Slipper Clutch

I think modern bikes are great, however the same limitations are still there waiting to deck you, just at a much higher speed. I don't know about this reverse steering stuff, I never have to do it consciously with my bike. All that's needed is to think where you want to go and it is there. If you gas it when cranked over, you are there before you expect it. You'd never try to use it on the dirt. The other thing that puts me off is a blind corner, where you ride by memory. The front brake is also one finger operation. I really like it.

How deeply satisfying-tempting Alan to read how secure and 'self' steering your Sleeley is when the going gets tough-tight. The thoughtless part fascinates me as racers must always be thinking when competing yet things happen so fast cycle better be self correcting on its own or as you say you only learn to ride slower fighting crashes. Slipper clutch might be the cat's meow while covering up its poopoo on grass, THE Gravel, snow or MUD travel > I can't take with 'spirit' w/o full attention-tension, Especially on power let off or actually wanting-needing to slow up beyond just coasting down. I've saved crashes a number of times on these slick surfaces - doing slowish-spirited down shifting to turn into drive ways or sharp blind turns from 3rd>2nd or 2nd>1st to have rear slip out trying to pass my hip so instinctively got back on hi throttle an instant to re-grip back inline then delicately- less swifly reduce throttle to hold rear traction to finish the turn w/o much or any drag.

I don't seek this state out to be thrust into Nth degree of IFFY traction control reflexes and only way its works out is by lots of riding time in varied conditions so cycle's behavior gets programed into muscle-spine memory by lots of little self correcting upsets. This is what drove me to discover what I call the reversed half of PHASE FIVE handling, ie: slowing up slippage instead of speeding up slippage yet can't lean much or power up/dn much or SPLAT. What loose-slick or roughness taught me is ya can blast around better if can always be on decent increasing power/acceleration. Its actually similar to parking lot sharp steering where they teach to either drag rear brake a bit or give slight throttle rather than swinging around w/o rear doing something active rather than just holding butt off ground.

I'd think slipper clutch would have to be somewhat adjustable as complete lack of rear drag can upset just as too much thrust around turns. My weird Peel straight steering only applies off road or going so harsh pavement behaves similar, ie: bike suddenly falling over on its own w/o help of counter steering or pilot English, so either must transition into flat tracker crossed up drift wide or let bars flip around w/o letting off accelerating power. I gave up on pressing moderns to this state as the stem angle/tail so sharp to ease effort of fatso tires they snap up in high sides that fling ya off or judder them selves outr form under to rub ya off. Peel can also turn an increasing radius easy counter steering fast accelerating sweeper into a series of sharply decreasing radii turns of short straight drag strips but that is so beyond other cycles capacity it won't make sense to expand on that here till video demo.

