83-84 ATC 250r Swingarm Pivot Bolt Reproduction.

[bkm]

I know these are sometimes hard to come by, so I was lent a good bolt to copy from BWard, and had a chunk of bar stock laying around so I decided to see if I could copy it. It turned out okay and should get the job done.


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[yaegerb]

Very nice work and glad to see you posting again!

[bkm]

Very nice work and glad to see you posting again!

Thanks man. I needed a little break, but as you know, I'm getting the trike itch again.

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[Leevvii]

thats a real nice job, curious as to the type of steel and if it is hardened at all?

[ps2fixer]

Couldn't you do the same logic for front axle bolts too? Same concern though, wonder what the harness of OEM is and I suspect you're not going though the hardening process?

I've posted measurements of an 86 ATC250R front axle bolt a while back. I could dig up the thread again if you wanted to take a stab at making them. I could pull more measurements with my caliper if needed. I was thinking some day I might pay to have them reproduced, but no clue what the costs would be.

Anyway, good luck with your project!

[Leevvii]

i just done the file test on the one on my 84 250R and it files ok, it feels a little harder than mild steel, but it doesnt feel like hardened steel to me, i know its not an accurate test, but can usually tell if its been hardened.
I found these Lonestar Racing Swingarm Pivot Bolts for the HONDA TRX250R 85-89, and they claim that theirs are "Machined from industrial-grade Hardened steel and zinc-plated to prevent corrosion"

[bkm]

I don't think the oem pivot bolts are hardened steel. I tried the unscientific file test to both and they felt of similar hardness. I don't feel as if the pivot bolt is under the same stress as an axle, but I could be wrong. I do know the steel I used is considerably heavier than the oem, but I'd be lying if I said it was stronger.

I think I'm going to buy some 303 stainless and make a few. I should have a few 250r front axles laying around I can try to make one of those as well.

I need to find a supplier that will sell by the inch. These pivot bolts use about 13" of material and most places sell by the foot.

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[ps2fixer]

Don't know a whole lot about machine metal supplies, but couldn't you get say 15 feet and get 16 units out of it with 2 inches of material for the cutting losses? Of course mixing and matching seems the most logical way, like order 2 feet and make one part that's 13in while the other is under 11in. Of course like I said, don't know how that all works exactly, so maybe I'm wildly off on my thinking, it's just what I'd do if I understand the situation right.

Never done a file test or anything for harness testing, neat idea though and makes sense. I'm pretty sure the front axle bolts are hardened just based on their finish quality and how they hold up for dents/scratches. I'd think if the Stainless is similar in strength, people would go pretty nuts for it since it's going to be more or less free from rust problems besides the fact new parts are always handy to have available. I suspect the parts won't be cheap though due to the much slower machining process? Not sure how much it costs to have parts professionally hardened and zinc coated to compare though or if there's much for options out there.

[bkm]

Buying in bulk is always the most logical, but 303 is not cheap. It seems to run about $25 a foot give or take a few bucks, then shipping is stupid. So by ordering that much, I'd be on the hook for quite a bit until I sold enough to start making my $ back. I'm not sure how much of a demand there is for these and the front axles? Everyone wants one until it's time to pay up.


There is a good metal supply shop about an hour away, but finding the time to get down there is another story.

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[ps2fixer]

Yea I get you on the market vs what people say they want, I've got hit with a couple harnesses that are horrible performers, but my #1 cost by far is time invested. I figured the supplies you were getting were from a local metal supplier, I couldn't imagine having metal shipped unless it was like by the semi truck load.

[bkm]

Yea I get you on the market vs what people say they want, I've got hit with a couple harnesses that are horrible performers, but my #1 cost by far is time invested. I figured the supplies you were getting were from a local metal supplier, I couldn't imagine having metal shipped unless it was like by the semi truck load.

You definitely know moreso than others that making these parts is more a labor of love than trying to make a buck. Since I'm not a real machinist with real equipment, I basically work for right at or below minimum wage. I figured I have 4-5 hours in this bolt taking my time.

You have me intrigued with the front axles though. I've been thinking of making a lightweight front hub and maybe toying with a titanium axle? This might be an excuse to try making that axle. I know CT Racing offered a light weight package for the 250r that included a front hub. Not sure about the axle though?

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[ps2fixer]

I don't know enough info about metals but I know google fu lol. Based on what comes up, density wise Titanium is 56% lighter than steel (aka the same bolt would be around 1/2 the weight if made exactly the same size), strength wise weight based, titanium is as strong as steel at 45% the weight. That tells me that if you made the bolt the same volume/size of the steel bolt, it will be 56% lighter, and something like 5-10% weaker. You'd have to make the bolt bigger to make it as strong and still be lighter than steel, of course that's not really an option so I suspect this is why it's not done.

