Topic: 73 CB350F/2008 600RR Mash Up Cafe Project

[alternativeauto]

This is my first post and I figured I would start here as I am building a 73 350F project bike. I haven't been on Forums in almost 6 years since I used to go on Honda-Tech when I was building cars. Figured it would be interesting to get everyone's thoughts and opinions and occasionally help where needed. The traditionalists are not going to appreciate what I'm doing, but I think the guys with an open mind and a wild hair will enjoy. I have pictures, but need to upload them onto Photobucket, so I will start doing that today to give everyone an idea what I started with and where I am at right now. -Shannon

[alternativeauto]

Here's what she was when I got her. Pretty clean for 20K miles. Still ran, but clutch slipped and carbs were half clogged.

[alternativeauto]

Last picture fully assembled. My thoughts, go big or go home.

[alternativeauto]

At this point, still no decision as to final build, but my son was really enjoying the tear down process. Yes he has a pony tail in the middle of his head (Mom wanted to grow a surfer haircut, but his hair was too thin and wouldn't stay out of eyes, corrected now!)

[alternativeauto]

From complete running bike to basket case in no time flat!

[midnightrider]

That's a quick start, my friend!  Looks like your son is going to be a happy wrencher! 

Do you have an "inspiration" bike for this project?    Lots of cafe parts available at Dime City Cycles in Largo - you may want to check them out - www.dimecitycycles.com

I'm starting a mild cafe on a '72 CB350f that I recently restored.  It currently looks a lot like your's before the teardown -you can see it in my build thread, linked in my signature.

This forum is a great resource - you may also want to check out dotheton.com - it's not the resource that SOHC4 is on the technicals of these bikes, but good for cafe stuff.

Good luck!
 

[alternativeauto]

Most of what you have seen was done 4-5 months back. Bike actually was purchased over the summer. When taking the bike apart, I had tentatively decided to build a rather traditional café racer. When purchasing this one, I also got a complete second bike, but not in running condition, baskets and baskets of parts, and a full brand new complete gasket/seal kit. I have since torn down the motor to reseal, but in the process found that it had a broken ring. Everything else looked to be in good condition, but now the wheels started turning as I have built multiple motors. I started researching my options for building this unit to make more power. The cost to make the power I would be interested in made me switch gears to a different power plant. I grew up at the race track and am a self admitted adrenaline junky. Hence the route I am getting ready to reveal. The resolution on some of these pics are lacking as I used my phone instead of the good camera.

Frame stripped, most brackets removed, forks fitted (2008 600RR), and engine ready for initial test fit (2008 600RR).

[alternativeauto]

Tank to Fork fitment.



Initial Engine/Frame/Tank fitment.

[alternativeauto]

Next set of pictures will be of the backbone frame mod required to allow for the throttle body/velocity stack placement. Moly tubing should arrive tomorrow and the bending/welding shall begin. I will post pics of the partial frame cuts I have made so far, and of the extra tank that I have cut the bottom out of to serve as a quasi air box. The hollowed tank will also provide a location to hide some of the wiring.

[JustinLonghorn]

I can dig it.

Good to hear that you will be modifying/beefing up that frame. The gigantic leap in HP would have ripped that frame apart, ha.

Will you also be mono-shocking the scoot, or leaving the twin shocks out back?

[alternativeauto]

My current plans are to leave the twins. I am going with the CRF450R swing arm as I've seen done before with this frame for a build using the 450R engine. I need to get some extra wheelbase as well as an axle/arm assembly that can handle the added torque. I like the look of the outboard shocks because as wild as the bike is going to be, I still want it to have the vintage facade. I will be running twin 1" .065 Moly tubes from the seat section to the neck. The whole frame will also be getting gussets in various locations where the torque would like to start tearing things apart. I did leave out earlier that I am building this for my fiance, so every step will be taken to assure that the bike is safe to ride. Now the throttle will be totally at the riders discretion.

[socalenduro]

so the 08 600rr fork how was that fitted?
im guessing thats not just a simple swap
what kind of rake and trail does that yield?
front wheel thoughts? brakes?

[alternativeauto]

so the 08 600rr fork how was that fitted?
im guessing thats not just a simple swap
what kind of rake and trail does that yield?
front wheel thoughts? brakes?

