Rear Shocks

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ajs350
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Rear Shocks

Post by ajs350 »

The original shocks on my 80 were worn out so I bought a pair of Progressive 412 replacements. These shocks came with the Heavy Duty 105/150 springs. To get the correct sag I had to preload the shock to position 4 of 5. Bouncing on the bike while stationary everything moved up and down nicely but when riding if I hit a significant irregularity in the road such as a bridge seam the shocks gave me stiff kick up through the seat. I tried changing preload positions but to no avail.

I have since swapped these springs for the next stiffest which are the 120/170's. These sag correctly by 1 inch on the first setting. Again I have lots of travel when sitting and bouncing on the seat but when riding the ride seems harsh. I can feel the back end pattering over small irregularities and I get a big kick up my rear should I hit soemthing significant.
I weight 225lbs and 240lbs with cloths and riding gear on.

I thought the front might be contributing so I replaced the oil in the front forks with 10w, filled 6 inches from the top of the forks with the springs out and forks collapsed.

Without being able to ride a "proper" CBX for comparison its hard for me to know whether this ride experience is normal or not. Any observations on your own ride especially if you have these Progressive 412's would help a lot.
Thanks
Ross

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Re: Rear Shocks

Post by daves79x »

Ross:
I know this sounds crazy, but most aftermarket shocks for the CBX are WAY oversprung, even with the standard springs they come with. I'd go with the lightest spring available and see what happens. The 1100F shocks I use on many CBXs are very lightly sprung and work wonderfully under most conditions, although good ones are getting harder to find.

Dave

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Re: Rear Shocks

Post by daves79x »

Ross and other recent new CBX owners:

Ross, you bring up a good overall point about actually riding and enjoying all of your hard work. You and several others here have put lots of work into these bikes that you may have actually never really ridden yet. Now that you have them done (relatively speaking!), what are they actually supposed to ride and handle like? A correctly sorted '79 is a fine enough handling bike, but the '80s are so much more complete for a host of little reasons. If you could compare good examples of the two, I think you would see what I mean.

Rear shocks are an issue - neither '79 or '80 stock ones are very good. Other guys can chime in hopefully on what they've done. My previous post outlines what I've done with the early models.

But overall, please give us your impressions as you get some miles on the bikes and if you can get to an event or two this summer, you can compare what others have done and like first hand. You can compare our Gold Wing to your CBX in NC in June!

Dave

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Re: Rear Shocks

Post by daves79x »

Found a pic of Don's bike under construction. Shows the 1100F shocks and swingarm.

Dave
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Re: Rear Shocks

Post by ajs350 »

Dave
Thanks for the shock information. I will try and get the next lowest springs to try and see how they are.
As for participating in a rally I have penciled in the Saluda event but have not committed as I want to get the bike running right first. As well as me riding different CBX's for comparison it would helpful for me to have yourself and others ride mine to give an opinion. Other than this last rear shock issue I have it as good as I think it can be so it would be interesting to see how it stacks up against a "good" one.
Ross

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Re: Rear Shocks

Post by ericfreeman »

When I bought my '79 from a buddy at work, it had Konis on the rear and they were so stiff they felt like rigid struts! Not sure what the spring rate is/was but I, too, bought a set of new Progressives to replace them. I wasn't happy with the Progressives either as they seemed way too stiff (I weigh about 240-50ish). After getting beaten up on some long mountain runs, I called the Hagon dealer, Dave Quinn, and ordered some Hagons. Much happier now. The Hagons are still a bit harsh at low speeds on bad roads but smooth out nicely when you get going faster. I'm currently on the softest preload setting as well.

