F: Frame Spring Strengths to be used with Fully Sprung Rear Seats and AVO Coil Over Dampers

Speedtwin

Speedtwin

Well Known and Active Forum User
VOC Member
I will be trying out the AVO coil over with the 275 spring to the rear next weekend, I have fitted the AVO damper to the recently refurbished front end along with new inner and outer springs in the Front boxes.
Rear pre-load is minimal at the moment, will be trying out some combinations on the damping compression and rebound settings.
When the team return from the island I am going to borrow the rear suspension logger for a weekend and fit it to the AVO rear coil over.Just to see if I can get a clue to the spring weight 275 does sound too light for me but it may be okay for my needs think I can deal with the odd BO on a bad road as long as it is not mid corner.....
I am looking for the gliding along on a cloud soft suspension, so trying to keep my spring weight down as low as possible.
Getting a balance between front and rear travel and damping is my aim.
Al
 
Bill Thomas

Bill Thomas

Well Known and Active Forum User
VOC Member
If you are running standard forks, Have a think about fitting an Hydraulic steering Damper ?,
Sounds like another one of our Forum Blokes has had a Tank Slapper ?.
Cheers Bill.
 
T

timetraveller

Well Known and Active Forum User
VOC Member
I got round to doing the calculations for what would happen if one replaced the original 8" long, 275 lbs/inch spring with two 4" long springs, one a 275 lbs/inch one and the other a 400 lbs/inch springs. I ignored any problems with having to provide a double top hat bush between the two to keep them in line and regard this as a very simplistic test as to whether a multi rate spring could be used.
The results are not encouraging. By the time the loading on the spring is 550 lbs, that is a twin with a 253 lbs/18.1 stone rider, the weaker spring will be coilbound and the stronger spring will have compressed by 1.38". Any increased load such as a 3G bump or a pillion passenger will only further compress the stronger spring. When the load gets to 800 lbs the stronger spring will also become coil bound.
An 800 lb load far exceeds any values shown in the earler table but not if a 3G load has to be taken into account.
 
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