I've a *great fear* of slipper clutch lack of drag dangers after Peel got a reputation a few states around spanking sport bikes in the 1st and 2nd gear 40's-90's mph chicane tests she wore out 1st's thin bush so when engine and drag loads matched, like coasting lazy down hill below <25 mph she'd pop out of 1st and speed up suddenly which didn't bother me at all UNTIL after blasting up a wagon trail bluff face 10-15 mph marked switch backs practicing P-3 flat tracker-ish cross ups straight steering and P-4 faster> parking lot stunt hi side leaps to twist in air to land right on smashed down rear patch to hit WOT torque into the next opposite turn with no traffic encountered in the blinds, i'd turned around to race down but got traffic in front so just coasted down extra slow on purpose to let traffic always be far enough ahead I could not see them, so was playing a bit by far over leans under 20 mph ***when rear crossed a plate size section of missing pavement about 1" deep that was unnoticed on Peel when on hi power > the instant of un-powered unloading popped out of 1st so next instant she low sided rubbed me off to run a few steps to be left standing in middle of road watching Peel continue to slide into railing a dozen bikes lengths as traffic pulled up behind me asking if I was ok. Got going again towards home w/o another thought to such a rare event - no damage, I was adrenalized out relaxed from the sports bike spanking practice runs - got to my driveway turn in, easy wide slightly down hill going 12 mph slow on purpose in 1st for slight rear drag, but road Grader had fluffed up THE Grit and left a 2 ft high loose berm on RH inside, like a RH mild sweeper with a wall on inside radius, Peel popped out of 1st to speed up 2-3 mph enough rear swung around to aim me up the 45' berm I was hugging close to but able to get control before cresting it into downed trees got re aimed downward obliquity for a straight shot coast into cattle grate entry a few bike lengths ahead > lack of rear drag or engine thrust got us again when front and rear got back to grade level she snapped instantly out from under to land full bike mass on my L pelvis, cracking crest of pelvis while twisting shearing-fracturing my congenital fused L5/S1 segment for paralyzing lightening strike nerve injury into butt out testicle into L foot. Got bike up pretty easy as still leaning mostly upright on berm still running i got on in 1st and stayed on some power to make it to shed 1/2 mile away then each of 80 steps to get to house I got lower and lower till literally crawled through door and didn't stand or walk upright like a man for 9 mo. But the silver lining was my body protected brand new $500 tank pain job and lumbar regrew new joint so free'd my life long resistance to touch toes, stand long in lines or have DC's try to adjust low back w/o me screaming in pain, can now pop low back just twisting or tipping head back to finish a drink and show off for patients bending over to touch floor with legs full locked.

Apparently the MotoGP teams spend a lot of time playing with clutch plates and adjusting the drag of the clutch on back-off. Seems it reaches an equilibrium, and rider preference comes into the equation. There is one thing I would say - anything which stops a beginner from crashing is a good thing. When I started racing, I was 27 years old and I'd been competing against my mates on public roads, very illegally for several years. At one of my early meetings, I still went to Phillip Island and crashed all over the landscape due to a drum brake playing up. I had a 90MPH crash onto the non-skid surface and rolled every inch of the way. It can finish your career in short order. Road racing is a really beautiful past-time and it can be done safely. However you need lots of racing miles without injury before you reach that stage. These days I never do the big get-off and cartwheel , I never go near it and trying to go slower does not change anything - past the 'crash and burn' stage.

Come on Alan, get real, motorcycle in general are stupid dangerous inventions just commuting on let alone risking life and limb for pure thrill and reputation. Cycles to me should be classed with dangerous addictive-expensive drugs or screwing married women of powerful men, its hard to know ahead of time if a poison included or husband shows up. Modern power plants have gotten so un-predicable they need helper devices for the less capable pilots. I"m glad that don't seem to apply to a good Norotn powerband and let off drag character. Still got to use some sense with Nortons but at least its within range for most racers. It took me a year to lean I could road race turn after I quit my stupid handling 1st Combat to redo it & got SV650 and upgraded it for long term & rid of overly dangerous Commando. THE Gravel was and still is a very harsh teacher so didn't know my pecking order till I took corner school and almost broke up Kieth Codes crew with nstructors refusing to let me out again. Thats where I leaned how unpredicable moderns can get even transitioning to Gravel jerky point shoot style. Then reading interviews of elite riders I recognized my risky jerky style and that other riders could not ride a bike set up for them as hi sided right off. To get around need of slipper clutches ya gotta learn to use brake not engine drag or better > go around even faster lower sharper, if the cycle can take it. The only cycle I could not do anything to uspet was tri-linked Peel, ridiculously dangerously tried to learn what I could get away with but never found limits so far and never on full grip street tires yet am too familiar with limits of cold to heated fatso race tires I abhor to have my level thrills on so just don't no more, as can only learn to go slow not to crash on them which leaves me rusting on the reflexes needed for Peel.

