Hyperpro lists the sag for my bike's (2011 GSA) front and rear shocks.
My chair has a new 2win shock but I can't find the instructions.
Does anyone know the sag (percentage of travel) the chair should have?
I would just ask Chloe about the ride but she's too busy having fun to notice that sort of thing.
Drew, the two people that I know...for a fact...would have that info, is Mike Paull, currently driving one of his many sidecar rigs around Europe, so he is not at home in his shop to have that info at his fingertips....and Chuck Loftin, on here as @54vintage, and I will send you his personal e-mail...via an e-mail to you.
Two Million Mile Rider
Exploring the World in Comfort
Chuck didn't have one on the shelf but he did give me a pretty good guess as to where the preload adjuster started. (Because he's Chuck and Chuck is awesome.)
I'm more interested in sag. There's a couple general rules for street bikes so I wondered if there was one for the chair.
Mike Paull generously took time to answer my question even though he's sidecar touring in Europe and I bought that shock a couple years ago.
Very impressed by that.
My takeaway is that shocks are generally set at about 25-30% of their travel/stroke. He didn't specifically say sidecar shocks follow the same rule as rear suspension shocks but that was the impression I got.
He went on to say that the 2WIN only has a 3" travel and when dealing with shorter travel (Harley/Indians) you use a sag figure of 15-20%.
These are starting points. Handling, your butt, and your monkey's enjoyment will dictate any further adjustments.
Here's his response in whole...
All 2WINs ship with the spring preload set for the tub’s wheel weight loading of round 280lbs. If you have a scale that will take the weight, place it under your sidecar tire and see if you are in the ballpark. If so, leave it alone.
If you want to adjust sag preload, the conundrum is that the stock 2win has a relatively short stroke of around 3.00”, A rule of thumb says that shock preload should be set for sag of about 20% ~ 25% of total stroke, but with only 3.00” to begin with, preload at about 15% ~ 20% is recommended to reduce the occurrence of bottoming out.
The best feature of the 2WIN is its 14-position damping adjuster. The shocks normally ship with the adjuster set at 6 clicks from CCW. What I recommend is that you find a section of road with some bumps in it. Run it both ways with the adjusters at six clicks. Run it a second time with all the adjusters set to full CCW. Run it a third time with all adjusters set to full CW. This will give you a “feel” for the range of damping adjustment available. Then set them at whatever setting works best for you, and don’t be shy about experimenting, you can’t break anything ;<)
That is a very nice and thorough explanation. Will be interested to see where you end up after a bit of travel. 😎
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