isolastics

Now you've done it.
Acrotrel here will tell you those Kawasakis had the best handling ever, and all Commandos were rubbish....

Hehe, see there, motorcycylist are mostly all emotional misfits with nothing making sense to all of em at once. Chris I lucked out to get a 68 P!! 2 yr in a row National drag champ build by a shop to rub 2toke noises in their smoke. It'd eat stock H2 digging deep down in gear box screaming like chain saws falling behind. With a drag slick much better though as on road tire could not give WOT till 65-70 or just spin even in 4th. 10.49 1/4 m best time by real pilot. I leaned to ski it as too low to lean much and that it was damaging to run much over hwy speed for long d/t the horrenous ViBrAtIoN. The 2tokes bikes could run circles around me in twisties though so thought they were great handlers back then.
Only one I know that lived on his P11 put Honda rubber mount bars on. P11's were famous for fracturing off parts. P11's were Commando's daddy but who'd buy one but to race over very rough stuff or stand painful numbness for a few seconds.

Trixie is my 2nd Combat and kept as factory as i can. Lovely antique that's good enough to enjoy sane zooming around and comfy to ride 1000 mile days and not want to stop. Keeps me humbled mechanically constantly. Killed my first deer on her and almost me too. Her GI tag key fob had Trixie scratched on it, so came named.

Ms Peel was my 1st no name good runing Combat that leaked 13 places so tore down to learn and fix it - to run into major items issues, so 5 yr to recover. I'd got a 'boney' SV650 in interim and spiffed it up via SV's popular forums info and got handy on it to point needed corner school to find out about skips and drifts and slides besides on THE Gravel. My SuVee will out handle un-tamed Commandos and likely out horsepower to weight all but super expensive ones. I only run non DOT race only tires on SuVee as only compound matters to grip THE Gravel. I can get them to gum ball in public or wire brushed off or draw out tire groove edges to 1/8" tags or leave exact imprint of road texture in them. I ran Scott's damper on SuVee too so know its help and hinderence, eventually it crashed me, so realized I was better than a damper and better off w/o it. Killed a big sheep dog, two goats that tore us up going slow, then a deer on SV at 75 with little injury & no crash so now travel 80's at night for safety and aim at deer agressively.

NInja 900 at Kieh Codes school taught me how to break free on heated race tires on tarmac to find it was simpler than pie compared to THE Gravel. Did stuff on it that got me banned to return and almost cracked school apart over Code allowing me too > screaming eye/eye spiting almost fist fights over me. Point being I got down all the faults and quirks of both Vtwins and inline 4's on fat tires and was so impressed I vowed to finish the stupid Combat and just tour to show it or be rid of it and its sloppy ass handling.

Was taken under wing by good mentors on modifying the no name Combat crank shaft to rod links, the last front link put on at a shop in the woods with serious trials course and hot to trot fellas on their GasGas and 250 Mx's, which I got to try too. Addicted me to raven drops and hill climbs and deer chases through head tall brush. All worked up by that took this new found wonder into wagon trail roads on bluff faces back and forth faster and sharper till reaching the G's the Ninja could delivered so expected that was it, tired to find break loose but couldn't at first, only pulled side ways wheelies with peg about grounded lean levels. DAMN, them fat tires couldn't grip that far over! Gave me the feel of frame wind up and release instead of tank slapping fights of the moderns, DAMN!. Pressed into turns even faster-harsher to finally get rear to break free and twist bike side ways to travel and fall down on its own then essentially let go of bars to get a saving hi side i found I could nail even more power on d/t tire patch so smashed down wider and push off the tire spring back as the frame un wound for breath taking spike in acceleration out of apexes at any angle I wanted. I was left in dumbfounded flabbergasted reality melted psychotic state after that. It was next day in my cage still tingling when I heard her name in my ear... Peel Ms Peel. Best handling I got out of her was on almost 60 PSI in tires, so if ya still look in awe at balloon tires and super rigid's, oh well I guess no one but me knows what they are missing out on with a disappearing smooth Ricochet Rabbit.

I just received my new bushes, etc from Old Britts today. Got silicone lube at NAPA on my way home. I also pissed of my lady. I think I'll go out to the garage and at least rebuild my front isos, and hide. At least my dog still loves me.

Rohan, An H2R was a good handling motorcycle. I've had tank slappers on my triton when the handle bars have turned into a blur crashing from lock to lock. It happened a few times when the front tyre broke away through cornering too hard at high speed. The answer to it is to get your hands right away from the bars and grab the tank until it stops. I've been flicked over the front by grabbing the bars too early, it looked as though they had stopped rotating. Another time I didn't get my hands off quickly enough and ended up going down the road on the top of my head with my legs in the air at about 60 MPH. Scared the shit out of an ambulance lady who watched it happen. I copped a separated chromo-clavicular joint - my only racing injury out of that one . However I am very conscious of the fact that I could have been killed by that ripple in the bitumen which did the damage to my shoulder. If that stuff happened to me with a standard road bike, I'd be extremely angry - there is no need for it, especially at the relatively low speeds involved in most road usage.

There is nothing wrong with isolastics that lots of arc welding won't fix.

