39.5 mph trying to break 40

G

give me vtec

New Member
since my new grubee is broken in, I finally got a chance to tune and weld my expansion chamber properly.

Its amazing what these things can do... after i set the notch on my carb down a space, i hit 39.5 on a straight with no other engine mods other than a filter. I am going to work over a few things and see if i CAN GET IT OVER 40.

thanks for looking... any comments or suggestions are welcome.

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Right on nice job!

Wait for the torrent of reply's stating that a bike speedo dont mean crap , need a pace car , or a gps yada yada yada.
 
muddybike said:
Right on nice job!

Wait for the torrent of reply's stating that a bike speedo dont mean crap , need a pace car , or a gps yada yada yada.
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it's cool.... I value all opinions.

to be honest... the speed really isn't what I'm excited about. it's not my first fast mb.

I'm really more excited about the fact i did the welds... I just got my first welder and learned how to use it last month. asside from my practice welds, this is my first real welding application.
 
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You either have less brains than me or bigger _____ than me to want to go that fast on a bike.

Very nice welds for the first try.......mine still look like chewed bubble gum after many tries.

Does the exhaust throw oil on the rim?
 
TxBikeRider said:
You either have less brains than me or bigger _____ than me to want to go that fast on a bike.

Very nice welds for the first try.......mine still look like chewed bubble gum after many tries.

Does the exhaust throw oil on the rim?
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Yeah, my wheel is already dirty from the oil... I'm used to it. That's why I buy $80 craigslist bikes now.

Thanks for the nice comment.
 
TxBikeRider said:
Got to ask......at those speeds, do the oily rims smoke before they start to stop?
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Lol... No.

I have lots of open road with little traffic in my area.... When I open it up I make sure I have plenty of room to coast to a stop if needed, I don't really use the brakes that much.
 
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i can't see the pic either. unless it's supposed to be a red "X." not too many 55+mph bikes out there.

but i do know of one...;)

if you wanna get up to 40, you just gotta tuck a little more and find a tailwind.:)
 
the next thing you have to think of is not the motor but the wind. after you get past 15 mph the majority of power goes to moving the air around your body. it takes more and more power to go even a little faster.

I would look at how long are your handle bars. you might try to cut a couple of inches off the ends of your bars and see if you can get your back flatter. try to avoid a more upright position. My seat is about six inches above my handle bars. The way I have my bike set up is about half as far down as I am on my road bike on the drops.

I was riding my motor bike without the motor going down hill behind a person on a cross bike. At the time I did not have a very big top gear about 73 gear inches, but I was able to catch up with him just by coasting.

The fastest bicycle on record now is 67 mph and that is with just pedaling.

mike
 
retromike3 said:
the next thing you have to think of is not the motor but the wind. after you get past 15 mph the majority of power goes to moving the air around your body. it takes more and more power to go even a little faster.

I would look at how long are your handle bars. you might try to cut a couple of inches off the ends of your bars and see if you can get your back flatter. try to avoid a more upright position. My seat is about six inches above my handle bars. The way I have my bike set up is about half as far down as I am on my road bike on the drops.

I was riding my motor bike without the motor going down hill behind a person on a cross bike. At the time I did not have a very big top gear about 73 gear inches, but I was able to catch up with him just by coasting.

The fastest bicycle on record now is 67 mph and that is with just pedaling.

mike
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Willing to bet a big mother fugging hill was involved too, and i would be willing to bet $$$ to donuts he wasnt going uphilllaff
 
here's a little blurb about that:


The main body overseeing this kind of endeavour is the International Human Powered Vehicle Association, which sets rigorous conditions for acceptable records. The outright speed record is based on speed over 200 metres, with a flying start, maximum allowable wind of 1.66 metres per second and a minimal down-slope (less than 1 percent). Devotees have scoured the world, especially the USA, for an ideal stretch of road and for the past few years have focused on a highway at Battle Mountain, Nevada.

This is where, in 2002, Canadian rider Sam Whittingham reached a speed of 130.36 km/h (81 mph) in the Varna Diablo II. This is a fully-faired, highly aerodynamic recumbent bike: the rider is virtually lying flat and the fairing is taped into position to minimise drag. (Considerably faster speeds - over 150mph - have been set on bicycles in the slipstream of a pace-car but that rather defeats the object.)

(from: The world's fastest bicycles: human speed records from 200 metres to 24 hours and beyond)

wind resistance takes on a huge factor once you start getting beyond normal pedaling speeds. i was using the "drafting/slingshot" effect on the last LA ride to fly passed everyone. pull in right behind a truck, draft it for a few seconds, then blast out from behind it.

i can't say i recommend/condone that (or any other) technique, but man has a built in desire to go fast. people will cry "oooh, it's just a bicycle, you'll kill yourself..." but we'll still do it.

it would kinda suck to have that on your tombstone, though. "he died riding the fastest moped in town..."
 
If I remember correctly it was John Howard went over a hundred and fifty behind a dragster with a wind barrier at the Bonneville salt flats in Utah in 1985

the new record is even faster. Like I said before its not the power its the way you get through the air.

The next thing I might try is to put a fairing on the front of my motor bicycle. perhaps it will work. right now I don't have a shift kit but I have been wondering if it causes more loss than its worth.

My bike right now has a disk brake hub that I set up with a kings rear cog and its a 36 tooth it seems to go at a pretty good clip, but the R.F. killed my speedometer( I now have a shielded spark pug wire.)

when I get it installed I will let you know how or if it made a difference.

Mike
 
TxBikeRider said:
it was a wait of over 24 hours........but we all knew it would happen.



I wonder.....if we continualy call each other liars, does it help? Really I have an issue with many who seek speed on the streets....but the seeking of speed has led to great improvements no matter where you look. Automotive, Air or space......they all have contributed.
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you don't think quality comes with a price? obviously if you spend less on something you generally expect it to be lower quality then a more expensive competitor right? thus a cheap speedometer will probably give you inaccurate readings and push you over that last .5mph.

i was assuming the reading you had was accurate, clearly your speed readings are a very sensitive topic for you.
 
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