Rear wheel conversion, or RPM fork valves

[the fan]

Is the RPM not adjustable for riide height/length?

Every aftermarket shock I have purchased has had this feature. I am somewhat surprised if it is not.

[FJmonkey]

Is the RPM not adjustable for riide height/length?

Every aftermarket shock I have purchased has had this feature. I am somewhat surprised if it is not.

The RPM shock does not have that feature. The other shocks had to fit a wider selection of bikes so they had to be adjustable. The RPM shock was designed specifically for our FJs. However, the 89+ FJs have dog bones that allow the height to be altered by swapping them with longer or shorter (dog bone) links. Or you could do what I am working on, convert my 86' to have 89+ rear suspension with the dog bones. I recommend that if you chose this path, wait till I can post up details of my project. I have a few bugs to work out to get the upper shock mount in the proper position.

I hope that helps.

[Pat Conlon]

I am not a suspension expert, but, according to all the guru's I have talked to (Jim Lindemann RIP, Ed Sobro, Dan @Traxxion) they all agree that on raising the rear height, it is preferable to do it with extending the shock rather than messing with the swing arm links.

[FJscott]

+1

[the fan]

I am not a suspension expert, but, according to all the guru's I have talked to (Jim Lindemann RIP, Ed Sobro, Dan @Traxxion) they all agree that on raising the rear height, it is preferable to do it with extending the shock rather than messing with the swing arm links.

Pat, I have always been taught the same. I assumed the RPM shock had this feature but never really looked into it.

[FJmonkey]

I agree with avoiding altering the suspension geometry (my current geometry is scary looking  ). But the amount of change is not that much if you upgraded to a 17" wheel and you want put the tire contact point back to OEM.

[fj1289]

I agree with avoiding altering the suspension geometry (my current geometry is scary looking  ). But the amount of change is not that much if you upgraded to a 17" wheel and you want put the tire contact point back to OEM.

I bet someone will have an aneurism over the rear setup I've run for years on my 89 - FZ1 swingarm, 94 FZR1000 knuckle, 94 FZR1000 shock, FJ1100 spring, and adjustable dog bones...all combined with R1 forks that are shorter than stock FJ forks.   

[ZOA NOM]

I am not a suspension expert, but, according to all the guru's I have talked to (Jim Lindemann RIP, Ed Sobro, Dan @Traxxion) they all agree that on raising the rear height, it is preferable to do it with extending the shock rather than messing with the swing arm links.

Pat, did they elaborate? I'm cutting some shorter bones to go with my GSXR wheel / RPM shock conversion.

[X-Ray]

I don't know if this will help as I'm still running the standard rear shock, but I went from the factory 12.5cm centre to centre dog bones to 11.5cm C to C.
Works great with around an inch seat height rise, but more importantly for me puts the back wheel closer to the ground when using the centre stand, nearly launch the bike through the shed wall now.  

Some interesting reading Rick here http://www.fjowners.com/index.php?topic=12381.0   and here http://www.fjowners.com/index.php?topic=12370.15

Hoo Roo

[ribbert]

I am not a suspension expert, but, according to all the guru's I have talked to (Jim Lindemann RIP, Ed Sobro, Dan @Traxxion) they all agree that on raising the rear height, it is preferable to do it with extending the shock rather than messing with the swing arm links.

Pat, did they elaborate? I'm cutting some shorter bones to go with my GSXR wheel / RPM shock conversion.

If you're only altering the height a small amount, go for it.

Those comments are technically correct but idealistic and based on the theory that the linkages in standard configuration offer the most efficient relationship between swing arm movement and shocker action as calculated by people with far more resources than us. Theoretically, any deviation from that diminishes it's performance.

The reality is that small changes will not have any perceivable negative effect, as shown by the many here who have done it, some with very high and hard mileages.

The other thing is, the OD of the 16" and 17" wheel is much the same because of the different tyre profiles but the bike's handling does seem to benefit from raising the rear end a bit. Unlike many of the touted improvements floating around, this does actually improve handling.

Go for it, there are many who have gone before you. Just don't fall for the trap of thinking more is better when it comes to how much you raise it.

Noel

[movenon]

"Just don't fall for the trap of thinking more is better when it comes to how much you raise it."

Been there... All I can recommend is don't get it to far out of balance.
George

[ZOA NOM]

Great feedback, thanks. I've laid out a set of bones at 115mm c-c, so I'm making the same change as X-Ray. Now if this damned rain would let up...

[ELIMINATOR]

The fork upgrade is on hold....................... I am splitting up with my partner of 15 years.

[Capn Ron]

The fork upgrade is on hold....................... I am splitting up with my partner of 15 years.

Sorry to hear that...it's a big change for sure with a lot of adjustments to make.  Hey, maybe it's time for an upgrade there as well?   

[ELIMINATOR]

That is why I am splitting up.