Topic: Assessing Rear Shock Life: How?

[my name is nobody]

One of my K1's had a pogo stick on the rear end,a definite sign your shocks have lost damping, all spring---

That's what mine did. No rebound damping whatsoever.

[Sigop]

I️ would say for the age of them they are fine. I️ would keep the bike original.  Did you buy it new?

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I did buy it new, and the miles I think have been mostly easy highway....

[Sigop]

Imo, they were trash when they were brand new.  I know that's not what you wanted to hear, but don't feel too bad, I think Yamahas and Kawasaki's of the era had much worse.  I also realize you probably are not out there trying to shave down your lap times...

A couple things to consider...
1.  I bet  in 40 years of ownership you have had to change your front fork oil at least once, hopefully several times, or you have witnessed the rebuilding of a long neglected set of front forks...the smell alone should tell you..."Something Wrong!"  Now realize that the rear shocks operate in a very similar fashion to the front forks...but they are not rebuildable.
2.  Your rear shocks are an important part of being able to control your motorcycle safely, even if you just ride around "normally".  Ever have difficulty cornering or braking on a bumpy surface?  I know that you do, even if you don't realize it.  This IS a safety issue, if you actually ride your bike.  Sure, your shocks still bounce.  I'm sure they always have and always will.  The real question is how and when will they stop bouncing.

Thanks SeanBarney.  Yes, I have refilled front oil many times, and this spring rebuilt the whole front end, except for the steering bearings (this winter.)  Hate to ask but should I be replacing the front springs also? Nevermind.

It was that rebuild up front that got me thinking about the rear.  Haven't noticed problems in curves, but I do have a bias for safety. I hear ya.  Thanks.

[Sigop]

I generally agree with Sean, especially the handling part.
The problem with shocks is the performance degrades so slowly you probably can't tell how bad they are now compared to when they were new.
The shocks still bounce but there's probably not a lot of dampening any more.
Also, there's no comparison between the performance of modern shocks and 44-year-old-49K-mile shocks.

There's a lot of new shocks available that have same appearance as the stock Honda shocks.

That being said, my K5 still has the original shocks and I know they're bad but I'm still riding on them anyway.

So you had me going all the way to the end-- until you're still riding on them. 
Thanks.

[Sigop]

as per the above, they were crap when new, even the Clymer manual (book of lies) states they're all used up by 10K miles.
have you ever seen excessive goop build up on them or brake side of the swingarm (it would be on the chain side as well but that just looks like chain oil )? that would have been the oil inside them leaking out. I knew my Progressives were shot when I saw new puddles of oil directly under them on the ground
as i'm sure you've seen there are many options for replacement from a hundred dollars or so up to several thousand, three to four hundred should get you something effective, rebuildable and probably standard looking. Ikon, Koni and Progressive all do stuff in that range
the cheaparse ebay ones (80 - 120 dollars) are generally crap but can be sorted with a good rebuild and can be done to suit your own weight, bike and riding style, should cost about the same as a pair of Ikons or similar that will be set to a generic level
 have a look here -
http://chrislivengood.net/wp/rfy-shocks-technical-library/

Thanks Spotty.  Some good leads.

[Sigop]

I have a set of original showas on my 550. They don’t leak and still have dampening. A lot of guys say they were junk when new, and maybe they were, but mine have been fine. I’m not dragging a knee with them.


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Were they all oil filled?  I have not noticed leakage.
Thanks.

[Sigop]

2.  Your rear shocks are an important part of being able to control your motorcycle safely, even if you just ride around "normally".  Ever have difficulty cornering or braking on a bumpy surface?  I know that you do, even if you don't realize it. 

This is how I determine how good (or bad) my shoals are.   One of my favorite roads has a fun high speed sweeper that just happens to have a bump in the middle of it.   If riding one of my bikes with poor shocks, the rear end of the bike will continue to bounce after hitting the bump causing a momentary slight loss of control (racers call it a "moment").

As stated above, some manufacturers have shocks that appear OEM, no they won't be original, but will perform better than original.

Thanks Steve-O,  have not noticed but will look for it.

[Sigop]

Agree with lostboy Steve.  Your bike will not handle any better with new shocks.  Keep it original and ride it.