On the talk of business, I haven't given myself a raise since I started my business in ~2013. More money goes into restocking and supplies than my own pocket (counting taxes, food, bills etc). Of my sales I see about 30% of it as income. As a whole business I make a little above min wadge, but the fact I reinvest into the business so much probably puts be at or below the line. I've learned that some parts I can off set the costs by charging a lot more for them to have a high profit per hour of effort to offset the pretty horrible profit of making harnesses. It's the small things that makes the "real" money, the big things like whole harnesses is like you say, a labor of love over profit. That's why I'm poking at ideas that expand the higher profit parts so I can have some actual spending money on R&D for more parts or seeing about having parts actually mass produced with my own specs. One of those things is the CDI project I think you've replied to. A fully programmable CDI is like $180 for the cheapest I've seen, so if I can make a quality part, targeting a little over half should make me own the market while making a nice profit since I'd be building 50% of it or more + doing all the programming/testing.

Anyway back more on topic, there are CNC style lathes right? Like you tell it the basic shape you want and it runs though the process of cutting it down to your specs? Another project for a micro controller lol, just not an easy thing to build/test when I don't have any of that equipment on hand. I wish these things were around when I was a kid and was going crazy trying to figure out programming ideas to do that would teach me stuff and be something useful. Instead I made silly programs like max speed estimator based on tire size, chain gearing, engine rpm, and assuming highest gear in the engine is 1:1 ratio (hint it's close but isn't). That was before everyone had the internet and a 100mb service manual would take like 4 hours to download. Gigabit internet can do that in less than a second now ^.^.

Besides swing arm bolts and front axle bolts, I'm not sure what else there is to make with a metal lathe. Hubs would be neat, but I suspect making the splines is a royal pain. I'm sure extended swing arms would be a hit, but you'd have to figure out how to efficiently get the piping made and assembled while also being plenty strong. Even crazier would be whole frames. I'd think the little things is where it's at though, like the recent thing about the 350x shroud brackets, seems like everyone is missing them, so a simple aftermarket solution might sell somewhat well. I'd think a simple flat bar thicker than OEM would probably work fine, doesn't give the pretty factor vs how the OEM one is made though. Maybe make it from AL and make it way thicker so it has the bling effect (that no one sees under the plastic).

Another thing I've seen recently that went out of production is the first gen ATC200X chain adjusters. Looks more or less like a thick waster with a stud welded to it. Partzilla even has a product photo of it, so it must have been a somewhat good seller. Most of these old parts don't get actual photos made of them like this.

https://www.partzilla.com/product/ho...c58209082df02b

Anyway, personally I'd say make the big stuff as a fun longer term project that doesn't really make you much money, but make small simple things that cost not much to make or much time, and charge a bit for them to off set the difference in income slightly. If it's a hot seller, then it really helps.

Another somewhat simple part I can think of are fork tubes, but I suspect it's probably easier to find aftermarket options than trying to reproduce OEM. Besides that, drilling out the center would take forever, a pipe is probably too low quality of steel to use and the chrome plating process I know nothing about (they are chrome plated right?).

The business world is a big game between making a quality part, and making it efficiently cost wise as possible. If your process is inefficient, either you have to drop quality or spend more in man hours. Kind of a triangle effect. I bet business books have some sort of version of that triangle idea, almost always happens when I have ideas like that and it works really well like that. Just think what it was like when Ford came up with the assembly line process. I bet their cars from that era were either the cheapest and the same quality as others, or similar cost but higher quality. Doubt they kept to the same quality and cost and pocketed the extra money, businesses just don't really run that way.

[bkm]

The titanium is a pipe dream. My machine is not setup for flood coolant. I can probably get away with spray coolant on stainless, but that's probably as far as I would push this lathe.

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[fabiodriven]

Stainless is not a good idea for axles, or at least certain hardnesses of stainless. Ronnie did some stainless front axles before he he passed and I saw Raffa bend his at Trikefest. He was going around the MX track when he landed from a jump, which bent the front axle, which stopped the front wheel from turning, which flipped the trike. I don't know what number stainless was used for those axles but I'm sure there's old information on these axles somewhere in this forum.

[El Camexican]

1. Awesome to see Bryan back on here!
2. Fantastic to see him working on trike parts!
3. I totally agree with Fab's SS is not a good choice when strength is a concern and sucks to machine. It can also promote oxidization to accelerate in the metals that come in contact with it, especially aluminum.
4. I'm guessing most OEM shafts are plane old carbon steel. Heat treating mild carbon steel does nothing.
5. My recommendation would be to use 4140 for any shafts I was having made. If corrosion is a concern have it plated.
6. Heat treating is not needed for 4140, but it can be done. However it would either need to be done in a fancy vacuum oven to avoid distortion, or made slightly oversized and then precision ground to final dimension after treatment. Again, not needed with 4140.