G: Gearbox (Single - Burman) Burman Clutch Arm 175X

[Martyn Goodwin]

Just wondering, in the search for lighter operation AND a more progressive action between engaged and disengaged, has anyone ever considered a modified clutch operating lever 175X where it is lengthened (as much as possible, and that's not a lot) in order to get some increased leverage?


Martyn

 

[Bill Thomas]

How about trying an 1.1/4" Pivot on your handle bar lever,
That's what I use.
Cheers Bill.

 

[Peter Holmes]

Surely you are going the wrong way Bill, if you are wanting a lighter clutch lever don't you want the distance between the pivot point and the nipple to decreased, not increased, I think it is the 7/8" handlebar lever that you want.

 

[Bill Thomas]

Don't know.

 

[Peter Holmes]

Don't know.

Well Bill, with the 7/8" lever you get more force from what is effectively the reduced distance of the fulcrum point, hence less effort required at the lever, but the trade off is you get marginally less clutch plate disengagement in relation to the available handlebar lever movement.

 

[Comet Rider]

Hi Martyn
I looked at this while my Burman is in bits, and there is not really enough room under the cap to lengthen the arm.
The limiting factor is the combined pushrod ass'y especially the stepped rod that the bump on the arm pushes against. I am re-designing these parts when I put it all back together, put as all the others say you can get a better feel by putting a higher ratio lever on the bars.

Neil

PS
There is enough room to put a Magura hydraulic conversion on, but if doing so I would put an axial needle roller on the end of the push rod before the clutch plate

 

[timetraveller]

If anyone wants one of the needle roller devices to go inside the outer clutch plate I might have one. I designed one for the Comet owned by the late Nick Wingrove, and now used by his son, after I designed the one for the twin clutch.

 

[Martyn Goodwin]

Well Bill, with the 7/8" lever you get more force from what is effectively the reduced distance of the fulcrum point, hence less effort required at the lever, but the trade off is you get marginally less clutch plate disengagement in relation to the available handlebar lever movement.

I can live with that.

 

[Martyn Goodwin]

If anyone wants one of the needle roller devices to go inside the outer clutch plate I might have one. I designed one for the Comet owned by the late Nick Wingrove, and now used by his son, after I designed the one for the twin clutch.

Would you post or email a copy of the design/drawing for the Burman version?

Martyn

 

[TouringGodet]

Maybe read up on leverage?

Lever - Wikipedia

en.wikipedia.org