun 20, 2002 10:53 AM
Its all a matter of finding a long, steep hill and getting into a tight tuck.

Ask him if he's ever tried putting a stick-shift into neutral and coasting on a hill? My draggy pickup truck will rapidly hit 70 on a grade that the bike will max out at about 43 on. The amazing thing is not that bikes can go fast downhill, its that they're not as fast as they OUGHT to be.

If you eliminate wind drag, by drafting a vehicle equipped with a windbreak, fantastic speeds are possible on a bike. The world record stands at something above 160 mph!
Power VS Air Resistance = 70 mphjose_Tex_mex
Jun 20, 2002 11:34 AM
There's lot's of ways of looking at your question. However, questioning donwhill speeds in excess of 50mph shows just how much of a couch potato your friend is. I have hit around 53mph and know that some of the boys in the tour descend close to 70mph. There are downhill ice moutain bikers that descend around 100mph or more.
With that said, I believe the land speed record for a bicycle, with fairings, on a calm day, on a flat course is close to seventy. Drafing a truck you can easily break a hundred. But if you expect to power past 70mph yourself, theoretically it's impossible. This is because it becomes exponentially more difficult to go faster as speed increases. If you were to graph such a situation you would see that it starts to get hard to continue increasing velocity around 40mph. A spike in the graph (asymptote) occurs around 70mph. Conclusion: the amount of power you need to push the air out of your way in order to do 70mph is not humanly possible given my constraints.
Check out - bicyling NOT motor pacingjose_Tex_mex
Jun 20, 2002 11:54 AM
As mentioned in the parent thread the record is about 70mph. Here's a site that backs that up
They quote a new reord of just over 72mph. However, I am unable to confirm this would qualify for Guinness' constraints. Still a great site and well worth the click.
54 mph on Tandem 50 on solo...rwbadley
Jun 20, 2002 1:44 PM
Just need a long downhill grade. I have spun a 53-12 to just under 50, I think it was 155-160 rpm cadence. That was downhill with a tailwind .
re: Help! Need info on highest speed on bicyclegbk
Jun 20, 2002 1:57 PM

Just been doing 59mph, here in flat little Denmark.
No big decent's to help me.
just hills on Appr. 100 meter altitude.

Tell him I did 76.5km/hr last weekend... 23tires... on DIRT!tempeteKerouak
Jun 20, 2002 3:56 PM
Coming down the road from the top of Scenic drive made a left to Abercorn (around Sutton, Quebec, Eastern townships).I love my carbon fork.

But my max speed recorded was on a mountain bike on such dirt roads... 90km/hr.

I reached the same speed (90k) on a road bike down Jay Peak (Vt)
I don't know nothing about miles per hour, except that this is over 50.
How To Do A Quick Guesstimatejose_Tex_mex
Jun 20, 2002 6:55 PM
After cycling in Europe I learned a quick trick to guesstimating your speed from kmh - mph. Just multiply by 6. Suppose you are going 90kmh - if you multiply 9x6 you get 54. You have to do a little decimal place dance in your head but it's pretty easy. 54mph is not a bad guess since the correct answer is 55.92mph.

If you need to do a speed like 74 kph, just seperate in to 7x6 and 4X6 Again keep the decimals in your head - adjusting to the right for 4x6. you get 42 + 2.4 = 44.4 the correct answer here is 45.98

It's really not that hard once you get used to it. I actually prefer the signs in km - it makes you feel as if you are cycling much faster as the 10 kilometer marks come by quick.
Mmmm... I get it. Thanks! (nm)tempeteKerouak
Jun 20, 2002 8:50 PM