Topic: 74 CB550 Modern Cafe - Isn't this thing done yet?

[calj737]

 I've seen and read so many great posts on this site that I felt obliged to offer my project up for criticism or congrats; whichever the viewer chooses.

The project is nearing its completion now and has started last Nov and should be fully on the road by the end of this November. Fortunately where I live in the US (Mid-atlantic) the winter is not so bad and one can generally ride year round without too much nastiness.

Bought a rusted out, hacked up butchered '74 550. Wiring was horrific, suspension poor, rear brake (what rear brake...?) and the front end was still awaiting its first service after 38 years. Though the engine kicked or button started first time, every time. Ran strong, pulled hard and seemed quite hearty. Estimate is less than 25k miles.

After the expected rusted screws, extractors and PB Lube, heat, Marvel, and Evapo-rust, the frame was free, engine side covers off, and front forks loosed from their allen bolts. So new uppers from Frank's, Progressive springs, seals, boots and fluid. Powder coated the lowers with all new SS fasteners.

Here's a pic of the mock-up of the front-end:

[calj737]

Some of the most ambitious changes to the bike will be the removal of the factory seat hoop and rear passenger strut. Sawed those off and had a new, hoop fab'ed and welded on. New shock bosses welded to original geometry and a new boxed aluminum swing arm. New Progressive shocks Heavy Duty units) installed on rear.

Here's a pic after some initial removal of the rear with the new hoop welded on:

Stock tank pictured after sandblasting, powder coating and lining with Red Kote. The PC is to be a base layer for the final paint.

[calj737]

All this work happened over last winter and early this Spring. Finally after accumulating all the parts, pieces, rebuilds, and decisions, re-assembly commenced.

Engine was soda blasted, then side covers removed and Glass beaded for a final finish. Frame fully powder coated and laid over to install engine.

In this picture you get a good look at the seat hoop with a pan welded to it to add support and provide a base for electronics.

[bjbuchanan]

Looking good so far, what are you gonna do with the front end? Emulators and straight springs would definitely put a bit more fight in that dog.

[FunJimmy]

Interesting!

[calj737]

Here's the bike after the rear swing arm and shocks, wheel installed.

The wheel is from an '81 750, 16" wearing 130/90 Conti tires. I like the meatier look at it evens the ride height out fron to rear with the 19" up front. Hubs powder coated in silver, rims in matte black, new Buchanan SS spokes and of course new bearings.

[calj737]

Next the front-end installed. Vortex clip ons in black. Same treatment as rear wheel for hubs/rims/spokes. You may notice I have the fork lowers on "backwards". That was intentional as I am running a front fender from Benjies and wanted to install the caliper behind the front fork. Still need to powder coat the fender bracket in satin black...

[calj737]

A quick look during the early stage of assembly with tank and seat on. Paint is Mercedes SLS AMG Monza Grey in a satin finish (not Matte). Gas cap is from same source as triple tree, headlight ears for consistency.

Seat is suede top and vinyl sides. Velcro'ed to cowl, cowl is "screwed" to frame for a secure ride. Pull the pad, then unscrew to remove and access the electronics under the hump.

Header is ceramic coated in flat black. Muffler came with the bike. Its sort of "hanging" in a spot, jury is still out on whether I will swap it. Thoughts?

Rearsets are DCC Universals fastened to custom brackets. Really pleased that the bracket lands as intended directly in front of swing arm and "disappears" somewhat.

[calj737]

A little safety equipment in the form of LED tail light and indicators. Have a set of indicators for front to match, but have to drill out the ears to mount into the headlamp screw sockets. Brake levers, clutch etc... I'll only be running a leftside multi switch to minimize the controls and keep the front super clean from wires and cables.

So still have linkage to fabricate, coil bracket to fabricate, modify shifter and kick start leg, rear brake actuator, mini gauge cluster, front indicators to install, Reg/Rec, battery, custom harness, brake lines for front (triple tree has a manifold built into lower to allow a SS line to terminate above, pass thru, then switch sides to left caliper (in a single caliper mode) to keep the lines very clean. Pretty stoked about the small things...

Once I finalize the fabrication and assembly, its off to wiring. Then off to a local shop for final setup and tuning on Dyno. Given the new K&N pods, Keihin carbs, exhaust and Dyna ignition, I think its best to have the pro's finish the setup. Heck, I've spent so much time and money, need to get the best result for reliability, performance and safety.

I'll have them double-check everything for torque, chain, tightness and leaks. Also adjust the valves during the setup because I have no idea about their status from the PO. Only removed the valve cover to glass bead, never to muck with the internals as bike was running very well. It still rotates easily off the stator bolt and I've kept it oiled and protected during the rebuild.

Thanks for looking, and any input on the exhaust is welcomed!

[Ewan 500K1]

Hi Cal , looking good. What is that triple T / yoke set at the front end off ?

[totty]

Apart from the exhaust I really like the style.

I'm a bit concerned about the seat hoop though, it looks like the frame will now bend like it's hinged in the middle - I'd want a brace in it much like the original triangle.

[Ewan 500K1]

Apart from the exhaust I really like the style.