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I'm with Sean. Not only is this not true at all but couldn't be further from the truth. A small investment in suspension will pay off in spades the more you ride the bike. Especially spirited riding. It's also a safety issue.

Thanks Slik,  At my age I don't need to go down.

[Sigop]

The expectation for new Honda shocks was about 15000 miles to replacement.

It takes some work, but you can test your shocks for proper function.
Remove them from the bike (you can do one at a time), remove the spring, and actuate the piston rod by hand while the shock is upright.  If you can feel resistance to movement in both directions, it's a good sign they still damp oscillations.  You can also feel if they operate smoothly for the entire stroke in both directions.  If they "skip" or bind during the stroke, they need renewal.

The damping action can vary from very hard and slow to move to "was that a wet noodle".  I think racers favor adjustable damping shocks to tune for their needs and track conditions.

Cheers,

Thanks TwoTired.  That is something I can do and is a helpful suggestion.  Will add to my winter list.

[Sigop]

You said new shocks would not improve handling.  That's just absolutely not true.

Nothing wrong with not caring about "handling".(except that a poor handling bike is less safe than one that handles better)  Just say so.

So put the original shocks in a box and go for a ride with a nice new set of Hagons(pull the Hagon sticker off and I bet most would be hard pressed to see the difference).  Easy enough to put the stockers back on for the Concourse or when it's time to sell.

Sean, I hear ya.  I will not sell this baby. Bought it new in 73 when I was young and dumb, and been a lot of water under the bridge since then, but, like "baseball" (Field of Dreams), my 750 has been one of my constants.  So I won't do the remove original to be stored and returned to the bike later.  I will give up on the original parts when it's time.

[Sigop]

He has a original 1973 750.  Getting rare seems like most everyone on here has upgraded there shocks. I️ would leave my 73 original hard to find them all original that’s all I’m saying. He did not say his bike jumps all around. He ask how could he tell if his shocks was bad or getting bad as he could not seem to determine by riding it.  I️ said ride it keep it original.  His bike looks to be in great shape.


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I think it's in great shape, but not totally blind to her beauty.  Except for the early years when I had no garage and the rain rusted out the original pipes, she's been stored inside and ridden off and on all those years.

[Sigop]

Sigop, l replaced my decent looking but poor performing OE shocks a couple years back after having a "moment" as Stev-o described: the bike was leaned over in a bumpy corner, the rear end started pogoing. I will never forget that corner on  Dexter-Chelsea Road.
 I was able to disengage the spring keepers by hand to perform the test as TwoTired suggests. Not only were the springs wimpy but both shocks had zero damping.
 I got the new Hagons that resemble the OE as Sean has mentioned and no more ugly "moments".
 We also have a member here, is it NobleHops ??, offering discounted Ikons to Sohc4 members.

EDIT: Yes it's Noblehops: http://forums.sohc4.net/index.php/topic,163109.0.html

Thanks Kevin D.  Seem to have read enough about Hagons to be a good choice.

[Sigop]

Anyone tried the replica shocks? I have a new set for my CB750 K2 build.  (spring adj in 5 steps)
I'll know next season if I had got all parts together.

I have Ikon shocks (setting 2,2) on my K6 which work fine, fork is very soft but handles very well despite higher speeds. I know that too stiff,  more pre-load (longer spacer) will cause wobble. Bike does not jump around the road for a sudden bump.

Fork springs can be in need of restore too. Progressive suspension is one brand still in production, I got mine 1989.

Thanks PeWe.

[Sigop]

i have adjustable ikons on my 73 500,ive used hagons aswell on 500s,if you have those shocks off put them on the shelf and get new shocks full stop,the bike will handle better which is always dependant on how you ride.

Thanks, Dave500.  I'll review the ikons.

[Sigop]

I had a lady back out of her driveway in front of me about a year ago, and had to do a panic stop.
When you have no damping from o.e. shocks during a panic situation, in a straight line, the front of the bike dives from the sudden application of the front brake. At the same time, the rear of the bike, raises. INSTANTLY.
Not a good thing. Know the risk your taking when you run original shocks. By this point in time,
they're just going along for the ride. I learned the hard way. I now run reconditioned konis, with my o.e. springs
and shrouds. They work well, are adjustable, and look stock. Koni's come up on ebay once and a while. a guy
in Omaha rebuilds them.

