Dragbike

[ehra]

All stock engines. Most times 1/8 mile racing.
This is a few years ago 5.5 slick, 65-66in, no lockup just heavy springs.

Now 7in slick, lockup, 67in, Dyna 4000sp.
We don't get to use delay boxes or throttle stops in our division.
It can run 6.30's but I shift at 8400 runs 6.60 so I don't have to keep my NHRA license current

 

[Hoosier Daddy]

Awesome stuff and great pics! I'm really keen on getting back to the dragstrip... this time on 2 wheels.
let me know when you are ready for some nooby questions on your setup

 

[rapidray]

Cool shots! Let me know when you are redy to go faster!!! Ray.

 

[Eli69]

how'd ya do against the 'busa?

 

[ehra]

Busa went red, Honda broke out, I won the final by about 6 inches ran 6.603 on a 6.60 the other guy ran 6.308 on a 6.30 dial.
Ray, thanks I will let you know if I need to go faster.

 

[trippivot]

bridging

bridging

very cool action photos!! Did you ever think that they are excellent tools for chassis tuning?

I waited to see if anyone else saw something to comment on - besides how cool you look winning on a mostly stocker.

I'd like to share an observation ... if I may..

There is a dragbike chassis tuning term called "bridging", it is when you launch the bike and have both the wheelie bar wheels AND the front tire on the track surface at the same time. You do not want both on the deck at the same time because it makes a few serious details wrong and unsafe.

I see your bike with the 5.5 tire launch and you are firmly planted on the wheelie bars while lofting the front tire in the air. That one looks great!! You want the front tire clearly off the track but low enough to clip the timing beam with the wheel not just the lowest edge of the tire.


can you can see what I am talking about ? (1st pic at the top is set good, the rest bad-except the #3 pic where you are still sitting still)

Weight transfer , traction , steering , and proper rear tire air pressure are all effected by BRIDGING.

lift your wheelie bars up a revolution or two. You may still have to experiment with rear air pressure when you get 100% weight transfer on the launch.
Micro bar adjustments can be made for steering after you get in the right rear tire pressure range.

use it for what it is worth, I just hope you don't mind the observation.

 

[ehra]

Thanks for the advice, this was the first evening with the new rear setup. That evening I raised the bar a little every pass and added static to the clutch. I settled with the bar 2 inches higher at rest by the next race. The pictures are a great tuning tool. I REALLY did not like the way it left with all five wheels on the ground.

 

[rapidray]

5 wheels? Ray.

 

[Eli69]

6.603 on a 6.60 the other guy ran 6.308 on a 6.30 dial.

that's tight. damn thousandths of a second.

how bad did the busa guy redlight? i use this information to torture my punk kid and his busa. you do not wanna know what he says about gs's. kids....