We rest our case.....

when rear tire slips outward enough and then regrips suddenly bike flips up and over with the either front or rear or your helmet leading the way... If rear slips out and don't stop, it lowsides. Any bike will have both these modes of crashing ability. Slides and drifts release loads and widen turns not sharpen em up harsher. Only a few cycles can take almost low sides and almost high sides w/o crashing but sure upsets most of em and if good enough to make a practice out of it then ya run into the un-predicable splash together of forces of innately bad motorcycle philosophy and construction. You can fairly easy low side on street in sand mud oil grass, road kill and holes w/o much intention to but you must really be pressing it to risk hi side in public. Low air zig zags can reveal this onset in your ride at sane speeds and same reflex reversed control skill as racers use to recover slip ups but usually the racer has more time and space to do so, while onsets going slow-ish can-will splat before can react.

If a cycle can take severe tire conflicts one can low side it enough that it hi sides back up just right in time way faster than humans can react so control inputs done ahead of time then hang on prepping to do the next intense imput ahead of time again and again, avoids all the race restarts at all the sharper places.

I believe that there is probably something in the limbic center of motorcyclists that is different from the others who don't understand why we ride. It's probably the same whether your taste is for crotch rockets, cruisers, dirt bikes, or race bikes. Of all the hobbies that I have tried, I always come back to motorcycling. I rode a friend's SV and it was a very competent machine, but more of a sewing machine than the KTM Adventure I was riding at the time. I am awed by those with the talent, skill and cojones to race motorcycles. I just don't possess them, so I'll just spectate and respect them. I have proven to myself that I am capable of riding on the back roads fast enough to scrape pegs, but the law of averages would catch up with me eventually, so I don't. Too many deer, elk, cows, bicyclists, patches of sand, bad drivers and you name it that might be lurking around the the bend. I enjoy the challenge of tinkering with my eccentric English bikes and I enjoy the company of others who do the same. Going for a ride, even if just around town put me in my happy place.

Getting back to my isolastics....
Not much trouble removing the front unit completely to disassemble. The rubber inside was nearly as bad as the gaiters. Very off-center, starting to crumble, and enough rubber stuck to the inside that I spent a half hour with JP cleaner, scrapers, and a power drill with a wire brush cleaning out the crud. I spray painted the outside before using any silicone grease. Will reassemble it tomorrow after the paint dries overnight; I borrowed a bush installation tool from a friend who restored his Norton last year.
If the rear iso is anything like the front was, I'll want to have the whole hole exposed. Do the rears tend to get as "mooshed" as the front? Or in other words, which ones tend to absorb more stress? Somebody already replaced the top rubbers; the easy ones, of course.

'So glad you're all contributing to this thread; I'm assuming this will be a winter project for me, if not sooner! Short of disassembling the iso's, is there a way to tell just how far they're gone? How much up-and-down is acceptable?

christulin said:

I believe that there is probably something in the limbic center of motorcyclists that is different from the others who don't understand why we ride.... I enjoy the challenge of tinkering with my eccentric English bikes and I enjoy the company of others who do the same. Going for a ride, even if just around town put me in my happy place.

Click to expand...

The latest theory is the nucleus accumbens. The number and variety of different behaviors humans have come up with to stimulate it is infinite, but motorcycles are as good as it gets IMHO.

christulin said:

If the rear iso is anything like the front was, I'll want to have the whole hole exposed. Do the rears tend to get as "mooshed" as the front? Or in other words, which ones tend to absorb more stress? Somebody already replaced the top rubbers; the easy ones, of course.

Click to expand...

The front's have a much harder time of it. There's a chance at least that you might be able to get by leaving the rear iso's alone for a while. It's twice as much work to replace the rear iso but the result isn't nearly as noticeable as what you'll see after fixing the fronts.

I noticed after I removed my gaiters that my front iso sagged about 1/4" just sitting on either the side stand or center stand. I have the center stand on the frame early style. The rear iso was pushed towards the front maybe 1/8" or less. After spending many sleepless nights worrying about this, I installed the MKIII spring arrangement. It brought the front iso up so it only sagged maybe 1/8" and pretty much centered the rear iso. The front iso takes a very large portion of the engine weight (not counting the head steady and since I have the heim joint type, it doesn't carry any weight). The result of the spring was a better low rpm vibes. Didn't notice much at road speed.

Bear in mind that there are supposed to be 2 styles of donuts, the early 750 and the later 850 which supposedly are stiffer for the greater weight. Some people have even been known to drill extra holes in the donuts so they are even softer. It would be interesting to have weight/deflection numbers for the various donuts from the different manufacturers.

Well, I have my front engine mount re-installed with new rubber and upgraded PTFE washers, shimmed to 10 thou, fresh paint, and enough silicon lube to fill a breast implant. It took me about 4 hours (first time I had done this job, so if there is a next time, I'll know what I'm doing and it won't take as long). Thunderstorms and downpours prevented a test ride, but with the bike started and revved in the garage, there is a notable decrease in how much vibration I feel through the handlebars and the motor does not look like it is moving around as much.
I will get to the rears eventually; probably next winter.