My XR650L conversion

[fabiodriven]

William, if we do make two right off the bat Steve won't be using his anytime soon. We could send it out to you. Again, that's assuming we do two right off.

[ironchop]

Cromoly is not a brand name. It is a type of alloy steel but the word cromoly or CrMo or Cromo denotes a type of steel alloy with Cromium (cro) and Molybdenum (Moly).

If it were a brand name, it surely would be trademarked. We typically use 4130, 4140, 4152 prehard ( for our firearm parts), 4145, 4150, etc.

The '41' in the first two digits denotes a steel alloy containing Cromium and Molybdenum in varying concentrations as well as other metals......the last two digits denotes the carbon content....example : 4130 has .3 % carbon and 4150 has .5% carbon in the alloy. More carbon content makes for a harder steel. Harder can also mean more brittle as John and DC aready knows.

All kinds of companies make cromoly steel so. I dont see how that guy got that idea

[ironchop]

This explains it better than I can:

http://en.m.wikipedia.org/wiki/41xx_steel

[fabiodriven]

I hear ya Doug. DC was telling me to bring up the number 4130 when I go back so I will. The steel guy and myself will be having a discussion, that much is for sure!

[Dave Little]

The steel guy and myself will be having a discussion, that much is for sure!

Don't bother...he hasn't earned it from you. I'd find another steel guy that don't do hot tub impersonations. My2

[Billy Golightly]

www.McMaster.com is great for small amounts of 4130. I've bought what totals a few thousand from them over the years I'm sure. They even have it in metric sizes which is pretty nice for certain projects!

[ironchop]

Yes, just ask for 4130 tubing. I've also heard it referred to as aircraft tubing.

We use McMaster Carr for many of our small billets but I will warn you that they are higher priced than most metal outlets locally. Our weld shop side inventories flat, billet, and tubing and it is considerably cheaper to buy 12' sticks and saw it up yourselves.

There was a great metal shop in Indy whose name I can't recall where I used to get oval and elliptical 4130 from when I built a couple of springer frontends for some choppers I built back ten plus yrs ago. Looked trick as F#$% !!

[fabiodriven]

After this tear down, I am declaring this bike officially built by me (and Steve).

The first builder obviously had the right idea and the template was there. Sometimes just taking the initiative is the hardest part, but the execution does show his inexperience in this build. This bike will be thrashed and it will have to stand up to that no matter what.











This is our gusset material-




















Nah just kidding. Now before you can say "calm down DOHC, not really", we are obviously using that chunk of steel that Steve just had "laying around" to make jig. If all goes according to plan, we (or maybe just Steve, who knows) will be able to make more swing arms after this one.

There will be a lot of gusseting and bracing added to the existing bike frame as well.

[jays375]

Is that braze I see?God Steve can't be sleeping these days.Must be all kinds of ideas rolling through his head.just document stuff please.I'm gonna need a new project.

[fabiodriven]

I thought it was braze as well Jays, but I looked closer and dismissed it as surface rust. Some of those areas were still covered by paint longer than others but now that someone else saw what I did I'm going to look closer.

[fabiodriven]

So far I've done this all by myself but again, I wouldn't be doing it without Steve's shop and equipment. Steve's part will be coming up soon and is a bit more in-depth then what I've been doing, but this stuff is just as important. We're not screaming right through this as we had expected. Life happens as you all know. Broads, beach, dames, Unadilla, skirts, Buell... There just isn't enough hours in the day as some of you know.

So very basically put, I cut out some gussets and welded them in. We're waiting on some aluminum stock for the jig which will hopefully arrive tomorrow.

[Dirtcrasher]

I simply cannot believe 3 places including our nearest steel distributor and a custom shop I stopped in said 4130 Chromoly was a brand name only and not a type of steel

Thats scary.......

[fabiodriven]

I wasn't going to post until we were done, as we've finally been moving forward again, but I couldn't wait. The swing arm should be done by next week. I've had a lot of big things going on lately including, but hardly limited to, a completely new line of work for me. Then Steve got hospitalized at one point, all things that are either important or beyond our control.

So obviously Steve is the machinist, I only assist in that aspect of things. I've said it before, I couldn't do this without him. We've both been a little surprised with how much is actually involved with keeping things lined up where they need to be. We have the luxury of having the old swing arm, which once straightened was a usable template. The jig holds the swing arm right where it needs to be and I'm leaving at least one leg attached at all times in order to preserve our dimensions, as one thing the previous builder did do was build it nice and straight. This is a massive advantage for us, as we both know we could build one from scratch just building and measuring solely off the jig or "free hand" so to speak, but it would be much more difficult. We did have to straighten the old swing arm before we could use it as our pattern as it did get very twisted. I am doing all of the welding, grinding, cutting, and bending. These pics were taken over three trips over to Steve's I think? I only have a few hours here and there though after work.

I am putting every bit of spare time I can towards this getting done ASAP, but I can't do anything on the weekends as I spend most of that time in Vermont. I have been blown away by the amount of dirt mountain roads up there, it's absolutely astonishing how far you can drive on the most beautiful dirt roads, it's literally endless. I have been up there enough without my trike and can take no more. I am really looking forward to destroying those roads as soon as I can!

Thanks for looking and thanks to Steve and DOHC for a killer deal on parts!

[jays375]

Looking good.Think Steve is getting into this project.Should be a fun one for sure.That little shop of his is really set up.What mileage were you getting out of a tank of gas?That was a major complaint I had about my XR.Tank was just a tad small for me.

[fabiodriven]

Thank you! The tank is small and she drinks it quick!