extra ISO under gearbox head steady delete

74 Cafe' said:
If you know those names, then you must remember Dr. Ozlee (sp), the genius behind those you listed, especially the purple microdot. Someone put out Christmas themed ones that were red and green.......
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Too far gone for me. I stayed with leafy greens.
 
mdt-son said:
Not a traditional one, but I think the rubber mounting (and the additional spring on the Mk3) does limit back/forth movements (pitch rotations). It certainly limits roll rotations. Granted, it's an imperfect system, and the reason why my crankcases and cradles have ovalized mounting holes!
The Norvil racing-type head steady is far more effective of course.
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The reason your crankcase/cradle has ovalised holes is because they were fitted with standard 3/8" bolts into clearance holes in both the crankcase and cradle. It will only be the three cradle to case holes that are affected as they are the ones trying to keep the engine fastened to the g/box and are subject to all the primary chain forces inflicted on them. The two front mounting holes will still be ok. There is a reason why the factory tuning notes stated to replace the cradle bolts with fitted studs.
 
mdt-son said:
You mean this post?
Doug MacRae

Thread 'Race Commando handling secrets revealed'

Not everyone wants to reveal their secrets especially in racing and I am not retiring from racing yet, although I fell off a few times in 2009 and lost to Kenny for the first time ( I should have retired right there ), I have slowed a bit.
It is possible that there is a better set up Commando chassis that turns in as quick, can be laid on it's side through an 90mph sweeper without a weave and is dead straight at 130mph. Anything is possible.
There is no credit for me, Herb Becker was the brainchild who built the bike, the ideas and fabrication were all his- I was amazed at the difference...
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- Knut
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more race tested info turned up

hobot said
Only a rump link allows the real handling potential to emerge yet only 4 people tried it so far but only 2 tested to race level (dunno if 1 being MacRae here) joys one being the late great Bob Patton.
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not much out there on Bob Patton

full hobot text
Hobot

Post in thread 'My First Commando...'

3000 rpms means over 50 mph in 4th and that just too fast for many situations so obnoxious vibes or risking too fast for safety to reach isolation. Down shifting to 3rd or lower to stay above isolation rpm means ya are chewing up dry/hot sleeve bushes which only ever get some drool down lube when in 4th. Original Commandos isolated about 1800 as Frankdamp Norton tester verifies so put that in your pipes and remember hobot beveling bragging suggestion - if feeling engine vibes after 2000-ish battery charging rpm, instead of hand of God turbo fan thrust in short shifting Harley like ease...
Make what ever rationales ya need to accept 3000 isolation but that's piss poor ignorance to hobot's 2 flying carpets. Ive ridden 5 others Commandos some builders shops farm out to restore, none felt as smooth as my corruptions. Hope to snag a cheap smart phone with vibe application to pass around for pecking order objective data.
I say buy new front cushions and bevel to narrow flat rim then put-add the 2 old big front cushions in rear iso stack un-beveled. BTW a breast support radius rod link or swash plates eliminates most sense of vibes from road texture and wind gusts so with a rod link head steady can give surprising deeper level of isolation for sane use. Only a rump link allows the real handling potential to emerge yet only 4 people tired it so far but only 2 tested to race level joys one being the late great Bob Patton.

Hobot

Thread 'Watt's like triple Helm linkage on Ms Peel'

highdesert wrote:
Steve, in language for dummies like me to understand, can you explain the function, set up, and perceived advantages of this rod linkage setup you have fashioned?
John
-----------------------------------

I'm scratching at straws to understand how
the rear, low, far from the isolastic mount linkage for leverage,
plus two slightly non rigid lesser helpers at front and top,
work to transform the ride and handling experience of my Commando.
I only know that at ordinary rates it feels Huge Monolithic Solid Inertia,
totally transparent to nuances of road texture, undulations...
Hobot

Thread 'Watt's Helm joint geomtery limits perfection'

Food for thought for the restless among you.
Only perfect if link radius allows free travel in the zone of pure linear
motion. Pre thought to rear and front rod end angle mounting required
to avoid bind at extreme loads. Most front links do not allow
for the rear link mounting limitations d/t chain and other vital items,
if retained in standard locals. Heady Steady is a non issue and don't
hardly matter a Whitworh as long as a bit compliant and no bind.

If ya still thinks a very rigid chassis, with some side load give
is the way to go, haha, ya just don't know what ya missing out on...
 
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dobba99 said:
The reason your crankcase/cradle has ovalised holes is because they were fitted with standard 3/8" bolts into clearance holes in both the crankcase and cradle. It will only be the three cradle to case holes that are affected as they are the ones trying to keep the engine fastened to the g/box and are subject to all the primary chain forces inflicted on them. The two front mounting holes will still be ok. There is a reason why the factory tuning notes stated to replace the cradle bolts with fitted studs.
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Whatever the facory wrote, the engine forms a hinge, affecting the front mountings as well. This is evident at my engine, whose front c/case and front mounting bores show up oval holes.

Edit: When I mentioned the engine forming a hinge, I meant the engine mountings, including the crankcase fixing points. Movement of all bolts is in the horizontal (X-Y) as well as in the vertical (X-Z) plane. There is a hinge for and aft at the engine.
Bolts move, irrespective of pre-tension, as long as there is clearance. Friction between bolt head and supporting plate(s) is usually not of a magnitude capable of resisting the movement. Avoiding this by tightening the stock bolts is wishful thinking!

- Knut
 
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dobba99,

your arrogance to differing views is not helpful in a tech discussion. "The two front mounting holes will still be ok" is your allegation, with no physical foundation.

- Knut
 
mdt-son said:
dobba99,

your arrogance to differing views is not helpful in a tech discussion. "The two front mounting holes will still be ok" is your allegation, with no physical foundation.

- Knut
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Of the five Commando engines i own, none display 'ovalised front mounting holes' One of these engines has well over 80 thousand miles on it (30 thousand plus in my ownership). So empirically that backs up my statement. The only reason your cases display wear is that the bolts have been loose at some point allowing the assembly to move about and cause wear. The engine is still not a hinge and never will be a hinge.
 
dobba99 said:
The only reason your cases display wear is that the bolts have been loose at some point allowing the assembly to move about and cause wear. The engine is still not a hinge and never will be a hinge.
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I would tend to agree that looseness is the greatest PROBABLE factor. Once even SLIGHTLY loose (imperceptible to 99% of riders), 'ovaling' of the hole(s) begins, with resultant increased rate of wear, in turn resulting in further ovality, ad infinitum. Once started, it can never return to normal without welding up and re-drilling (in perfect relative dimensionality), and including replacing the offending fastener with appropriate hardened bits.
And, once the deterioration begins, there is SOMEWHAT of a "hinge" effect, as the looseness induces previously restricted movement in SOMEWHAT of a "hinge" (for lack of a better word, AT LEAST) manner (ASSUMING the other points are NOT 'ovaling' and thus serve as hinging points within their allowed/rubber buffered plane of movement.
 
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