I need suspension help please.

General forum on frames, brakes, suspension, wheels and tires

Moderator: rztom

Post Reply
Posts: 11
Joined: Wed Jun 07, 2017 10:59 pm

I need suspension help please.

#1 Post by DFB » Sun Aug 20, 2017 1:34 pm

Hi, I need help with set up. Currently have a RZ with 2007 R1 front end (2000) and a fz600 read end with a ohlen shock. The problem is in turns at higher speeds the bike feels like its twisting as if the front end is and read end aren't communicating together. I'm 195lbs 5-11. Could it be that the rear is set up to stiff? I read somewhere that if you stand over the bike and push down on the center of the bike and it goes down all at once, thats a good start to a even suspension? And it does this...


Posts: 401
Joined: Fri Dec 28, 2012 9:23 pm
Location: Quincy, FL USA

Re: I need suspension help please.

#2 Post by waltmil » Sun Aug 20, 2017 10:02 pm

Could be you have a mismatch with a stiff modern front end, early '80s frame and '90s rear end. Not to mention tires.
Red/White US '84, Spec II pipes, Y-boot w/K&N, Fox Shock, Mikuni carbs?

User avatar
Posts: 9695
Joined: Sat Oct 10, 2009 4:33 am
Location: Sydney

Re: I need suspension help please.

#3 Post by JonW » Sun Aug 20, 2017 10:12 pm

its probably the bendy frame in the middle of the better tyres and suspension. I'd seek out a suspension shop and ask them what they think.
My Projects:
see them all at www.2smoked.com

80 XT500 Supermoto!
81 RD350LC Resto
82 RD 421 LC Hybrid
82 RD 250 '51L' YPVS LC
83 RZ350 LC2 Resto
85 RZ350 F1 Resto
84 RZ500 Resto
86 RZ350 F2 Hybrid

Like Watches? Try www.PloProf.com and www.DeskDivers.com

Posts: 11
Joined: Wed Jun 07, 2017 10:59 pm

Re: I need suspension help please.

#4 Post by DFB » Mon Aug 21, 2017 12:04 am

Thanks for the insight guys. I talked to a friend today an said I should look at the rear shock. I checked the set up from the previous owner and the rear shock was spun down way to much and the rebound was all the way tight. So I loosened the spring about 1/2 of an inch and adjusted the rebound to 3 clicks from full. Took the bike for a ride and all is well. It was like a pogo stick before and now they work great.

User avatar
Posts: 142
Joined: Thu Aug 05, 2010 2:21 am
Location: Alberta Canada

Re: I need suspension help please.

#5 Post by OldTZracer » Tue Aug 22, 2017 12:36 am

Look for a copy of Andrew Trevitt's book - money well spent...
https://www.barnesandnoble.com/w/sportb ... 1009150851" onclick="window.open(this.href);return false;
"...its a 2-stroke ya twit - Its supposed to smoke..."

User avatar
Questo vecchio rz
Posts: 854
Joined: Sun Aug 16, 2015 5:55 pm
Location: Reconquista of California

Re: I need suspension help please.

#6 Post by Questo vecchio rz » Mon Aug 28, 2017 2:51 am

The R1 front end is likley a issue, unless it was revalved. The stock RZ is generically set up for a 370lb bike & about a 150lb rider.
A orig R1 frontend is sprung approx. 450+ lbs plus rider. So if you have not had it revalved...it's a mismatch. In addition some math/measurement is in order to determine your existing rake/trail & offset, as well as ride height /sag etc.. for the rear.
Your rear end is the most common RZ swap there is...but there's a (lot of variables) in the rising rate system that can be a factor, the dog legs have likley been cut, for ride height which affects alot of the geometry .
As far as your frame..it is what it is...but IMO ..the flex is nowhere as bad as some make it out or have been led to believe it to be, especially on the street. The bike frame design for what it is handles quite well under even the most demanding situations, most problems are suspension setup/condition and rider input issues.
As mentioned above talk to a good suspension shop, and get it sorted, you can revalve to a certain point but over 100lbs many new spring rates are not easy avail... but combined with lower rate springs and oil weight can usually be brought to a acceptable range.
Stock R1 forks are 100% the wrong rate...period.

Your rear end Ohlins shock should be just fine w the exception of finding your ride height and comp/rebound settings.

You should determine your existing dog bone length to determine what was done. (Again variables) You can research it here likley in old posts.

Even with a stock suspension setup it can go all wrong real quick..with the wrong setup, (when you change to new offset,rake,trail and ride height and suspension linkage rate, and rear wheel centerline) , it gets even more complicated. For average street use, you likley won't require the same precision a road race bike would require..but be careful obviously..as on the street there always a good chance a crash will be your last.
The author mentioned above was paralyzed riding too fast on a public road..testing race compound tires...If you ride hard on the road...make sure all is setup 100% as it should be. (We all do it)...just be careful.
Trevitts book as well as a call to Race Tech or Linderman Engineering or equiv will do you good. Ed Sorbo now runs /owns Linderman suspension LE, he's a 2 stroke guy albeit TZ250s but shows love to the RZ, he's giving me great advice on my RZ project and will be setting up my suspension, likley on the GSXRs too. He's local to me
Sounds like you made some progress, but any info helps.
Good luck and safe riding.
Banshee (Baja) race bike, Lonestar A-Arms, dual 9" L.E.Ds, FMF, Toomey,19cc domes, IMS tank, run flats.
96 GSXR SRAD, Future Yoshimura Lucky Strike rep.
85 custom Tri-Z
RZ/YZR track bike(project)
86 VFR750 RC24 Merkel replica (project)

Post Reply