TTi box false neutrals

I use this. The ones on Ducatis had a bit less curvature :

https://www.feked.com/replica-tomaselli ... evers.html

Cheers Alan, that is the first time I have seen the matador figure quoted, useful, 30mm. And if you don't mind flipping it over you have a spare in the box!

Only possible downside is that I have small hands, which is why I like dog legs! Though I think I had a set of these on my Fastback many years ago.

The longest pivot centre I have seen is here:

http://www.motocicliveloci.it/inglese/c ... bri_uk.htm

Scroll down to Tommaselli Grand Prix at €54, perhaps still not cheap, and since I am in France I might as well go to Italy for Italian parts! :wink:

The GP is also available from a UK supplier at around £90!

I prefer a split perch for obvious racing reasons!

Yikes, they're coming out of the woodwork. I Bing'd "Tommaselli Grand Prix Lever assemblies" and came up with these. The third one down has a 32mm fulcrum and is priced a lot more humanely.
http://www.biketorqueracing.co.uk/controls/general-use-lever-assemblies

Steve
Not wanting to be teaching the sucking of eggs – but have you checked the steel plates in your clutch for flatness?
The reason I ask is that I ran a NW mini diaphragm clutch for a number of years and had continual problems with the steel plates warping into a cone shape. This had the effect of creating a dragging clutch and required a lot more lift to get the clutch to free. My solution was to cut radial slots into the steel plates starting from the inside edge and going to about ¼ in of the outside edge. My theory (guess) behind this was that the depth of the steel plates was far too deep and the difference in expansion between the inner and outer edges of the plates promoted the cone shaped warpage. The remaining continuous outer ring was sufficient to transmit the torque to the tangs and the surface area was essentially unchanged so the torque capacity was also unchanged. It makes it behave more like a modern clutch which generally have a much narrower friction surface. I think Jim C was also messing around with thinning out the friction surface of standard bronze plates for a similar reason and it was described somewhere on here.
In my experience the NW clutch didn’t slip with the power of normal running but was only good for about 3 or 4 clutch starts before it started to warp.
My bike used the standard commando clutch release mechanism but with a 7/8 clutch lever. The lower lift of the triumph style release mechanism in your TTi box might simply be exacerbating a basic underlying clutch drag problem. Hope this helps.

I use a Manx clutch with the TTI box - no problem.

Hi Seeley Weslake, can you post pics of those radial slots you have cut into the steel plates please?

I did see bronze plates for sale with a narrow friction surface, but I guess they wouldn't be much help against warped plates.

SeeleyWeslake said:

Steve
Not wanting to be teaching the sucking of eggs – but have you checked the steel plates in your clutch for flatness?
The reason I ask is that I ran a NW mini diaphragm clutch for a number of years and had continual problems with the steel plates warping into a cone shape. This had the effect of creating a dragging clutch and required a lot more lift to get the clutch to free. My solution was to cut radial slots into the steel plates starting from the inside edge and going to about ¼ in of the outside edge. My theory (guess) behind this was that the depth of the steel plates was far too deep and the difference in expansion between the inner and outer edges of the plates promoted the cone shaped warpage. The remaining continuous outer ring was sufficient to transmit the torque to the tangs and the surface area was essentially unchanged so the torque capacity was also unchanged. It makes it behave more like a modern clutch which generally have a much narrower friction surface. I think Jim C was also messing around with thinning out the friction surface of standard bronze plates for a similar reason and it was described somewhere on here.
In my experience the NW clutch didn’t slip with the power of normal running but was only good for about 3 or 4 clutch starts before it started to warp.
My bike used the standard commando clutch release mechanism but with a 7/8 clutch lever. The lower lift of the triumph style release mechanism in your TTi box might simply be exacerbating a basic underlying clutch drag problem. Hope this helps.

Click to expand...

The problem showed up after a season of racing. In rebuild the only thing I had done, due to appparent wear on the ends, was shorten slightly the single home made push rod (3mm) to reshape and then reharden it!

At the moment is has a push rod made in two pieces by Norman as originally installed by him, but never previously used by me (I intend to insert a 6mm ball between the two parts when next open!).

In the season it did 24 races, probably nearer 30 race starts due to red flags, 11 in its first race weekend! Of course it makes sense to look for other wear and issues like warped plates, so good pointer.

When out they looked fine. I also spoke to Norman. I can also tell you that the clutch as made in 2014 has 4 friction plates, apparently not all NW clutches do, and they have a narrow friction material strip around the outer edge of the plate, they are not fully covered in friction material and the bronze material surface has spiral grooves. All dust was cleaned off plates, drum and centre.

I found wear in the actuator mechanism and a reduced lift potential due to the handlebar lever pivot centres of 1" compared to more typical 1 1/16!

Though of course I now understand some are using 7/8" apparently successfully, though with different clutches and as Ken Kanaga says, needing care with set up.

But I also observed that, due to a long cable adjuster, the actuator was rotated further towards it's end of travel when at rest, possibly setting a limit on lift, difficult to be definitive when the box is buttoned up.

The currently fitted lever has a shorter adjuster and measures at the lever pivot 1 1/8" or 28mm. Cable free length now seems better and the actuator is properly closed when at rest.

Of course the original lever seemed OK at the start, and was on the bar when Norman made and fitted the clutch! So it may come back to the wear now eliminated.

Brooking tells me has a modern style short lever on his bike, which again may be the source of the problem he has. He doesn't have a NW clutch.

Here is a pic of the modified NW clutch plates that Brooking850 asked for. I have included a Bob Newby plate in the pic as well ( above) – it’s interesting that he does something similar except of course that his plate drives from the inside not the outside. As you can see my slots are cut rather crudely and I think this contributed to the odd plate cracking after a while ( but they lasted at longer time than they when they warped)
I first drilled a 1/16th hole and then cut the slot to it using a handheld dremel cutoff wheel. This was a bit wobbly – with hindsight I probably should have drilled a slightly larger hole and radiused its edge. My defense is that I was in a bit of a hurry at the time.