We are going to put a hack on a 94 harley bagger we own.
A Harley side hack could be the easiest solution since they were designed for the bike. Unfortunately I live on a nasty washboard dirt road. Four miles of 3" deep ruts on 12" centers most of the summer.
A factory Harley hack has a rigid hack frame with leaf spring suspension on the car itself, the wheel is unsprung. I was told that HD hacks pull and bump steer more than a hack with a live axel when the hack wheel hits a bump. Perhaps someone reading this who has driven a HD factory hack on dirt roads could tell me if severe washboard roads are just a mild annoyance or a real nightmare on a Harley factory hack. We keep the speed down below 20 mph to keep from shaking the bags right off the bikes anyways. BTW the bikes handle the abuse fine.
The lack of suspension is the main problem with the Harley car. The placement of the stock damper doesn't lend it's self to "Bump steering".
The wallowing effect is due to the assymetrical design of the rig and placement of the wheels with the sidecar wheel being about 8" ahead of the rear bike wheel the rig gets thrown from side to side on washboard roads.
This phenomenon is less less apparent with a independently suspended sidecar since they lack the direct mechanical connection of a rigid car.
The leaf spring suspension of the Harley car body is for passenger comfort and is useless in controlling sidecar wheel bounce.
Best answer, Slow down or go to a sprung hack.
Lonnie, Rigger
Northwest Sidecar
The talk of unsprung wheels brought back a memory for me. Back in 1947 i was trying to follow my buddies on an uphill washboard gravel road. I couldn't do it. My buddies had English Matchlesses singles with sprung rear wheels, I had a rigid hard tail Matchless. Everytime I gave it gas the bike would slide sideways off the road. I ended up getting off the thumper and pushing it up the hill.
I would imagine that a rigid wheeled sidecar would do all kinds of wierd things on a washboard road.
We live about on emile off th ehard road. Have run rigid hacks up here a few times and ,yes, they bounce, drag and pitch and roll around quite a bit. The Harley bodies bounce all over the place on the springs especially in empty.
Getting a spung car is an option of course. Grading the road may help for a while. Actually running lower air pressure in the hack tire helps too but this old hardtail trick may not be acceptable on the road.
Tough question and really no great answer to it.
Admittedly, Harley sidecars are not the best on a washboard road but they can be improved. I use a 50/50 hydraulic shock on mine. it goes between the front tub mount and the lower frame. This helps to dampen oscillations from a washboard road. It really does help. I've yet to see another Harley with a smilar shock setup.
As far as the negatives of having a solid frame, I do believe that the steering is less mushy. I've ridden sidecars with swing arm frames and frankly, I don't like them. So for every plus, there's a minus.
The negatives of a Harley sidecar mounted on a Harley are more than made for up by the beautiful-fitting mounts and general nice fit and finish of the parts.
By far the best way to avoid difficulties on a washboard road however, is to stay off of them.
And if these comments should start a start a firestorm of anti-Harley bashing. It's OK with me. I enjoy it. Hee Hee. LOL.
Oh yeah, and I don't mind personal attacks, either.
Well, you should be in Hog's Heaven here!!!
Ol David with his wooden spoon. Hee hee!
