Topic: I lowered my standards

[Terry in Australia]

Speaking of calipers and (regrettably) completely irrelevant to the SOHC/4 discussion, a couple of months ago, I upgraded the brakes on my GEN1 Vmax to Hayabusa calipers.   Let's just say that brake improvements are one of the BEST things you can do for a vintage machine.   Since this photo was taken, I've added Galfer braided steel lines.

I'm not yet up to speed on the options for the 750 without changing fork lowers, but there "must" be adapter kits available.

Night and Day.

Nice work mate, I've got the same calipers on my VTR-1000F, and installed a pair on a set of Kawasaki Z1-B forks as I was going to install lester wheels which allowed a bit more bulk on the inside of the disc rotor. I installed a PM 4 piston caliper on the front of my 1994 Harley XLH1200 and it pulls it up magnificently. My K2 has dual drilled cast iron discs, braided lines and a Yamaha FJR1300 master cylinder, and it hauls the old four down as good as any modern bike (well, from the last 20 years at least) so I don't think it's necessary to go any further, but there is an aftermarket 4(?) piston caliper setup available from Beringer for SOHC4's, if you don't mind the hole it'll leave in your wallet. This will do me.

https://beringer-brakes.com/wp-content/uploads/2021/05/Catalogue-2021-EN-interactif-1.pdf

K2 Bitsa weekend 2-3 May 2021 1 by Terry Prendergast, on Flickr

Brilliant Terry!  If one is good, two must be better. Right fork tube lower is already machined to accept the adapter and caliper. Looks like I just need to source the parts!  I think I'm going to do this!  Did you simply run two lines from the master?

Honestly, this will probably be after I can get a couple of other items squared away. And perhaps after some of the heat in Arizona dies down...only 47C today.

(Apologies to Scott for hijacking his thread that incredible acquisition)

Thanks mate, and 47 deg C (116 Deg F) is close to one of the hottest days I've experienced here mate, that was the temp here in Victoria on "Black Saturday" in 2009 when nearly 200 souls were lost to massive bushfires across the state.

I run twin hoses from the Yamaha FJR1300 MC which is a way better MC to use with a twin disc setup, the OEM MC doesn't work as well with the setup as a later MC designed for modern bikes with 4 or 6 piston calipers, I've used several MC's over my 43 years of CB750 ownership, and the stock MC is way down the bottom of my list when it comes to powerful braking setups. Same/same for the OEM discs, drill them, surface grind them, do what you like, they won't work as well as cast iron rotors, full stop. If you decided to change your MC (and I strongly suggest you do) don't buy an FJR master unless it has a mirror mount, (some do, but not all) so use an XJR1200 or 1300 MC as that will have a mirror mount.

It'll also have a brake light switch on the MC already, so you don't need to use the OEM junction fitting below the headlight unless you want to, and I must say the single hose to the junction piece does look neater, but I didn't care as I built my bike from parts so originality wasn't an issue, so I never had the junction piece anyway. The right caliper bracket is just a left caliper bracket with the top "T" turned 180 degrees, and you need to space the bracket out from the forks so the swinging part is parallel with the disc rotor.

There's a thread on the conversion somewhere, which details the mod to the caliper (piece of cake) and speedo drive. (ditto) I won't steal any more of Scotts thread, but to give this a Ducati reference, I picked up a heap of parts for my BSA C11G 250 project from a guy today, and in his garage, beside his Porsche, his Corvette, his Ford Torino GT, his Norton 750 Commando and his Kawasaki Mach III 500, was his 1978 Ducati Darmah that he bought new. Of course it doesn't run, but it looks really nice as a piece of "Garage Art".

[desertrefugee]

Thank you Terry - and sorry Scott. 

The ONLY Duck I lust after is an old SS.  A 900 would be nice and a 750 would be nicer.  Neither of which is likely to be in my future. 

[Scott]

No worries at all guys.  I enjoy reading about the brake mod for the CB750.  I have the extra bracket and caliper ready to go plus I have one drilled cast iron disc.  Hopefully I can find another cast iron disc and then the master cylinder.  I have all the bits for a 1000CC engine for the CB750, but just need the motivation to finish it.

Speaking of Ducati SS, my mate who sent me the Darmah master cylinder just missed out on a 750SS for a stupid low price a few weeks ago.  He is living over seas part way through a 5 years contract and the prices where he is are around half the "asking price" of Australia.

[Scott]

Got the exhaust fitted and electronic ignition.

Have fired it up yet so can’t be 100% sure I wired up the ignition correctly.

[Scott]

Meant to put side on photo

[Medyo Bastos]

I got my cast iron drilled rotors from rob in oz. super quick shipping too!


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[Terry in Australia]

Yep, Hugh Robinson in Bathurst is excellent, I bought my discs from him, he does great work. If Scott needs one (or a matching pair with the same drill pattern/ size etc) he’s selling them on a changeover deal (you send him your old disc/s he’ll mount the new cast iron rotor onto your disc carrier) on Ebay for $190, or $150 just for the rotors but personally I’d rather have Hugh do the work, 40 bucks wouldn’t cover his labour.

[Scott]

Cool

I know who you're talking about.  I used to chat to him at a couple of race meetings, but lost his phone number.

I got my first disc of him and then he had to shut down for a bit.  Great news that he is up and running again.

I've actually got a couple of carriers ready for the disc and also the bolts with the oval shape nuts.

