Grease Fittings (Zerks) Why not ? ? ?

[tripled]

I'm replacing bearings in my second dirt bike. I know a few bikes have some. But, mine has one and it's a 2007

Why don't more bikes have zerks on more bearings?

Besides locating them to not hit other parts of the bike or any trail debri/stumps/rocks, why shouldn't I just put zerks on every bearing? ? ?

[KJ790]

Most bearings are not in sealed cavities. The steering head for example is open to the rest of the frame in most bikes. If you put a zerk on the steering head, you would fill the whole steering head as well as the rest of the frame before the grease pushes through the bearings, this would waste a lot of grease and add a ton of weight to the bike. The hubs would also be completely full. You should just take the steering head and suspension links apart once or twice a year and regrease them, it only takes an hour to do, but it saves a lot of work in the end.

[tripled]

Excellent points KJ. So, fittings on frame bearings wouldn't work because they are open to the rest of the frame. It won't help me, but seems like it wouldn't be hard for the factory to make those small places sealed off.

Ok, so I have to continue with those.

How about the swingarm linkage and swingarm bearnigs?

[William1]

To add to KJ's advice, when using a Zerk, not all the old grease is always pushed out. If some has dried out and become caked, the grease entering will travel the path of least resistance. This results in a not completely greased fitting.

Zerk's are not bad to give a shot of grease to something but they do not replace disassembly, cleaning and hand re-greasing.

A down side to Zerk's is also the potential (always something) for one more thing to vibrate out. That would present dirt and water a convenient path inside.

[matt4x4]

Not to mention potentially creating a weak point on a component by drilling it for the zerk.

As well, the seals are not meant to have the pressure of the grease push outwards - the seals could pop out or shift, causing premature wear and potential early bearing failure.

[Slackkinhard]

I think it has a lot to do with the fact we don't demand it. The OEM's will provide whatever we demand. Engineers can do it, I know ?

[RedRider_450]

I think it has a lot to do with the fact we don't demand it. The OEM's will provide whatever we demand. Engineers can do it, I know

I agree, it wouldnt be hard to design components that would be appropriate for regreasing without complete disassembly. However, in my case its kind of a good thing because when its time to regrease linkage and steering stem its time to change the suspension fluid, so its a one shot deal. ?

[N7SLC]

How about the swingarm linkage and swingarm bearnigs?

Yeah, why not? The DRZ has zerks on the rear linkage...

[k digitty]

Yeah, why not? The DRZ has zerks on the rear linkage...

A mate of mine fitted a lowering link to his GF's 06 YZ125. Came with Zerks(which I assume is another name for a grease nipple?)

[YamaLink]

Grease zerks, aka grease nipples or zercs, can be a good thing in the right application, but should not be a total replacement for long-term maintenance and a complete overhaul especially if a bike is ridden in the mud and rain on a very frequent basis.

[sonobob]

Not all rear suspension linkages will have enough clearance throughout the range of motion for a grease fitting to be installed. The last time I had my CR250's rear linkage apart for regreasing, I was looking at it and there just isn't adequate clearance on some of the parts to get a fitting to clear other parts. And if I can't get a fitting in one of the parts, there's really no point in installing them in the others...I'll still have to tear the whole assembly down to service at least one of the bearings anyway...

[YamaLink]

For sure. Either the rocker or connecting rod hits something at one pivot. Like you said, if you can't get all the pivots what's the use?!

Not all rear suspension linkages will have enough clearance throughout the range of motion for a grease fitting to be installed. The last time I had my CR250's rear linkage apart for regreasing, I was looking at it and there just isn't adequate clearance on some of the parts to get a fitting to clear other parts. And if I can't get a fitting in one of the parts, there's really no point in installing them in the others...I'll still have to tear the whole assembly down to service at least one of the bearings anyway...