Different shocks

[kirmit77]

will 1981 YAMAHA XJ650H MAXIM rear shocks work on my 79 special???

[John]

I wouldn't think they would be heavy-duty enough for a bike that weighs over 550 lbs. and I don't know if they have the different size bushings in the lower eye of the shock, they way the are for the XS.

[Jerry]

I'm going to flesh out John's answer a bit.

The shocks on an XS 11 have different bushing sizes on the 2 shocks, However, this can generally be overcome by using the bushings from the old shock.

A more difficult questionn to answer is wheat type of ride do you want. Do you want to lower the bike as well, or raise it? How much do you weigh, and what type of riding do you do?

The stock shock is about 12.5 inches eye-to-eye when extended, and carries a dual-rate spring. This means that it takes less force to compress the shock spring the first couple of inches than it does the last few inches. If you look at the springs, some coils are closer together than others. (This denotes a dual-rate spring. Same thing applies to fork springs, by the way.) You can buy shorter shocks to lower the bike, or longer ones to raise it. However, both will affect the way your bike rides, and going to a shorter shock does cut down on your suspension travel, This may be OK if you are a light guy or or never carry a passenger.

A few more differences in shocks. Damping, or the ability if the shock to control the rebound of the spring once compressed, is different on different shocks. Some have adjustable damping, allowing you to adjust this to your liking. On my XJ the damping is adjustable, I don't think it is on the XS and doubt if it is on the 850, but it is worth-while checking out. The last thing is shock diameter, which translates into heat capacity. Larger shocks can handle the higher heat generated by movement of the suspension. Smaller shocks handle less heat, which means they will fade under hard use, and the intenal fluid may break down sooner due to overheating.

So, the physical fit is the least of your problems. I would guess you can get the shocks to fit by swapping bushings, but the resultant ride may not be what you want, and may even be dangerous if the shocks overheat and can no longer control the action of the rear springs.

After-market shocks are available plain (non-adjustable damping) or with adjustable damping, Some are available with different spring rates, and all are available in different lengths. If you want to improve the handling of your bike, go with a good quality after-market spring with specs near those of the OEM shock (length, spring rate) and add the adjustable damping or other features that you may want to have that can customize the ride to your preferences. However, this can get pricey for a top-end set. Plain-jane units are available and will work better than the 18 year old set you are now riding on. Use the Search tap at the top of the screen, use replacement shocks for the search criterion, and you will get a number of threads about what shocks people are using as replacements on their rides.

[John]

Wow Jerry!

You must love to type!

[Jerry]

Well, not really, but one of the goals of this site is to extend knowledge, so once in a while I try to live up to that goal. Have to do something to earn my keep!

[DiverRay]

And Jerry, the XS DID have adjustable damping! The shocks on my MNS are stock, with the adjustment and the E model STOCK shocks had the adjustment. You lost it on the standard when you put the "full dress" kit on.