'73 CB350G take II: The 3-4-5 - Designing and 3D printing stockish parts

Rimmy

Member
Edit: added the name The 3-4-5 since the mains parts are coming from a Honda 350, 450 and 550. The main bike is a CB350. The front drum is CL450 and the front suspension is from a 550.



So, I've been working on this bike and another project on and off for the past few years. The CB350 was to be a cafe style bike, and my other CB125 project was a fun little tracker. (build threads in my signature) I finished the tracker, enjoyed it for a few months and I've since sold it. Now, I don't want to go back to the half-assed cafe bike I was building out of the CB350.


My new goal is to rebuild the bike with some period-correct upgrades and a few modern ones. I'm going to toss a CB550 front end on there with cartridge emulators. CB550 front hub with dual discs too and I'll be installing new aluminum rims on the hubs. Still have to figure out what to do for the rear suspension, maybe Hagons or something like that. While everything is apart I'm also going to toss new bearings/seals/whatever anywhere there is a consumable part.


I'm considering the practicality of making the covers and fenders out of composite material, for a more custom look, but not too far from stock.


For this year I plan on leaving the motor stock, though I am considering a winter rebuild with all new seals and everything. Maybe after a year or two of enjoying these upgrades I'll hop the motor up a bit.


First things first though, I've got to finish the front-end rebuild.


Dual discs! I've already got a caliper setup from another bike and will be salvaging the 2nd caliper from the exisiting CB350 front-end.


 
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Rimmy

Member
Re: '73 CB350G take II: resto-mod

I've managed to get a set of OEM rear bushings for a reasonable price. With these I can finally finish the teardown of the hubs and have them powdercoated.


 

Rimmy

Member
Re: '73 CB350G take II: resto-mod

Finally got the piston out of the second caliper. I tried a few things, but the grease gun trick ended up working. Now that I have all of the components sorted out I can get to actually get to mocking up the dual disc setup.


 

hillsy

Active Member
Re: '73 CB350G take II: resto-mod

davedogg said:
Dual discs for a CB350? Seems like overkill to me.

Have to agree - unless you use light weight discs, you're pretty much just adding extra weight to your wheel without a real benefit.
 

Rimmy

Member
Re: '73 CB350G take II: resto-mod

It is indeed overkill, but I'm alright with it. In fact there are a few other functional things that I want to add to this build that will likely be considered overkill.


For far future plans I know there is an aftermarket set of discs that are 5mm thick instead of 7mm and someday i might swap out for them, or try to adapt a better caliper with lighter discs. But for now I'll stick with heavy 70's era tech.
 

Rimmy

Member
Re: '73 CB350G take II: resto-mod

Slowly but surely making progress on the bike. Finally got the new All Balls tapered steering bearings installed, and the CB550 stem in(after some work with the angle grinder). I'm now ready for the 35mm forks! Next step is getting some odds and ends powdercoated so I can put the forks and front hub back together.


 

Rimmy

Member
Re: '73 CB350G take II: resto-mod

After lots of swearing and hammering I finally got the bushings out of the swingarm. Also disassembled and pulled the bearings from the hubs. Getting ready for powdercoating. I plan on having a running, driving bike again by spring (hopefully). Some of the longer term plans will have to wait, but I plan on finishing the wheels/tires/suspension then buttoning it back up in otherwise stock form for spring.
 

Rimmy

Member
Re: '73 CB350G take II: resto-mod

New fork tubes from cycleX for the 35mm front end. Also finally got to mount the 1 1/8 bar risers that I plan on using to the steering stem. Pretty excited to get the front end back together soon.



 

Rimmy

Member
Re: '73 CB350G take II: resto-mod

Finally have all of the bits ready to go off to get powdercoated. I still can't decide between dual disc CB550 front end, or a drum CL450. So i think I'm just going to end up with both... I guess it'll be a gametime decision and I'll have a spare setup for a future project!


Before...



Hopefully after will be pretty soon...
 

Rimmy

Member
Re: '73 CB350G take II: resto-mod

I'm 1 week into the 2-3 week wait for powdercoating to be done. In the meantime parts keep arriving in the mail.


New controls!
 

Rimmy

Member
Re: '73 CB350G take II: resto-mod

It's like Christmas! Time to start reassembling! (and waiting on more powdercoating...)





 

Rimmy

Member
Re: '73 CB350G take II: resto-mod - front suspension!

I've got the front suspension ready to go back together. Full 35mm suspension from a CB550. New CycleX tubes. It also has RaceTech emulators, adapters, and springs. Plus new preload adjusters, seals, plastics and even rebound springs.


 

JadusMotorcycleParts

Active Member
DTT SUPPORTER
Re: '73 CB350G take II: resto-mod - The 3-4-5

Whoah, if things continue coming up to this current standard, this is going to be one beautiful bike! Nice job.

Do you have any more info on the fork rebuild you have conducted? Where did you get the info etc on the emulators? Cheers
 

Rimmy

Member
Re: '73 CB350G take II: resto-mod - The 3-4-5

Thanks JadusMotorcycleParts! I have to say I'm really impressed with your work on the SR250 and love the 3D printing prototyping! I'm hoping to something similar with phase 2 of this project, but want to get it back on the road first.


Most of the model-specific information I got directly from talking with Matt at RaceTech via a phonecall. Luckily the 550 front end on a 350 is relatively common in the vintage racing community so he was able to give me very detailed information on how to set it up. In addition, with the emulators a static rate spring is required and he helped me to pick the ideal spring rate for me and the bike too. I highly recommend contacting them.



Useful links.
One of the better write-ups for vintage Honda
http://forums.sohc4.net/index.php?topic=86371.0



RaceTech has a wonderful description of how the emulators work.
http://www.racetech.com/page/title/Emulators-How%20They%20Work


and a good tuning guide too
http://www.racetech.com/page/title/Emulator%20Tuning%20Guide
 

JadusMotorcycleParts

Active Member
DTT SUPPORTER
Re: '73 CB350G take II: resto-mod - The 3-4-5

Thanks a lot for the info man! I look forward to building the next bike with a bit more on road performance so i think these will be essential for the old SR forks.

Will be cool to see your progress with this build :)
 

Rimmy

Member
Re: '73 CB350G take II: resto-mod - The 3-4-5

Picked up this KTM Duke 390 to keep me entertained while I finish up the CB350 project. The hope is to still have the CB350 roadworthy sometime by the end of summer.


 

JadusMotorcycleParts

Active Member
DTT SUPPORTER
Re: '73 CB350G take II: resto-mod - The 3-4-5

Have followed these cool bikes from their release date. Pleeease give us a bit of your own review :D Pretty keen on them myself!
 

Rimmy

Member
Re: '73 CB350G take II: resto-mod - The 3-4-5


Finally dropped the frame and swingarm off at the powdercoater. Keeping things moving along.

Regarding the new bike...
The KTM is fantastic. A bit twitchy with a sensitive throttle but that just makes it more interesting to ride. I've been bombing down some fire roads and getting it pretty muddy. The Pirellis are fine on the street but not so good in gravel and dirt. For a 390 cc single I'm actually quite impressed with how quick it is too.
 

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