250 nc rear shocks.

[Bevel bob]

I would like to check the rear shocks are suitable, any information on length, 11.5inch?--spring poundage? look like oil Girlings with exposed chrome springs and i weigh 12 stone. .(these are new fitted by previous owner, the correct length should be 295mm ?, springs seem far too strong).

[MotoMike]

Bob we hashed this out a bit here. Over there Hagons seem like a good choice. I think possibly Nigel mentions they are based on the Girlings
Mike

viewtopic.php?f=3&t=372&hilit=+shock

[Eldert]

Hi Bob

the original shocks where about 300 mm so i would go for 12 inch .
Nigel and me both use 14 n/mm springs or 80 Lbs/inch

Eldert

[Jon Pegler]

The shocks that Hagons sell as a standard fitting for a Ducati single are 300mm long and come with a 14kg rated spring.
These are an updated copy of the old Girling shocks, with a spring rated at the same rate as the original Marzocchis.
Whilst Eldert and Nigel Lacey find this OK for racing, I think the spring is too stiff for road use and always get Hagons to fit 12kg springs.
Those original Marzocchi shocks were never very good in my opinion.
They were too stiff and often leaked.
Bob, if you're finding the old Marzocchi shocks a bit stiff, get some slightly softer springs fitted.
Don't be tempted to go as low as 10kg though.
You will bottom out the suspension travel on almost every bump.
The UK roads are not as smooth as most race tracks so I think a lighter spring helps a bit, Isle of Man excepted.

Jon

[Bevel bob]

Thanks all, usefull info, As my rear units are almost new i was thinking of just fitting a softer chrome spring,my problem was , working out what i have, and what it should be, seems like the shop that built the bike just used what they had in stock, too short and too strong.They appear to be girling copies similar to those sold by Geoffy, I may still be able to just swop the spring if the length is not a problem 11.4 inch units?, but beginning to think that 300mm 12kg hagons may be the way,just cannot contemplate the cost as my pension has desintegrated!.I have been round the IOM but only in a 32 year old camper ,wheels firmly on the ground.

[Jon Pegler]

Bob

You could always just go and buy a set of 12kg springs from Hagons and fit them to your existing dampers, assuming they are the correct size..
They will sell them seperately.
New springs from them measure:-
OD 53.25mm
ID 40.5 mm
Free length 215mm

Jon

[Bevel bob]

Thanks Jon, off to the garage with tape measure.------Hmmmm__38id-- 50od, 225 long. Just out of interest what does 80lb mean? it takes 80lb to compress 1inch? ,would be nice to know exactly what i've got already.

[Jon Pegler]

80 pound springs require 80 pounds to compress 1 inch.
12kg springs need 12 kg to compress 1 cm.

Jon

[Bevel bob]

Thanks Jon, I shall now spring into action.80 lbs thats about half a woman, on one leg, i'll ask her while she's still sober.Hagons have springs the right size, soon sorted.