Swingarm and linkage greasing solution

[Kaybeach007]

I have read many posts regarding the greasing and maintenance of the swingarm and linkage system. Many forum members have gone to enormous lengths, like installing grease nipples and the like. I would like to through an easy solution into the pot.
There is a fantastic material called vesconite. It is an extremely hard polymer (plastic) that can be machined, but best of all it doesn't rust.
Next time you strip and maintain your swingarm and linkage system, drop them off (swingarm and linkage knuckle) at your corner engineering shop. Have them press out the needle roller bearings and throw them away for ever. Machine vesconite bushs with an OD and ID of the roller bearings. Now press the vesconite bush into the swingarm and knuckle, it should be a press fit. Put a light smear of grease onto the steel bush and slide into the vesconite bush, this should be a nice easy fit, not loose, not tight. Now reassemble and give the bolt a light grease smear. Now, once a year, just remove each bolt and smear the bolt lightly with grease and then reinsert and torque and repeat with the next bolt. Don't strip the entire suspension. You never have to completely strip your suspension again, ever. Vesconite is amazing stuff. We use it at work in heavy, high speed machinery and the stuff lasts for ever. I have a 98KDX200 and replaced the needle rolls in 2000 and have been running the same vesconite bushes for 4 years now. Where we ride there are 6, knee deep river mouths (salt water) that I cross every other weekend. I laugh at salt water nowadays. Suspension maintenance is a breeze now.

 

[andrew]

mate, just had a look at it on the web. Sounds great, but I have not heard of it here in australia. I did try a polyurathane bush in the linkage of my old '88 KDX, but it collapsed dramatically. Vesconite sounds like it's worth investigating. How much did it cost you to get it done?

Andrew

 

[Kaybeach007]

Andrew

Speak to an engineering shop, I am sure that they will know the material. It cost me about R600 South African, that's about $120 Australian, $100 US for material and labour. That's about half of what it would cost for the full needle roller bearing kit here.
Have the engineering shop first clean the steel bushes, if they are damaged, then machine the vesconite bushes to the new size.
You can throw the rubber seals away too, just remember to regrease the bolt once a year, which is a simple excercise now. I timed the job a few weekends ago and did it in 6 minutes. Not quite good enough for F1 or NASCAR, but I did take a few gulps of beer in between. I'm sure that slowed me down.

 

[andrew]

Ok, thanks for that. A bit more browsing and I found a link for a site over here, so I've bookmarked that for the next time I need bearings. Y'know, that stuff sounds just the ticket for a chain guide slider as well...!

assembling bikes and sucking beer? I'll drink to that!!

Andrew

 

[canyncarvr]

I've been experimenting with something the machinist called Nylarod. I have a bushing of that material in my lower shock bushing now. Looking at the spec sheet on the Vesconite site, they don't list a whole lot higher (30%) loading limit over nylon6. But then, I don't know how Nylarod compares to nylon6, either.

For any do-it-yourselfers reading this...keep in mind that machining any material like this, you will end up with different measurements than the bearing you're replacing. The crush of a steel-caged bearing isn't going to be the same as something else. I'll betcha if you machined a piece of vesconite to the exact same measurements as the ID/OD of the bearing...it's not going to fit worth a hoot. The machinist that worked on my Unitrack had to do some considerable 'testing' to get a proper fit between the nylarod, the Unitrack and the SS302 sleeve he made.

I have something along the line of 400 miles on the nylarod bushed shock. Last I checked...I did see it move. So...it doesn't seem to be a suitable replacement.

I sent 'em an email (vesconite) regarding bike suspension specifically. Will be interesting to hear what they say.

Thanks for the tip! Four years is a darn good track record!!!

 

[kelseybrent]

CC,

I typed to you about the lower shock bearing before and was hoping that the Nylarod would work.

I put in a caged needle bearing halfway through last season. I tore it down over the winter and ... it was rusty, but still in one piece and the rollers weren't smashed. I was worried about the smaller number of rollers in there, but that didn't seem to be a problem. I think the problem lies in the fact that the lower shock seals don't "seal" any water out.

I guess I'll just keep replacing that bearing.

 

[GreenPeace]

007

I installed vesconite December in my KDX swingarm & did a couple of Transkei trips since.( Mud, salt river crossings & dust )
Will strip the swingarm this weekend & give feedback next week.
Where in EC are you?

