Zerk fitting debate...

[Fark]

I want to hear facts and opinions on the subject.  How come quads have zerks to lube chassis bearings and bikes do not?

Is there an actual downside to fitting zerks or is it a matter of assembly line efficiency?

 

For those interested, there is a how-to here: http://www.4strokes.com/tech/overhaul.asp

Some good info on other subjects as well.

 

[marcusgunby]

Ive read modern bearing seals are not designed to work with the grease pushed past them.

 

[Camstyn]

I believe the bike should be torn down periodically anyways to inspect for worn out and damaged parts, plus a good thorough cleaning of places where the brushes and hose don't reach.

I think that quads and some trail bikes come with zerk fittings because they figure the owners won't be taking them apart to be greased, a bit of a different type (hate to generalize though) than those who buy race bikes.

 

[Studboy]

The RMXs came with zerks installed from the factory on all of the suspension linkages.

 

[Rcannon]

I dont think I like them. The idea is a good one, but unless they are positioned perfectly to wash out ALL old , dirty grease , you have nothing.

Has anyone taken a linkage apart after it is packed with waterproof grease and powerwashed? Gross!

 

[KawieKX125]

IMO, if you just add clean grease, it does not get rid of the old or get rid of the dirt, just pushes it around. Do it the right way and take the bike apart and clean, dry and grease the bearings.

 

[Casper250]

Originally posted by KawieKX125
IMO, if you just add clean grease, it does not get rid of the old or get rid of the dirt, just pushes it around. Do it the right way and take the bike apart and clean, dry and grease the bearings.

I agree but i wish there was an fast and easy way to grease up parts. It seems like everytime i go to clean the needle bearings in the linkage i drop one and freak out while i search for it on the gerage floor. :silly:

 

[kawdude]

I vote for zerks. If its greases regularly the new grease will push out the old grease and debris. My KX has standard off the shelf needle bearings that would accept grease from a zerk.

My guess is that bikes don't come with them because it would cost more to manufacture the part and without zerks it either forces people to go thru the hassle of taking everything apart or the owner could just say @#$% this and let the bearing wear out. I bet there is a high percentage of riders who don't pay attention to this (but of course, not in this forum). I didn't and learned the hard way.

Because of the icky, time consuming job the manufacture can make $$$ off people who say !@#$% it and don't take the time to grease (since they didn't provide an easy way to do it) and wear out the bearing and swingarm.

Thus creating revenue for the manufacter...

Just my .03 cents!

 

[zero_it]

I tried to install zerks on the rear suspension pivots on an RM 125 once. It's a bad idea! The pivot pins and bushings are hardened and you cannot drill them to get proper grease distribution. Installing the zerk itself is no big deal, but you have to have grease holes through the bushings to actually reach the bearings. My old RMX 250 was set up quite nicely with zerks from the factory, which I thought was a good deal. The KTM's I've had are just sealed very, very well. The swingarm, steering head and shock end bearings stay clean and dry, so they last forever. Proper seal design is the best alternative to zerks.

 

[kawdude]

Originally posted by zero_it
The pivot pins and bushings are hardened and you cannot drill them to get proper grease distribution. Installing the zerk itself is no big deal, but you have to have grease holes through the bushings to actually reach the bearings. 

 

That's a good point!  Then you would also need to worry that drilled hole was smooth for the bearing to ride on.  If not, it would probably destroy the bearing.

 

[RM_guy]

I've gone both ways and decided that I'd rather just tear it down can grease them. On some bike it's impossible to get the fitting in the right place to distribute the grease. On the needle bearings I've EDMed a small hole through the hardened bushing to get the grease in the right spot. Since you can get a fitting on some bearing and not others (and you have to tear down anyway to get to the un-zerked bearings) I just tear down to do them all. It's a good thing to do anyway so you can check out everything else.

I suspect that "enduro" bikes come with fittings because they usually see much harsher conditions than MX bikes. The wetter the ride, the more often you should be greasing the bearings.