Can anyone tell me how I can get in touch with Serco or how to use modern fork tubes and yokes /modify Tri Cub Sports 1.375" fork sliders ?

i have seen a serco website ( once) and wasn't able to find it again,

the best way i'm told is to use new mazoki fork legs either 32 or 35 mm stantions, the slider can be turned down to almost 'paper' thin and dropped into your original sliders

you could re use your original yokes or have some alloy ones made up from an alloy billet

all this doesnt come cheap although you will have the ultimate p65 forks, state of the art modern trials forks inside your original sliders and all p65 legal

the guy who sorted me was dave varley at www.dcclassicmotorcycles.co.uk

Hi Guys.

I have Martyn Adams Phone number in front of me,it is 01484 715288. Fax No 01484 721289.

i think his web site is still being built.

Regards

Charlie Prescott ( Banbury Dans. side kick).

I have had the Serco mod. but the springs for the fantic are not high enough spring rate to return the front end ride height on a cub.

Does anyone know or tried higher rate springs for the extra weight of a cub over Fantic.

I have already tried the WES multi-rate - no good and played with different oil weights and levels for hours!!

What length pre load spacers have you got?

You have got pre load spacers in havent you?

My B40 is running about 35 mm ones.

Every Cub and C15/B40 i know of that uses Betor or Marzocchi internals has some ammount of pre load.

You need to aim for about 20mm of "sag" when the suspension has been bounced and returns to it's static position.

Good luck

got about an inch and a half in my original cub/ betor's still waiting on the edge of my seat for my new mazokkis..

I have had the Serco mod. but the springs for the fantic are not high enough spring rate to return the front end ride height on a cub.

Does anyone know or tried higher rate springs for the extra weight of a cub over Fantic.

I have already tried the WES multi-rate - no good and played with different oil weights and levels for hours!!

Try shortening the springs a little- between 1 and 2 inches, and making up that amount with a spacer. If you shorten a spring it becomes stronger, strange, but true. Sammy Miller does springs for your purpose, allegedly Bultaco Pursang items, but i've found them no stronger than the ones i've removed.

ridden a b40 this weekend with the main spring an inch or so shorter and valve springs instead of spacers very firm.... one for us FAT boys!!

Thanks everyone for the interesting disscussion.

Perhaps I should have written a longer question.

I live in New Zealand, Though (Charlie) I grew in Banbury area and lived in Brum before emigrating.

I actually have a Bantam trials bike with a D7 175 motor, which is probably lighter than a Cub ?

I am currently using some Betor forks off an old 70s trail bike; too log, the geometry is all wrong and the springs a bit soft.

Presumably you guys are referring to Betors as on Bultacos and Marzoccis as on modern trials bikes ?

looks like I will have to send some sliders over to Serco.