Can anyone tell me how far the clutch pushrod should protrude from the end of the 5th gear-shaft on the right side of the engine? Mine protrudes 1/2” (12.5 mm) from the end of the gear, a bit more from the seal. When I had that seal out for replacement I found a ball bearing lying near the engine. Since it was the same diameter as the pushrod I assumed it was the ball bearing found between the two pushrod pieces and had rolled out while the seal and the pushrod were out. I replaced the seal and today shoved the ball bearing and the pushrod back in. I believe the pushrod is sticking out too far and binding the clutch lever when I try to tighten the gearbox cover. I’m using the extended lever which goes through a slot in the cover. If anyone has that dimension it would be helpful. I don’t want to take out that seal, turn the engine on its side and shake it, unless I have to.
750SF1 Clutch Pushrod Protrusion
- Thread starter RJS
- Start date
hooksey
Hero member
- Location
- Vic , Australia
Get yourself a magnet on a stick, and go fishing!
Tippie
Hero member
- Location
- Dr?bak, Norway
That is the length of the pushrod. On my bike the bit protruding out past the gearbox shaft is 11mm, this will vary according to wear on the fibre clutch plates.
If the seal is in good condition it will bite on the shaft and hence the ball bearing, if you want to get it out you may need to carefully remove the seal.
You're right.
Paul
sfc vintage
Hero member
Hi
You Can find the data on Andy Wagner : gear box
You Can find the data on Andy Wagner : gear box
piranha-bro2
Hero member
- Location
- Melbourne
After I fitted new fibre plates (they were factory spares I'd have for decades) I found that the clutch lever action was no good, as the lever at the motor was vertical and the lever at the bars wouldn't adequately disengage the clutch (ie angles all wrong resulting in reduced travel of the pushrod). I spaced out the lever holder assembly at the motor using two M6 washers and this moved the angle of the lever out so the start of disengagement was say 1 o'clock and full disengagement 11 o'clock - max possible travel from the available throw of the handlebar lever. With the extended lever (and CUT slot in the sidecover! 
) it gives just enough to enable finding neutral and no binding of the pushrod assembly when the lever at the bars is released.
) it gives just enough to enable finding neutral and no binding of the pushrod assembly when the lever at the bars is released.I had new friction plates fitted lots of years back and that resulted in my extended lever hitting the engine case before full pull, so I made a slightly longer outer rod to increase it. But I made it out of stainless steel and that was too soft. It self-shortened in about 30 minutes of use. The std rods are made from Tool Steel and need to have both ends case hardened to stand the pressure and friction. Every single mm is critical to get the best clutch action. It works really well now with its Kevlar plates and extended lower arm, nice light pull and easy selection of neutral.
I’ve determined my pushrod length is 112.3 mm and that it protrudes 11.1 mm so it doesn’t look like I’ve got anything extra inside the shaft. The problem must be that the extended lever is wrong. I wonder if extended levers for twins and triples are different. In comparing my stock lever with the extended one, it looks like the extended one angles outward so much that the slot would have to cut right through to the inspection hole in the gearbox outer cover to give the lever enough travel and that isn’t right.
The Sock
Hero member
- Location
- London, England
I’m fairly sure that the extended levers do require the case to be slotted to the inspection hole.
Tippie
Hero member
- Location
- Dr?bak, Norway
Try fitting two gaskets? It does sound like the extended lever is the problem. There isn't really a "right" with extended levers, they are just modifications various people have fabricated. I agree that it is neater if not cut through to the access hole. The dogleg one from DAM avoids cutting the cover at all but for me is not important as I will never be refitting the short original lever even for selling.
Well... there are actually 2 types of stock lever and perch for the clutch pushrod. If the parts are mixed, the lever position/angle will be seriously altered and action will suffer. I have yet to find differing part #'s for these bits, seems like Breganze just let the change flow into production without documenting it. Twins and triples use the same stock part #'s.
The earlier (?) perch version has a 8mm roller on which the lever pivots, the later has 10mm, each has its dedicated lever. Or was it 10/12mm? Can't remember exactly. The differences are miniscule and hard to detect if not aware of what you're looking for. Extended levers are mostly modelled from a random stock pattern, so depending on which type that was, the extended lever can play quite a bit of havoc. The larger roller is definitely the most common.
To precisely set up extended levers, I've often resorted to lengthening or shortening a pushrod as required to gain maximum mechanical advantage, which is badly needed to get optimal performance from this mod.
I'll try to dig out the parts to illustrate.
piet
The earlier (?) perch version has a 8mm roller on which the lever pivots, the later has 10mm, each has its dedicated lever. Or was it 10/12mm? Can't remember exactly. The differences are miniscule and hard to detect if not aware of what you're looking for. Extended levers are mostly modelled from a random stock pattern, so depending on which type that was, the extended lever can play quite a bit of havoc. The larger roller is definitely the most common.
