racetech fork spring install questions

[trevinator]

the new springs i have are shorter than the stock springs by 36mm (stock-307mm, racetech 90kg springs-271mm). the stock preload spacer is 121mm, and according to racetech, the preload should be 10mm. measuring from the top of the racetech spring to the bottom of the spring adjuster, i get 143mm, so i should in theory need an additional 32mm spacer to get the 10mm of preload. the question is, where do i put the spacers? should i put them on top of the existing spacer, should i put them under the springs, or between the spring and the existing spacer? i plan on getting a section of sch40 pvc to make the spacers with, i just dont know where i should put them. im thinking i should add them under the springs, but i dont know if that will effect the dampening any by possibly covering fluid paths into the cartridge?

also, i checked the fluid level with a tape measure, and it appears to be about 165-170mm from the top, which from everything i have read seems low, so i ordered a liter of 10wt oil and a fluid level tool to swap out the oil.

if anyone has insight as to where i should install the new spacers, i would appreciate it.

[trevinator]

i think i have a plan in mind for the spacer. i can use some round stock to machine a spacer on my mini lathe to fit over the underside of the stock spacer and fit into the spring so it keeps everything centered still.

a pvc spacer on the bottom doesnt seem like a good idea as there is a piece that it can interfere with on the rod. pvc above the stock spacer has the possibility of the stock spacer going off center, and same for under the stock spacer, the spring could slide from side to side. thats the plan so far.

[OZVFR]

Don't add bits and pieces, just make a new spacer the correct length.

Racetech sell the uncut aluminium spacers, lots of people also make them out of PVC.

The new spacer can only go where the original spacer lives.

 

Edited May 29 by OZVFR

[trevinator]

1 hour ago, OZVFR said:

Don't add bits and pieces, just make a new spacer the correct length.

Racetech sell the uncut aluminium spacers, lots of people also make them out of PVC.

The new spacer can only go where the original spacer lives.

 

if i just replace the entire stock spacer with a piece of pvc tube, how would you recommend i go about keeping the spring centered on it so it doesnt hit the side of the fork tube?

[trevinator]

i still think a piece of metal machined on my lathe to go over the stock preload spacer and fit inside the spring will be the best option currently. pvc will be much weaker, not to mention much harder to keep the spring centered like stock.

[OZVFR]

There is a stepped washer on either side of the spring, this keeps the spring centred. At least i think there is, but could be confusing it with my VFR. 

Edited May 29 by OZVFR

[Ride365]

I used Racetech for my springs on my last bike, won't be going with them again.......going with drop in same length as OEM springs from someone like K-Tech.

Edited May 29 by Ride365

[miweber929]

7 hours ago, trevinator said:

i still think a piece of metal machined on my lathe to go over the stock preload spacer and fit inside the spring will be the best option currently. pvc will be much weaker, not to mention much harder to keep the spring centered like stock.

It’s a spring that compresses and flexes, it will still hit the sides of the for while in motion. Don’t overthink it, make one spacer, put it on top and be done with it. 

[trevinator]

6 hours ago, OZVFR said:

There is a stepped washer on either side of the spring, this keeps the spring centred. At least i think there is, but could be confusing it with my VFR. 

there is not on my fj. the centering is done with the spacer at the top.

[trevinator]

1 hour ago, Ride365 said:

I used Racetech for my springs on my last bike, won't be going with them again.......going with drop in same length as OEM springs from someone like K-Tech.

i already have these springs, so they are what i will be using.

[trevinator]

54 minutes ago, miweber929 said:

It’s a spring that compresses and flexes, it will still hit the sides of the for while in motion. Don’t overthink it, make one spacer, put it on top and be done with it. 

i would be fine with that, however, the spacer will be long enough that at full compression, if the spacer is all the way to the side and not centered, it can hit the top of the lower fork tube and would likely result in the spacer shattering.

[betoney]

From memory, I cant recall what the inner fork looks like on the FJ/Tracer but does it have a spacer like this Fork Spring Spacer   You could make one that is about 160mm on the lathe.  Remember that the fork caps have preload adjustment to make up the difference so the spacer wont need to be accurate to the exact millimeter.  With correct spring rate your sag should be much closer and you will be dialing in much less preload, if any, on the fork caps.

 

[trevinator]

1 minute ago, betoney said:

From memory, I cant recall what the inner fork looks like on the FJ/Tracer but does it have a spacer like this Fork Spring Spacer   You could make one that is about 160mm on the lathe.  Remember that the fork caps have preload adjustment to make up the difference so the spacer wont need to be accurate to the exact millimeter.  With correct spring rate your sag should be much closer and you will be dialing in much less preload, if any, on the fork caps.

 

its exactly that spacer. the problem with machining one that long, is my lathe is small enough that a spacer of that diameter wont fit through the chuck, so the stick out will be a lot and likely have chatter. its also a lot more material to use making the entire thing and a lot more machining. my plan right now, is to make a spacer to fit over the small end of this, with the correct length i need, and with that same style nub to fit into the new spring so it all stays centered and everything else fits as designed.

[skipperT]

The easier thing to do would be to cut the stock spacer in half, and install a piece of material in between those cut piece to match. 

The spring doesn’t care how it looks, only that it has pressure applied from above and below. Doing it that way would keep the holes in the spacer at a convenient place for assy/disassy  using the appropriate tool and still fit into the upper portion of the spring. 
Just another idea. 
-Skip

[RD52]

On 5/29/2024 at 7:28 AM, Ride365 said:

I used Racetech for my springs on my last bike, won't be going with them again.......going with drop in same length as OEM springs from someone like K-Tech.

Sonic Springs also has them in a 300mm length, drop right in. Back when I owned the company I worked with Nick Stolten to develop a size specifically for the FZ-9.