Rear suspension spring reversal

Hi Barry, and thanks for your reply, it shows someone at least does read these posts and spins it over in their head.

Also well done to you for working out there is at some point, full compression of the softer coils which then becomes unsprung weight. Now we have to imagine (or monitor the movement on a real road or racetrack) what gives the best tracking of road undulations.

Tyres absorb the smallest ripples. Soft springs absorb slightly larger ripples, and strong springs absorb the big bumps.

Having said that, everything moves at once, and even the tiniest ripple moves the strongest spring!

BUT...what is important is the DISTANCE the item is caused to MOVE. Movement, or speed of movement,is the source of INERTIA, and inertia is energy that has to be absorbed if a suspension sytem is to work. The faster and heavier an object is, the more energy or inertia it contains.

We then have to have an idea of the ratio ofsmall ripples to large bumps found on the surface as to which we use the machine. As the bikes look pretty sporty I would suggest sweeping roads or tracks rather than a muddy field. There I would suggest a rippling surface would easily outnumber full suspension crashes.

So, as I explained within my first post, we have to deal with more ripples than big suspension movements and the best way is to let the soft spring section "see" the fast ripple movementDIRECTLY and not be driven by a long section of heavy spring. By keeping the shortest section of spring responding to the fast movement rather than try to move the entire spring at a high frequency, we will have the least inertia to disipate, which surely must be better.

On the relatively rare occassion that (soft section at bottom set up) the softer coil becomes coil bound the extra weight is hardly a concern when the whole machine and it's massis lurching into a large bump.

If the usage was for off road, perhaps a motocross event,then one could say large bumps were the most common, and perhaps the spring would be better with the soft coils at the top as at most times the soft coils will be coil bound and as you correctly said Barry, whichwill create unsprung weight.

Anyway, it is just my opinion, and perhaps Ohlins would be kind enough to give their opinion and scientific data, and if there is something I've mised, I will be quite happy to acknowledgethe error in my thinking and theory if I am wrongKevin. Thank you for your reply too.

Hi Lionel.

Thanks for reading through my post and very attentively it would appear!

I think the part you are referring to is:

"If the usage was for off road, perhaps a motocross event,then one could say large bumps were the most common, and perhaps the spring would be better with the soft coils at the top as at most times the soft coils will be coil bound and as you correctly said Barry, whichwill create unsprung weight"

I agree entirely with your logic,and I realise now that I have left off a bitfrom the sentance or just poorly described what I meant. I should have said:

"If the usage was for off road, perhaps a motocross event,then one could say thatlarge bumps were the most common, and the spring would be better with the soft coils at the top as at most times the soft coils will be coil bound andwould otherwise create unsprung weight if they were left with the soft coils at the bottom.

So Lionel, I think you see the it in the same way as I do, and thanks very much for pointing out my error in what I wrote.

Some might argue that the difference is quite small, and in practice would perhaps not be that noticeable, buteven if the differenec is small, why not get the benefit however small it is...it comes totally free of chargesince the same effort is required to assemble the shocks with the spring either way round, and I know I would choose the orienatation that at least some scientific backing to support the chosen method.

By the way, even though I emailed Norton twice and had it confirmed they would at least read my suggestion., I never received any reply...not even to say "get lost, we don't give a damn" which to be honest, I would have prefered rather than to have them just bin it without comment.

It seems that perhaps there is still some old styleways left with British companies and indeed Norton. Perhaps ignorance is bliss.but it makes me wonder what reply you will get when you contact them for help when something goes wrong with your new Norton.

Anyway, please don't hesitate to point out any thing else I may have slipped on...it's all usefull information as far as I'm concerened.

Wishing you all the best Lionel

Les H