"Test Mule" '74 850 Monoshock build

Status
Not open for further replies.
splatt said:
Enlighten me, as I look at it the rear iso mount could be refabricated and a modified swing arm could be mounted in exactly the same place.The pivot tube bolted between the frame tubes would also stiffen it up the frame.
Click to expand...

I believe the "weak link" would then be the rear frame tubes' diameter and bracing.
 
The bike will be receiving rigid upper and front stabilizers 9already on-hand and prepped for installation), I believe I'll take the advice of installing a lower one as well. I never argue logic when it is presented in a reasonable manner!

As to the "just for show" aspect, I think it's a far superior bike to some "show bikes" (Norton based) that have been posted here and are in all actuality un-rideable on actual roads (recall the one with the clear gas tank, and another resembling a bicycle).
 
grandpaul said:
Ludwig - now I am even more keen to get the bike out on the track and really put it through it's paces.

I do not disbelieve you, just that my blue bike has exhibbited no ill effects whatsoever in this configuration, in standard riding conditions. i really MUST go to the next level in a safe environment to get a better picture of what is going on.

I will go back to my notes and get the rake and trail figures, they vary slightly from my CAD drawings to the actual bike, and I don't have precision equipment to measure them in-situ. This must be what the new guy was referring to as "shoddy"; I'll accept the criticism in technical form, but reserve the right to dispute it in actuality!
Click to expand...

Ah, the age old battle between theoretical and actual. If Ludwig doesn't believe the bike should handle perhaps he should get on a plane and fly to Texas. I'm really sure Paul would let him take a spin on it. :mrgreen:
 
grandpaul said:
I believe the "weak link" would then be the rear frame tubes' diameter and bracing.
Click to expand...
not really that much smaller than the swing arm already
 
swooshdave said:
grandpaul said:
Ludwig - now I am even more keen to get the bike out on the track and really put it through it's paces.

I do not disbelieve you, just that my blue bike has exhibbited no ill effects whatsoever in this configuration, in standard riding conditions. i really MUST go to the next level in a safe environment to get a better picture of what is going on.

I will go back to my notes and get the rake and trail figures, they vary slightly from my CAD drawings to the actual bike, and I don't have precision equipment to measure them in-situ. This must be what the new guy was referring to as "shoddy"; I'll accept the criticism in technical form, but reserve the right to dispute it in actuality!
Click to expand...

Ah, the age old battle between theoretical and actual. If Ludwig doesn't believe the bike should handle perhaps he should get on a plane and fly to Texas. I'm really sure Paul would let him take a spin on it. :mrgreen:
Click to expand...

Swoosh ludwig explicitly stated that he would not ride a bike like this because it is flawed in design, unpredictable and potentially dangerous.

This is crazy! To start playing around with geometry and suspension and not understand all of the variables and potential issues!? I could say yes please go to the track and test this mono-thing and these threads may just go away permanently, but that would be just too cruel and wrong because you are playing around with your life here. You test a design that you do not fully comprehend. You may unleash such a wobble coming out of a turn that it could end up something terrible. Please consult with a professional before you needlessly risk your life.

What's even crazier is that these mono-bikes were offered for sale! Here! In the forum!

PS Jim Schmit's frame basically puts a Norton engine into a qausi-Ducati frame.
 
As Kenny Dreer built and tested the monoshcok design before he sold me the first swingarm I installed, I'm not at all worried that I'm risking my life riding it.

My design results in perhaps a simpler and more sturdy arrangement, albeit at the expense of a bit of added weight.

Who is it with the famous quote "Go ahead and do it, you're going to anyway"?
 
ludwig said:
grandpaul said:
.. far superior fully adjustable suspension unit (compression, rebound & pre-load adjustability).
Click to expand...
But that is precisely the problem :
You simply don't have an adjustable suspension , because you have no control over it !
What's the point of having a micro -adjustable preload , while your isos allow it to move all over the place ?
Click to expand...

So with this logic it's a waste of money to put good shocks on a Norton. If you're correct then a stock Norton would have the most horrible handling in the world and would be completely unsafe.

Unless I'm as daft all he's theoretically done is replaced the twin shocks with a single. It still locates the shock from the swingarm to the frame, just as the twin shocks do. Why would this move around any more than the twin shocks?
 
Thanx for the additional input, it is appreciated and will not be discarded lightly.

