CB650 "Parts Bin Special"

[pae]

Hi Andy, I have put a master cylinder that looks very similar (think mine came off a CB750F?) and it doesn't pump enough fluid to work with dual discs. At the moment I've taken one disc/caliper off and it's OK but could never get enough pressure with twin discs.

Haven't ridden it like that but I'm working on the assumption that the 750 it came off was single disc so single on the 650 will be OK, but obviously I'd rather find a 650 m/cyl and put it back to twin disc set-up.

I've bought a few hoses off this guy - good quality and service. http://myworld.ebay.co.uk/thracing09. He deals in Venhill hoses and fittings.

[andy120t]

Cheers Phil. I like the price of those hoses - & they are all stainless fittings too.

nb - There's an article in Back Street Heroes this month (page 56 or thereabouts) about brakes / master cylinders & braking forces which I really should read more closely. Apparently there is some science behind it all! & it may help me understand the best way & best m/cyl vs caliper set-up which will work. May be worth a look if you are still wrestling with your set-up.

[andy120t]

Polished my other fork today!!!! But no pictures of it....progress is slow, yet steady.

[pae]

Cheers Phil. I like the price of those hoses - & they are all stainless fittings too.

You'll like them, excellent quality and service every time, more than happy to recommend him (no association, just a happy customer)

There's an article in Back Street Heroes this month (page 56 or thereabouts) about brakes / master cylinders & braking forces which I really should read more closely. Apparently there is some science behind it all!

Yes, I remember vaguely from building off-road buggies and playing around with the size of master and wheel cylinders to adjust braking force and set the bias more towards the rear brakes, but can't recall it exactly off the top of my head (I'm going back 25 years now, crikey, had forgotten how long ago it was!).

[andy120t]

Jan 12th 2010.

New Year! & it

[Seamus]

Good progress Andy. Just make sure that the engine sprocket and the wheel sprocket are in line.

You can download a manual from the US site

http://forums.sohc4.net/index.php?topic=17788.0

May be worth a read.

Good luck

Seamus

[UK Pete]

Nice project Andy, cleaning the cylinders up is a real pain, i blasted mine but a friend of mine done his by submerging in a tank of thinners and leaving for a few days.
Pete

[pae]

Looking good,

Phil

[hector2800]

What about an F2 m/cylinder they run twin discs? Looking good by the way.

[matthewmosse]

These might be of use to you if you've not sourced some elsewhere

[andy120t]

Thanks Matt. PM'd you regarding these.

[andy120t]

 A quick update on progress (of sorts) but without any piccies at present.

Rolling chassis is making good progress - it's been a pain to match up the front axle but have now found a small engineering shop in Hertford who are willing to remake a spare rear axle to fit my forks. It means I'll have a 20mm front axle rather than a 15mm one so am also getting spacers and wheel centre tube made to fit. Speedo drive will be junked as I'm using a bicycle one.  Appropriate wheel bearings arrived from  www.simplybearings.co.uk - fast and efficient service & a great website....just forgot to order the head bearings too!

At the back, my swingarm appears to be dodgy. Scraping off paint reveals a lot of filler around the inner arms at the front (ie the inside of the "U" shaped  - and with paint underneath the filler, so I can only assume this isn't a factory moulding. Will post some piccies to get your thoughts on this soon but I'm now looking for an alternative s/arm. This one will do for now to get the bike built.

The rear axle is a  CB400 17mm one combined with the CB400 wheel. All slots together and just requires additional spacers - again, piccies to follow. One minor issue is that the chain adjuster slots are a little over 17mm so require a top hat spacer to fill this out. Also, my CB650 chain adjusters are far wider than the 550 swingarm so a bit of a gap which is currently filled with a 4mm spacer either side. Again, requires either the correct adjusters or a strengthening plate welding to the s/arm to handle the 650's spacers and associated power increase. I think this second option will be the chosen one.

 I plan to redo the rear with the larger CB650 20mm axle which will involve new bearings, centre tube and spacers, but also needs the brake hub plate maching out to take the bigger axle. Depending on time this may or may not happen before I get her on the road.

Sourced a disc and a CB750F2 aftermarket mudguard plus assorted spacers for

[andy120t]

Progress is slow and steady!  I've had a lot of parts delivered including exhaust, front mudguard, decent swingarm, loom, misc. bits & pieces. Piccies to follow.

Key thing has been sorting out the front axle. I've struggled to find one in the UK but then I found a cracking little machine shop in Hertford and decided I would have them machine down a spare rear axle to the right dimensions. Awesome spot - a one man band in a huge shed full of oily lathes and presses and lord knows what else. My favourite tool was a huge mechanical hacksaw that was steadily and slowly sawing through a huge lump of steel. Saw moving at about 60 cuts per minute so very relaxed - looked as if it would take all day to cut the block. The owners said it was a museum piece but he rather liked it & I was inclined to agree. Certainly more fun than looking on "fleabuy" for an axle.



In the photo the original front axle is at the back of the picture & you can see that the new one is far fatter (being a rear one originally). It's nicely stepped at one end to fit into the threaded fork bottom whilst the other end has a machined groove to take a retaining bolt.

I also needed to have wheel spacers and a bearing spacer for inside the wheel made up. In the foreground, the original bearing spacer is on the left and the new one on the right. You can also see the external spacers which will be either side of the wheel on the outside (I'm not running a speedo drive). They don't look too exciting but will do the job for the time being. Now I just need to make up the little tabs that hold the internal spacer in place, fit the wheel bearings and I'll be ready to roll!

[matthewmosse]

I have one of these old power haksaws, weighs a tonne but excellent bit of kit, shame is it needs welding and a new con rod to be back in commision. I use a clarke horizontal/ vertical one at the moment but it isn't a patch on the old saw. The motor on the bandsaw burnt out after 5 years very light use from new, I've now put the motor off the cast iron antique power hacksaw in it's place, still going after who knows how many years heaver use - it's so old that the motor is mounted using leather and steel as a vibration protection method. Quality kit. A lathe is a great piece of kit to have, I think mine has paid for itself several times over in the 5 or 6 years I've had it. Good to see progress is being made. A great project to see unfolding, right up my street, using whats available to make an interesting and useable bike.

[andy120t]

I've found time this weekend to complete my seat.  Materials required for this were a seat base (made a few weeks ago from the casing of an old boiler), a