Interesting read
The thing I would be worried about is what happens when you lose engine braking, as the Norton has heaps of it, will your brakes be up to the challenge?
Slipper clutches I believe were made to allow the modern racers better control of the braking systems as they are that good engine braking is not required?
Second to first stuff up.
I know what happens when you drop down to first gear with a big gap from second, my experience is with my TR250 Suzuki which runs the T20 Suzuki standard gears, big jump from first to second, then nothing , but on the other side if you dropped from second back to first you left black strip on the tar plus crap in your pants as others past you :roll: . Result I purchased and fitted first and top gears from Ellis Moore UK which has made a vast improvement.

My 1955 Manx, well this bike was made for push starts with a tall first gear but, it was hopeless on the clutch starts as I had to slip the clutch until I got up and running, the five speed Norton's just disappeared on the starts.

Anyhow interesting

Burgs

With both retard coming through use of close ratio gears and very good brakes combined with geometry which causes the bike to tighten it's line coming out of corners under power, you can get around a road race circuit very quickly without decking yourself. Especially if you are well-practised, the risks are 'minimised to a level which is tolerable to all stakeholders' i.e. SAFE. So why are you calling bikes dangerous ? Only some of them are - a modern bike is safe for a beginner up to at least my race speeds. However the envelope has been moved - the same distortions still happen, however at a much higher speed. In the end the same level of skill is required. If you fail the crash can be horrendous with a modern bike, where with our commando based bikes it all happens at slower speeds if we are applying the same amount of effort. I have one theory - however fast you go, you have to be prepared to get off at that speed. So I never get silly on a race circuit where there are solid objects to hit if I slide down the bitumen. If I'm going to stick my neck out I'm careful about where I do it.

Burgs said:

Interesting read
The thing I would be worried about is what happens when you lose engine braking, as the Norton has heaps of it, will your brakes be up to the challenge?
Slipper clutches I believe were made to allow the modern racers better control of the braking systems as they are that good engine braking is not required?
Second to first stuff up.
I know what happens when you drop down to first gear with a big gap from second, my experience is with my TR250 Suzuki which runs the T20 Suzuki standard gears, big jump from first to second, then nothing , but on the other side if you dropped from second back to first you left black strip on the tar plus crap in your pants as others past you :roll: . Result I purchased and fitted first and top gears from Ellis Moore UK which has made a vast improvement.

My 1955 Manx, well this bike was made for push starts with a tall first gear but, it was hopeless on the clutch starts as I had to slip the clutch until I got up and running, the five speed Norton's just disappeared on the starts.

Anyhow interesting

Burgs

Click to expand...

When I had the T250, I blew off a fairly new TZ350G with it. I was using methanol. I didn't have a decent ignition system and I hated the gearbox. I sold it to a young guy who used it in historic races, he won 28 races and 5 championships with it. They kept copying the porting, and the frame mods. I raced against it with the Seeley at Winton, ran out of brakes, ran wide and had to catch him again rather than be beaten by a bike I'd built myself.

Until recently a friend was racing a fairly late 500cc manx in historic racing. I'd bought the 6 speed box and told him about the high first gear problem. He said that he has three first gear pairs for the manx gearbox. I was kicking myself because I'd never really thought clearly about the problem. With a slipper clutch, it should be possible to use the very low first gear with minimal risk, and even get back to first during a race, if in a tight spot. I've got those gears in about three boxes I have in my shed - DOH ! !
(The TTI box costs about $5000 - a Ducati slipper clutch about $1000 )

I am really annoyed with myself for not doing my homework. It pays to read about what the superbike and MotoGP guys are doing.

I am a bit confused here, as I thought you were looking to fit a slipper clutch to your Commando to improve lap times?
No way did I insinuate that racing or riding motorbikes was unsafe otherwise I would do neither??? Thrilling YES!
Best Regards
burgs

This link from Nortoniggy is particularly useful :

http://www.sigmaperformance.com/slipper ... setup.html

I am a bit confused with the slipper clutch as I believed it only worked on the over run, deceleration, not the acceleration viruses the slipper clutches used in Drag Bike?
Regards
Burgs

Alan, could you post a photo of your seeley please? Ta

J

If you follow the photobucket link I posted on the first page before the thread went into 'la la land it shows how the OEM type slipper works.
The drag race clutch as you say is for acceleration with adjustable bob weights, it could perhaps be called a adjustable lock up clutch.