If you ask anyone that has dealt with me, they will confirm that I take criticism well, learn from my mistakes, and am above all, honest and forthright in standing behind my work.

If this bike is anything short of perfectly safe, proven in rigorous testing, it won't leave my shop.
 
swooshdave said:
Unless I'm as daft all he's theoretically done is replaced the twin shocks with a single. It still locates the shock from the swingarm to the frame, just as the twin shocks do. Why would this move around any more than the twin shocks?
Click to expand...

The relocation of the stresses induced at the head of the monoshock from the point where they are loaded into the frame by twin shocks is indeed a consideration.

Resulant forces on isolastics are somewhat different, although I don't believe the difference is that critical.
 
There was more than one monoshock bike. The 951 show bike never ran.

But, I never asked why the final design reverted to twin shocks, maybe there's something to it?
 
SNS. I'd suggest its time to give it a rest, or perhaps to move on. There's enough nastiness in the real world without bringing its poison to a forum such as this.
 
grandpaul said:
There was more than one monoshock bike. The 951 show bike never ran.

But, I never asked why the final design reverted to twin shocks, maybe there's something to it?
Click to expand...

It might not have anything to do with engineering and more to do with marketing. A mono-retro bike may not have the same appeal. Hence the reason Triumph and in some cases Ducati chose to go twin shock for their retro bikes.
 
bsaboss said:
SNS. I'd suggest its time to give it a rest, or perhaps to move on. There's enough nastiness in the real world without bringing its poison to a forum such as this.
Click to expand...

Agreed.... just came back to the forum having been too busy for a couple of weeks (Work) a good design/engineering discussion is interesting to follow but best to keep the discussion civil and avoid patronising/flippant comments. I am not saying anyone has posted in that manner but by its nature text based communication is fraught with the possibility of misunderstandings which can cause friction...obviously all IMHO.

Cheers Paul
 
What appeals to me is that this is as the title says - "TEST MULE". its a project to try something and see what it does. I take my hat off the GrandPaul for trying it out. He's laying out the money and the effort and we get to participate and learn something. It may work it may not work, but we get to learn something that Norton didn't do. Science and engineering is all good and neccesary, but consider the Isolastic. In 1967 the rubber mounting idea was scorned. Norton engineers Bauer, Hooper and Flavill concieved the idea, made up the first rubber mounts on the test mule and the vibration was terrible! Dr Bauer's solution was - Cut the rubbers in half and see what happens! And on the 3rd go, they found the vibration diminished at 2500RPM.
I think GP's mono-shock is a really interesting project and when its done and ready for test riding, I wish I was there. Then will find out what its like.
Keep up the good work, looking forward to the track reports.

Mick
 
Well said ML.
Paul, please don't stop. This has to be seen through to completion.
 
Personally I find it very interesting. I'm sure GP will test it in increments and back off and modify if he runs into problems.
If humans did not modify stuff we'd still be driving motorcycles with belt drives, oh wait I guess some of you are....
Kenny Dreer may also have gone to the dual shock again for production and cost reasons. It would be interesting to ask him since GP knows him.
 
GP, don't sweat it. I remember hearing from either Kenny or the guy that did the 880 frames that the stock shock mounts were all over the place. Add to that iso frames need exactly balanced shocks to keep from getting in a bind by canting the whole subframe, and you have some good reasons to go at a monoshock. If you got it perfect right out of the gate it would be a miracle, (personal experience), if you don't keep after it till you do, it would be a shame.

Months ago you mentions a 'big bearing swingarm' from Kenny Dreer. What's that?
 
My Blue bike has the "big bearing" conversion, I believe it's one of only 2 or 3, with David Edwards having one of them.

The pivot section of the swingarm is upgraded to an approx. 2-1/2" diameter welded-up tube, and a set of beaings is employed in lieu of bushings.

(This is the 880 MkIII cradle with provision for the Spyke e-start.

"Test Mule" '74 850 Monoshock build
 
grandpaul said:
My Blue bike has the "big bearing" conversion, I believe it's one of only 2 or 3, with David Edwards having one of them.

The pivot section of the swingarm is upgraded to an approx. 2-1/2" diameter welded-up tube, and a set of beaings is employed in lieu of bushings.

(This is the 880 MkIII cradle with provision for the Spyke e-start.
Click to expand...

Good Lord that looks dangerous, I mean where do you even put your bum?!!!?!?!? :roll:
 
Status
Not open for further replies.
Back
Top