project sl350 dirtbike/scrambler

[shane_lxi]

Just bought this sl350 last friday. I've been sick, so I haven't had much time to mess with it, but I've been obsessing over it. It's a '70, but I'm assuming it's actually a '69 that carried over to the '70 model year since all the '70s I've seen have had the tube frame, and this is still a stamped frame with a single down tube like a cb350. Anyway, I got this and a 2 cl350 parts bike. One of my cl350's is a title frame, and I've been toying with the idea of swapping this motor into that frame since it might be a little easier to clean up. The bike runs great, but the splines on the shifter were all stripped out, so I haven't gotten a chance to ride it yet, only start it and hear it idle. Anyway, here's some pics and some of my plans.

Bought this rd400 tank for $30, think it'll look nice on the bike. Tunnel needs to be pounded out a little bit, and i'll need to make some custom mounts, but I think it'll fit well.

Here it is resting on my parts bike's frame.

My 2 cl350 parts bikes. Also have one extra motor, the one in the pic is frozen.

I've ordered some clipons and headlight ears and a few random odds and ends. I'd like to go a little lower on it. The rear shocks are 13.5" long (as opposed to my cl350's shocks @12.5"). Looking into some 11.5" shocks and maybe swapping some cl360 front forks into my stock sl350 triples to drop the front without having 3" of fork sticking out of the top clamp . Planning on still kinda having a dirt bike/scrambler feel with a little bit of cafe influence. Bike will more or less be a semi off-road use commuter. Going to be making a really low seat as well. Haven't decided on exhaust yet, either keeping the stock units or swapping out to a set of cl350 scrambler pipes. This is my first build, so progress may be slow, but I will keep this thread updated as I do new things!

 

[shane_lxi]

Did a bit today. Still waiting on my handlebars, but I got the old ones stripped off and the controls/wiring out of them (about 2 hours later ). Going to more than likely be getting cl360 forks so I won't have so much fork sticking out over my triples, but this is fine for mockup. Also stripped alot of other stuff off. The headlight lens shattered as soon as it was loose from the housing, so going to have to order something else for a headlight. Also put my cl350 shocks in to see how it would look a little lower on the back. Too bad they're completely blown . Also removed fenders and gauges. Still not sure if I am going to run any gauges at all, well see. Anyway, pics.

Going to probably be ordering a set of these in also in 100-90-19 and 110-80-18.

 

[shane_lxi]

So I found this today... Yeah, that's jbweld. Kinda makes me wonder what other super sketchy things got leftover from the previous owner.

So I was looking at those cb350/cb360 billet uppers that Bullit Custom Cycles has for sale in the classifieds. They say they'll fit my sl350 k0, but I am not sure. I have an extra cb350g upper, but it's wrong. The fork spacing is correct, but the hole for the stem is off. Thinking of trying my sl350 forks and wheel in the cb350g triples (the cb350g forks are bent, otherwise I'd just use the whole setup). Well see, I have a few options here.

 

[DrJ]

Same thing happened to the top tree of my 69 SL350. I wanted to use a CB top tree but the offset is different, won't match up with the bottom tree. I had mine welded back together.

 

[shane_lxi]

I figured. That's what's keeping me from buying that upper clamp from Bullit. I have a sneaking suspicion it isn't going to work with my k0 lower.

 

[shane_lxi]

Tried the stem and upper off my parts bike with my sl350 forks and wheel. Wouldn't work. The cb350g front end is very very slightly wider. Looking for a used clamp right now. They have quite a few NOS uppers on ebay, but I'm trying to avoid the $100 price tag if possible, lol.

 

[shane_lxi]

Fixed! Bought another parts bike for $50 and used the triple off of that. Also got my clipons in the mail and test fit them. I'll post pics tonight or tomorrow. Also got a 130link chain for stretching my swing arm. Will be about 3" longer. Btw, 130 links was waay overkill. I have enough chain for a 6" stretch, lol.

 

[shane_lxi]

Not much of an update really. Got the front end put back together and put the clipons in position. I don't know if this is the proper position for them to be in, but it feels comfortable to me. Plan is to mock up the tank, extended swingarm and my seat pan, then tear the bike down and paint/polish/rebuild everything. Should get a bit accomplished on wednesday after I clean the garage up a bit. Might have to get a little creative with the tank mounts. Honda tank slips onto bushings mounted on the frame, but the rd400 tank is the opposite. I'll figure it out...

