roll centre

[Martin P]

ok, ive just got a couple of set up sheets and on them they say roll centre- 1mm lexon spacers, or somthing like that.
What are these? and what do they do? ???

[MattW]

Martin. These are spacers that are placed under the inner lower pivot blocks. The front is only semi adjustable, but the rear is infinately adjustable with as many spacers as you wish. However it is generally accepted that the 2mm spacer in the roll centre kit is a little too much, hence 1mm adjustments have been popular.

Although personally i usually leave the rear unaltered!

[MarkB]

Hi Martin,

I wonder where those set up sheets come from ;)

The Roll Centre kit was a Schumacher option part - U2575 - with parts to to raise the front pivot pin and spacers to raise the rear. The front I leave alone like Matt (gives better mid corner grip over kit setup for me), and I differ from Matt by using no spacers or spacers between 1 - 1.5 - 2.0mm to tune the handling. For low grip we reduce the size of spacer, for high grip surfaces larger spacers.

Oh and the 2.0mm spacer helps turn in to tight hairpins like those at Bedworth!

For a fuller explination of how roll centres work, read the XXXMain Chassis book!

Cheers
MarkB

[Remo]

Oh and the 2.0mm spacer helps turn in to tight hairpins like those at Bedworth!

Cheers
MarkB


Oh... so that's why.... Remo's busy taking notes.... ;)
My front roll centre mod has been there sin cethe car was built but never ran the rear....One question Mark... would the rear spacer help the rear to go round instead of snapping off at the apex of the hair pin? Cos I am having a bit of that at the mo but nothing serious
Cheers!

[jason]

Remo,

Raising the rear roll centre takes away some of the grip but makes the break away more progressive.
The only place we regularly use the full rear roll centre kit is Bedworth but I did run it at Snetterton once this year.

Jason

[Remo]

Cheers Jason... I shall give that a try when I get a chance...

[mkdean]

Hi, could anyone help re replacement front pivot pins, i have fitted the roll center mod to my sons car but desperately need some replacement pivot pins as one is bent but cannot find the correct size listed in schumachers parts list, i beleve that i neeed 51mm pins, is this correct and if so could you tell me where i could get them.

Many thanks.

[adyb]

I believe Titianuim pins for roll center Mod are U1580 and you can get them from a company in Berkshire ;)

[jason]

I normally just get a longer one and cut them to length with a dremel.

Jason

[MarkB]

Jason's method will work - have Dremel will travel!

I've since found that the 48mm titanium pivot pins fit straight on (an filing!). Part number is U1580 as has already been said.

Cheers
MarkB

[mkdean]

Great, thanks Mark, Jason and Adrian for the replies. Think i will go with the Titanium Pivot pins.

Thanks again

[Menace PJ]

just emember that you have to cur the plastic steering mounting snuggly to the roll centre mod alloy block ot Titantium or not You hit something its Gonna bent it...

Trust me I know..lol

Stopped me racing at DMS.

nice to see Spashett show that he can smash em up like the best of us...heheheh