72 frame for flattrack?

[wildman]

All that talk about Maico killing 72 Piner framed 400 got me thinking. I know nothing about dirttrack frame specs but I've got a 72 chassis to use. What would be needed as far as setup changes or even different forks or triple clamps to work even fairley well at dirttrack or ice. Any suggestions? My low budget version of a KR/Penton Special. Thanks, Wildman

1975 250 Cross Country, 1974 175 Jackpiner, 1975 125

[firstturn]

Wildman,
  Interesting take on building a low budget Penton Flattracker.  In my opinion you need to get the rake changed to where the bike will turn[^] and work on the overall height of the bike to bring it into the concept of following the frontend through the turns.  I can lay out the rake angles and height for you if I can get some time off work or possibly some one else can measure the rake of their  Kenny Roberts Penton.  Great Idea.

Ron Carbaugh

[tmc3c]

I hear you wildman!!!Spool wheel and a flat tracker seat,down swept expansion chamber and you are ready to go!!!

Thomas Carmichael

[Larry Perkins]

If you want it to turn like a short tracker run Marzocchi triple clamps that were for the leading axle forks and put in them 35mm Betors.  If all you have is Ceriani straight legs run 14"-14.5" shocks. Throw it sideways.

Larry P

[wildman]

Thanks for the replys. Firstturn, could you amplify the concept of the bike following the front end. I think this means more weight on the front end so the rear can slide? Longer shocks brings in the front end and quicker steering. Changing the triple clamps for less rake should do the same thing. What I'd like to know is proper fork angle and swingarm angle, I know these make a huge difference in handling. Any other critical factors? BTW, I knew a fella by the name of John Kolenda who raced dirt track on an XR750 and thats what he said " Hundred miles an hour into the mile turn and just throw it down, Just THROW it down" Shiver!      Thanks, Dan Pagel

1975 250 Cross Country, 1974 175 Jackpiner, 1975 125

[rob w]

Oh Danny boy, I've got the set up for you. You'll can use the triple clamps off of a steel tanker. The straight-thru holes and the fork tubes being off-set from the handlebar clamps allow you to slide 35mm forks up as much as you'd like. Making the fork angle steeper. I also have some 35mm Betors you can have.

The whole thing about having a steeper rake in the front end is more important in short track than it is in half-mile. Around here there's not many short tracks, and it's not like you'd ride against pros so it matters even less. Having a fast motor and a 19" front wheel is more important to get started, then you can always modify it more as you get more serious.

Side Note: I was telling Dan the other day, I've had this plan for awhile to build a Penton streetbike. That's why I kept a '72 Piner frame and that's why I bought a 400 engine a month ago. Yeppers, someday, coast-to-coast on a Penton. What'a ya think?

Bob

[tmc3c]

Hey Bob,Remember a while back there was a Monty who visited POG and he worked for NASA and he had a 400 that he was making a street bike out of it.I haven't heard from him in a while I wonder if he completed it.....also on the flat tracker,they don't seem to get them sideways like the old days ! Even in the short tracks,could it be the tires of today? There used to be a guy named Jimmy Manus who was from Augusta G.A.and on a XR750 he would go into the corner and pitch it sideways and it looked like the handlebars would rub the ground.

Thomas Carmichael

[wildman]

Bob W, sounds great. I'm sure we can trade stuff, you're too generous. I have a 19" front wheel from my ice racing days, it was on my 250 Penton. I have been looking at a KTM motor ina crate at Slicks, maybe I'll ask about it tomorrow.Man, this might really come together.
Your street bike idea reminded me of a guys 175 Jackpiner I worked on back in Dirt Works days. He kept coming in with a seized piston. We would repair it and he would come back in
a week or two seized again (pretty pissed after awhile). Couldn't find any reason why. It turns out he road rided it most of the time. I showed him how to richen with the choke slide and never saw him again

1975 250 Cross Country, 1974 175 Jackpiner, 1975 125