Hi guys:

I wanted to run something by you. I've been wanting to upgrade the bolts and bearings on my buggy axle to something more durable and have chosen to go with 6804 RS 20mm - 32mm - 7mm bearings. These should fit the standard buggy hubs, and the axle I've built can be modified to fit whatever size I need. (See my prevoius topic)

Now comes the problem, finding the 20mm hardened stainless steel bolts. Not the easiest. But here's the thing... 3/4 inch bolts (which are readily available) are only about 1/32 of an inch smaller in diameter.

What do you guys think of using them instead. Metric anything over m-12 is just so damned hard to find around here.

I am no machinist, but I dont think you can harden StainlesSteel. You may want to go with a high grade steel bolt. If you can setup your axle to accept 3/4" SAE, you will be just fine. Plenty of selection available in different materials (SS, high grade, plain zinc, etc.) and cheap as chips too. Good luck!!

Sean

Good point. I think 12.2 high carbide steel would be ideal.

What about the sizing issue? Do you think that slight bit of play between the bolt size and the bearing is gonna matter? My assumption is that it would be O.K. considering that the inner part of the bearing and bolt are actually locked together with the side pressure (you could theoretically use a much smaller bolt than the bearing opening, provided it had a wide enough flange, and was tightened sufficiently)

I wouldn't use a 1/2 inch bolt in a 20mm bearing, but come on... 1/32 of an inch of difference.. Is that really gonna matter?? I would love anyone's input on this matter.

I think you are worring about nothing here, it has got to be something massive to bend, say a zinc plated 20mm bolt 8.8 grade that they use in structural steel work, and about a fith of the price of stainless.....you will NOT bend that bolt in a buggy

IMHO 20mm bearing needs a 20mm bolt

Yes, it's was hard to look for those sizes but fortunately found it in my hometown. You can find 304 stainless steel A2 material made 20mm bolts and nuts at www.metricmcc.com which I had replaced all rusted zinc coat hardware fittings for my all buggies.

Pondering...

Still thinking...


Should I say something about the natural process of rusting.
Should I mention that, in a salt-water environment, using stainless steel bolts on a stainless steel buggy doesn't give that process a place to happen and one can probably end up with an unrusted, naturally self-welded one-piece buggy?

Just replace the rusty bolts once a year.

Or maybe I could mention something about just learning that the bearings provided with the buggy are crap.
Out of the barrel.
To keep prices low (as the marketplace demands) cheap bearings are installed.

Just upgrading to better bearings, a relatively easy thing to do, will allow better performance, and at a very low price.

Should I say something.....

Naaaaah!!!!!!!!!!!!!!!!!


Safen Up! Buggy On!

"Often wrong... Never in doubt"

the coreylama

Naw, you shouldn't say nothin', Corey. "Restrained" is always the term that comes to mind when contemplating your demeanor.

You shouldn't mention the 1/32" gap, when exposed to huge side forces, has as much negative affect on the bearing as a bent axle, neether. Crooked is crooked, a gap is a gap, and at 50mph, a wheel wobble is a real bummer, leading to a siezed bearing... an even bigger bummer. Not to mention heat buildup against plastic wheels. Your last thought will be, "What's that nasty burning smell?". Just before the wheel leaves the buggy.

Naw, no point in mentioning any of those things... after all, close is good enough.

sorry to say this but your bearings will spin on your axle rather than spin insidewhere they are supposed too, Ive had a simular problem when buying standard size bolts seems the shafts are actually a smaller diameter when manufatured I believe the threads are rolled on hot its not uncommon for a 5/8 bolt that I use to be .005-.010 of an inch smalleraround the shaft, it will be even more evident as your tire size is increased so is the inertia ( center of gravity moves closer to the outer diameter of the wheel ) with a standard wheel and hub assembly it is closer to the hub. I used a chisle to dent the shaft enough to make contact with the ID of the bearing, this might probably wont work for your 1/32" difference,

I also am curious where you found those bearings normally 32mm OD bearing will not be available with a 20mm inside diameter and 7mm seems rather thin too. I'm not saying you are wrong its just I havent seen this before, My wheels are 2 piece aluminum aircraft wheel by Azusa, the bearing is 35mm od-5/8" id and width of 11mm
I wanted to use a 3/4" axle but the largest ID bearing I could find was16mm . so I stuck with the 5/8" of which Ive only ever broke one standard grade 5 bolt using 18-8.5-8 tires, which I since don't use anymore. I have never broke anything with a standard size tire.


cheers
Jim

There are bearings that mix SAE and metric, ie: 47mm outside diameter and 3/4 inch inside diameter. Harder to find, but it will solve the size problem. If you want I can ask around to see if I can find a source....

