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Unless there is a ton of speed parts for that it will be a waste of time. 50cc street bikes and 50cc race bikes are worlds apart. Other than the capacity they bear no relation to each other.
 

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quote:Originally posted by Hoofhearted

Unless there is a ton of speed parts for that it will be a waste of time. 50cc street bikes and 50cc race bikes are worlds apart. Other than the capacity they bear no relation to each other.
The local club has a Derbi class. They actually have them going at a good clip. If your bike is slow as shit but so is the person your racing, it makes for a good race regardless.

Aaron
 

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Ask not nicky . . . he's a winner and yes, they make SPEED parts!! That thing is FAST.
 

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I was thinking of a 20hp (+ or-) with a top end of around 115 or so. And you a are correct in saying that speed really doesn't matter if the racing is close.
 

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we got the 80cc reiju up to 105mph.

top end speed and corner speed are two entirely different things all together.

texy
 

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Tex, you must admit that bike was worked to the hilt. Hoof was running an air-cooled (van veen?) Kreidler in their heyday, those bikes put out 20 or so ponies and most of the contenders made and topped those speeds. 30 years ago. If that class had continued to flourish the tech that would have been developed... it boggles the mind. Really. Totally different approach to engineering than today's street 50's.
 

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The biggest difference between racing 50s (of my time) and road 50s was rideability. My Kriedler (it was a VanVeen) came with a dyno cert for 20hp at the crank. The power band started at 14,000 and it could be revved to 17,000 if you were in a hurry. Under 14,000 there was nothing. Its engine life was 150 miles. You had to keep a log on all practice and racing miles as it wouldn't last more than a couple of miles beyond 150. Streetable it wasn't. It was clockead at 112 in the Isle of Man. In the same race Robert Dunlop was clocked at 115. That was on the flat. Carrick had a slight downhill straight where Robert could top 120 and I could get about 118. Those figures pale compared to one works VanVeen that was clocked at 128 in Holland. One of the problems in "racerizing" a street 50 is the engine. The ports are too small and usually there isn't enough metal to get them big enough. To make enough power the rpm ceiling has to be raised radically. Bearings don't last and finding genuine race bearings to suit your application can be difficult. I've seen a number of attempts at converting a street 50 and none of them were particularly successful. One attempt was we grafted a Minerelli cylinder onto a street Garelli. The rpm ceiling went from around 7000 to over 12,000. You could pee longer than the crank would last. Its one of those things. If you want ot race a 50, get a racer.

105 from a street 80 is extremely impressive!! You should think about bringing that to Bonneville. You could kill a few 100cc records with speed.
 

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I always said modern 80cc racing would be fun. If eveyone had Kreidlers or if everyone had RS125 with cr80 motors in them, that make for a good race. I never got around to building one, but the idea still lingers in my mind.

Aaron
 

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A friend that just moved to Texas has an RS 125 with an 80cc motor in it. Looks pretty cool. But a late 70s/early80s VanVeen Kreidler would kill it.
 

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no question the difference in tech between a g.p. racer and a glorified moped (sans pedals) made up like a streetbike. frank uch giannini & cosmo worked with dr. wagner and his daughter terry to set some LSR records back in 98' or 99' in the 100cc class. i saw the porting to those heads and cylinders...it was impressive. here is what "uch" has been up to lately......

Dateline: September 28th, 2003
Location: East Coast Timing Association, Laurinburg Airport, NC

F.F. Giannini readies Dave Meyer at the starting line while the ECTA techs his minimoto.

Dave Meyer of Virginia Beach, VA makes it official. The new land speed record for a pocketbike is 63.888MPH. Riding a 50cc minimoto built by F.F.Giannini of Giannini Racing with a 50cc custom barrel designed by Trevor Sellars of the United Kingdom and special porting work by Scotty Finlay breaks the existing record and goes over the 55MPH mark. The new engine design which included a Giannini Racing PVL digital ignition and a Giannini Racing custom built cylinder-head ran flawlessly through multiple runs down the one mile airport runway under the guidance of the ECTA personnel.

here is some more of his craft:


this little piggie spins to 17,000 rpm


this 4 stroke 90 spins to 16,500 rpm. it's so powerful it has already been outlawed by some mini moto sanctioning bodies.

he is also working on a new super secret development for the world of mini moto racing....this new project will again put mini moto on it's head when he is finished. he is truly a mad scientist and an awesome tuner!

texy

links: http://www.gianniniracing.com/r-2.html
http://www.gianniniracing.com/r-3.html
 

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Discussion Starter #12
Dude's wearing full leathers, gloves, helmet, and..... dress shoes. lol


But crazy 4 stroke engine. 16,500 is what the Yamaha 600RR revs to. Insane from a little single. I feel sorry for those little valve springs. The must have a lifespan measured in minutes.
 

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funny! they look like doc martin steel toe shoes.

uch built a dyno for developing the mini motos. he said when the 4 stroke is wound out, he feels like he should be wearing a flak jacket standing that close with his hand WFO on the throttle. says he hasn't thrown a rod yet.

tex
 

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Those are some impressive figures. Especially 63mph out of something you can't tuck in on. I'd love to see where the power band on the four stroke is. I can't say I blame him for wanting a flak jacket. On some of the road courses where the race length was maybe 30-35 miles and you were tucked in for most of the lap the ringing off the Kriedler would have you hearing funny for a couple of hours afterwards. Heres a link to Aalt Toersen's Kriedler on a dyno. A couple of times you can hear it hit the pipe. Sweet sound (for a two stroke that is).
 

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Nice link, absent the gay music. But I know others in here like gay music, so enjoy.

Check the pass at 4:37 on the clip. I'm going to do that to sotomoto next year.
 

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Wow. Hey Unga what track day are you doing on Thursday? Isn't Carl 101 on Wednesday?
 
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