hello friends,
caution:
this is a project and i do not know, wether i will succeed or wether i will fail. maybe i will loose my interest during the building process? who knows what the future brings?
the history behind this project:
it was in the mid 70ties when I started my "bike career". first bike was a 2 stroke 3cyl 350ccm kawasaki followed by a sohc 750 honda. it took not long and I visited some race tracks in our country, preped my sohc for racing and was often found at the track as a competitor or as a visitor as well.
it was the epoche of all the 2 stroke TZs, later Rgs, in the beginnings some 3 cyl kawas. but one thing was obvious: when you wanted to be member of the serious racers, when you wanted to be really fast, you had to have a clattering dry clutch. a wet clutch was for the hobbiists, a dry clutch for the winners.
later, 4 stroke racing became popular. even there the above mentioned rules didn´t change. the RCB was maybe the most famous one, a winners bike, dry clutch. i do not know, how often honda took the endurance WC titel. but when honda was beaten by the winning GSXR, they had dry clutches as well.
this time I ordered a complete factory kit from honda with all the goodies for my bol d´or: pistons, conrods, crankshaft, camshafts, transmission, dry sump and dry clutch conversion. i will never forget this technical jewel.
theoretical stuff:
nowadays i play with my sohc. some of you know, that i do have two modified engines running. one of them i am converting to a dry clutch.
the plan is: because this is really a lot of work, i do not want to add an old fashioned dry clutch, as it has been used 30 years ago. no, i want it all (or nothing): the dry clutch conversion must have a slipper option as it is used in modern MotoGP bikes. if one will use the slipper option can be decided by the user.
my first thoughts went in the direction to voxonda, how already has a dry clutch running, but without slipper option (as far as i know). second thought was of ducati. they are using dry clutches for many years, for their race bike, as well as for their street legal stuff. unnecessarily i bought a second hand STM slipper clutch for the 1098er series. this was the wrong one, because their max diameter of 155mm was a tiny bit too large. next thing i recognized, the rotary direction makes a big difference. not critical with a non slipper clutch, but essential with a slipper one. i do not want to have the slipper effect under accelerating
. what to do? i searched all day long, but didnt find a clutch rotating clockwise (right side mounted). all the new bikes do have a gear driven primary, our sohc is chain driven resulting in a viceversa rotation direction. next thought: for a slipperfunction the clutch uses ramps (back plate) and steel balls. either i can machine a mirror back plate myself (?) or i can find a producer how can make a "mirror back plate".
i first sent an inquiry to ? (have forgotten the manufacturer
) . no response. the company is not flexible enough or willing to answer my questions. next on my list: suter clutch, switzerland. suter technology is well known in racing, they provide half of the Moto2 field with excellent racing chassis (2010 Moto2 constructors champion). the complete field race their suter clutches. suter is on the winning list in MotoGP as in SBK championship too.
my inquiry to suter was answered the same day: there exists a 138mm slipper clutch for the 748 to 1100ccm ducati. it is easy to reverse the slipper effect by reversing the back plate, was the answer. this problem seems to be solved.
but: how about an external starter, paddock starter? the slipper mechanism will inhibit a starting procedure by slipping the clutch.
suter sent me drawings from their clutch. a close up view showed me a "rack element set (for bikes without starter)". this 3 heels function by centrifugal forces. the clutch standing still, the heels inhibit the slipper effect. the clutch rotating, the heels give free the slipper mechanism. viola, all what i need!!
practical stuff:
at the moment i am taking measurements from the primary drive, oem clutch, transmission main shaft, crankcase. this measurements will be put in a simple corel draw drawing. currently i see the need for a longer main shaft. something like a clutch hub fitting on the primary has to be machined too. all the aluminium covers will be easy to do (hopefully) and will be done by myself.
thats all for now.
see you
mec
