Hitchcocks Forum

Hello there. As a matter to cool the minds, or at least to make laugh some of you, I'd like to adapt the rockers system of the latest 250 Crusaders to my CO, using the most of original parts, especially the rockers spindles and arms. It is mainly due to the lack of original parts, but also for the "fun" of the thing. I know that our host makes a substitute for my bike, but I'd like to test it. The idea is, or to adapt the Crusader's rockers housing to the CO head, or to make one. In the second solution, I'd fit needle bearings instead of bushes. I precise that the CO has been a bit tuned (28mm inlet port, alloy rocker pushrods and valve collars, HC piston, Amal TT10 carb, and "real" bearings supporting the now caged roller big end crankshaft) and so could benefit of lighter and better supported rockers. Has any of you has allready done something similar ? All your (positive) contributions are highly welcome. Claude

WD: I would be wary of needle- roller bearings in that place, they do not take kindly to heavy loads and when they disintegrate can make a bit of a mess. Otherwise, the project should be interesting.

I too would be a bit wary of using needle rollers in rockers. They will generate very high contact pressures, leading to wear over small areas and become "notchy". Needle rollers are better used for components that rotate or have a greater range of angular movement.

Thank you guys for your answers, I'm not at all focused on the needle rollers bearings, it was just by construction facilities and lubricating matters that I thought about that. So there'll be bushes. I got some plans of the rockers arms from Allan, and it seems there are no big geometry differences between the CO rockers and the Crusader ones. All that will be of course checked in situ. I had previously worked with some success on the CO rockers housing, as the geometry was poor, hope there will be some more gains there. The best for you. Claude

Needle roller rockers were used on Fury track racers in the USA and are still available, I bought a set for my Big Head project.



Fourth item down: http://www.enfieldracing.com/page/28582-Enfield



A.

Thank you Adrian,
It's something like that I was thinking about. The difference with the Crusader's rockers is that the rockers are detachable from their spindle. So they could benefit of bearings monted on the housing. I could so use "Nadella" style bearings, with external and internal cages. The benefit of this being that there isn't wear on the spindle nor the housing... I'l order the parts to H's to see how all that fits. The best to you. Claude