 

[canyncarvr]

From a VescoPlastic Sales email (not from a post on this site):

In my experance the only place you can replace the original bushes and bearings on a bike is the swinging arm bushes. The peak loading on the bushes on the suspension is too great. Usually they use a full compliment needle roller bearing which can withstand high loads.

kelsey: Explain 'caged'? I've heard that word used to refer to an outer shell that holds the pins in at a smaller diameter pin machined on each end of each pin...but also to an actual cage that holds the pins inside the shell. In the case of the latter, the pins are not placed side by side, but spaced apart and held by the cage.

Just curious.. The oem Kawi part is of the former design.


Jury still isn't in on the Nylarod stuff. I had three sets made, so still have a couple to experiment with. This first one I put in without the seals. Thought was (machinist's and mine) that water getting in would be a good thing. I did put it together with a bit of Permatex Anti-seize. The next time I'll use the seals and give it good Hydrosyn grease job.

 

[Woodsquest]

CC, when you take the bushing out and examine it, will you be able to tell if it is worn (lost material) or perhaps crushed? Maybe weighing the bushing before and after would tell if material was removed during service.

 

[kelseybrent]

Caged as in spaced apart and held by the cage. So it has fewer needles than the OEM style, but a little more room for grease.

5905K76 on www.mcmaster.com, catalog page 1023.
"Needles are retained in a cage, housed in a drawn steel outer shell. Outer shell is slightly oversized for snug press-fit installation. All have a large lubricant reservoir. Use on hardened and ground shafts. "

 

[kdxtaz]

I've been experimenting with something the machinist called Nylarod. I have a bushing of that material in my lower shock bushing now. Looking at the spec sheet on the Vesconite site, they don't list a whole lot higher (30%) loading limit over nylon6. But then, I don't know how Nylarod compares to nylon6, either.

Funny you mention that, I was thinking of doing something similar. My CR125 has just a hard rubber bushing at the lower shock (stock). It works great, needs no grease, and never seems to show signs of wear. Those lower shock bearings are a real pain in the :moon: , are'nt they?

Please keep us updated on your results.

 

[Kaybeach007]

I think that everyone is overly occupied with the up/down impact load ability of the material used in the linkage, hence the preoccupation with the hardness of the material. I think this is wrong. The linkage on the KDX was designed to change this up/down impact energy into a smoother, more progressive loading energy absorbed by 5 different points on the shock, linkage and swingarm. It is not just the two bolts at the top and bottom of the shock doing all the work. One must look at the entire rear suspension system and analyse how the system shares the loading induced by the big mac burgers floating around our guts. Kawasaki use roller bearings out of convenience more than anything else.

Just to set your mind at ease. Check out the site www dot vesconite dot com. Go to top right hand corner, click on "no grease suspension" then click on "Applications/success stories" then click on the articles on suspension applications. You will be sold on it immediately. The material is used by Toyota, Colt, Isuzu, Nissan, Mazda, Ford and Pajero on the suspension shackle bushes on their rally/offroad vehicles.

Read the article on "suspension bushes for heavy transport vehicles", If it works on a fuel tanker with a few tons of load as well as Bell Earth moving equipment, then it will do just fine on my 100kg KDX with my 85KG backside. As I said before "throw the roller bearings AWAY"

Ultimately the material you chose to replace the roller bearings is up to the individual. On previous boneys, I have used brass and bronze bushes, which have worked just as well and since they are metals, people tend to trust them more than plastic.

Whichever material you chose, the aim of the exercise is to remove the unreliable, grease hungry roller bearings and replace them with reliable, low maintenance, cheap, one piece bushes.

Vesconite in the US - For more details contact Tony Ball, at 561 736 3950 or e mail tonyball605 at bellsouth dot net

 

[Tom Cox]

KX Lower Shock Mount Bearing

For those of us talking about the short life span of a Kawasaki lower shock mount bearing, the problem stems from Kawasaki's design. The original seal is designed to rub against the aluminum opening in the linkage knuckle as the linkage goes through its travel. This wears a groove in the aluminum so the seal, even a new one, is not effective anymore. It doesn't seal against anything. I recognized the problem on my 92 KX 250. What I changed and have used since, is using a correct diameter wrist pin, I machine the length to span the width of the lower shock mount yoke opening. Also the ID of the wrist pin has to be of the correct diameter to accept the mounting bolt. I then purchase seals that are the correct OD to be a tight fit in the linkage knuckle opening and then the effective seal is around the wrist pin bushing. The seal is now on a hardened machined surface and not a rubber seal lip wearing on aluminum. The wrist pin I get from Weisco. The seal from a local bearing / seal supply house. I've done this to all my KX or KDX machines since 1992. This fix doesn't make the bearing last for ever, its a pretty harsh environment it lives and works in, but I'm not changing the bearing multiple times a year. I grease it a couple times a year and change the seals when I grease it and probably on the average change everything out every other year. I know people that don't perform maintenance on this bearing until its gone because they know its going to fail fairly regularly.

