Drilled Swinger Bolt?

[York Racing]

I was wondering just HOW MUCH drilling a swinger bolt and adding a zerk fitting weakens the bolt. This is on a 450R MX quad that hits doubles, tabletops, and a sky jump thats 105 long. I'm concerned about weakening it but I would LOVE a zerk on my swinger bolt.

 

[wwholden]

I would think it should be fine. I know my kx125 thats set up for mx is hollowed out. I might try doing this myself to my blaster. I was thinking on drilling and tapping zerk fittings on the swing arm but this may be better. Defiantly post back on results of you do go through with it!

 

[dksix]

To grease the bearings, a 1/16 hole would be plenty big enough and the lose of strength would be a moot factor. Although drilling that depth with a 1/16 drill would be a task. Another option would be to only drill the hole mid way into the first bearing and mill small slots on the surface of the bolt for grease to travel to the other areas needing lubrication.

 

[York Racing]

Alright I will be looking for a donor bolt. I'm going to try it.

 

[wwholden]

Please come back with results and pics. Im very interested in this alos.

 

[YZ Otis]

You'll have to do your own safety evaluation. The safety cops may come up with a consensus but till then it should be considered dangerous ... I don't think a 1/8" bore is an issue, it's the holes from the outside of the bolt into the bore that could be a problem ... I used a pretty tiny drill for that and drilled in at an angle ... don't know if that matters ...
You can find my version here ...
http://www.blasterforum.com/suspension-130/another-homemade-swingarm-24993/index8.html
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1/8" drill on the lathe and a little patience ... let me know if you get a 1/16 to work, that should take a bit more patience ... the grease also needs to get through the hard sleeves that are the inner race.
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No big deal ... only takes a couple minutes ... here's an old dead sleeve cut as an example since the nice one is in the Blaster ...
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[slickerthanyou]

Intersesting !

 

[Awk08]

Holes in the bolt do not get the grease to where it is really needed, only between the bolt and bushing, unless the bushing is also drilled, grease will not get past it into the bearings, neither will a grease zerk on the pivot tubes, as the needle bearings are encased by the bearing race on the outside, the only reliable way I see to get grease into the actual bearings is to pull the bolt, and the bushings and apply grease directly to them.
Anything else is a recipe for a well greased bolt and the false sense that your bearings do not need any routine greasings.

 

[wwholden]

Can you get a drill bit long enough to do this on a lathe? Also I think this would work well since the bolt comes in direct contact with the sleeve and if you notch the sleeve where the bearings are the grease should pass right through.

 

[Awk08]

there used to be hollow stainless steel pivot bolts with a grease fitting available for the blasters on ebay for $60....... IIRC ?

i do not see them listed anymore, i do see reference to snyder motorsports in a google search, but snyder has now become mainly a mini/drr parts dealer ???

if you notch the sleeve where the bearings are the grease should pass right through.

i'd be suspect of "notching" the sleeve, thats very tiny needle bearings inside there ?

 

[YZ Otis]

Can you get a drill bit long enough to do this on a lathe? Also I think this would work well since the bolt comes in direct contact with the sleeve and if you notch the sleeve where the bearings are the grease should pass right through.

Lotsa drill options ... most hardware stores carry a 1/8" x 12" drill ... check eBay for 1/8 & 1/16 x 12" aircraft drills
Think I had to go in around 7" so don't bother with a 6" drill ... you need to peck & clear chips so it takes a little time if you're feeding by hand.

 

[best]

Holes in the bolt do not get the grease to where it is really needed, only between the bolt and bushing, unless the bushing is also drilled, grease will not get past it into the bearings, neither will a grease zerk on the pivot tubes, as the needle bearings are encased by the bearing race on the outside, the only reliable way I see to get grease into the actual bearings is to pull the bolt, and the bushings and apply grease directly to them.
Anything else is a recipe for a well greased bolt and the false sense that your bearings do not need any routine greasings.

Actually, I remember bikes that came this way years ago.
The holes put the grease between the bushings/bearings, and you may want to drill holes or grooves in the bushing/bearing spacers so the grease goes inside and outside, or just cut a couple grooves in the end of the spacer. There is usually enough clearance on the diameters to flow the grease. The best thing this trick does is flush the water out of the bearing with the new grease.

Yes, taking them apart is the best practice, but a couple pumps of grease after a water run would go a long way...