CBX Racing

[EMS]

Rick may be thinking of the H16 Andreas was working on at one time. It was two flat eights joined above each other and the valve train was intended to be gear driven. There may have been a brief discussion about it here.

[Rick Pope]

The fog is clearing and....... You're right. The V-12 was built with cam chains. George Dillaway (CBXtc?) was asking for cam gears from a late VFR so they could convert it to gears.

[FalldownPhil]

Phil,
I believe Andreas was upgrading from chains to gear cassettes as I recall. I am not sure if he ever completed that.
I remember being asked to help source the parts for the change.
Best,
Phil

[EMS]

Again, I don't think the gear drive was supposed to be for the CBX V12. He was working on a different, wild design. Goerge had asked me if I could find out what the Porsche Flat 8 ignition sequence/crank spacing was.

[Syscrush]

Oh yeah, gear driven cams...? There is heaps of room for either a stack of conventional gears or a rod and pinion set up in the existing cam chain space.

As someone who has daydreamed about this a lot, I think that the trickiest part would be dealing with the crank. There's a chain drive sprocket on the stock crank, so the options as I see them are:

1. Run a short chain from the crank to gears that drive the cams. Seems like the worst of both worlds.
2. Build up the stock crank by layering molten welding rod and then machine a gear out of the added material and heat treat it. Lots of potential to weaken and/or warp the crank between the welding and heat treating right in the middle - but looking at what Andy Millyard does with cams, it might be possible.
3. Add a 2-piece gear that's either welded or mechanically fastened in place. Seems like lots of potential for failure.
4. Cut the crank, weld on a 1-piece gear, and weld the crank back together. Seems like robbing Peter to pay Paul. Sure, now you have a one-piece gear, but how messed up will the crank be?
5. Full custom crank. Very high probability of working well, but must be very pricey.

The 2-piece design of the camshafts seems like it would open up more possibilities. Also, unless I'm mistaken, full custom cams are quite a bit cheaper than a custom crank. Going gear-driven would let you do 2 cams instead of 4, too - if you saw any benefit.

[Warwick Biggs]

I hesitate to venture into this discussion but what is the problem you are seeking to address?

Chain technology has improved dramatically since the 70's and why not just run a modern Morse chain? I noticed recently that Thierry Henriette has combined a Morse chain and a pinion gear ion his Brough Superior/AMB prototype.

A modern chain with tighter tolerances could just use the existing sprocket and if the cams and valves were significantly lighter then higher speeds should be possible, shouldn't they?

[Warwick Biggs]

But back to less esoteric matters and I have ordered a custom set of carbs for the lump from Jyo Bito San.

I am hoping that his design will solve most of my unresolved problems with the straight bank of CR Specials. In particular, cleaner gas flow, well engineered linkage on the outside of the bank instead of in the middle crammed up against the rear engine hangar, lighter throttle pull and easier set up with uniform rubbers and improved accessibility to things like the idle adjustment.

My existing carbs are destined for another life in a CBX somewhere else.

[Syscrush]

I hesitate to venture into this discussion but what is the problem you are seeking to address?

Well, you brought up the possibility of gear-driven cams for ultra-high RPM engines.

As far as my interest, the problem I'd be seeking to address is lack of cam gear whine.

Good luck with the new carb setup - I really hope it gets you what you need.

[Warwick Biggs]

Well actually it was you Phil who raised it originally and referenced it in the earlier thread and I quote:

Since posting this and doing a bit of follow-up research a year and a half ago, I've been daydreaming about a CBX converted to gear-driven cams. This is strictly in the daydream file, but I can't help wondering if it would be possible. Of course, everything is possible, it's just a matter of cost & reliability.

As for the 'whine', I think we can all be forgiven for that during the current health crisis, given the general paucity of good leadership. I remember when Kawasaki introduced their Z1 900 the motor had a very refined whine. Not all whines are created equal, the gear whine in an NC or RC30 also notable in this respect and then there are the belt whines, perhaps the least aurally satisfying altho' they can look good.

[Warwick Biggs]

I should have added thanks for the encouragement Phil. Not sure who is reading this in the current grim international environment. All I can say is people should feel encouraged that it is possible to defeat the virus if we all do the right thing and don't stand on ceremony. Community transmission has been eradicated in Oz despite an aggressive, seemingly out of control second wave, simply by the overwhelming majority of people being sensible and responsible in a total lock down.

Racing old motorcycles must seem incredibly indulgent and silly by comparison with a world wide pandemic but it is actually an example of up lifting human spirit that we see at the track. Respect and generosity of spirit are still stand out features of road racing. It is not easy to explain, just as it is not easy to explain why a 68 year old with arthritic hands and all the agues of old age should continue with such a dangerous and physically demanding sport, competing against much younger, fitter and more talented riders.