 

[canyncarvr]

Just ordered a sealed caged bearing from McMaster.

Thanks to kelseybrent for the info!!

...two bearing wholesalers in town have told me there is no cross reference for that bearing..that it must be a Kawi proprietary part. I didn't even look in McMaster's catalog because of that.

...should have known better.....

Thank you!

 

[fundgh]

Kaybeach007,
Why don't you have a few dozen of em made up and sell em to us as a kit?

 

[Colorado Mike]

uh,,Kaybeach007,,,, what's a "boney" ??

 

[Kaybeach007]

Fundgh

For a new boney it wouldn't be problem, but on older boney you have to machine the bushes to fit the existing wear parts (the steel sleeve) or else machine up new steel sleeves to fit the bushes. Can be done, but could be a bit of a mission. Shipping costs from South Africa to USA for a 1kg package ranges from $50 to $80, so it is goning to be a no starter business proposal. Better idea for someone in the States to start a little side line business, just find the Vesconite agent in the States and a good machinist who works for beer and peanuts.

Colorado Mike
Boney (a combination of BIKE - BONEBREAKER & PONY) is that green, red, blue, yellow, orange monstrosity that sucks cash out of your pocket and hurts you when you're not concentrating.

 

[Kaybeach007]

2 to 3 rides per month, average 60km per ride and now 6 years worth of use and finally the 3 vesconite bushes on the linkage knuckle are wear, especially the small one in the lower shock mount. $15 to have new ones machined. I hope I get another 6 years out of this set. Throw away the needle roller bearings and install vesconite.

 

[canyncarvr]

Along the line of updates...

It's been quite awhile..don't recall for sure, but I thought nylarod spec'd as good as or better than vesconite. My nylarod setup worked better than the OEM bearing, but not good enough. Around 400 miles on the lower shock bushing at it was showing signs of 'wear'.

The caged roller double sealed bearing is working much better. At 600 mile service intervals, it's been fine. Working on 1000..about time to check it again.

Good to hear you're happy with Vesconite in your bike!

Cheers!

 

[strider80]

canyn, did you find replacement bearings for all the linkage and swingarm bearings? Or just the lower shock bearing?

 

[canyncarvr]

I didn't look for replacement double sealed bearings for OTHER than the lower shock. I don't have 'issues' with any of them.

I went through 3-4 lower shock bearing/sleeves a year using the OEM stuff.

 

[strider80]

Good to know, I think you saw the pics of my shredded shock bearing and rocker arm. I put in Moose chinese bearings all around, so I need to keep an eye on them, especially the shock bearing since it destroyed my rocker the last time. I will have to put in the McMaster bearing next time.

 

[strider80]

My question is why the shock bearing is so small compared to the other linkage bearings when its loads are just as high if not higher?

 

[canyncarvr]

The sealed bearing isn't bigger, actually it's 'smaller' (fewer rollers) due to it being a caged bearing.

It's protection that's the issue. The so-called 'seals' on either side of the lower shock mount bearing are obviously not up to the task.

Keep in mind that the shell of the sealed bearing being wider, the seals need to be machined to fit..if you intend on using them anyway.

 

[X Fab]

Bushing or bearing, as soon as the fit is less then tight the bushing/bearing wear dramatically increases. I replaced my swing arm, linkage and front wheel bearings with Pivot Works items last fall. When I went to replace my lower shock bearing I thought I would save some money and use a stock Kawasaki bearing. What a piece of crap. After installing the new roller bearing in the link, installing the new bushing and bolting up the shock I moved the rear wheel up and down and found the new Kawasaki bearing had free play in it! The more miles I put on it the worse it got. I rode it that way, with the rear end chattering under braking, until I got a Pivot Works shock bearing to replace the new factory one. Now my rear end is tight (not like that! :laugh: )and has been for a year now. A tight fit is crucial to a long bearing life, bushings too.