Thanks, My Name is Nobody.  Yet another model to check out.  Couldn't I reproduce what you experienced in a safe parking lot? A slam stop?

[Sigop]

to test old shocks.

..take the spring off..and pump them together and pull them open..they must not take air and get easy/free to move..if they have a light spot..move easy..there is missing oil..and there are suckt air in the damping mekanism..
i have splitted mine and filled in atf oil ..but dont overfill..it vill make them stone hard..just fill to it feels right..and leave a bit ekstra aut..
not all types can be splitted..had to drill and tap a fill hole in my cbx types..

Thanks strynboen for another maintenance/check idea.

[Sigop]

If you really want it original you should follow TwoTired's advise to disassemble and test for proper function. If they're good, keep using them. I think some have documented a way to at least change the fluid in original style shocks, drilling a hole, tap, flush, fill. Might have been for smaller bikes though? Either way, worn out shocks will feel more bouncy over bumps, the bike will not be as well settled which can be dangerous in corners particularly.

If you want original appearance, I run Ikon shocks on my bike as they appear nearly identical to the factory units. Shorter spring cover and slightly different top attachment but at a glance they look original and work WAY better then my old originals did.

Thanks Dunk.

[Sigop]

One of my K1's had a pogo stick on the rear end,a definite sign your shocks have lost damping, all spring---

OK, I get that. Not there yet.

[Lostboy Steve]

You can put really expensive shocks on an old jeep and it will still ride like #$%*. There are limitations to what a shock can provide.


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[Sigop]

You can put really expensive shocks on an old jeep and it will still ride like #$%*. There are limitations to what a shock can provide.


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Good one LostBoy.

[RandomOrbit]

You can put really expensive shocks on an old jeep and it will still ride like #$%*. There are limitations to what a shock can provide.

If your CB750 handles like an old jeep there's something wrong with it. You probably need new shocks.

Also people DO put really expensive shocks on old Jeeps.

[CycleRanger]

So you had me going all the way to the end-- until you're still riding on them. 
Thanks.

Yes, I'm still riding on them but it's more out of a combination of cheapness and laziness than any particular love of them.
I do plan to replace them with some modern retro-looking models and I'm sure when I do the improvement will make me realize that I should have done it much sooner. 
Actually, I do have a set of NOS Showa cartridges I was going to fit on the K5 but i decided to put them on my K3 when I get it finished.

[my name is nobody]

I had a lady back out of her driveway in front of me about a year ago, and had to do a panic stop.
When you have no damping from o.e. shocks during a panic situation, in a straight line, the front of the bike dives from the sudden application of the front brake. At the same time, the rear of the bike, raises. INSTANTLY.
Not a good thing. Know the risk your taking when you run original shocks. By this point in time,
they're just going along for the ride. I learned the hard way. I now run reconditioned konis, with my o.e. springs
and shrouds. They work well, are adjustable, and look stock. Koni's come up on ebay once and a while. a guy
in Omaha rebuilds them.

Thanks, My Name is Nobody.  Yet another model to check out.  Couldn't I reproduce what you experienced in a safe parking lot? A slam stop?

Not something I'd recommend. My oe shocks were ineffective. No rebound damping at all, rear tire not planted well=less stopping traction. Rear brake locked easier. Made me nervous
on curves as well, at times. Mine were on my 550. My k5 750 might have acted different with more weight, dunno. What is certain is, that a shocks duty is to keep the tire on the road under all conditions.
Road conditions change constantly when the bike is moving, so there's a lot going on. Good rear shocks
stabilize things. The koni rear shocks are no longer made, but if you find a good set (ebay, ebay, and more ebay)..they can be reconditioned. (as I understand it, Ikon bought koni) but Ikon does not service koni

[Stev-o]

but Ikon does not service koni

RestoCycle is a Ikon dealer and may service your Konis. Look...

https://www.restocycle.com/ikon-suspension-products

[jonda500]

+3 on removing the springs to check the dampening and smoothness of operation - I have one oem set off ebay that looked great but when I removed the springs I found one of them had no oil (zero dampening) - the seal had obviously failed and the unscrupulous seller had cleaned off all the leaked oil 
John