PV shock position

[Mick Milakovic]

Hi All,
I was wondering what advantages/disadvantages there are in running a '75 frame in the laydown position?  Obviously more travel and quicker turning response from less rake, but what about shock operation?  I'm thinking about doing this for Ambr's bike at Combs. By the way, the shocks are Progressives.  I know they're not the best, but they've been OK for now.  Will running them laid down blow them out?

Mick

[brian kirby]

The only practical issue is when you lay the shocks down it increases the leverage. This requires a heavier spring rate compared to a shock that is sprung for the upright position. The Progressive shocks are not rebuildable but they will work just fine, Mike Murphy's Rokon has the shocks mounted similar to the 75 Penton and he uses Progressives.

Brian

'73 Berkshire

[Mick Milakovic]

Thanks Brian.  Ambr proably won't push the bike as hard as some, and she doesn't weigh as much either.  She'll be happy to hear me say that, I think! [:0]

Mick

[brian kirby]

Mick,

I think she will be fine. Combs is very rocky, but otherwise the trail is easy and the speeds are low so the extra plush suspension will work well. The tests when you "race" are fairly tight too, so I think she should not have any problems with the shocks in the laid down position. See you next weekend.


Brian

'73 Berkshire

[tomale]

laying down the shocks not only gives you more travel and steerablity but once you get he right spring rate, the springs will be more progessive. which means that the bike will hook up better. Moving the shocks forward on the swing arm will give you more travel but you loose the progessive feel of the shocks. The bike will tend to hop instead of track and it will spin the rear wheel more too. I once hear Jim Pomeroy say that when he set up a bike he would sit on the front of the seat and then check to see how much sag he had from and back. If the bike is set up right the sag should be the same front and back.

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)