has anyone changed rear shock height?

I am thinking about raising my rear shocks from 13.5" to 14-14.5". Has anyone here done this?

I see alot of folks with extended swingarms, how do you know which shock length to use for them?

Bike: 82 kz1000m csr
Current Trail: 106mm

it all depends where your shock mounts on the swing arm are.i have 10.5 inch struts on mine.

Squints, This may or not help. In my fiddling w/suspension I try to keep ride heights centered IE; the center line of bike morre or less parallel to earth.w/rider in saddle. as steering head angle/fork/shock travel/compression rates were figured out long ago by someone more savy than I to the relations of weight distribution/handling during braking and acceleration. more by luck than design, I've hit a very nice combination on my 77 kz1000, ie progressive suspension fork springs @ 1" pre-load, gs1100 swingarm w/ 14" Olin piggy backs. ride is comfy, platform dead nuts stable regardless of speed and and exibits mone of the typical heavy steering under downhill braking.(the 1st thing one would notice by raising the rear end) hope this helps, G

I have a set of longer LTD shocks off an 80 model on my 78 KZ1000 and a shorter set of I think 650 ? shocks on my lowered big motor bike. I cant tell any difference in the way they ride

cool, thanks boys!

Lots of guys have the ass end way up. As a matter of fact thats what the racers did back in the day. my bike was built by a race shop and they moved the upper shock mount down and forward. this increases the rake and makes it turn quicker. the z's are dead slow in the turning department in there stock trim.
the stock rake is 26*,mine is at 25 now and could stand to be 24* i'd say . i'm still playing with it .
I see lots at 24* or less.
Keep in mind that u need good sound bearings in the swing arm and steering head,and the rear rim must be in line with the front(straight in the arm). to prevent speed wabble.

mark1122 wrote:

... my bike was built by a race shop and they moved the upper shock mount down and forward. this increases the rake and makes it turn quicker...

Mark, or anyone else, can you shed any light in moving the upper rear shock mount forward? I have seen this and it appears they just drill through the frame and add a mount (bolt). I was wondering how the frame may have been supported or if the bolt was shouldered to enforce the frame where drilled??

My back end used to run about 1" up from stock because of the stiffer shocks I had. One thing: careful to allow more slack in the chain when adjusting on the center stand. The longer shocks meabs the swing arm is lower which shortens the chain length and then when you sit on it and it goes close to level, the chain will get too tight.

any chance that the chain will rub on the swingarm axle?

I was looking at it last night, too cold to mess around for too long, and it looks close. Cant wait for some warm weather to mess around with it more.

squints wrote:

any chance that the chain will rub on the swingarm axle?

Yes. Mine would "clack" on it if the chain had a little too much slack, but otherwise OK.:laugh:

supercharged wrote:

mark1122 wrote:

... my bike was built by a race shop and they moved the upper shock mount down and forward. this increases the rake and makes it turn quicker...

Mark, or anyone else, can you shed any light in moving the upper rear shock mount forward? I have seen this and it appears they just drill through the frame and add a mount (bolt). I was wondering how the frame may have been supported or if the bolt was shouldered to enforce the frame where drilled??

Should not drill through the frame.
Best to use a tab welded to the frame.
If drilled, must be a "bossed" hole.
"Bossed" is where a separate cross tube is welded inside the frame from one side of the frame to the other, which creates a solid "tunnel" through the frame with an interior diameter just large enough to accomodate whatever size bolt is being passed through the tunnel.
This is commonly seen in the front down-tubes where the motor attaches. It is akin to welding a spacer crosswise inside the frame.

Here's an earlier thread that better explains this.

Drilling Hole Through Frame

Good Luck!

My shocks were laid down as they say , when i bought it from the race shop. I believe they did this to improve the angle from the swing arm to the shock. there is an optimum angle that improves the shocks angle.
A by product would be that the ass end sits higher, but they could have just ordered longer shocks to achieve that.
I changed mine back to stock because i changed the whole rear end. I felt the zrx shocks were too long to get the ride height that i wanted so that’s why i changed the upper mount back to the stock location.
The race shop drilled a hole in the frame and welded in a new machined mount on both sides of the frame. I’m sure if u weld it on both sides it ends up stronger than stock. jmo.