Self steering and top speed

BTW acotrel, do you run a steering damper? I have come to fear them myself,

I run a steering damper on the Seeley because I've had the experience of the hamdle bars turning into a blur on that triumph when the I've lost the front. I was forced by the meeting officials to remove it at the first meeting I attended with it fitted - they thought the damper wasn't historic - in my opinion is it a safety feature. The Triumph motor was orginally built by Baldo Meli, an Irishman who worked for the Triumph factory in the fifties. It was a 650 which hasd been fitted with a 63mm stroke billet crank, barrels shortened by 12mm, to give 500cc. It was a nasty piece of shit. It still exists in the next town -Glenrowan, and might race again. A friend has it now. He sold off the 7R hubs, and fitted Norton ones, so it will probably have braking problems. Baldo got a 12th on the IOM with it in about 1948, back in the days when a lot died there. I only ever persevered with it because the motor was indestructible - revved to 10,500 without blowing up. THe motor is now fitted with sane cams, and should be a lot better. One thing it never had was mid-range torque, it was all top end. It was good to ride on a big circuit like Phillip Island. I crashed there 4 times in one day in 1967, when I had a dangerous front brake with too much self-servo. The guy who had it before me stuck himself into the armco at Skyline Corner at Bathurst and broke an arm and a leg. If you backed off in a fast corner, and it dropped off the cam you had a real problem when it came back on - instant sideways. I didn't learn to ride on that bike, I learnt how to stop crashing. The Seeley is easy ! I love it !

Hobot, You are interested in the Triumph ? :

http://www.youtube.com/watch?v=g6p5vjVIw_0

If you lost the front on the Triumph, it would go into a tank slapper. It was essential to ge t your hands off the handle bars and grab the tank to stay on. One day I whistled over the top of a guy on a CB750 at Calder and grounded a footrest - lost the back. So I threw it back upright , and it did it's tank slapper thing. After a few yards the handle bars stopped whizzing around, and the bike smoothed out, so I grabbed the bars. It instanly flicked me over the front onto the bitumen. The guy on the CB750 stopped, and said 'I thought you were going to stay on it''. I told him 'so did I until I grabbed the handle bars'. Bastard of a motorbike, I was glad when I sold it after twelve years of its nonsense. I'm going to get it again and ride it in a period 3 historic race in the next couple of years, it was fast for a 500cc four stroke. Some of the historic guys think they are pretty quick, and I'd like to have a look at them.
In this life you have to keep your sense of humour.

Gosh acotrel you are modern vintage hero for me to read your exploits and crazy crashes. I rode my friends '69 Bonnie to point of fork oscillation rather slower than even our un-tamed Cdo take it so swore off pressing that, but otherwise handy as can be below rally pressing it. I've been crashed by Scott's steering damper in conditions I routinely save w/o one and its annoying extra effort when not working plus it would not allow Peel's sail boom tack snap across the deck fast enough either. The stunt guys that ride a lot of stoppie use em set pretty stiff. 10.5K rpm is dang noteworthy on Brit Twins, too bad the rest of it can take it.

I was in a quandry and dilemma for a time, knowing I could get along THE Gravel faster if I sort of skied it and overwhelmed traction before turns so whole rest of the turn is more like a crash recovery with all loads being let off of through apex instead being maximum point of loads. Many say sticking in two tire traction in smooth curves is fastest way around the fairly tights. Then too Code's School and got into show down with his head instructor who put the apex X marks down. He was severely pissed all ready so shot off w/o warning, I was both afronted and surprised, but saw him commit to his apex aim, so nailed it my way to end up a whole gear shift ahead and straight upright ready to snick another out of there, but looked back first to see him just arising out of apex max. There was nothing smooth in throttle, lean or rear behavior for rather funner way around as Code likes to express it.

Anywho your Seeley sounds like mean steering machine that may take it like Peel can, just ain't had the opportunity to test new limits. I've heard it can hurt when it don't work as expected of course. If good set ups didn't self steer then I'd be in way over my head too quick.

My `74 H2 came stock with both a steering stem friction damper & an adjustable hydraulic steeering damper, the effects of which were no improvement, making steering sluggish if turned up , but not altering fundamental geometry issues. I can see why off-road racers use them for fatigue reasons, but I dont like them on roadbikes, I recall asking if I could turn it off riding while riding a Ducati - & being told it didn`t have one, chopper rake & W/B just gave it that feel...

One was always carefull not to lead Jap Bikes into corners on the Pre unit Bonneville , out on the Highway . Commando would run bends lent way over smoother but lighter steering .



