AMP Research research

[Lloydstrans]

Re:

I have those little screws, And bushings for the frame, forks. Shock bits and pieces and brake crap. PM me. Did I say cheap. Postage sucks.

 

[RockiMtn]

Re:

i share with you my current collection of spare forks! i also have two F2 forks in use on bikes, and F4 BLT on another. i did have an F1 steel leg as well, but recently sold it to a friend in need.

left to right: F2, F3 XC, F3 XC carbon, F4 BLT

 

[Gerard]

Very nice.....need some bikes for them!

 

[Akula]

Nice collection, need to get myself some F4s

 

[Gerard]

I've been doing some work on my F4 dampers (oil refill) and in doing so was intrigued by the spring pretension. This can be adjusted by moving the wire clip up and down the body groves.
The springs are different colours on the dampers, black and green. I understand is correct from another member here.
So looking at the F3/F4 manual on the AMP website archive for more info on the springs, position, colours etc, I notice section "C" (pg 2- which covers changing springs is missing. Does anyone have a copy of this?

 

[danson67]

Hi Gerard,

I don't have those specific pages, but there's a section in the Frame & Fork manual on their site that includes B4 spring removal:


Basically, compress the spring with the lower saddle enough to remove the spring clip, then slide the saddle and spring from the shock body.

All the best,

 

[Gerard]

Thanks Dan.
I have a copy of that. It was more the replacement of springs as I hoped this might provide some insight to the spring rates of the various colours; the different location of the body clamp and effect on spring rate/sag.

 

[danson67]

Aah,OK.

The spring rate is usually printed in tiny white lettering on shock springs.
I'll have a look at my BLT at home at the weekend. I think it has black and red springs.

The body clamp position will increase spring pre-load and shorten the fork length and travel.

For the folks at home:
3 spring weights available on the parts list: 350, 400 and 450 lbs/inch, but we don't know which colour is which.
I think they go up in order: Green, Black (Standard), Red.
We should be able to work out the colour coding between us.

EDIT: Sorted

F4 BLT Springs:
350lb = Green (Standard) Wire thickness 4.4mm/0.173"/ 11/64"
400lb = Black (Standard) Wire thickness 4.6mm/0.181" / 3/16"
450lb = Red (Special)

Standard set-up is 1x Green + 1x Black

All the best,

 

[RockiMtn]

i have both green i believe on the F4 BLT fork on the small B4 I have and it's pretty soft. so maybe green is soft. also have black/green on the spare F4 BLT and it seems stiffer. but i need to confirm that, as well as the position of the spring collar on the damper body.

 

[Gerard]

i have both green i believe on the F4 BLT fork on the small B4 I have and it's pretty soft. so maybe green is soft. also have black/green on the spare F4 BLT and it seems stiffer. but i need to confirm that, as well as the position of the spring collar on the damper body.

Thanks, very helpful.
My F4 has green & black. The black spring is one "ring" lower than the green spring. Looks (judging from marks on the aluminum) as if this was as it came out of the factory.