Post by StewRoss on Dec 20, 2006 4:04:15 GMT -5
Hi,
Personally as a general guide I wouldn't put in more than say 10cc's extra a leg and then try it out. Do it in stages. However, as Wizz954 has done a bit on the SR's suspension of late 20cc's is probably OK.
It doesn't matter whether the springs are in or not for filling, but it does make it easier to pour the oil into the legs. Keep the amount even between each one.
Another trick is not to remove both fork caps at once with weight on the forks...instant deflation and springs all over the workshop...amusing to see.
...if the bike is on the centre-stand though it is usually OK.
Perhaps it's good to use the standard 182cc's and try 15 wt oil for a start.
One other issue is related to hydraulic locking...don't go overboard on the oil quantity...too much and it will hydraulically lock the suspension...not good!
...a small tale from experience ... when I got my first road bike several years ago now...heh, heh...a Honda S90, I wondered why when I went around most corners the bike would handle badly and the front end would wash out. Perhaps they were meant to do this??? (yeah right!) I eventually took the bike to my local Honda dealer, who noted that the forks didn't compress very much. When they checked them they found that the legs were almost completely full of oil at full extension. Nice bit of home maintenance by the previous owner...
They then made me change the fork oil and so started a long 'apprenticeship' in bikes. Eventually I when I was about 17, I ended up working in the shop part-time on and off and I learnt a lot from that.
From those days only one of the mechanics is still around on the Earth and I am indebted to them for their patience (sometimes)...they taught me a lot.
As Wiz954 said the damping on the SR's is fairly free and to slow the forks down it would take heavier oil. I put 25wt in my black cafe racer years ago and it worked fine. Gives a stiffer ride though, more sudden damping. This matches the sudden damping on the rear Mullholland shocks.
Missmatches between the front and rear suspension both in damping and spring strength will unbalance the bike and make it do things like kick up at the back (too stiff a rear)...or tank slap at the front (too hard at the front)...there are a also a lot of other reasons for tank slapping at the front beside this, such as loose head stem bearings, etc. so don't take this as the only reason.
The ideal situation is both ends going down together for a relatively balanced ride. The stiffness of your ride is related to how you want the bike to feel and the type of riding you do.
For Wizz954's racing use, the suspension should be fairly stiff. Not a nice ride on a roughish country road though...horses for courses...
Better springs are required for a stiffer ride the damping only controls the speed at which the spring will work, not the spring rate itself. This can only be changed by another spring, and then you need stiffer damping and so on...a never ending cycle until you're happy.
The ideal answer is probably to use a gold valve or similar and then to dial that in to suit. This can be a specialised task and may involve a suspension guru.
Properly sorted suspension is worth the time and effort.
SR
Personally as a general guide I wouldn't put in more than say 10cc's extra a leg and then try it out. Do it in stages. However, as Wizz954 has done a bit on the SR's suspension of late 20cc's is probably OK.
It doesn't matter whether the springs are in or not for filling, but it does make it easier to pour the oil into the legs. Keep the amount even between each one.
Another trick is not to remove both fork caps at once with weight on the forks...instant deflation and springs all over the workshop...amusing to see.
...if the bike is on the centre-stand though it is usually OK. Perhaps it's good to use the standard 182cc's and try 15 wt oil for a start.
One other issue is related to hydraulic locking...don't go overboard on the oil quantity...too much and it will hydraulically lock the suspension...not good!
...a small tale from experience ... when I got my first road bike several years ago now...heh, heh...a Honda S90, I wondered why when I went around most corners the bike would handle badly and the front end would wash out. Perhaps they were meant to do this??? (yeah right!) I eventually took the bike to my local Honda dealer, who noted that the forks didn't compress very much. When they checked them they found that the legs were almost completely full of oil at full extension. Nice bit of home maintenance by the previous owner...
They then made me change the fork oil and so started a long 'apprenticeship' in bikes. Eventually I when I was about 17, I ended up working in the shop part-time on and off and I learnt a lot from that.
From those days only one of the mechanics is still around on the Earth and I am indebted to them for their patience (sometimes)...they taught me a lot.As Wiz954 said the damping on the SR's is fairly free and to slow the forks down it would take heavier oil. I put 25wt in my black cafe racer years ago and it worked fine. Gives a stiffer ride though, more sudden damping. This matches the sudden damping on the rear Mullholland shocks.
Missmatches between the front and rear suspension both in damping and spring strength will unbalance the bike and make it do things like kick up at the back (too stiff a rear)...or tank slap at the front (too hard at the front)...there are a also a lot of other reasons for tank slapping at the front beside this, such as loose head stem bearings, etc. so don't take this as the only reason.
The ideal situation is both ends going down together for a relatively balanced ride. The stiffness of your ride is related to how you want the bike to feel and the type of riding you do.
For Wizz954's racing use, the suspension should be fairly stiff. Not a nice ride on a roughish country road though...horses for courses...
Better springs are required for a stiffer ride the damping only controls the speed at which the spring will work, not the spring rate itself. This can only be changed by another spring, and then you need stiffer damping and so on...a never ending cycle until you're happy.
The ideal answer is probably to use a gold valve or similar and then to dial that in to suit. This can be a specialised task and may involve a suspension guru.
Properly sorted suspension is worth the time and effort.
SR