In retrospect , tying the swing Arm Spindle to tags on the rear subframe wouldve got it away from the odd wallow . Pillion at the ton through a drop off on a dirt road after the
Mad Farmer made off with it , had the swing arm flick left right left 3 or 4 in at the axle .Ordinarrilly only barely evidant on tarmac . But being 15 stone and all muscle from many seasons haybale hurling 10 weeks per annum , the chap didnt tend to back off , as it wouldnt get the better of him physically .

exhaust trimmed in like that , it'd only pull 110 in Third . :lol:

after the Farmer ran it hard for a season , his Father asked me if the Oil was supposed to be INSIDE the Engine , or OUT . :lol:

Rebuild with .060 over & Unit ( lower geared ) primary saw him on ' running in ' on return from a Rock Concert change into 2nd approaching lights , at about 60 .
At the same momet , the light turned green , turning the throttle ' ON ' ( the stop ? ) it stood up ( pillion incuded ) through to the shift into 3rd and through to 90
& the shift to 4th .Between the lanes of Traffic .

Was later ( a few years ) told ' there were to be No More Motorcycles ' for Him , as they were to dangerous .I thought that was the ute and the Christmas Spirit ,

I always use the old style Kawasaki steering damper, you cannot afford to have the handlebars turn into a blur as the front crashes from lock to lock. Once I over braked slightly on Winton when a friend did the stupids, and popped in front of me and used a disc brake. The drum front brake on my bike used to be hair-trigger (one finger). I hadn't raced for about 10 months, so I didn't get my hands off the bars quickly enough, when the front broke away, and the bike went into a tank-slapper It spat me over the front at about 70 mph, and I slid down the road on the top of my head with my feet in the air. By the time I reached a small ripple in the bitumen, I was on my side. I dislocated my collar bone - my only racing injury in 12 years of regular participation. I'm very conscious that it could easily have been my neck.
I know I've got a real psychological problem. Even these days , as soon as my backside hits the seat, I am never going to crash again. Fortunately (?) I've done it many times, and these days it happens in stages . I never do the high speed cartwheel. I would never ride without a steering damper - that is just asking for a beating ! If you ever find yourself looking at a big crashing wobble in the front, get your hands off the bars immediately and grab the tank, and keep throwing the bike upright . Be very careful when you go to grab the bars again, all the energy comes through them, and it might launch you. If you watch racing regularly you will s ometimes see guys get chucked off, but the bike stays upright and keeps going for a really long way - you can stay on if you don't get flicked off by hanging onto the bars . I know this sounds horrible ! - Sorry !

Funnily enough, even both Kawasaki dampers together would not prevent the H2 from whipping wildly from lock to lock, but I never let go, & it always self-corrected. I prefer lighter bikes, if you weigh more than 1/2 of what the bike does then you have more influence over its dynamics.

" even both Kawasaki dampers together would not prevent the H2 from whipping wildly from lock to lock "

even half a dozen steering dampers arnt going to stop the frame from flexing . :lol: 8) :shock:

Its not a matter of frame flex Matt, compare H2 swing arm location to a pre-unit Bonneville, torsional rigidity-wise, the Triumph is a joke, so it is a steering/dynamics factor, not stiffness.

In our historic racing Jerry Kooistra built a G50- in A MK3 Seeley fra me, and Bill Horsman rode it. He told me he thought he could feel the front of the frame flexing. I've got a chrome moly tube bolted in from under the steering head down to the engine, and I've never felt the frame flexing. The original Seely had two thin tunes in a ladder construction. My front down tube has a bend in it to give a bit of spring. I also use rose joints on the two head steadies. I think it is very stiff laterally.
A unit Triumph was a much better thing than pre-unit - they actually handled as good as a featherbed Norton. A BSA twin or even a gold star/B33 frame with unit Triumph fork yokes works very well with the pre-unit motors. The head angle is 26 degrees - like a Yamaha two stroke (26 degress) (Seeley is 27 degrees) - all using 18 inch wheels.

In FACT the quickersaki has , in engineering terms , hideous engine to chassis mounts .

While it may be controlable to a determined nutter on a race track , the irregularities in ' our ' road surfaces in N.Z. are beyond its working limits , if pushed .

Look at a 73 TR 750 frame . Good ? . those things weaved through lack of dimensional stability under load. A cheap little H2 frames going to be no better.

Also , while a 61 Triump H wt. framr may not be perfect , the quality of material 7 workmanship at least have all the joints secure , and on dirt roads where
yr buzz box would end up pogoing into the bushes , its irregularies merely function to warn the pilot that the limits of adhesion are being approached .

