A class, PS class discussion

[ol38y]

Eric, as Slim said I would be careful about changing the attitude of your bike to drastically. Slim had the ability to accelerate out of the problem. You, probably will not with your 250. You might want to look into a lowering link that would maintain your original suspension. Then, I would think, you'd want to lower the front as well. Have fun on the salt and go fast. Wish I could be there.


Larry

[racer x]

 What I have done is lower the back about an inch .Using lowering links. . Not to drastic. It gets more of the fairing above me and makes it easy to slide bask. I am a big guy on a little bike.Yes you are correct.I can not accelerate more. I have only 30 hp to work with. It is more the weight that I have removed from the front fairing and the sliding back part that makes me wounder if it will shake its head with 40 or 50 hp. And What is the plan when or if it did. Let off or hold the throttle? let go of the left grip ? jump?
I am sorry for taking this post so far off topic

[tomsmith]

Dean is right.  Flexing anywhere in frame or suspension is asking for it.  You can get a wobble caused by any (or all of) three different kinds of problems; the standard wobble, a rear suspension weave or the capsize mode.  Excess trail can cause a wobble, and a steering damper can cause a "weave" wobble.  I personally would hate to get my front wheel sideways more than a degree or two at high speed.  If you hit the steering lock you are in deep doo doo.  The 15 degree lock is wishful thinking unless someone can explain it to me more better than I think.  Once you get it rigid, then start on weight and aerodynamics.

[John Noonan]

I have always run less than the required 15 degree minimum, if you want to know why come by the SDRC pits and I will Show/Explain it to you.

John

[DahMurf]

I have always run less than the required 15 degree minimum, if you want to know why come by the SDRC pits and I will Show/Explain it to you.

John

Ok, count on me for the in person demo! If I can retain it all I'll pass it on to Eric at the next ECTA meet.

Deb

[ol38y]

Since I won't be able to make it to the salt this year, does it have anything to do with your fairing?

Larry

[Dean Los Angeles]

My first lesson in frame geometry was with a Kawasaki 500 H1 triple two stroke. I borrowed one from a friend and went canyon jammin. The (insert cuss word here) poor swing arm bushing and feather weight frame flexed like a mad man. When you stuffed it into an "S" turn it would go in ok, but loading twisted the frame. When you came up and wanted to go over the other way you were off to the races. Actually making the corner was optional. Whoo Hoo!

A lot of steering angle is a good thing if you need it. I had the opportunity to test a speedway bike at El Mirage. Full lock and WFO. Hard to get more fun than that.

Restricting steering to 15 degrees or less is not a bad thing. More isn't needed for LSR. It just doesn't have anything to do with saving your butt when your less than perfect setup catches up with you.

[tomsmith]

I happen to own an original owner (me) Kawasaki H1 and I agree that going around corners is scary.  Modern bikes are so much better that it is hard to remember what the single tube backbone frames were like (unless you own an H1).  Steering locks are great to keep your fingers from getting smashed, and I believe in them - especially if they are really sturdy.  I have only been in two tank slappers at 150 mph, so I have no experience going fast.  My first 150mph tank slapper happened so fast that I didn't realize what was going on until I noticed that I was was off course and going in a different direction.  In the second one I kept going sort of straight.  Note that modern swing arms look like girders and frames are wide with lots of gussets (like Ducati) or with alloy box sections.  Manufacturers have learned a lot about rigidity.

[ol38y]

Dean says,
Restricting steering to 15 degrees or less is not a bad thing. More isn't needed for LSR. It just doesn't have anything to do with saving your butt when your less than perfect setup catches up with you

Well said Dean. That's the point I have been trying to make.

[racer x]

I learned to ride on an H1 500 triple. I loved the bike. I was 15 years old weighed 125 lb soaking wet and did not know the first thing about riding a motorcycle.It was that or a 900 z1
  The closest I have come to a tank slapper is setting down the front wheel. It was not straight and it all most through me.I still have a lot to learn.

[tomsmith]

My tank slappers were both on a fuel Triumph 650cc.  I have had some squeamish moments on a Harley big twin, but nothing remotely close to the Triumph.  Back in the dark ages when I was 18-19 years old, I weighed 124 pounds - about 100 less than I weigh now.  This helped out on my Harley Hummer and at drag races, but was a big detriment at Bonneville. 

My H1 really sounds nice when riding it - almost as good as my Ariel Square 4 did.  But off to the side it sounds like my Hummer.