Building a "first bike" for my 17yo son...

VonYinzer said:
How much for the apes?
Haven't given it much thought yet. Figured I'd get pics of the sale pile tomorrow and get a list going. Got anything I can't live without for a trade? Maybe some motocross style bars? some perches for clutch and hydraulic front brake to fit 1" bars? or....?

If not, just make an offer. I imagine the shipping would be a little awkward just because of the size, but they're lightweight of course.

Going to take a look at this swingarm and see what I can do. It's a little over an inch too wide at the pivot bolt, but I'm hoping I can work that out. It's 3" longer than the stock CL360 swingarm and doesn't look all sport-bikish. If things go well I'll open up the adjuster and slots for the 3/4" axle, tig some shock mounts too it and clean the tabs and such off it. If it doesn't work I'm not out much :)
Got some time in the garage this afternoon. Swingarm came in Monday. It's definitely worth the $50 (shipped) I spent. Longer and wider...


Kicking myself now, but I didn't take pics of the narrowing process. Basically I pulled the pivot bolt, caps, and washers. Using a drift pin against the spacer and a ball peen hammer, I knocked out the roller bearings on each end and the spacer. Width on the SV650 arm was 1" wider than stock, almost exactly. Intially I overcomplicated it in my head... I was going to find the center of the axle, and run a line perpendicular to the pivot tube, then measure out exactly half way in each direction from that line. Then I decided I'd just scribe a line a half inch in from each edge and go for it. If I screwed it up, I wasn't out much. So after using my digital calipers to scribe a line around both tubes I went to work with the cutoff wheel. I then dressed the cut edges, and ground down the welds where they interfered with the caps.

Worked like a charm.

I've got some interference issues at the side tubes on the frame, and I have some ideas on how to deal with it, but didn't have time today.

Once I got that far I wanted to mock things back up. But I had started swapping out the fork lowers the other day but didn't have a seal driver to finish it up. Ended up cutting a piece of 1.5" pvc pipe about 18" length and splitting it lengthwise. Worked perfect to drive the seals in. Put in the clips, poured in 9.7 ounces of new fork oil in each tube, and reinstalled the gators. Put the tubes back into the triple trees and installed the whole thing in the frame.


Serious pain in the ass to install the wheels since I was working alone, but I mocked it up. I picked an available point on the swingarm (I think it was a chain guard flange) and stuck in a temporary bolt so I could hold the back of the bike up with the angle pre-punch from earlier. Tried out that sportster seat I posted earlier. I think I can make it work, but it needs some serious reshaping first.

Looks a little strange right now... the swingarm REALLY stands out. But I think it will be ok as things come together, get painted, shocks get mounted, etc. It does look better getting that back tire moved out.

Found a cool ass tire at a local collector's shop. I think the big ol white letters look cool. Just need to find a second one :)
Crappy pics (I didn't feel like wheeling it to a less cluttered background). Played with the rear frame section a bit last night.



For comparison, here's the previous profile:


Current profile:


I plan to section the rear mount on the tank to angle its profile to follow the new lines of the frame. The cut tubes will be replaced by a one-piece hoop that will also form the rear seat mount and fender stay. Just need to find someone who can bend a tube to what I need :)
Funny you should mention that... already drew something up and asked him :)
Not a huge update, but more progress has been made. I mentioned before that I wanted to lower the back of the tank some to more closely follow the new lines of the frame. Decided to attack that tonight. Notched the rear tank mount at the center gusset and at the two edges where they bent down. Then flexed it a bit in the vice until I got it close. After trying it out and adjusting things, I got it where I was happy with it without having to do major surgery. I also cut out the old tank mount and will fab a new one in the near future once I decide on how I'm doing the seat.




One thing I've never liked is the huge tunnel in the back of the tank. It was fine with stock lazy-boy seat from Honda, but looked like ass with anything more sleek in my opinion. So I started with a chunk of federally funded template material.


Didn't have much laying around for sheet metal, but I found the old chain guard in the pile of stock parts. Traced the pattern and attacked it first with the body saw, then the cutoff wheel, then the bench grinder.


Seemed to work ok.


Spent the next half hour welding a small stitch at a time, then dressing the welds. Still has a good bit of metal finishing work to go, but I'm not in a hurry. I plan to strip the tank the rest of the way before really going at it. In the meantime, it will allow me to better come up with how the seat is going to work.


Alright, back to work. You might remember we left off with a sectioned frame and a big aluminum swingarm, looking like so:


The loop I designed came in. I talked to the tubing bender and modified the design slightly to eliminate the 'S' curve portion. I didn’t take a lot of pictures of the install, but this should show you how it worked out.


I lopped off the original shock mounts and seat support sections. I birdmouthed the ends of the frame rails that were left. The old seat support plate was split, and the top rails heated and spread to the wider width I wanted for tire and fender clearance.

You can see in this rear view how wide the gap in that plate is currently. That started as just a .040 wide gap left from the cutoff wheel.


I chopped an axle I had leftover from the SV650 swing arm into 5" slugs, and used it to join the new loop to the old frame at the diagonal sections

Sharp eyes will notice that in the last two pics, the old swingarm is back in place. I decided to give it a shot instead, though I do have the monoshock from sv650 on it’s way and may toy with that idea more before all is said and done.

That being said, we can’t do a whole lot with this short and narrow stock swing arm. So let’s make it longer, shall we?

I started out using painters tape to give me a guide for cutting, as well as have some witness marks to make sure the axle plates got back in place straight.




