Sportster drags

[Hightop]

Originally Posted by conv90

very short forks , very short shocks , 6000 rpm and dumb the clutch and stock tires, advanced position seat? Is this the recipe to not flip the bike while letting the clutch lever? With my sportster if I let the clutch like this, I can't avoid tipping over..

When you use short rear shocks, the swingarm pivot is much lower than the center of gravity, all your power is pushing here, forcing the front up. Better to use shocks resulting in a level swingarm angle, IMO

If you tie the front end down instead of lowering it, you force the bike to raise the weight from the lower legs, brakes, and wheel and tire right from the hit, making a wheelie more difficult. If it's just lowered, you'll get an inch or so of extension before making it do the heavy lifting, and it's already moving in that direction, kind of like it's easier to wheelie if you pull back on the bars when you crack the throttle to get it moving

[Tomcatt]

Originally Posted by conv90

very short forks , very short shocks , 6000 rpm and dumb the clutch and stock tires, advanced position seat? Is this the recipe to not flip the bike while letting the clutch lever? With my sportster if I let the clutch like this, I can't avoid tipping over..

Don't "dump the clutch". Slip the clutch to control wheelspin / wheelies. Adjust your launch rpm so you can pretty much hold the throttle wide open thru first gear while slipping the clutch.

[conv90]

Originally Posted by Hightop

When you use short rear shocks, the swingarm pivot is much lower than the center of gravity, all your power is pushing here, forcing the front up. Better to use shocks resulting in a level swingarm angle, IMO

If you tie the front end down instead of lowering it, you force the bike to raise the weight from the lower legs, brakes, and wheel and tire right from the hit, making a wheelie more difficult. If it's just lowered, you'll get an inch or so of extension before making it do the heavy lifting, and it's already moving in that direction, kind of like it's easier to wheelie if you pull back on the bars when you crack the throttle to get it moving

Correct. I see now the video that alla are with front tied.
About the rear it seems they are all with very short shock with the pivot point of the swingarm slightly lower that the center of the wheel (probably almost rigid like ).

[conv90]

Originally Posted by Tomcatt

Don't "dump the clutch". Slip the clutch to control wheelspin / wheelies. Adjust your launch rpm so you can pretty much hold the throttle wide open thru first gear while slipping the clutch.

I was referring to the video. It seems they are all skilled guys.
They dump the clutch, you can see for example the second pass of the guy in the left lane letting the lever during start.
There is no squat , the bikes seems rigid.

[madnss]

Originally Posted by conv90

very short forks , very short shocks , 6000 rpm and dumb the clutch and stock tires, advanced position seat? Is this the recipe to not flip the bike while letting the clutch lever? With my sportster if I let the clutch like this, I can't avoid tipping over..

There is only one recipe and you have to find it yourself. I sent my 17 year old son on a 6000 rpm launch, only because I firmly believed I knew what the bike was gonna do. It did both with my combo, it ran like hell and it also blew the tire off.

Imho any bike with an adjustable clutch has the advantage.

[Tomcatt]

Originally Posted by conv90

I was referring to the video. It seems they are all skilled guys.
They dump the clutch, you can see for example the second pass of the guy in the left lane letting the lever during start.
There is no squat , the bikes seems rigid.

Look more closely. As he stages he lets the clutch out to where the friction point starts and then feeds it out when he launches.
Their rules must prohibit struts. The rear shocks many are running appear to be bottomed, on the bump stops, effectively struts. Along with tied down forks. It looks like a pretty serious bunch.

[wrkdWS6]

Them boys can ride, fun to watch them in person. They really get those bikes moving out the hole.

[rejeanprimeau]

You need at least one flip to start understand why you have a clutch.