I finally broke down and bought a Works Peformance Rear Shock for my 95 CBR. The things that make u angry is to get the shock and find that it is 1/2" shorter than the shock you took out. What I didn't think about was how much that really affected the geometry of the swingarm. That 1/2" made the rear wheel sit approx 1-1.5" Higher than the old shock, which means the back end of the bike sat at a "Negative" attitude BEFORE sitting on it. I felt like I was riding a sport harley with hangers, cuz the bike sat so low. Then come to find out that the shock was not NEAR stiff enough. I had to crank the pre-load adjuster to almost full to get the bike sag set CLOSE. Not right, but close.. So needless to say I have taken the shock back off and sent it back to them for a 1/2" adjustment and another spring.

Now my question for some of the more experienced CBR folks out here, what is the proper weight loading to use for the rear shock to get the bike at least back to stock? They wanted to know the weight I wanted to use, and I told them 250, since that is close to my weight. But good grief, if they set it for ONLY 250 that doesn't accomodate acceleration weight, bike weight, or even passenger weight. I definately need some help for this... The way they sent it to me, I was going to have them double the weight and set it for almost 400 because of the fact of how much preload it took me just to get the sag set right. Besides, with the adjuster set at almost full compression, it would surely unload when I compressed the shock and it wouldn't ride as well as it should. I spent my hard earned money, and I want it right!! So I definately am looking for some good advice!!

My riding style leans more toward the aggresive side, I like high speed sweepers, and transitions.. That makes my day go by with a grin.. I don't really want the back end hard, but I would like the option available if you know what I mean.

Thanks for all your advice in advance. Please, if you can help me I need all I can get. I want my bike better than the way it was before, not worse!! I had lost all confidence in riding her with that shock. Just saying that made me depressed..

Take care and God bless you all.

 

Not knowing what the original spring is puts me at a disadvantage but if you had the static and free sag numbers to forward to them, with their knowledge of what spring they used, they should be able to dial that in on the nose. If you have those numbers, forward them to the assembler. That would give him everything he needs for the re-spring. Also, if you have the chance, maybe get him to raise the rear 1/4" or so. The high caster on these bikes could take that amount without even thinking about it and probably more if you were experimenting. I don't know the exact ratio in the linkage on these but it's typically between 2 and 2.5:1 so about 1/16" to 1/8" longer eye to eye should do it. Hopefully they'd have that info. You'd think they would if they're doing this work.

I don't know what construction this shock is but many of the aftermarkets will have the ability to adjust or shim the clevis to raise that height. Something you might be able to do yourself once you have the thing on your bike. Something you could ask them about in your conversations.

Anyway, with those three numbers, 1)the static sag, 2)free sag, and 3)the spring rate that accomplished those numbers, even if not the desired numbers, it's all calculable and very precise to put any combination you want in it. They should be able to dial the pre-load, bolt in the shock, and be correct in all aspects, totally and accurately predictable, without any further adjustment.

BTW, I have a good used stock shock for that if you need one. A proper re-spring if the sags weren't good would probably have accomplished everything you'd need for the street. Good luck.

 

Does anybody know what the Standard Spring Rate of the rear is?

 

No, I don't. BUT.... if the free sag (no rider) is about 1/8" to 1/4" and the static sag (rider aboard) is about 7/8" to 1 1/8", then it's in an OK range, whatever the spring number actually is. I prefer running the stock exhaust but for those who have changed to aftermarket, you've gone a long way to improving the rear springing due to a measurable weight savings at the rear. At 205# for the rider and stock exhaust, I find mine a little bit soft but acceptable.