The slipper clutches simply lift the pressure plate in a controlled and continuous motion, if there is no torque reaction from the rear wheel they back off and reply based on rear wheel rotation.
They also have inner diaphragm springs, in the GSXR that goes from one to three depending on the engine, that fine tunes the preload.
The GSXR type also has three adjustable pins that contact the cam set along with inner diaphragm springs.
Aftermarket have ball ramps with a outer diaphragm spider spring for fine tuning.

Sorry it's not a more recent photo, I'll try to take a couple more tomorrow.
I have trouble keeping paint on the exhaust.

That be one bad ass ugly racer Alan, thanks for showing it as it was. When ya got a really good predicable power band and great neutral handling - the more your competition needs tricky pilot protectors the more ya see then as un-competive cripples with only advantage being power/wt into the opens when slipper clutch is meaning less extra mass and complexity. Two ways to go around fast, innate design allows it or with a bunch of crutches to prevent falling down too fast. I've taken my Suvee and Peel over the ton on THE Gravel with sharp blind turns zooming up so learned to down shift clutch in using brake only and then on high throttle so no rear drag as clutch engaged again then fast throttle feathering down if wanting to slow more or just stay on increasing throttle to zoom into the next open. Fast rain riding can teach this too.

Burgs said:

I am a bit confused here, as I thought you were looking to fit a slipper clutch to your Commando to improve lap times?
No way did I insinuate that racing or riding motorbikes was unsafe otherwise I would do neither??? Thrilling YES!
Best Regards
burgs

Click to expand...

Burgs, my comment about safety was in response to Steve's (Hobot) remark.

Steve, what really surprises me is how good the bike is with the 850 commando engine - I never believed in it. Gearing has always been the big problem, it has massive torque and you can really feel the effect of the heavy crank. However with the American CR 4 speed gearbox, it is excellent. When I started racing, all races were push start and I was expert at getting a blistering start. As the four cylinder bikes came on the scene, some of the guys would press the start button during the push start. Also the fast guys were complaining about losing races because they had to push their bikes. In a push start there is no problem having that very high first gear in the CR box. With a clutch start, using the CR box, the problem occurs only for the first few meters as the motor has to heave the bike into motion. I've only ever had one good start in a clutch start race using the CR 4 speed box - I gave it a big heap of revs and rode the clutch out. The risk is you can spread the gearbox doing that. Just as you can if you avoid the problem using a very low first gear and then accidentally shift into it during a race and expose the box to the full inertia of the heavy crank. I believe if we fitted a slipper clutch, under normal circumstance it would not need to operate unless the rider was balked somewhere and lost track of what gear they were in. I remember with my T250 Suzuki, I always had to consciously stay right away from first gear. The slipper clutch would remove the need for 5 and 6 speed gearboxes in commandos.

Interesting on early lack of faith in Commando engine as exactly my early on opinion valve floating shut down trying to pull in front of semi pass on 3rd day and getting out hp'd by about everything at timed drag strip. My SuVee took practice not to be on/off throttle jerky compared to Commando so rather more easy to skip out rear while letting off in spirited rides. I've push started too much so know only do it in 2nd or 3rd as 1st tends to skid too easy. I found a fairly fast clutch release in 1st close to 6000 rpm will not bog but freaking wheelie leap forward to have to ease throttle some or wheelie over then hanging on WoT till rpms ready to pull like crazy in 2nd and up ward.

