Suspension setup offroad

[ahutcheon]

On tarmac I've been happy with the 1150GS suspension pretty much "as it came out the box", just tweaking the preload at the back up from "standard" (from about 1/3 to 2/3 of the adjuster travel) to compensate for pillion and luggage as required.

I now find myself riding metalled (gravel) roads which often have sections of corrugation particularly on uphill stretches - a series of shallow troughs typically around 10cm deep and 30 cm apart I'd guess. At reasonable speed (e.g. accelerating out of corners moderately in 2nd) the back tyre doesn't track these very well. It seems to lose traction over the lip then drop hard into the next dip, which can feel fairly brutal with the shaft drive as the tyre bites again.

Rather than just change things at random, I wondered if anybody already knows the answer? Should I:

Turn up the preload to drive the suspension down into the dip?

Turn up the compression damping?

Turn down the rebound damping?

Just live with it (= "buy Ohlins" given cost, but would better shocks be more effective...)?

Slow down before I break something (but surely this bike should be better on these surfaces than a Toyota Corolla...)?

If the answer is in the preload/damping adjustment, can anybody confirm (or deny) that the adjustment on the stock rear shock is for rebound damping? In that case, does "more compression" equate to "less preload and rebound", or does that just mean "far too soft"?

Many thanks for any enlightenment. I'm experiencing this on Tourances at road pressure, if that makes any difference.

Andy H.

 

[Mzokk]

Don't do any off road on the GS myself but there isn't any compression dampling adjustment on the standard rear shock.

 

[cookie]

....but there isn't any compression dampling adjustment on the standard rear shock.

or on ohlins

 

[ag1s]

On tarmac I've been happy with the 1150GS suspension pretty much "as it came out the box", just tweaking the preload at the back up from "standard" (from about 1/3 to 2/3 of the adjuster travel) to compensate for pillion and luggage as required.

I now find myself riding metalled (gravel) roads which often have sections of corrugation particularly on uphill stretches - a series of shallow troughs typically around 10cm deep and 30 cm apart I'd guess. At reasonable speed (e.g. accelerating out of corners moderately in 2nd) the back tyre doesn't track these very well. It seems to lose traction over the lip then drop hard into the next dip, which can feel fairly brutal with the shaft drive as the tyre bites again.

Rather than just change things at random, I wondered if anybody already knows the answer? Should I:

Turn up the preload to drive the suspension down into the dip?

Turn up the compression damping?

Turn down the rebound damping?

Just live with it (= "buy Ohlins" given cost, but would better shocks be more effective...)?

Slow down before I break something (but surely this bike should be better on these surfaces than a Toyota Corolla...)?

If the answer is in the preload/damping adjustment, can anybody confirm (or deny) that the adjustment on the stock rear shock is for rebound damping? In that case, does "more compression" equate to "less preload and rebound", or does that just mean "far too soft"?

Many thanks for any enlightenment. I'm experiencing this on Tourances at road pressure, if that makes any difference.

Andy H.

When I take mine off road, depending on the surface I adjust the front preload to position 3 or 4 (at 5 the nose stands the highest) and reduce the rebound dumping on the back. How much depends on how fast you go.

The effect you notice with the rear does not depend imo on the quality of the shock. What I think happens is that when on gas, the telescopic shaft inside the paralever arm is reluctant to either expand or contract due to stiction. Exactly the same happens on my bike with both the standard and wp shocks.