 

[shane_lxi]

Just realized that my rear brake is cable operated instead of rod operated like my cl350's. This creates a bit of a problem with the swingarm stretch. Is there anything keeping me from running a rod in place of the cable on this hub/brake when I install my lengthened swingarm? I have both a cl350 and cb350 rear wheel also, and the actual mechanism/lever looks about the same on the wheel side. Brake pedal looks similar to the cl350 also.

 

[DrJ]

You can replace the rear brake cable with an extended rod. BTW that brake cable is worth a tidy sum on ebay.

 

[shane_lxi]

Good to know! Thanks. Going to try and sell the left over steering dampener assembly also

 

[shane_lxi]

Ordered some cl360 forks yesterday, I hope they work. Should be about 2" shorter, so I can go a little lower up front without having 4" of fork sticking through the upper clamp. Also pounded out the tunnel on my rd400 tank and test fit it, looks rad. Should be getting my "seat pan" tomorrow, then I can start mocking up the tank/seat combo and get an idea of how it's going to look. Will be getting the materials for my swingarm stretch hopefully on thursday as well, so should have alot of progress this upcoming week .

Sunday was wasted cleaning up my nasty nasty garage. So much nicer now that I have some room to work. This side of the garage was mostly storage, so I never kept it clean. Unfortunately now that I am working on a bike, I need that second bay .

before:

after:

 

[shane_lxi]

Crappy pic, but here's a shot of my rd400 tank mocked up and also a rough draft of my seat pan. It's a 8.25" skateboard deck. A little too wide, need maybe a 7.5" or 7.75" deck, but this will work for test fitting, and I can use it as a template for the finished seat pan. Will be upholstered, but will still be very very low. More updates on Thursday

 

[shane_lxi]

Big day! Swingarm lengthened 4" and also cl360 forks (2" shorter). Bike is low low. About 36" at the highest point (my truck has 37"s on it, so I used it to give some perspective in the pics). I just finished bolting the swinger in, so sorry for the dark pics, I did what I could . More updates to come. I haven't gotten a chance to mount the chain yet, this is a very very rough mockup.

 

[shane_lxi]

Got a little progress today. My new shocks and shoes finally showed up, so I went to work and mounted them up. Also sprayed the wheels a matte black so I could see if I liked it. Plan is to powder coat matte black eventually. Shocks are 14.5" cb750 units. Extremely stiff. I also went with a slightly smaller tire out back for a little more seat clearance. I wanted to be able to take my wife out on rides too when this thing is done! Anyway, now I just need to finish detabbing and getting rid of anything else I don't need like that fucking huge horn and the brackets for the steering dampener. Then I can disassemble and start painting/polishing! More updates soon.

 

[shane_lxi]

So I was detabbing my frame today, and started to get a little nervous the more I thought about how thin this metal is! Did I got too far? should I have left some more structure up by the backbone? I left all the support and metal around the shock mount. You can kind of see where I was going to spot some square tube in and then my plan was to weld about 8" of 1/8" steel on as well to ad some rigidity. What do you guys think?

 

[shane_lxi]

Cut out some 1/16" steel to box in the seat rails. Just spot welding everything for now, will be welded more solid when I strip the bike down, but I am pretty pleased with how everything fits. Will have 2 cross sections for both support and to mount the seat to.

 

[shane_lxi]

No pictures to post, but I have been working on this bike. Doing boring things like welding in seat brackets, replacing controls with simpler stuff, finishing seat hoop, and making a rear fender. Also sent my cables out to motion pro. So nothing cool to photograph, but still lots of important things getting done! Pics when it gets more assembled!!

 

[75xl350]

how much do custom cables cost? it would be nice to get a few of mine shortened.

 

[shane_lxi]

I'm not sure yet. Getting throttle, clutch, brake and speedo cables, thinking it'll be around $200, but not sure. There's a local shop over herethat will shorten them, but I just don't trust it, so I opted to just spend the money.