Trail Question

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I can get my knee down with a 180. Scrubbing a 200 means you're really heeled in. If you want to get rid of the chicken strips sit on the bike (no hanging off) and push it under you (try not to crash while doing this). That'll use the rear up well enough for any posing opportunity.
 
Moved the forks up 4mm, for a total of 8mm of anodized tube showing above the top clamp. Pretty big difference. Turns much quicker with little effort, very easy to get the bike leaned over.

The only potential downside I can see is maybe less stability as pace increases.
 
bp_SFV4 said:
Moved the forks up 4mm, for a total of 8mm of anodized tube showing above the top clamp. Pretty big difference. Turns much quicker with little effort, very easy to get the bike leaned over.

The only potential downside I can see is maybe less stability as pace increases.
Click to expand...

It may also wheelie more and potentially drift wide on exit as it can effect anti-squat and swingarm angle
 
My calculated trail given Ducati's specs: 24.5 degree rake, 30mm offset and a measured 295mm front tire radius from the center of the axle to the ground is ~101.5mm trail. Going off the text from the book you posted, I should be at 100.5mm trail now (4mm change in fork height is about 1mm trail). I may go to 10mm of anodized tube to get to an even 100mm of trail.

I'm going to order that book. I have a flight coming up and it will be nice to have a good read.
 
baggerman said:
Raising the fork tubes in the triples adds anti-squat.
Click to expand...

Having more fork above the triples lowers the front of the chassis and decreases swingarm pivot height in relation to the rear axle. Therefore swingarm is more parallel to the ground and therefore has less anti-squat. Whether it’s noticeable is debatable. I don’t notice much difference
 
bp_SFV4 said:
I may go to 10mm of anodized tube to get to an even 100mm of trail.
Click to expand...

Don't do it. You're set up is starting to look like mine (even worse would be like Andy's he changed the head bushing which changes rake and trail l but leaves the antisquat and CG alone mostly). Totally dangerous, almost unrideable. The rear on mine is probably a bit higher though (steeper, more anti-squat).
 
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SuperDomestique said:
Having more fork above the triples lowers the front of the chassis and decreases swingarm pivot height in relation to the rear axle. Therefore swingarm is more parallel to the ground and therefore has less anti-squat. Whether it’s noticeable is debatable. I don’t notice much difference
Click to expand...

The front axle, rear axle and swingarm pivot describe a triangle. When you raise the forks in the triples the axles become closer together. The swingarm pivot moves down but less than the change at the front.
 
Raised another two. Surprisingly the wheels didn’t fall off. Did feel a slight bit squirly.

Lowered the forks so just 2mm of anodized tube was showing. With this change, from 10mm anodized tube showing to 2mm, one can see the tradeoff between responsiveness and stability. They’re not huge changes, but noticeable nonetheless. In the end I returned it to OEM with 4mm showing.

I want to actually measure trail and see if it’s the same as it calculates out to be. Adjusting trail is a backseat to getting the suspension setup. I used some custom fixed DES settings roadracerx provided a while back and I like the consistency of that over the dynamic.
 
bp_SFV4 said:
Raised another two. Surprisingly the wheels didn’t fall off. Did feel a slight bit squirly.

Lowered the forks so just 2mm of anodized tube was showing. With this change, from 10mm anodized tube showing to 2mm, one can see the tradeoff between responsiveness and stability. They’re not huge changes, but noticeable nonetheless. In the end I returned it to OEM with 4mm showing.

I want to actually measure trail and see if it’s the same as it calculates out to be. Adjusting trail is a backseat to getting the suspension setup. I used some custom fixed DES settings roadracerx provided a while back and I like the consistency of that over the dynamic.
Click to expand...

It's tough to actually measure trail in the real world. Best I could come with making a trail tool is some "straight" angle iron and aluminum bar stock and a tape measure and fixing the angle iron to the fork leg to get a "centerline". I used the bar stock as a straight edge to extend that centerline to the pavement. Then I took a straight edge to get a line perpendicular to the axle center. The difference between these points would be trail. I was a real faff. I ultimately said screw it because it's a relative number all said and done.

I've seen a laser pointer pointed through the steerer with front wheel and mudguard off as well.
 
I did a combination of things, I installed some Corsa frame bushings that pushed out the triples 10mm for braking stability. Dropped the forks to flush with the upper triples for stability and weight transfer to the rear for traction. And put some IMA triples on with a 31mm offset to quicken the steering and turn in. The only way I know of to get accurate chassis numbers is with a chassis program like Motospec.
 
Forewarned said:
I did a combination of things, I installed some Corsa frame bushings that pushed out the triples 10mm for braking stability. Dropped the forks to flush with the upper triples for stability and weight transfer to the rear for traction. And put some IMA triples on with a 31mm offset to quicken the steering and turn in. The only way I know of to get accurate chassis numbers is with a chassis program like Motospec.
Click to expand...

😱
 
Forewarned said:
I did a combination of things, I installed some Corsa frame bushings that pushed out the triples 10mm for braking stability. Dropped the forks to flush with the upper triples for stability and weight transfer to the rear for traction. And put some IMA triples on with a 31mm offset to quicken the steering and turn in. The only way I know of to get accurate chassis numbers is with a chassis program like Motospec.
Click to expand...

So what trail figure were you targeting? And were you suffering from brake instability?

Motospec uses the same geometry and trig as those simple spreadsheets. For doing simple trail adjustments, Motospec is a bit overkill.
 
SuperDomestique said:
So what trail figure were you targeting? And were you suffering from brake instability?

Motospec uses the same geometry and trig as those simple spreadsheets. For doing simple trail adjustments, Motospec is a bit overkill.
Click to expand...

I wasn't shooting for a specific trail number, I just needed my bike to finish the corners better on the gas. And I was also rubbing my front tire on the radiator shroud under braking at turn 14 of Thunderhill resulting in the rear tire dancing and coming up too much. So I was solving multiple problems when I did all those mods.
 
Forewarned said:
I wasn't shooting for a specific trail number, I just needed my bike to finish the corners better on the gas. And I was also rubbing my front tire on the radiator shroud under braking at turn 14 of Thunderhill resulting in the rear tire dancing and coming up too much. So I was solving multiple problems when I did all those mods.
Click to expand...

What trail figure did you ultimately arrive at? And was this for a V4?
 

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