Aftermarket rear shock - how to adjust mechanical preload?

[EJD87]

I recently bought a Wilbers type 641 for my 2015 FJ09. While it has preload, rebound, and high/low speed compression adjustment on a reservoir, the preload adjustment is mechanical. Unlike the stock shock, however, the preload ring is at the top of the shock, while the rebound adjustment is at the bottom. How on earth are you supposed to adjust the preload on these types of shocks? When installed on the bike, wouldn't the preload ring by pretty inaccessible? I'm pretty sure I can buy the hydraulic adjuster separately if it comes down to it, but I'd rather not spend that extra $350 unless I absolutely had to. Besides, I'm not sure how difficult installing it on the shock would be.

 

If anybody has experience with mechanically adjusting preload at the top of the shock on these bikes, I'd appreciate the input! This seems to be a common configuration for fully adjustable shocks, so not specific to my model.

[RaYzerman]

There is a hook-shaped wrench for such adjustments, depending on the shock.... unknown if the ring is accessible when installed on the bike.  Perhaps someone else can answer that.  If not, then likely no choice but to remove it, tweak the adjustment, reinstall and try it.  However, measure your sag once first installed, that should give you an initial direction.

If you bought the shock new, then I presume you had it sprung for your weight, so should be in the ballpark right away.

[EJD87]

48 minutes ago, RaYzerman said:

There is a hook-shaped wrench for such adjustments, depending on the shock.... unknown if the ring is accessible when installed on the bike.  Perhaps someone else can answer that.  If not, then likely no choice but to remove it, tweak the adjustment, reinstall and try it.  However, measure your sag once first installed, that should give you an initial direction.

If you bought the shock new, then I presume you had it sprung for your weight, so should be in the ballpark right away.

Yeah, I know about the wrench, my question is if it’s even possible to use it if the ring is way up inside the bike instead of closer to the rear wheel like on the stock shock. And I bought the shock used, sprung for a rider slightly lighter than me. 

[bwringer]

Two ways:

- You may or may not be able to access that end of the shock with a tool by raising or removing the tank.

- Motion Pro sells a long brass-tipped punch for this purpose. Even though it's brass-tipped, some slight damage to the rings is almost inevitable. You'll also want to spritz a little something slippery onto the threads because these things just love to gall. You may or may not be able to access the rings with the punch without raising the tank.

https://www.revzilla.com/motorcycle/motion-pro-shock-spanner-punch?gclid=Cj0KCQjwnMWkBhDLARIsAHBOftpP2wDK73884b-ZMoimrw5zq_jEQpL-D1JX-htX4fGdeSSFWMVtWpYaAmUhEALw_wcB&sku_id=913353

A little is a lot; I don't know what the leverage ratio is, but a small movement makes a big difference.

 

 

The other thing to consider is that once you've raised the tank to access the shock from the top, you're 80% or more of the way to having the thing out completely.

[EJD87]

31 minutes ago, bwringer said:

Two ways:

- You may or may not be able to access that end of the shock with a tool by raising or removing the tank.

- Motion Pro sells a long brass-tipped punch for this purpose. Even though it's brass-tipped, some slight damage to the rings is almost inevitable. You'll also want to spritz a little something slippery onto the threads because these things just love to gall. You may or may not be able to access the rings with the punch without raising the tank.

https://www.revzilla.com/motorcycle/motion-pro-shock-spanner-punch?gclid=Cj0KCQjwnMWkBhDLARIsAHBOftpP2wDK73884b-ZMoimrw5zq_jEQpL-D1JX-htX4fGdeSSFWMVtWpYaAmUhEALw_wcB&sku_id=913353

A little is a lot; I don't know what the leverage ratio is, but a small movement makes a big difference.

 

 

The other thing to consider is that once you've raised the tank to access the shock from the top, you're 80% or more of the way to having the thing out completely.

Thank you, this is super helpful, especially about the shock spanner punch!