First time on the dragstrip!

[Guest]

Got the wheelie bars mounted this week. With the longer swingarm, the old upper mounting points didn't work. I wound up welding a couple 3/8" coupler nuts to the underside of the frame. I don't weld often; one looked good but on the other side I blew a hole in the frame tube. A buddy of mine with a lot more experience patched the hole with his tig. Should be good to go!

Hoping to do some shakedown runs this Saturday.

 

[storm 64]

Got the wheelie bars mounted this week. With the longer swingarm, the old upper mounting points didn't work. I wound up welding a couple 3/8" coupler nuts to the underside of the frame. I don't weld often; one looked good but on the other side I blew a hole in the frame tube. A buddy of mine with a lot more experience patched the hole with his tig. Should be good to go!

Hoping to do some shakedown runs this Saturday.

Sounds great! The wheelie bars should be good for about a .5 of a second. Plus it will help with your consistancy.

 

[Guest]

Progress last night ... did a handful of passes in the 10.1xxs, with a best of 10.150. The sixty-foot time for that run was 1.613. The wheelie bars definitely helped. If nothing else they let you think less about clutch control.

The engine's running well, though I'm going to probably lean out the needles a clip, and the main jets a size, depending on what the plugs look like.

The big challenge / unknown is chassis tuning. My friends / pit helpers say the frame's flexing a lot, like it's hinged in the middle (and that's what it feels like). The rear tire is lighting up during some passes, not in others. I played around a bit with tire pressure and wheelie bar height, but still thinking on what's working and what's not.

 

[bobgroger]

Progress last night ... did a handful of passes in the 10.1xxs, with a best of 10.150. The sixty-foot time for that run was 1.613. The wheelie bars definitely helped. If nothing else they let you think less about clutch control.

The engine's running well, though I'm going to probably lean out the needles a clip, and the main jets a size, depending on what the plugs look like.

The big challenge / unknown is chassis tuning. My friends / pit helpers say the frame's flexing a lot, like it's hinged in the middle (and that's what it feels like). The rear tire is lighting up during some passes, not in others. I played around a bit with tire pressure and wheelie bar height, but still thinking on what's working and what's not.

You are doing great! Way better than me, I am scared to launch decently with a stock wheelbase no bar bike. I am going out a week from Wednesday, hoping I do better. I have also lost 60+ pounds since last time I was out pre-Pandemic. Should be good for a couple tenths. And my leathers fit now. Actually, that was the whole reason for the diet. I was too cheap to buy bigger leathers

 

[Rob S.]

I've just read the whole thread, and I didn't see where you mentioned what bike it is, or was. For some reason I'm under the impression it's an 1150. Whatever it is, 10.15 is damn impressive. What mph did it do?

I've read that even if a bike has a slower E.T., if it reaches a higher mph, it means it's a more powerful engine, and would probably win in a longer race.

Some pics of the entire bike would be nice. Are the wheelie bars removable? Could it still be street legal?

 

[steve murdoch]

A bunch of passes under 10.20 is fantastic!

 

[Guest]

@Rob S. the bike started life as an 1150, but has a 1229 kit in it. The best time was at 132 mph. What still blows my mind is that my top speeds have been pretty consistent, even as the elapsed time drops (My best ETs of 10.755, 10.392, and 10.150 were all at 131-132 mph.) Intuitively if you're getting 'up to speed' more quickly (especially as the 60' times drop) you'd think you'd also get up to a higher top speed ... at least that's how my intuition goes.


I'll get some more photos. Yes, the wheelie bars are removable: two 3/8" nuts at the bottom, two 3/8" screws at the top. Bike could be put back on the street, but would be very 'purposeful', with the total loss ignition, square tire, etc. Let's say that I'm not planning on riding it on the street! Per my earlier post, getting the wheelie bars 'tuned' is a big to-do. A friend is willing to loan me his GoPro. I figured I'd put it on the facing rearward, to get an idea of what the rear tire and the bars are doing.


Thinking back on my many years road racing, if I did it over again (or if I pick it back up again), I would have run a video camera during practice ... not to post social media videos but as a training tool. I don't know about other folks but I can only take in so much information while I'm riding. Being able to truly 'replay' what happened, after the fact, would be helpful. Any suggestions on this front are appreciated.


I pulled the plugs today and they look pretty good, so I might just hold on the jetting.


Next step on the mechanical front (besides wheelie bar tuning) is a lockup clutch. I'm talking with @rapidray and he's getting me set up with a two-stage setup. After that I'll probably start heading to the bracket races on Wednesday nights (though I'll probably still do Friday/Saturday 1/4-miles, because they're fun!)


I rode my Husky up to the bracket races last Wednesday night at PIR, to check it out. There were a half-dozen bikes there, from a stretched Hayabusa with nitrous, to a couple well-loved (and well-worn) SOHC Honda 750s.


@bobroger, I hear you about launching a stock wheelbase bike without bars. I'm still getting comfortable launching a stretched bike with bars! What's your local track, SIR? (I see Enumclaw next to your name on the forum.)

 

[Baatfam]

A slider clutch, with a 1-2-3 auto cut trans would help a ton.....

But it won't be street ridable anymore, and you need a tow scooter.

 

[Guest]

Finally got my hands on some photos from my friend Seth, here's one:

 

[Guest]

Getting ready to go out:

 

[Guest]

Just got a shipment from @rapidray - thank you! Lockup clutch parts!

On the hunt now for some tired clutch springs, for initial setup. I think I have a couple handfuls in my spares boxes. Bringing the bathroom scale to the shop, to use with our press ...

 

[rapidray]

Any luck yet?
Ray.

 

[Guest]

I got the lockup clutch installed last week, and finally broke into the nines this Friday!


Initial passes were with ~190# of spring pressure. The first pass the bike hooked up real quick - I figured that ?I?ve got it!?. The second and third passes, though, the engine bogged pretty good off the line. I suppose the clutch was hotter those additional passes.

Pulled back to the pits, replaced the six ~32# springs with three ~50# springs. (The 32s were the lightest I had, so the only way I could think to drop the spring pressure was to run the clutch with fewer springs.). That gave #150 spring pressure.

The bike then began launching real well; no bogging, but I don't think too much slip either. 60' foot times were down in the 1.4s; without the lockup the best I could get consistently was 1.7 or so.

I did around four or five passes at 10.0xx; the nines were so close! Finally the starter recommended I line up in the 'groove' at the start (seems obvious now, but ...). Then I broke into the nines, with a 9.941! Very excited!!

Big thanks to @rapidray for the initial setup recommendations on the lockup.

 

[Guest]

I wound up buying a 0-100# spring scale from Comp Cams, to measure the springs I had. Luckily they were all pretty close to as-advertised.

 

[Guest]

Off the line; photo from my friend Ned T.

 

[Baatfam]

A 1.4 60' is very respectable.

 

[Rob S.]

9.anything is very respectable! That's an old liquid cooled 750 your running, correct? Well done! :clap:

 

[steve murdoch]

Congrats on getting into the 9s!

 

[Guest]

9.anything is very respectable! That's an old liquid cooled 750 your running, correct? Well done! :clap:

His bike is a gs1150 air cooled motor.

 

[Guest]

Great job on the improvements and getting into the 9.?s.