Before I cut them, I remembered to indicate right and left as well ;)


The swingarm is roughly 1.25 OD and surprisingly was only .0625 wall. This gave an ID of about 1.12”. I hit the local Alro Metals Plus and picked up a chunk of 1.125” OD tubing with .188” wall. Math guys will notice that the OD of the DOM is larger than the ID of the swingarm. That’s ok. We like interference fit here. The fun part will be fitting the pieces together.

This starts out with creating a tapered lead on the tubing. A couple quick spins on the bench grinder and it looks like it should work (fingers crossed).


After a few smacks of the ball peen hammer, the DOM slides inside the axle plate end of the swingarm tubing about an inch before bottoming out


At that point I repeated the process, tapering the other end of the tubing and driving that side of the swingarm in place. I clamped the whole thing in the bench vise, and since I wanted a 3” extension, I marked 4” on the tubing from the end of the cut swingarm, allowing for an inch to be slid into the remaining swingarm half.


Once they were cut, it was a simple matter of tapering the exposed cut ends of the tubing, aligning them using the witness marks from earlier, and driving them together until I reached the desired 3” dimension.


Before welding, I wanted to be sure the legs weren’t going to move on me radially, longitudinally, or laterally. So using a piece of 5/8” all thread, a handful of nuts and washers, I secured the assembly good and tight.


A few welds later, and we have a very solidly extended swingarm.


I will clean up the welds with the power file, and then when it comes time for final frame finishing I will fill the lower areas with reinforced body filler. Before that though, it will get a brace ahead of the tire that will also serve to mount the front of the fender, plus it will get better shock mounts.

In the meantime, I did a little work with the welder and flap wheel shaping the rear of the gas tank a little better. It’s far from perfect, but another hour or so and it should be ready for stripping the paint, body work and prep.


By the way… I sold the ape hanger bars on eBay. So we’re looking for ideas. I picked up a set of these in a trade for other old parts we don’t need. I think they might look good on there.

Tried the bars, don't like em. So far we like the stock bars the best, but I don't understand why every set I have of them has a crooked cross bar. :?:

Set the motor back in so I could make sure I had all the mounts (bought a set on ebay since mine were missing when we got the bike). I think I have everything other than there's a small gap on the left side of the lower mount behind the motor. Is there a spacer that goes in there?

Installed the extended swingarm so I could get an idea on shock mounts. Stock length doesn't look to bad at the moment.

Also made a quick seat pan. The tank is out to a buddy's getting smooth and primed, so I can't do much with the foam yet.

I think I am going to sell the stock exhaust and look for a CB setup or maybe make my own. Can't come up with anything I like using the high mount.

latest pics:



i would brace the swingarm if i were you, now it is longer it will endure more torquing force...
jungalist said:
i would brace the swingarm if i were you, now it is longer it will endure more torquing force...

yep, that's on the list of things to do. the brace will double as a fender mount.
personally i would brace the underside because you already have your shocks over there...

they are also at an pretty horizontically angle...

anyway, looking forward to the result. i'm in on this one ;D
jungalist said:
personally i would brace the underside because you already have your shocks over there...

they are also at an pretty horizontically angle...

anyway, looking forward to the result. i'm in on this one ;D
Shock angle may change. They work where they are (about 1.5" sag when my 200# sits on it) but I'm still looking at options. Then angle on my 2003 Harley shocks are VERY similar. You can see it in the background
Forward progress!
Found a deal on a fender that was the right radius for my tire. Oh, speaking of tire, I picked up new tread for that back wheel yesterday, too. Anyway, this is how the fender fitting progressed today:
Started out with a make shift spacer. A scrap of garden hose makes a nice flexible spacer that will hold a uniform distance to the fender. Stick it with some painter’s tape and start laying things out:


Fender comes with plenty of extra material as you can see…



I thought I took more pictures of this process, but I guess I didn’t. Basically, I marked the swingarm where the fender needs to be. I then removed it and laid a piece of 3/16” plate across and traced the inside of the fender. I cut that out, then bent some scrap sheet metal to match. After welding it up, I drew out roughly what I wanted to leave for a fender mount.


I drilled holes for mounting the fender, then clamped the plate to the swingarm once again to double check things were centered, etc. I marked the plate for cutouts, and did the final trimming.



After welding:


And then back on the bike:


temporary bolts




Had some chain laying around, so I tacked up a quick fender strut idea. I’m not sold on it. And yes, I know it looks a bit janky and crooked…it was more just a proof of concept trial for now. Thoughts?
Well, since you asked....

The chain fender strut looks stupid. Not because it's hastily fabricated just to look at it, but because it's, well, icky. :)

Try experimenting with some square stock with a twisted section in the middle.

That fender is going to hit the frame loop. You need more clearance than that. I realize that your shocks may be different, but this is mock up. Now is the time to square that away. It will piss you off if you smash the fender the first time you hit a bump. You were generous with the tire to fender clearance. I suggest you start by making the fender hug the tire much closer.
I actually like the chain fender mount idea, at least it's a bit different. put some tension on the chain before tacking it so it's nice and straight.
good progress!
have you considered how to tension your chain? if you run the fender too tight to the tire, you loose chain adjustment.

i'm not sold on the chain fender struts either. tried a mock up on mine once and scrapped it.

your boy doesn't look too heavy. could set shocks quite stiff and avoid fender hitting frame loop, however, it looks pretty close. got any longer shocks around?
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