Isolastic system lateral restraint

I've never seen any mention on this forum of a component that was part of our experimental bikes, and I don't know if it made it into the production version.

On the outboard end of each isolastic unit, where it would come into contact with the fixed frame, where the engine mount was free to move vertially, the prototypes had silicone-impregnated polyurethane discs between the fixed fram and the engine/transmission "pod". The intention of these was to restrain lateral movement (vibration) of the engine, but allow the vertical oscillation to be absorbed by the isolastic bushes without restraining it, except for the relatively minor friction of the polyurethane. On a four stroke twin where both pistons move together in the bores, there's a rocking couple caused by the fact that one cylinder is on its compression stroke when the other on is on its exhaust stroke. This is a secondary vibration compared to the basic reciprocating weight, but it isn't insignificant.

Did production bikes have those discs? I've never heard mention of them on this forum, but they were considered an important feature of the design at the prototype stage.

frankdamp said:

I've never seen any mention on this forum of a component that was part of our experimental bikes, and I don't know if it made it into the production version.

On the outboard end of each isolastic unit, where it would come into contact with the fixed frame, where the engine mount was free to move vertially, the prototypes had silicone-impregnated polyurethane discs between the fixed fram and the engine/transmission "pod". The intention of these was to restrain lateral movement (vibration) of the engine, but allow the vertical oscillation to be absorbed by the isolastic bushes without restraining it, except for the relatively minor friction of the polyurethane. On a four stroke twin where both pistons move together in the bores, there's a rocking couple caused by the fact that one cylinder is on its compression stroke when the other on is on its exhaust stroke. This is a secondary vibration compared to the basic reciprocating weight, but it isn't insignificant.

Did production bikes have those discs? I've never heard mention of them on this forum, but they were considered an important feature of the design at the prototype stage.

Click to expand...

Yep, they have them. When they get worn the bike is barely ridable. Jim

Doug MacRae isolastic has 3 robust swash plates and late UK oil man Gerry Bristow made a nylon swash plates for headsteady but otherwise no factory sold versions but verifies what I knew in my heart that the clever designers had made provision to tame isolastics but bean accounters cut their knees off like adjustable gaps.


BY FAR my main carrot to invest in next Peel is d/t one robust plus two compliant helpers, radius rod helm joint links in a Watts like linkage that both uncanny smoothes isolastes and flabbergastingly handles decreaser turns like even I can not believe and never found a limit but did have visual tunneling and focus issues. Not too long prior to hanging Peels hair out I was disqusted by Brit clunker so longing for real thrills of 100 hp Ninja > not no more the poor dangerous buzz bomb corner cripple. HehehehahahaHoHoHo off to funny farm no cure sought. Until Peel I thought there was only two phases of steering, straight up to 12ish mph then transition to counter steering, Peel has 3 more. A phase change is same as melting ice to water then turning water to steam but steam can be turned to plasma and plasma into pure radiant state of energy.

Bryan Tryee 70s Breast support, Bob Patton 90s robust rump control, 2004 hobot head rod triangulated. Next Peel has added 2 swash plates for mid swing arm back up just as crappy looking as these the whole rest of Peel build around.