CB550 Project Scruffy Racer

Sderbyshire

Into Sailing, classic Triumph cars and motorbikes.
New Handlebars arrived today so spent a happy hour swapping them onto the bike

They're a couple of inches lower than the old ones, and a couple of inches narrower too, but with very much the same look as they are just the European spec.

First i lined them up to judge if they would be ok ......

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Then i removed the old bars from the bike, extracted the switches and wiring, one of the locating pins was broken inside the switch but otherwise all ok, i took the opportunity to thin out the wiring of the left switch as i'm not using the 'dim indicators for sidelights' feature of the US models.

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Re-loomed the wiring and they went in to the bars really easily as the bars were correctly pre drilled..... unlike the lovely Renthal bars i fitted to the CB390 which not only were not drilled but also being aluminium were thick walled making getting the wires through 'interesting'

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test fitted to the bike, all good except the throttle is a little sticky and the light reluctant to turn back on after the starter is released, may need a new switch.

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I'm really pleased with the shape of them and the riding position is just a little more 'cafe' than with the originals :)

hoping for more deliveries in time for the weekend....

Steve
 

Sderbyshire

Into Sailing, classic Triumph cars and motorbikes.
I’ve chaged the thread title to reflect my plan for a period sympathetic racy restoration.

i’m aiming for making the bike a bit more sporty but in keeping with the period.

hence twin disk conversion but retaining the cb550 forks, lower bars but still correct for a european model.

i might change the indicators as i think they’re hideous.....

steve
 

Maritime

Well-Known Member
I agree on the indicators. I hate those ones. You can source ones that look very similar but at 1/4 the size in LED so just as bright or brighter. Give you a period look but much more streamlined.
 

pidjones

Well-Known Member
I love the Euro bars. Have you had the cover off of the alternator? Hope it has stayed dry. It looks like the two bad carbs were on the left side. Probably stored for years on the side stand with petcock open/leaky float and the water pulled into the fuel collected there.
 

Sderbyshire

Into Sailing, classic Triumph cars and motorbikes.
Not much progress to report but here’s a pic of how it’s looking ( from the good side !)

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twin disk brakes plumbed in but i’m having trouble getting any lever pressure. I rebuilt the master and tested on one caliper so i know it works, but even after pushing fluid up from the caliper bleed i can’t get any kind of pressure at the lever. Must be air in the system still.

i’ll pressure bleed it when i get my bleeder back from loaning it out before lockdown......

i’ve also epoxy glued and tapox sealed the old tank, expecting it to be a while before a replacement arrives this might allow some test running at least, nothing much lost if not.

one of my carbs is still overflowing, so i’ve ordered the ‘shaped’ bowl gaskets, and some jets, from 4into1 so will look at them again when those arrive.

also awaiting regrec from Sparckmoto, some Uni Pods, replacement indicators and headlamp mounts.

hoping to report more progress next week !

let me know if you have a decent tank, or exhaust can ( even the Mac replacement would be ok)

steve
 

pidjones

Well-Known Member
Have you checked the bowl overflow tubes for cracks? When you pull the bowl, fill it with isopropyl alcohol and see if it comes out. They are bad about the brass tube cracking.
 

Sderbyshire

Into Sailing, classic Triumph cars and motorbikes.
Have you checked the bowl overflow tubes for cracks? When you pull the bowl, fill it with isopropyl alcohol and see if it comes out. They are bad about the brass tube cracking.
Thanks, i did check the tubes by filling the bowls with petrol and they were ok.
pretty sure its a float / valve issue
 

Sderbyshire

Into Sailing, classic Triumph cars and motorbikes.
Investigated the lack of brake pressure and seems the master is not pumping.

strange as i rebuilt it and was working nicely when tested on a single caliper.

in the absence of my pressure bleeder i think i’ll take it off the bike, rig it up on the bench and suck fluid through it with a vacuum pump

i’m thinking maybe there’s a bit of crap in it, or seals upset from the reverse fluid pumping?

any other thoughts before i buy something to replace it !

steve
 

Sderbyshire

Into Sailing, classic Triumph cars and motorbikes.
So... i vacuumed the master cylinder, using a syringe sucking through half an old brake hose, and the master is pumping again !
now the ‘rebuilt’ second caliper is pissing out fluid !
and yes it dripped all over my newly painted disk , grrrrr

so i’ll rebuild that when i can get a new seal....
 

pidjones

Well-Known Member
I’m getting that way.... think the new master cylinder seals might be leaking now!
Make sure the secondary piston hasn't slipped forward past its bump on the rod. If not lubed up well with brake fluidfor assembly that can happen (maybe from vacuum bleeding or from getting initial fill).
 

Sderbyshire

Into Sailing, classic Triumph cars and motorbikes.
Make sure the secondary piston hasn't slipped forward past its bump on the rod. If not lubed up well with brake fluidfor assembly that can happen (maybe from vacuum bleeding or from getting initial fill).
Thanks for the tip, not sure what you mean by ‘secondary piston‘ though?
 

Sderbyshire

Into Sailing, classic Triumph cars and motorbikes.
In order to distract myself from the ‘bleedin brakes’ thought i’d mess about with the lights.

ordered some ridiculously cheap led indicators last week and they arrived today, so swapped out the 1970’s ‘Super Trooper’ indicators for the tiny leds, i like the look but will want better quality items.

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also did some CAD to mock up a mount for a new, smaller but not too small, tail light

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for the brakes i think i may replace the master cylinder, really needs a larger bore anyway so will see whats available that fits the bill.

i have many items on order, deliveries are being delayed quite a while at the moment, bloody virus !

steve
 

ex119x

Member
The M/C for the GL1000 works well on a double disced 550. That is what we used on our CB550F racebike with the 590 engine. Those brakes worked well enough to haul us down from top speed for turn 5 at Road America.
 

Sderbyshire

Into Sailing, classic Triumph cars and motorbikes.
The M/C for the GL1000 works well on a double disced 550. That is what we used on our CB550F racebike with the 590 engine. Those brakes worked well enough to haul us down from top speed for turn 5 at Road America.
thanks yes thats an option.
is that a 17mm diameter do you know, i think it is
 

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