Fastest Bicycle On Earth

Was just reading about this....I'm thinking of the old bicycle I had, no way would I trust that to 200 mph, that guy is nuts....now he claims he has a faster design,!

More balls than brains...

http://www.gizmag.com/francoise-gissy-333-kmh-rocket-bicycle/34663/

And no seat belt. He must have one heck of a grip. Yet still has puny cycle breaks to stop from that speed. He has some faith.

He probably used baggy pants and real strong suspenders to stop.

Hydrazine fumes are not good.....

I am no chemist, but what have Hydrazine and HT Peroxide (propellant on this bike project) to do with each other? As far as I am aware, the exhaust of HTP is not poisonous....

Both are used in Rockets I believe.....but together? I am very unsure.....

I am always willing to lean so please point out what I am missing here.

Thanks in advance.

Andy,

I apologize , this bike power involves nearly pure hydrogen peroxide passed through a catalyst to produce high pressure steam.

No hydrazine involved.

No worries.

My chemistry knowledge lies so far back, you might have made a correct and valid point. I was interested as I could not make Hydrazine from HTP in my head from the chemical components, so I needed some help......you gave it!! I wasn't wrong after all....

Thanks for replying and have a great day.

https://www.youtube.com/watch?v=WREyAicJXkM#t=24 wonder if he went with ceramic wheel bearings?

Ceramic bearings would be the last of my worries. Those appear to be stock bicycle wheels. Now, I have a collection of 10 bicycles, mostly ones I rebuilt, and a wheel collection enough to equip them all 3 times over, so I know bicycle wheels. I managed to warp a pretty good set once on a panic stop from 50mph on a hill before a rr crossing by nailing rim brakes really hard. (my 100+ kilos are tough to stop) Those rims really aren't that substantial if he hits anything, like a small stone at those speeds. I had a rim blow out on me once after some 5 years of use , so they are rather thin. I'm sure, for rolling resistance reduction on a smooth course, he has those tires close to max pressure. The shock on the front is not very effective on small bumps - they're made for cushioning short drops, as they have a rather slow reaction time. Really wouldn't help much with a quick sharp hit, like a small stone. He had better be sure the track is very well swept before each run. A little debris as I mentioned and he would be out of control very quickly.

And continuing with the wheels, being so thin walled, there is a thing called rim flex as well. Rarely noticed at normal speeds up to 100 kph, but start doing the speeds he's doing and..... I hope his wheel builder is very good. I believe Sir Bradley Wiggins could point him in the right direction for a wheel builder. No-one less than a professional bike team builder will do.

Well, I guess they worked fine as he hit a top speed of 333km/h and the tyres stayed on the rims, and he stepped off smoothly. No doubt he will go about breaking his record again.

Yeah - this time. I ride a "normal" bicycle around 5000 km each year. Most of my serious wrecks have been on trails (mostly off road rider) I've ridden dozens of times before. They are very squirrelly machines and just cause you get there get safe once, or even ten times, it doesn't mean you will the next time. Two tires and a human brain for balancing means an error will occur some time. On the off road side of things (mountain biking) we say if you don't wreck, you aren't riding hard enough.

Really wasn't worried the tires would come off - pros go 100kph down mountains with just glued on tires. These look to be clincher style rims. Only clinchers I've had come off were the very low pressure style with tubeless configuration. He is running substantial pressures in those tires. I am worried some day he will manage to flex the rim enough to put the thing down.

Without these wheels he has no stopping power. I am curious as to where the frame and rocket pack will end up going, as the rocket pack and frame is dependent on the lad being on the bike to keep it in a straight line and bring it to a stand still at the end of the run.

And the lad hitting the road surface at 300km/h, well that is really going to hurt.

I was a week end drag racer many years ago and saw a very stupid surgeon lay a drag motorcycle down at top end where he was going about 150 mph (240 kph) - he survived but never operated again. Bet his insurance didn't cover that.

I saw EJ Potter "The Michigan Madman" step off his V8 Chevy small block with two wheels attached after he discovered it would not shut down at the end of the 1/4. He figured it was down to about 80mph when he left it. They found leaves and dirt in the cylinders after they unwrapped the frame from the block.

Wow! I remember EJ, saw him run in Houston. Man has to have balls of steel to ride that machine.

You can Google him, some amazing stuff!

He appeared to only brake right at the end, almost stopped....he obviously is V.careful.

Braking is done with hydraulic activated disc brakes attached to the hubs. Not worried at all about that. That is the one thing way over engineered on the modern bicycle. My 8" disc on my 29'er will, and has, pitched me over the bars if I don't feather the front brake. The wheel is still about the same as it was in 1960 (design like earlier steel ones - aluminum wheels came around sometime in the 60's) and as explained not nearly as rugged as the brakes. That is why I keep so many wheels as that is the one item most likely to get tweaked on a ride, after the riders skin.

The other frightening thing I see is the crank is still active - now that rear hub is supposed to free wheel when not pedaled, but..... and I see he doesn't put his feet on the pedals to be sure the hub continues to free wheel.

Excuse my error in my first reply to your post 14 - I looked at the pix again and those are old fashioned V brakes that grab the rim. That's a bit surprising because any rim flex and they will rub and scrub off some speed. Discs can be set up to be dragless, if you know how to tweak them in, and for the hub to flex - well - that's not going to happen. Wonder if he is only familiar with the first round of disc brakes which always seemed to drag a bit?

Oh well, since braking is not an issue on this application so why not go with a lighter set up such as he has?

I mounted a MAC 90 cart engine on a 20" bicycle and scared my ghost out.

Coaster brakes do not work properly above normal bicycle speeds, and the absence of suspension becomes noticeable.

Saints preserve us!

Coaster brakes do not work properly above normal bicycle speeds

Uh, yeah, that's for sure. That's why they make bicycle hubs with disc brakes - those things will grab tight enough to launch you if you're not careful. Get a bit hot on descents - the disc will glow red.

Dang, I thought my electric bike was neat!

There was a guy that was killed awhile back running a bike down a hill trying set one of these records. Seems the tires are not designed for the heat that builds up internally. I guess they just could not handle the pressure.

These folks that do these thing have a tendency to drive up everyones insurance cost because of the stupid stunts they pull. To bad you can't regulate stupid.

People will always try to set records and explore what is not possible. It is human nature to test theories and why is not 'possible'.

Insurance companies drive up prices as they do not like to loose bets. If people did not attempt these 'stupid' things NASA would not be exploring space, aeroplanes would not exist, cars would not exist, and all the nice technology one uses today would not exist.

Stupidity is regulated. Read the fine print in your policies.

Tyres need to be blown up to maximum pressure for running fast, for ANY vehicle.

Some previous land speed record cars have even had solid tyres in the past for that reason.

I run my car tyres at the maximum manufacturer recommended pressure for a fully loaded car. The result being a harder ride that you only notice for the first few days, lighter steering (yes even with power steering! Good modern steering gives feedback!), lower tyre wear and less heating of the rubber at speed/load.

Plus I find the car more responsive to steering.

I have NEVER ever had the "text book" tread loss in the middle of the tyre....they must have had double the max allowed or so (Guessing!).....

Many do not believe it, but tyres usually explode from overheating due to missing air pressure/overloading......and they can eventually explode, but the main danger is damage that can cause VERY sudden deflation at a later time with absolutely NO warming or warning.

Which is why its a good idea to feel the tyres occasionally (when stopped!), on any journey just in case there is too much heating for ANY reason!! I usually drive about 30Ks and then stop and check....

My English grammar just gets worse each time I post!! Apologies to all....

On the up side, my German Grammar keeps on improving!!!