Aftermarket Triple Clamps question

So you're saying they would physically change the angle of the steering stem by altering the frame... then to compensate for the reduced amount of trail, they would increase the offset so that the trail was near the stock dimension?

 

^^ i thought you said offsets don't change the rake... (to emry paper)

 

I dont think he literally meant "offsets were used to decrease the rake angle," I think he meant "after the rake angle was changed, offsets are used to keep the trail close to stock."

 

No, late 90's superbike rules only allowed material to be added to OEM frames, no cutting or removal was allowed. The steering stem was never moved relative to the frame. By changing the fork axis (via the insert, adjustable triples were allowed) and the offset (same insert) you could decrease your rake angle and add offset to keep the trail you would normally lose. Angles were normally 0.5, 1.0, and 1.5 degrees with about 15mm of offset change available if I recall. Yes these upper and lower are machined as a set and color coded, they could be reversed though to add rake and decrease offset for example. Mixing and matching is not possible.

Changing only the offset does not change rake angle.

Tillerpilot - we are talking race bikes right? Ignition switches are not a concern and steering stops are (should be) already extremely limited. Early clamps had differnent positions for the stops to be attached, later versions used a eccentric.

Here guys, play with some math.
http://www.tonyfoale.com/software.htm

 

I don't quite understand how that works. Are you saying you would change the offset of each the lower and upper in different amounts to change the rake and keep the same amount of trail? I feel mildly retarded right now.

 

Johnny had the upper and lower triples on his 06. I remember looking at them one day

 

^^ oh ok.

 

Assume the inserts are machined as a pair, at the same time. When the hole is drilled for the steering stem, if it is 0degree vertical and in the center of the insert you have same rake and offset as stock. If you drill at 1degree off of vertical and 10mm away from center you would change the rake by 1 degree and the offset by 10mm. So by changing the angle and the point at which the hole is drilled you can alter the rake and offset as desired. Of course the actual machining and math is a little more involved than that. Look at the orginal pic I linked, notice that the black insert is centered, but the reds are offset. Black was stock, reds were a different angle and offset.

 

^^^ gotcha... couldnt tell the holes where cut at an angle.... everything is crystal clear now. Thank ya

 

The holes in the clamps and the inserts on those Yosh triples are not cut on an angle...they only change the offset from the stem to the center line of the fork tube.

 

ahhhhh!!! Ok, those exact pictures show just a triple assembly that changes offset, but hypothetically speaking, you could cut the stem holes in the inserts at matching angles so that when they are inserted in the triple they change the rake angle, right?

I don't know why I'm so worried about rake, I don't have any intentions of changing it... guess I'm just curious.

 

Lets just say it would be a very complicated setup, it would be far easier to use the off set bearing races, and they can be a pain in the ass...I wouldn't worry so much about changing the rake.

There are a whole lot of really fast guys running around with stock trees and it doesn't seem to hinder any of them...spend the money on tires, seat time.

 

I agree with Britt, unless you are trying to hop up a superbike from a decade ago just run what you have, most manufactuers got their geometery pretty close on anything modern.

Sorry I get caught up in the tech questions. I plead the "he asked..."

 

Thank you, that is what I have been saying for 4 pages now.

 

yeah, had no intentions in taking it this far, but it just kept going so i kept asking questions.

I def agree with britt also, at this point I won't change anything geometry-wise bc I def. am not pushing my bike. thanks for the input tho guys, big help

 

good reads, thanks

 

The guy that started this thread is talking about making parts for his streetbike, that he does track days with and he only has a picture that someone posted, to go on.
I'll guarantee he still has and ignition switch and needs to plan ahead for that issue, Attack offers plenty of ignition mounts for their clamps, but you are responsible for your own clearance issues. As far as steering stops, I wanted him to realize that making one dimension adjustable requires many things to be adjustable. If he draws this all up in Solidworks ten times he'll be wishing he chewed on a slug before it is finished.

 

It's actually straight race... no ignition, just a toggle. But thank you for giving me things to think about prior to design.

 

Video With Offset Triple Info

Video Posted on OTT with good info on offset triple clamps....

Updated Print Information

Todd

 

Good info.