Greg I found the stock spring to have very little travel and the Hydraulic Pre-Load Adjuster was low on oil which further limited the available travel to about 3/4" when the wife was on the bike with the dog in the sidecar. At the time we had an Aussie and he weighed in at 75 lbs. I weigh 270 and the wife 100 lbs. So that's 370 on the bike plus the sidecar with ballast and a dog.
To correct that I replaced the stock 900 lb spring with a Progeressive spring that's 1,000/1,200 progressive rate. I also refilled the Hydraulic Pre-Load Adjuster with Fork Oil to get the full adjustment of 1 1/4" vs what was less than 3/4". Before that with the stock spring and the deffective Pre-Load at the full 25 setting there was only 1 to 1 1/2 of travel and we bottomed out at every bump in the road.
With the Progressive spring that changed to about 2" of availaible travel on a good day with the Pre-Load at 25 which still wasn't enough for the larger dips and pot holes.
As time went on the Aussi died and we got three Australlian Cattle Dogs, two of which are always in the sidecar and sometimes all 3. The result was that we were always ridding 2-up plus a sidecar full of dogs.
To help the situation the local Dealer found a Suspension supplier for standard rate springs and we got a 1,400 lb one. It took a little modification to use it due to the shorter length so a new groove was cut into the shock body for the keeper snap ring for the differance in un-compressed length. I also added a spacer to the assembly to gain a little more travel later and got the whole thing to provide 3" of available travel with 1" of Overtravel with 2-up on the bike and 3 dogs in the sidecar along with a trunk load of normal stuff.
If I were doing it again I would use a 1,300 lb spring and cut the required groove to add the needed preload without using a spacer.
Note that it is common to find that the Hydraulic Pre-Load Adjuster is low on oil especially with the earlier 1800's. The later 1800's seem to have a better chance of being full. To test it you can set it at 0 then raise it up one notch at a time untill you hear the electric pump start loading down. When you hear it you will understand. Mine wouldn't start "Working" under load untill about 14, that is until I filled the system. Honda won't cover this under warranty untill it won't work at all. That is if it only functions at 24 or 25 it is "OK" per Honda. That leaves most of us with low Pre-Load Oil on our own to correct it.
If yours starts taking on a load at anywhere below 4 or 5 it will probabably be OK but if it is much above that ask about how to re-fill it.
Jerry
Thanks Jerry, I'll test it as soon as I get back to Ca. Mine is an 07, so maybe it works OK. Before I added the sidecar, i ran it on 6-7, was too stigg at 20+.Have never botoomed it out that I ktow of.