Like the Kawaski , the tyres at the time of its production ( std Fitment ) would not have had enough adhesion on tarmac to transfer suffecient load to overstress the function.
Put anything with grip on , and youre outside your design parameters.But at least the breeding of the Triumph makes it so any wayward characteristic s are still manadgeable,
whilst exceeding the capeabilities of a Jappwer 10 years its junior . Or perhaps it was just the superior abilities of the driver . :lol:

And NOTE : with Nervous pillions it was seldom possable to opperate in a determined manner , their instability influanceing the steering . We had a few people try to
climb out the passenger window appraoching bends in a car or two . This sort of behavior on the rear of a motorcycle does not enhance the behavior . Only uninhibiting
pillion on Commando was of the other gender . Young Henry was usefull approahing bends at speed nonchalantly , his input would set the machine on the lean .
aS DRIVER IT WAS ONLY NECESARRY TO catch at correct angle of lean . He was dead steady with Jandles scrapeing with the rear pegs directly on the alloy mounts .

goes to show , with them mounted on the risers , as per standard , thered be a further 10 degrees or so of lean available before they ( pillions feet ) grounded .

Matt, if by "FACT" you mean delusion, then you may be close, 8 widely spaced mounting points on H2 mill, good enough to hold in place well over 100hp..
From Classic Racer Sept/Oct `07 J.P.N. feature, P. Williams gives his reasons for using the leading axle front end;
"The more weight one can get back to the line of the steering head - thus reducing the polar moment of inertia around the steering itself, the easier & more +ve the steering will be." `72 J.P.N.s had 50/50 [fore & aft] weight distribution.
Kawasaki triples have a rearward weight bias to promote better traction, but at the expense of steering precision, but so what , with riders like Du Hamel who didn`t mind if they wriggled around a bit..

I'm very conscious that it could easily have been my neck.

Click to expand...

Conscious enough the animal part of ya shudders or squeals as it sinks in now & then?

Appreciate all the reviews of the various ways other cycles can deliver up their deadly blows, I survived my lesions to flat swear off all other cycles that go nutzo and need crutches to handle their corner crippling ways for so little increase in thrill before they do so, no thank you very much and hope you all stay wisely cautious and healthy having best times ya can on what ya ridding. Report back if ya solve things enough to look forward to accelerating into decreasers too fast.

Yes, Hobot, that is why I stuck an H2 mill in an RD/LC chassis, it fits in well, & steers much better than it did with the Yam mill -you can feel the gyro-forces from the crank, so counter-steering works well as a result, & it also weighs in ~100lb less than the stock Kawasaki, + NO attention grabbing headshake/tankslap antics either.

The World renouned H2 kawaski frame , the forerunner of neumerous er . .



Ive always thought with twice the power , at about 130 , things might get intresting with that LC device , stress wise . :?:

As for ' wide based ' held on to tangs with little tags , isnt really getting the best out of them . See pic , More Brackets OR frame Tubes .
youd wonder how its possible to get them to weigh so much . 436 Lb for the 500 . good Grief Charlie Brown .

Kawasaki Australia was the centre of development for the H2R. Neville Doyle had Hansford, Sayle, Willing and Toombs riding them. I watched Ron Toombs on Calder Raceway leading a young guy on a trick home built H2R with the racing frame. The young guy got about two thirds of the way down the front straight, and the bike stepped out and flicked him down the road. Year later I looked at the bike under a house in a Melbourne suburb and tried to buy it. The back tyre was about 3 inch diameter. It is easy to build something which will grab you by the throat !

my folly : it is based on an H1 with rd350 barrels, egli copy

Matt, those 400+ lb H1s were all metal, no plastic tanks or panels unlike a Yamaha[or Commando!], they strip down readily though, the racing ones got down to ~285lbs.
Gary Nixon , former factory Triumph racer was asked why the big Kaw triples wayward steering didn`t bother him as much as it did Paul Smart [ who paid for a Seeley frame for his], he said that it is roadholding that matters, & its a riders job to keep the bike rubber side down, so just get on with it,- but coming from a dirt tracking background - that was most likely the reason.
You have to take into account that roadrace motorcycles with 100+ hp were a move into the ughknown at that time, so chassis/tyre tech had some catching up to do, & J.P.N.s could still give them a good run for their money under the right circumstances,- P.Williams finishing 1st equal points scorer with
Y. DuHamel in the `73 Transatlantic Series, for example.

About Kawasaki two strokes - this might interest you:
http://www.youtube.com/watch?v=BRqk2UL17DY

Barry Sheene & Wayne Gardner talk about Crashing [their elite over rigid balloon tire 'puterized wanderers]
Examples galore

[video]http://www.youtube.com/watch?v=ChuyTfMaJKI&feature=relmfu[/video]