To precisely set up extended levers, I've often resorted to lengthening or shortening a pushrod as required to gain maximum mechanical advantage, which is badly needed to get optimal performance from this mod.
I'll try to dig out the parts to illustrate.
piet
Possibly. It can alter the angle of the lever to the point that it doesn't allow full travel, "bottoming" at either end if mixed bits are combined. Of course, incorrect attack angle of the clutch cable causes at least some of the "heavy-clutch" syndrome, but this angle is also determined in part by the thickness of the clutch linings/pack thickness, wear at the ends of the pushrods, cross bar and/or intermediate bearing ball. Not unknown to find wear at the lever itself, where the outer 5/16" bearing ball that acts on the pushrods is located. Especially on aftermarket extended levers made of inferior material. All this wear adds up. Minimal slop and regular lubing at the handlebar lever and a well-lubed and routed cable should be considered a matter of course.
Heavy clutch syndrome is often compounded by unnecessarily heavy springs, often fitted to diguise warped and buckled plain plates that are the most common cause of slipping clutches. 120° triples (possibly MkII triples as well) were fitted with spacers (part # 33 111 121) under the spring washers ex-factory to reduce spring pre-load and ease lever pull a bit. Given the superior torque of the 120s, clutch slip on 180s is very rarely due to tired springs.
piet
andre g
Hero member
I never had big issues to pull my clutch. My SFC 1000 and my RGS have this hydraulic system and it is hard but ok to pull it, also after 400 k on small roads. When I had my 1200 180 deg engine with a cable actuation , but new cable and levers and no conversion of the lower lever, it was more easy than the hydraulic. I do not see where is the problem.
I am not going to a gym for hand force training.
I am not going to a gym for hand force training.
My 3c was BRUTAL when I first bought it. It was 15 years old, had a race history and was very rough so who knows what wear or mods were done to it. I would do a full lap of the Old Rd from my place, approx 3hrs of Suburban traffic and 50ks of hard-charging a bunch of 35kph bends with lots of clutch pull and gear changes, heading home my left hand would be cramping to the max. I would have to move my thumb from under the handlebar to over or it would hurt like hell. My first big ride, 3000ks including 350ks of dirt fire trails through some remote bits of our Alpine high country resulted in numbness and constant pins and needles in my left hand and wrist. I was doing serious damage to both plus braking 3 or 4 clutch cables a year. UNSUSTANABLE. The best mod I ever did was the extended clutch arm. Just my experience, plenty say there's is fine and dandy, heavy but usable. I wish I had measured its pull with a Fish Scale just to see how strong it was. I tried rerouting a new cable and every other fix I could and nothing helped. For it to be a non-issue it's funny how there are so many modifications being made available by the major Laverda Engineers to fix this non-issue. Thankfully mine is now really good, There is now minimal physical effort required to enjoy it in its natural habitat, fun windy roads.
Dellortoman
Hero member
- Location
- Tasmania, Australia
The clever previous owner of my jota had (among other awful bodges) shortened a pushrod to accommodate worn plates and put washers under the clutch springs to stop it slipping, although it still slipped when giving it a handful of throttle in top gear.
When I fitted a stack of Red's nice Kevlar friction plates to my Jota. The pushrod system was too short. I couldn't get any action at the lever. It needed about another 5 or 6mm of pushrod.
I didn't have any suitable round bar to make a longer rod, so I took the primary side cover off and made up a spacer washer to go between the square toggle bar and the clutch pressure plate. Did the same job but didn't need to be made of anything fancier than billet aluminium. I suppose it also has an advantage over a longer pushrod because I can put a thinner one in as the plates wear. But that hasn't happened yet. The Kevlar plates have hardly worn at all in 10 years.
When I fitted a stack of Red's nice Kevlar friction plates to my Jota. The pushrod system was too short. I couldn't get any action at the lever. It needed about another 5 or 6mm of pushrod.
I didn't have any suitable round bar to make a longer rod, so I took the primary side cover off and made up a spacer washer to go between the square toggle bar and the clutch pressure plate. Did the same job but didn't need to be made of anything fancier than billet aluminium. I suppose it also has an advantage over a longer pushrod because I can put a thinner one in as the plates wear. But that hasn't happened yet. The Kevlar plates have hardly worn at all in 10 years.
piranha-bro2
Hero member
- Location
- Melbourne
Pretty much what my 'washers-under-the-lever-boss' trick did - I didn't want to fuk around shortening or making longer pushrods - then have to reharden. I wanted it done pronto so I could fill the motor with oil and start it up and ride it! Cam's trick with the spacer under the square section bar inside the clutch drum does the same thing as well.
I like to visualise the lever action as the hands of a clock, where full lever travel is through the same number of minutes each side of 12. Similar concept with gear levers with rearsets or any system using connector rods.