Basic fitment on the forks. I am going to try and machine a set of the 600 inner cups to fit the 350 neck so to be able to keep with the 600 bearing set. I also have a local bearing shop (Miller Bearing" that is very helpful when creativity is required. As the dimensions go, everything fit up nicely, the stem was exactly the proper length, the turn stop tab on the 350 and tabs on the 600 fit up and stopped perfectly with room to spare, and the 350 top nut was the same thread pitch and fit perfectly with the 350 washer underneath.

I haven't done the calcs on the trail as of yet, but the offset is approx 1 1/2" less than the 350. (10 minutes later) Okay, so taken the 600 offset is 30mm (350 looks to be approx. 30mm more). Tire diameter of 600mm give or take. I honestly don't know what the stock rake is on the 350, but eyeballing it I'm going to guess in the 26 range. This should put me around 110mm of trail. If I'm wrong I take no offense in the correction ;-)

I plan on using 17x3.5 front wheel with 120/70-17, spoked supermoto wheel with oversized single rotor.



Hope I answered most of your questions and somewhat accurately.

[alternativeauto]

Wheels finally arrived. Moly has been on back order, but is scheduled for delivery tomorrow. Back to it!!

[Toxic]

OMG those wheels are stunning.  Can't wait to see how this one turns out.

... and the calipers will work with those oversized rotors???

[kajtek]

totally totally awesome. amazing! cant wait to see it built

[alternativeauto]

@Toxic - If I use the 600RR Caliper, I have clearance from the rotor to the rim, but not from the rotor to the spokes. The back side of the caliper has interference. So if I go with this option, I will likely have to machine an adapter plate to bring the rotor out. I'm still up in the air. I'm just gonna wing it and make decisions as I go. It will make the experience more memorable 

[alternativeauto]

Just an FYI, due to the nontraditional approach to my build, I am ending up with an enormous amount of good stock parts left over that I will not be using. When I get more time I will post something in the Parts for Sale section, but for now I figured I would mention it here. Anyone interested, email me at cycleworks321@yahoo.com.

[alternativeauto]

Update: First set of frame mods complete. Time to hang swing arm, rear wheel, and work on final engine placement. More pics to come.

[johnny]

Wow! Can't wait to see the progress. Great work so far!

[Syscrush]

This is a very interesting project.  You know this, and I know that you know this, so forgive me for saying it, but:

BRACE THE SH!T OUT OF THAT FRAME!

You're looking at about a 6x increase in power, more than enough to tie that frame up in knots.  In addition to bracing, consider using the engine itself as a stressed member.


Very cool, very interested to see how this all turns out.

Are you keeping the RR EFI, or changing to some nice downdraft carbs?

[alternativeauto]

This is a very interesting project.  You know this, and I know that you know this, so forgive me for saying it, but:

BRACE THE SH!T OUT OF THAT FRAME!

You're looking at about a 6x increase in power, more than enough to tie that frame up in knots.  In addition to bracing, consider using the engine itself as a stressed member.


Very cool, very interested to see how this all turns out.

Are you keeping the RR EFI, or changing to some nice downdraft carbs?

I still have 6' of moly tubing and I'm not real concerned about adding a few pounds, so it will likely look like one of those old playground spherical things when I'm done ;-)



I'm definitely keeping the EFI. Not much of a carb guy except for with my Harley/Custom.

[Greggo]

Cool project man!  Can't wait to see the finished product!

[Syscrush]

I still have 6' of moly tubing and I'm not real concerned about adding a few pounds, so it will likely look like one of those old playground spherical things when I'm done ;-)

Groovy.

I'm definitely keeping the EFI. Not much of a carb guy except for with my Harley/Custom.

Wicked!  Are you going to reuse the stock ECU, or go with MicroSquirt?

[alternativeauto]

I still have 6' of moly tubing and I'm not real concerned about adding a few pounds, so it will likely look like one of those old playground spherical things when I'm done ;-)

Groovy.

I'm definitely keeping the EFI. Not much of a carb guy except for with my Harley/Custom.

Wicked!  Are you going to reuse the stock ECU, or go with MicroSquirt?

I am going to use the factory ECU to start, but I may need to switch over to the microsquirt if I end up having to eliminate the secondary injectors. It's going to be a tight squeeze and some tricky mounting in order to assure they spray properly.