OzVMX Forum

Clubroom => Tech Talk => Topic started by: Nipper on November 29, 2016, 01:26:01 pm

Title: 1976 RM 370 rear shock length
Post by: Nipper on November 29, 2016, 01:26:01 pm

Hi I am after the length for the RM 370 rear shock eye to eye.
Can anyone help me here either by supplying the length of the shocks or knowing where to reference this info.
I believe that the A and the B model bikes had different length shocks.
Cheers Phil.

Title: Re: 1976 RM 370 rear shock length
Post by: shelpi on November 29, 2016, 03:42:44 pm

15" (380mm)

Title: Re: 1976 RM 370 rear shock length
Post by: John Orchard on November 29, 2016, 03:59:01 pm

My friend has a 250 A & B with stock shocks, the A has 390mm eye to eye (non reservoir), the B has 375mm (with reservoir), the B seems wrong, they seem too short as the rear of the bikes sits quite low?

I think both bikes should have 380mm.

Title: Re: 1976 RM 370 rear shock length
Post by: Oldfart on November 29, 2016, 04:17:04 pm

Correct length is 375 mm  eye to eye centres from factory 

Title: Re: 1976 RM 370 rear shock length
Post by: Nipper on November 30, 2016, 01:19:13 pm

thanks guys for the info, will there be a whole lot of difference if I use a 380mm shock vs a 375mm shock? just asking

Title: Re: 1976 RM 370 rear shock length
Post by: shelpi on November 30, 2016, 03:42:05 pm

Quote from: shelpi on November 29, 2016, 03:42:44 pm

15" (380mm)

ish lol

Title: Re: 1976 RM 370 rear shock length
Post by: Oldfart on November 30, 2016, 06:50:03 pm

Do your maths .  measure your shock shaft travel and rear wheel travel = ratio 

Title: Re: 1976 RM 370 rear shock length
Post by: shelpi on December 01, 2016, 04:30:41 pm

Quote from: Oldfart on November 29, 2016, 04:17:04 pm

Correct length is 375 mm  eye to eye centres from factory

Yes you are absolutely correct 375mm is exactly right!
I have found on average a replacement after market hover around 380mm eye to eye, so like you said do the maths get the shaft travel length, most important, as most shockers (not all) these days are length adjustable (eye to eye)
we are setting up suspension atm on a pre75 motocross sidecar have 80mm shaft travel and can have eye to eye 335mm to 350mm
so will get 2 pieces of tube that fit inside (telescopics) make them say 350mm eye to eye long, mark 80mm travel then can position get my shocker mounts and 4" of axle travel
I have also made up a board with a pivot point, swing arm ( just thin flat bar) then can mark shocker positions on swing arm and top shocker mount then give the shocker travel and get the axle travel ( it comes in handy)
cheers