Another really major factor is the wider the patch the quicker the grip decays approaching edge so as moderns tip over while slowing the good grip they sensed going in can disappear suddenly from engine drag. My firm opinion is never brake but full upright full in line or just wasting time dividing tire loads up which leaves less of either load capacity left. Dragsters don't get best hook up unless aimed dam straight ahead and short cycle stopping contests are done same way. You see this wisdom all the time demo'd but the best elites when they can't take a corner then straighten up to be able to really brake well before shooting off the tangent to maybe recover back to race.

I'm not good at it but time to time have let drag skid rear into turns on THE Gravel but not balls to the wall just short intervals to keep in mind how easy it can happen and how to handle it. Still the Commando spiral slot slipper has extra lock up potential so would love to see them installed and may follow suit for that feature.

I get the feeling that because of the heavy crank, the commando engine under load tends to rev up at a fairly constant rate regardless of what gear it is in. The acceleration rate of the bike seems to accelerate faster coming up through close gears than with the standard box. I think it is because the crankshaft keeps spinning without losing so much velocity. I would have thought lower ratios would help the bike accelerate faster. It is as though the torque curve has a pronounced peak in it. The high first gear problem is strange. Heaving the bike forward off the line in a clutch start is not a problem if you are brave enough to risk spreading the box, by revving the tits off the motor and dropping the clutch. If you simply ride the clutch out at full throttle without a heap of revs, the bike is very sluggish.

I spent couple years looking for hydraulic drives and other 'infinitely' variable transmissions of belts to cones to electric drive coupling but nothing found that could handle the rpm, weighed less than the pilot or a size could fit on a cycle. Another thing THE Gravel teaches that applies to road racing and slipper clutches is the mysterious power pulses frequency/intervals effect on rubber tire grip that work both ways, slippage accelerating or decelerating in various ratios. Rear is not good for slowing at high speeds and worse if leaned any so absolute worse use to me is trail braking with the front weght shift lifting rear out of full traction so engine drag can too easy over come it. On Peel I ran out of 1st too soon but loved the pull of 850 2nd ratio, hated waiting on 3rd to finish so could hit 4th to feel the efficent pull again. Peel has similar self steering reaction to throttle as you describe with your Seeley beastie helping to over steer sharper - to point she'd fall over on her own - which is the corning transition rodeo broncho cornering I crave more of. There is a saying I've heard, When in Doubt Gas IT!

To transition to straight steering you have to be going harsh enough it will definitely crash if ounter steering by the front slidding to snatch a low side which then can too easy regrip next instant to hi side. If staying on throttle to slide rear out crossed up its got to re-grip almost as soon as throttle let up or swings around too far and hi sides too harshly to control. A slipper clutch would not allow the almost instant re-grip so would prevent higher energy handling while leaned so not interested in them for my off road 'road race' style. With infinitely variable ratios one would just stay in best power rpm and work a lever or 2nd twist grip to match the accelartion grip to load engine just short of bogging.

The P!! dragster could not lean much and ya can't lean much on THE Gravel or on wet pavement so developed a taste for pitching over a bit & 'too hot' into a turn so could easy over gas just little to set rear spin exactly as much as I want so it skip/slips out a few tire widths but hooks right back up w/o any throttle let off to be better aligned & able nail higher throttle out of there. I think this is called 'backing into a turn'. Must have very predicable power response to throttle, very good sense of tire grip threshold and cycle's reaction to the sudden re-grip while cycle still has some pendulum like momentum pivoting on its CoG. The tricky parts is knowing if wil do this while still counter steering or will get a bar tank slap into straight steer. Often enough got so loose I had to cut throttle for engine drag to hook rear back up in time so think slipper clutch would be dangerous by inducing a crash with rear of bike and your butt leading the way. But not if going as slow or slowing entering sharp turns as the elites fatso tires have too so can brake half fast leaning with engine drag or trail braking low G forces, pashaw.

Take a model mc in hand and play with it like the hand of God holding it up and twisting it around turns like magic, that's how it felt on Peel, just wish your way around and it goes where you are looking w/o much thinking or skill or need of pilot device helpers.