[Terry in Australia]

Cool

I know who you're talking about.  I used to chat to him at a couple of race meetings, but lost his phone number.

I got my first disc of him and then he had to shut down for a bit.  Great news that he is up and running again.

I've actually got a couple of carriers ready for the disc and also the bolts with the oval shape nuts.

Yep, he was pretty unpopular a few years ago when he and his ex had a bad breakup. She got everything, including his shop, and he couldn't even get in to return several customers bikes and parts, so he had to start over again, but he seems to be doing well. I also used his engine main bearings in My K2 when I rebuilt the engine, and that thing runs like a new bike.

[Scott]

Yeah I chatted with him on the phone when that was happening, but haven’t spoken since.

I looked up the disc on eBay and it has a different drill pattern to what he used to do. The one I have here has 36 holes in the outside row while the one he does now had about 20 I think.

Anyway the titanium side cover bolts turned up today.

[Scott]

Gently kicked it over and started 3rd kick.

Good to hear it running for the first time.

Obviously hooked up the electronic ignition correctly.

[MauiK3]

Very cool

[Scott]

Still waiting on the wheels maybe have them back Tuesday.

I’m going to run this tank, I think it adds a bit of style.

[Scott]

Got the wheels back freshly painted. Had to get tyres sent down from Brisbane (1 month wait otherwise)

Fuel tank liner dry, new fuel taps & hose.

Took it for it’s first ride in over 10 years today.  Just a short 10 minute shake down. Once I got a bit of oil through the clutch and it actually disengaged it was much more relaxing. 

Mate it sounds nice and feels good to ride. So stable on the road and so nice around corners.

Can’t wait until I get it out on the open road.

[Terry in Australia]

Looks good mate, well done.

[Stev-o]

I’m going to run this tank, I think it adds a bit of style.

That will have a few guys scratching their heads wondering what you have there!

Always wanted a vintage Duc....maybe one day.

[Scott]

I just put the CB750 tank on there so I could take a photo and send it to my one eyed Ducati mates.

I used to have a 900SS Ducati that I loved, but it hurt my back to ride it and I sold it for nearly 50% more than I bought it. I remember when I first bought it for $16K that I was spinning out how much money I spent on a motorbike and then within a year people were selling them for more.

I have a lot of mates that only ride Ducati's and one was selling this project that I picked up for a couple of grand under what it was maybe worth.

I've watched the price of these things slowly climb from even before I bought my 900SS.  So while this was not purchased solely as an investment, it's not a bad place to put some money compared to having it sit in the bank doing nothing.

Most parts are still available, but some engine parts are getting a bit pricey.

Stevo a vintage Ducati should definitely be on your "maybe one day list"

[Scott]

The Honda’s welcomed the Ducati and they’re all friends

[RAFster122s]

You start riding the Duc too much that can quickly change, women tend to be quite jealous... 😉
Nice looking trio...

[Scott]

Update on the Ducati

[ekpent]

 Why the tear down ?

[Terry in Australia]

Ha ha, you've never owned a bevel drive Ducati obviously Eric, "they all do that." My 1979 900SS looked just like Scott's Dramah when I sold it, with the engine in several boxes. Sorry to see it Scott, I hope you get it sorted.

[Scott]

I took it on a couple of short test rides when I got it going.  The second test ride I could hear a noise when stationary, it was a noise to make me look down at the engine, but hard to describe, maybe a whirring type of sound.

The noise came and went, but I figured it would only get worse and wouldn't fix itself, so out came the engine.

I have a mate who has truck loads of experience in these so I went to his place and labored for him while he pulled it down.

The crank shaft had no shims which is wrong, giving the crank too much end float.  I forget the name he gave the main bearings, but they need pre load. The balls don't run in the center of the race, they need a bit of pre load so it pushes the balls to run slightly off center where they are meant to be.

I'm thinking this was the noise.

I'll send all the bits and pieces to the appropriate places for blasting, polishing, plating, checking etc and then go back to my mates for the re assembly, so a pretty easy job for sure and I want to keep this bike so am happy that I can have confidence in the engine.

[Terry in Australia]

What are all your gears and gearbox bearings like Scott? Mine was so bad that the crank pin assembly was shot, and all of the hardening on the gears had gone. That was in 1990, and the bill was $3750 for parts, and probably a couple of thousand for labour.

I'd been posted back to Melbourne and the engine was at V2 Motorcycles in Brisbane, so I was on my way to the PO in the city to send V2 a money order for the work when I walked past a bike shop that had a minty 4 year old BMW K100RT with high mileage (60,000 miles) out the front. I took it for a test ride and loved it. The salesman said the price was $7K, I said I only had $5500, and he took it. I was a bit worried that something might be wrong with it because he was so quick to take my money, but no, I rode it to Canungra and back for a promotion course, and several rides to my home town, plus my daily commute to work, and it went like a bird.

I sent V2 $500 and they packed the engine into boxes and sent it down to me, and I sold the Duke at the Bendigo swap meet. It was an OK bike, but not a great bike.

[Scott]

I've found the bearing that was making the whirring noise I reckon.  The hardening on the gears is pretty good to excellent.

I will replace all bearings any way.  The crank has been sent away to be pressed apart and checked, it may only get new big end bearings, but time will tell.

I've only ridden this Darmah for about 4 reasonably short rides, but I love the feel of it.  It has heeps of torque, responds very well with the standard 32mm carbs and feels light and easier to steer than I remember the SS