Revisiting Rear Suspension

[detours]

Hey 2LZ, I tried installing the progressive spring and it won't work. Compared to the stock spring, the progressive is too wide. The upper and lower collars on the stock shock are flat and the spring won't stay centered.

[2LZ]

Originally Posted by detours

Hey 2LZ, I tried installing the progressive spring and it won't work. Compared to the stock spring, the progressive is too wide. The upper and lower collars on the stock shock are flat and the spring won't stay centered.

Thanks for the heads up detours! Much appreciated. I think I may take just one more turn out of the stock rear spring. I have it really close right now.... One more turn and then I have some good quality fork fluid coming to swap out also. I'm hoping that helps the forks as much as swapping the TT fluid did. The RX3 forks aren't bad....but there's always room for improvement. Both should really help balance the bike....but I'm amazed at how well the RX3 handles in stock form. Very tossable.

[3banger]

Here is the bumper being squashed buy the full weight of the bike with out the spring in place. The travel used up to this point was quit a bit less then the full available of 5.6 inches.

[3banger]

Now after trimming the bumper and this allowed for just about full travel of the rear wheel. When you do this the initial rear wheel motion is a lot for not much shock movement but at the top of the travel it looks to be about 1:1 or possibly more.

Detours I trimmed the bumper with the aluminum knife you see of to the side in the previous pic I posted. I have no idea why own an aluminum knife or where I go it it but it prove to be just the thing to cut through the foam with out damaging the chromed shaft. I have lots of oddball stuff in my tool box. I think a sharp plastic scraper would work as well.

[detours]

Thanks for the additional info, 3banger!

After my Webster Pass ride, I realized that I didn't have enough preload on my spring. The suspension could extend and drop into holes much easier, but could not handle bumps as well because I kept hitting the shock bumper on compression. After adding preload, the ride on road improved. I imagine the ride offroad will be even better now.

I'm still considering trimming the shock bumper like 3banger to allow more compression travel. If I do, I will trim in small increments of 1/4" because a little goes a long way. But I'm still on the fence. I'm in no danger of hitting the fender on full travel, but I don't want to risk damaging the shock internals in any way.

[3banger]

If it gives you peace of mind detours, I've used every bit of the available travel on petty rough trail; Alpine loop specifically.

[detours]

Originally Posted by 3banger

If it gives you peace of mind detours, I've used every bit of the available travel on petty rough trail; Alpine loop specifically.

Fantastic! Yes it does. I know you ride the rough stuff, but wasn't sure how much you tested the modified bumper.

[pyoungbl]

I got the new (and softer) shock spring from CSC. It covers a wider range of resistance than what came on the shock. One thing to note is that this new spring is significantly longer than what I had.

With minimal preload I now have about 1.25" of static sag so I'll probably add in a touch more preload. My first ride really did not feel much softer but that might be because I have not been riding the Zong much this summer.

Peter Y.

[detours]

Peter, just make sure to add enough preload so you're not sitting on the shock bumper.

[jbfla]

Originally Posted by pyoungbl

I got the new (and softer) shock spring from CSC. It covers a wider range of resistance than what came on the shock. One thing to note is that this new spring is significantly longer than what I had.

With minimal preload I now have about 1.25" of static sag so I'll probably add in a touch more preload. My first ride really did not feel much softer but that might be because I have not been riding the Zong much this summer.

Peter Y.

P, Is that the new 375 spring?

Does CSC have it in stock?

jb

[pyoungbl]

jb, yes that is the new 375/465 spring and I got it from CSC. You can see the specifications on the spring itself...might be hard to read on some monitors. I think the spring was about $75.

Peter Y.

[jbfla]

Originally Posted by pyoungbl

...... You can see the specifications on the spring itself...

Ahhh. Thanks.

jb

[jbfla]

Originally Posted by pyoungbl

...... My first ride really did not feel much softer.....

Peter Y.

Maybe I should wait until they have 350 spring....

I checked the specs of the spring on my DR 650, a suspension that is really kind to old bones, ...

....it's 247.5

jb

[pete]

Originally Posted by 3banger

Now after trimming the bumper and this allowed for just about full travel of the rear wheel.

yer don't think the bump stop is that length for a reason ?..
when they designed the shock do you think it's just possable
they designed the bump stop length to stop the piston hitting the
floating gas/oil separator under full compression and stop it getting crushed
between the valve piston & the top of the shock body...Or the xtra travel
over pressuriseing the gas and forcing it past the seal on the floating separator then puttin
gas bubbles in the oil..... yer damping will be real great then..

the internal torances in the shocks are pretty fine....

so be very careful not to bottom out the suspension....



..

[ChopperCharles]

Questions:

Is the progressive shock longer than stock?

With knobby tires, the progression shock without spring installed, and the unmodified bumper, will a knobby rear tire (say a Kenda big block) contact the fender or airbox?

Same question with modified bumper.

Charles.