Of course, it helps a lot to have encouragement. So, many thanks to all the members who have offered words of encouragement. I really appreciate it even tho' we have never met other than virtually thru' ICOA. I'm working on the hand and looking forward to receiving my extra special set of bent JB CR Special carburetors for the CBX. I can't wait to see how they perform.

[Syscrush]

Good luck with your hand and the new carbs. Does your hand feel like you can train it? I know it can be hard to find the balance between sufficient training to see gains vs. overtraining & setbacks - I had some grip strength goals but found that I kept getting to a certain level of strength and then having to back off due to injury.

[Warwick Biggs]

Thanks Phil. Yes, same experience as you but very slowly improving I think. Just back from the track after 2 days and more than a dozen sessions on the GSXR. In the end the hand was starting to go a bit numb and I had to call it a day after missing a few shifts but I reckon I should be able to race the NC30 in February, touch wood. Attached is a pic of me in the pits looking pleased that I could manage 2 days altho' my times were nothing to write home about.

My custom carb set for the CBX has reached Sydney after nearly getting stuck in China with whom we are on the verge of hostilities. Hopefully the incoming President will help to reduce tensions because the last one did not act like the ally that Oz needed and we have been collateral damage in the US trade war. Strange coincidence too because the guy in the pits next to me today was from Taiwan and his girlfriend was from Hong Kong, both places really feeling the belligerence of Chinese nationalism.

After being smug about Oz eradicating Covid, Sydney now has another outbreak coming from the US. The airlines flatly refused to quarantine their flight crews and brought it in, so Sydney is going back into lockdown for Xmas. Thanks guys, you're real pals.

At the track our club president presented me with some 2 Wheels mags from '78-79 from the club's archives featuring the CBX's inaugural production race victories at Calder, Castrol 6 Hour, etc. I will scan them and try to post them here when I have a bit more time. Proddy racing was huge in Oz and NZ in the 70's.

[steve murdoch icoa #5322]

How about a pic of you astride The Lump the next time you have it at the track.

Certainly i am following along with all your track, mechanical and physical trials and tribulations.
The vast majority of it is out of my league but it doesn't mean i don't enjoy reading about it.

[Warwick Biggs]

Thanks Steve, I realise this is really no place for selfies on Suzukis but at this stage I have 2 problems.

My hand is still not fit enuf' to handle the clutch on the Lump. It's clutch is considerably heavier than the GSXR or the NC30. The gixxer trackie is really physio for my real racers and getting race fit. It is incredibly easy to ride and encouragingly, when I started it was easily the quickest bike in my group but I faded fast. Sad to say it is not just the consequence of the operation on my hand but arthritic wrists as well. I might try acupuncture but its a pity I can't just drill a hole in the joint and fit a grease nipple. How come our medicos haven't figured out our all too mortal joints yet?

The other problem is that the Lump is sans carbies. After I finally got them properly sorted (after 18 months of frustrations due to hard to spot hairline splits in the bottom of the rubbers causing some cylinders to run way too lean) I pulled them off and posted them off to another CBX racer (I won't name him without his permission but he hails from North Yorkshire and there are not a lot of us to pick from). My new Bito V line carbs are now stuck in Sydney and because of the lockdown there and slamming shut of borders, cancellation of flights, etc. I don't expect to see them b4 Xmas.

Hopefully, that still leaves time b4 the Classic Master of Mac Park in February to get them fitted and tuned and if the hand has improved enuf' by then and we don't have anymore Covid disruptions I will definitely give the Lump an outing then. I also need some coaching to sharpen up my riding and get me back into a competitive frame of mind. I find track days are really just practising to go slow as my mind wanders and I become distracted. That might sound odd but after a brief shot of adrenaline from a 150 mph wheel stand over a hitherto un-noticed bump in the main straight I just can't get excited going around and around with the weekend warriors. That sounds a bit pompous and I know others feel differently but I need a race or a concerted push to focus and really get going. A number of our members are young pros returning from the BSB, AMA, ASBK, etc. and they will be holding some coaching sessions over the holidays in the new year and that will help me get back up to race pace.

I promise to post some more CBX stuff shortly, so please stay tuned.

[Syscrush]

Would your CBX pass tech if you set it up so that you used the right foot pedal for clutch? Rear brake could be the left hand lever, or a thumb lever on either side, or linked to the right hand lever - I have no idea how often you use your rear brake on the track. If you use it a lot, this would not be of any help, but if you just need it to pass tech inspection, then offloading the clutch work to your right foot might help.