Sean

Whatever it takes to get it done, buy the same size bolt and bearing. Im pretty sure libre bugs have 20mm rear bolts, just buy a couple of those to use.

Scoop

Wow!

I don't check up on this site for a few days, and suddenly.... Tons of responses... Great!!

Well, first off:

To Popeyethewelder...
As always, you have my greatest respect. (Love and envy what you build) Well , I went with 8.8 grade. More than enough. I'm gonna rip the tires off of the rims before I bend those suckers. I also found a thin PVC tube spacer that takes care of that small gap between the 3/4" bolt and the 20mm bearings. Rock solid now.

To TracktROB...
Thanks for the website. Good to know.

To Scoopy...
Unfortunately, the standard Libre bolts are far too short for my application. My setup requires the bolt to pass through a steel housing, then be secured on the far side with locking bolts. Thanks though.

To everding5792...
The bearings I mentioned are 6804 2rs bearings. They are indeed 20mm-32mm-7mm, and readily available on Ebay. Yes, they are rather thin, which is why I've chosen to double up bearings on each side. They fit, and leave only a bit of bearing wall sticking out. Additionally, properly tightened with an appropriate sized support tube in the center (2.25" for standard buggy wheels. 3/4" pipe works) The bearing are doing what they're supposed to be doing (i.e. the outside spins with the wheels and the inside stays locked in place with the axle bolt.)

To Jonesing4wind:
If you know of any sealed bearing that have 32mm O.D. and 3/4" I.D. that would be helpful. (and thanks for the tip. Those are the responses I was looking for.)

To coreykite...
I understand the stainless into stainless isn't a good thing at high torque. (stainless steel, because of its combination of low hardness and minimal malabilty gives it a tendancy to sieze, particularly with another piece of stainless (which can be overcome with a liberal application of stainless steel antiseize, and proper torque setting.) However, this is a completely different proccess than the gradual oxidation of iron into iron oxide (i.e. rust) One is based metal deformation under stress, The other is a gradual degradation of metal through oxidation. They're not the same. They're not even similar. I'm not sure why you paired the two? Please elaborate. (By the way, If anyone's curious, stainless steel and galvanized steel DO rust! But because of the high chomium 6 and zinc content respectively, they oxidize into chromium oxide and zinc oxide, both of which are U.V. protectants and oxidation inhibitors, hence no further oxidation. And my dad said all those Chem courses in college were just a waste of money. HA!)

However the point is moot, as I'm not using stainless axle bolts (not because they seize, but because most commonly available stainless bolts only have the equivelent hardness rating of about 3 or 4.) I've instead chosen 8.8 grade hardened steel for the main axle bolts, and am using stainless nuts on either side of the wheel to lock the bearing assembly and bolt in place (I figured this would help protect most of the main axle bolt from the elements)

To Lack-o-slack...
I've addressed the problem of "the gap" with a thin PVC tubing that slides the 3/4" bolt allowing it to fit perfectly into the the 20mm bearings. This, in combination with the locking nuts on either side, ensure that the bolt and bearing are always perfectly alligned, even when removed from the frame of the buggy (I dare say, a much better alignment than even the Libre's standard setup.)

And on a personal note:
I posed a question on this forum as a method of trying to evaluate certain ideas I had. To throw them out there amongst a group of my "peers" and perhaps generate a "facts based" discussion on the pro's and con's of an idea. For the most part, that's what I got. Much of the information gleened from this forum has gone directly into the modifications of my buggy. Unfortunately, a few of your responses (although having technical merit) scream of sarcasm, snobbery, and elitism!! How can you expect to generate any open discussion of a question, when you ridicule those that pose them?!?