Shock question

[CookMySock]

Ok I have put a different shock on my bike and now its, uhh, behaving completely different so I need some advice.

Pre-upgrade, the rear was really hard to push down, nasty-rough on square edged bumps, but I could pillion no worries with only a little sag - not enough sag to upset the bike.

So now I have a 90's suzuki shock, and it was VERY soft right away, so I wound the spring preload right up, and pumped the external gas cylinder up to 180psi, and now its slightly too firm - I'll tickle the gas pressure down slowly.

Question: Even though its a little firm with just me on it, if I carry a pillion, the damn thing drags its arse around on the ground. Tyre hits under the seat, stand hits on the ground, so it's completely unrideable like that. How do I resolve this?


many thanks,
Steve

[Maha]

Sounds more like a rebound adjustment is need Steve...

[Robert Taylor]

Ok I have put a different shock on my bike and now its, uhh, behaving completely different so I need some advice.

Pre-upgrade, the rear was really hard to push down, nasty-rough on square edged bumps, but I could pillion no worries with only a little sag - not enough sag to upset the bike.

So now I have a 90's suzuki shock, and it was VERY soft right away, so I wound the spring preload right up, and pumped the external gas cylinder up to 180psi, and now its slightly too firm - I'll tickle the gas pressure down slowly.

Question: Even though its a little firm with just me on it, if I carry a pillion, the damn thing drags its arse around on the ground. Tyre hits under the seat, stand hits on the ground, so it's completely unrideable like that. How do I resolve this?


many thanks,
Steve

Short of you providing specific info i.e what you have fitted it to and what year make and model the shock is off it appears that the shock is woefully undersprung. Shocks are not just a ''if it fits'' scenario. The internal valving must be ''in concert'' with the motion ratio that the linkage imparts to it. Some linkages move shock shafts rather slowly, some rather fast. Damping force produced is totally proportional to shock shaft velocity.
Gas pressure is not a means of tuning! The gas pressure is only there at a high enough level to preclude cavitation. Increasing gas pressure increases seal friction.
Aside from other likely issues the shock needs an appropriate spring for the bike, that sounds likely to be a reasonably substanial increase. That being the case at minimum it will need more high speed rebound shimming to control the firmer spring.
The bike sounds dangerous to ride.

[Robert Taylor]

Sounds more like a rebound adjustment is need Steve...

Internally

[cowpoos]

Question: Even though its a little firm with just me on it, if I carry a pillion, the damn thing drags its arse around on the ground. Tyre hits under the seat, stand hits on the ground, so it's completely unrideable like that. How do I resolve this?

how do you resolve this??? put the stock shock back in you idiot!!

[CookMySock]

Yes it felt most disturbing to ride while carrying a passenger. I lasted about 1.5km on it, and then rode it back home very quietly indeed. It feels perfectly fine to ride one-up, with about 25-30mm sag (with rider.)

I bought the shock as a "rebuilder" for cheap - the previous shock was a sealed non-serviceable boat anchor, so now at least I am in a position to move ahead. I put it on just to see what it would do, and whether it did in fact physically fit (I had taken advice that it would.)

So it seems a rebuild, respring, and revalve is in order.


Steve

[Robert Taylor]

Yes it felt most disturbing to ride while carrying a passenger. I lasted about 1.5km on it, and then rode it back home very quietly indeed. It feels perfectly fine to ride one-up, with about 25-30mm sag (with rider.)

I bought the shock as a "rebuilder" for cheap - the previous shock was a sealed non-serviceable boat anchor, so now at least I am in a position to move ahead. I put it on just to see what it would do, and whether it did in fact physically fit (I had taken advice that it would.)

So it seems a rebuild, respring, and revalve is in order.


Steve

If it was off a Hyosung I know the rate of that spring and its way different to whats typically on the Suzuki shocks. You will have trouble finding an alternative spring that fits that Suzuki shock, in an appropriate rate. It will not require a spring quite as firm as Hyosung original because at least the Suzuki shock is double acting, it has compression damping where the Hyosung has very little. We dyno'd one a few years back. This could all end up being an expensive mistake, if you had contacted me before you committed I could have told you all the above. I am happy to do that for people.

[CookMySock]

Ok, off it comes. Oh well.

Steve