Eric

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Re: Rear Shocks

Post by Don »

I can't say enough for Dave's recommendation that I go with the 1100F shocks on my bike. In addition to the 5 preload spring settings, the compression is 3 way adjustable and the rebound is 2 way adjustable - You can set them up to work well in just about any riding situation - They are a HUGE upgrade for the stock CBX shocks

The trick as he mentioned is finding a good, low mileage set for a good price, which is getting harder and harder to do . . . . there are only so many 1100F's out there to pick from - Luckily for us, low mileage engine failures seem to be somewhat common on these models, so there are parts out there to be found

If you can snag the whole rear end . . . . swingarm, caliper, torque arm, chrome chainguard and the shocks, it all is an excellent 'bolt on' upgrade for early model CBX's. The swingarm is much more rigid and the chain adjusters are a much better design

Don

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Re: Rear Shocks

Post by ajs350 »

To conclude this thread I ended up keeping the Heavy Duty 105/150 springs. The ride is still harsh over a series of bumps but this is the best compromise. The 90/120's were too soft and the 120/170's too hard.
I have the 105/150's on preload position 2 which gives 1 1/4 inch of sag on the shocks which have a total travel of 3 3/4.
My thanks go to Bill at Tims who sent me different springs to try and who at one point point quipped "you now have more springs than me!". :D
Ross

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Re: Rear Shocks

Post by ajs350 »

ericfreeman wrote:When I bought my '79 from a buddy at work, it had Konis on the rear and they were so stiff they felt like rigid struts! Not sure what the spring rate is/was but I, too, bought a set of new Progressives to replace them. I wasn't happy with the Progressives either as they seemed way too stiff (I weigh about 240-50ish). After getting beaten up on some long mountain runs, I called the Hagon dealer, Dave Quinn, and ordered some Hagons. Much happier now. The Hagons are still a bit harsh at low speeds on bad roads but smooth out nicely when you get going faster. I'm currently on the softest preload setting as well.

Eric
Even after a few years of riding the Progressive units never did get any better so I recently bought the Hagons as Eric suggested. I bought them from David Silvers for $204 so not too bad. The ride is much better now and the sharp jolt over road joints has been eliminated. Ross
6017 6018

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Re: Rear Shocks

Post by NobleHops »

Those look 'correct' too Ross, I like them a lot. Glad you're happy with them.
Nils Menten
Tucson, Arizona, USA '80 CBX, sort-of restored :-)

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Re: Rear Shocks

Post by ericfreeman »

Glad to hear you're happy with the Hagons! I just got my CBX out for the first good ride in a while (too many bikes!) and my Hagons are still working great. One of the best improvements I made to the old girl.

Eric

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Re: Rear Shocks

Post by Neiko1967 »

Dave, do you know the difference between the CB1100F shocks and the CB900F shocks? I got a set of 900's that I cleaned up and was going to try and put them on my 79 with stock swingarm. They look identical to the CB1100F shocks. Do you know what a good starting point for settings is for a 220# rider?

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Re: Rear Shocks

Post by daves79x »

The 900F shocks have to be adjusted for compression damping (top adjuster) with a tool and the 1100F ones you can just turn the top collar by hand. At least that's my recollection. Don't know what internal differences there are, but if they are in good internal shape they'll be far better than stock '79 ones. One note - 900F and 1100F shocks eventually 'bind'. They'll just stick partway compressed and very slowly release. Makes for a rough ride and you'll know it pretty quickly. Almost like the piston seizes partially. I've had good 1100F shock work well for years however, and it's worth a try.

If the damping is still good, I'd put the top adjuster at 2, bottom at 2 and spring about halfway.

Dave

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Re: Rear Shocks

Post by Neiko1967 »

Thanks Dave, they do go down smoothly and come up smoothly but a little slower and I can notice a difference when the bottom is switched from 1 to 2. No binding that I could tell on the bench. I will try to figure out the setting on top as I took them apart to repaint but never paid too much attention to the setting part.

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Re: Rear Shocks

Post by daves79x »

If you're putting the shocks on a stock '79 or '80 and mount them as they are supposed to go (reservoir rearward), the right one will hit the rear caliper, unless your chain is well worn and you have the swingarm adjusters way back, or you have a longer- than - stock chain. Trick is to lengthen the torque arm by 1/2 inch and it'll clear fine. Or mount them backwards. Everything clears, but the left one is pretty close to the stock exhaust.

Dave

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