I'm a bit concerned about the seat hoop though, it looks like the frame will now bend like it's hinged in the middle - I'd want a brace in it much like the original triangle.

oh yeah .. hadnt noticed that ... theres going to be a whole lot of strain on that single join between the engine cradle part of the frame and the rear half of the frame with the seat on it,  as the swing arm flexes up and down !!!

[Bankerdanny]

Apart from the exhaust I really like the style.

I'm a bit concerned about the seat hoop though, it looks like the frame will now bend like it's hinged in the middle - I'd want a brace in it much like the original triangle.

oh yeah .. hadnt noticed that ... theres going to be a whole lot of strain on that single join between the engine cradle part of the frame and the rear half of the frame with the seat on it,  as the swing arm flexes up and down !!!

My comment too. Why remove the rear triangle tie in? It's a key part of the structure if you are retaining the twin rear shock setup.

[knowsnothing]

Its hard to see, It also looks like the exhaust and the rearsets are attached to the swing arm....not sure if that is a good idea.

[mono]

Its hard to see, It also looks like the exhaust and the rearsets are attached to the swing arm....not sure if that is a good idea.

I can't tell - the pic is too small.  But if so, yeah bad idea.

I love the this build, though - very nice work and looks cool.

[calj737]

Let me respond to a few questions and comments:

Ewan asked about the triple tree. It's from Joker Machine in California. Beautifully made stuff. Pricey, but it fit the build from a design aesthetic.

A comment was made about the exhaust hangar and rear set mounting: those are both attached to a custom bracket on the frame. It lies in profile to the swing arm and is difficult to see (intentional) to keep as many lines clean to the eye. (There's a pre-assembly picture where the triangular steel brackets are visible).

Seat hoop/triangular tie-in - this has been questioned by many people in person too. Te specs on the new hoop is 0.83 DOM Cro-Moly 1" tubing tig welded. There are 2 lateral braces across the hoop, and then sheet steel pan welded on top. This design and fab was done for me by race car frame builder (Bobby Creech). After the welding, we tested the hoops strength by attaching a 1500lb stress jack to the end of the hoop, no shocks and pulled down on the hoop with the front of the frame secured. (A pure frame stress test). Total deflection was less than 3/16. That's awfully rigid.

If you add the support of the shocks, bounded by swing arm, there is not enough travel upward or downward to move the frame. Removing the weight of a second rider beyond the shock lessens the importance altogether of the secondary strut.

He told me when I asked about the logic of even wanting to remove the strut "those are provided for support of the passenger, and due to inferior steel used 40 years ago".

Everyone who what's sat on the bike, with or without shocks attached comments on the strength. So i am pleased with the look and very confident with the strength.

I am still evaluating the exhaust aesthetically.

[Ewan 500K1]

Ewan asked about the triple tree. It's from Joker Machine in California. Beautifully made stuff. Pricey, but it fit the build from a design aesthetic.

are they standard offset yokes Cal (ie 45mm) ?  No engineering genius but that frame set up would still make me nervous but I'm sure their are far more qualified folk out there to comment than me !

[calj737]

Ewan - they are factory dimensioned trees. I actually test fit them with the factory lower and stem through new top, then vice-versa. Aligned perfectly.

I think what throws most people off is the "appearance" of a geometry change. There is none in the front or rear whatsoever. It's all aesthetic. With the exception of course of the brace being removed as I discussed above.

Essentially, this bike employs a very similar rear structure to a mono shock single seat bike. They frequently have no rear brace. The shocks tie the hoop to swing arm, they rebound and coupled with the riders weight between frame and shocks, it's all very encapsulated. If anything, I may need to soften the setting of the shock so as not to ride like a Harley rigid.

[Ewan 500K1]

cheers Cal ... found them at http://jokermachine.com/products/cb750-triple-tree.html
I'm looking for a set with a reduced offset of 30-35mm . Best I have in UK so far is a quote of £420 for a one off CNC alloy set .

[knowsnothing]

Sounds like you have thought things through, carry on 

ps - bike looks great

[calj737]

Appreciate the compliment. It's turning out well, got all the last minute details to hash through to get it done... And still gotta resolve the exhaust as it bugs me a bit.

[Ewan 500K1]

I dont like big bean cans on the end of exhausts and suppose I like symmetry really , so I'd have four into two or four into four or four into one under the seat.... if i had the cash and all that. I like my drag ones ones    .... cyclex do a similar one. http://www.cyclexchange.net/Honda%20500%20-%20550%20Exhaust%20Page.htm Less is more after engine and wheels to me I hope

or take the can off yours and leave it open ?

[calj737]

The longer I've looked at the exhaust, and other examples on this forum, I contacted Chris at MotoGp. I've out my order in for one of his setups (a day late as he just sold his last available unit). So in about 60 days should have that available for the bike.

Dropped some other bits to the PC'er and arranging a visit to Shaun from Slingshot for SS brake lines (conveniently he only lived about 20 minutes away).

Received a new drilled/slotted rotor and will pop that on this weekend while I'm dealing with Shaun and the brake lines. Still gotta get the linkages and final fab done so I can get this thing wired. Weather has been fantastic and rode my sons bike n Sunday for about 3 hours because I couldn't take not riding while waiting to get this project done....

Besides, got another '73 500 waiting that's in worse shape than this one to start for the winter!

[calj737]

Finally got some bits back from powder coat.

[calj737]

Front fender, new rotor and caliper mounted