Café au Lait
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- Jan 18, 2024
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- 294

This is about a ROAD bike - not about racing (again!!)There is a thing which many people do not seem to know about road racing - if a race circuit is half corners and half straights - when your bike is 15 MPH quicker in corners - to stay ahead of you, the others have to be 15 MPH quicker down the straights - but quicker in the corners gives a head-start down the straights. I used to race my 1958 Triton 500 against Z900 and H2 Kawasakis and still stay near them. Most of my racing was between 1969 and 1975. On a really big circuit, it becomes a different game. But my horror was about coming into corners too fast behind other bikes. With my bike, I could not back-off in corners.
Al, the thing is, the CB750 is different and needs to be learnt. It will impress as you explore it more. That said, I've no idea how good the original shocks were on the Honda vs. the Commando.I rode a CB750 when they first came to Australia, If I had never ridden a motorcycle they might have been OK. It felt like riding a brick. All of my Triumphs had race cams and handled better than the CB750. My best Triumph was actually a Tribsa 650. The BSA Gold Flash was a useless motorcycle, but my Tribsa had the fork yokes from a 1963 Bonneville with the BSA frame. My first race bike was a Triton - it did not handle as well as the Tribsa 650. But the CB750 was disgusting.
I don't think Norton sold many Atlas 750s. My mate had a Manxman - it was excellent.
Maybe so, but the brits did that before Honda I believe with the Scott.Yep - but Mr Honda got it very wrong with the CB750.
People joke about the maintenance-requiring flaws of the Commando but it's nothing compared to the CB750's major cock-up.
"let's put the hyvo chain in the middle - you know, between cylinders 2 and 3!"
Changing the Commando's primary chain is an absolute breeze compared to the Honda's primary!
There, you have to pull head & barrel off, then split the crankcases to pull the crankshaft out. I'm not sure if 2 conrods have to be removed to get the chain off the crankshaft, but I suspect so.
It's why you heard so many of them idling with a "chunk-chunka-chunka" as the worn chain snapped tight then loose. Better that than the humungous job to change it.
Kawasaki fixed that with gear-drive to the clutch - which all the other Jappa's then copied in succession - including Honda with the CB750F.
"let's put the hyvo chain in the middle - you know, between cylinders 2 and 3!"
Thanks Les, but the same issue exists - but must have been somewhere in the early "K" era that they changed to the toothed hyvo.The CB750 had two single chains not a Hyvo chain.
https://www.cmsnl.com/honda-cb750k0...346/chain-kit_00000kit0017/#compatible-models
but must have been somewhere in the early "K" era that they changed to the toothed hyvo.
But, A Commando was considered a race bike to many. The early Norton Factory ads for the 1968 Commando featured racers like Art Ninci and George Kerker road racing them with great success in AMA class racing and they and MC magazines pushed the 1/4 mile and braking abilities of the Commando. Many feel it is the First Superbike. I got into Commandos because of a friend's 1968 beating all comers in street racing, and my used 1970 S went to the 1/4 mile drag strips and was holding it's own against others in the mid1970s. A street bike that can race really earned the name Commando. The bike that stormed into the enemy camps, and took no prisoners. TC really inspired many and proved his Nortons could take on anyone in Top Fuel with his blistering times. For me a Commando is all about racing and winning over new friends and fans and showing how great a street bike can be. I know my bikes and racers impressed the old time racing greats and fans at the old Laconia track for the several years we got to race there.This is about a ROAD bike - not about racing (again!!)
The Commando can be a race winner, properly set up and ridden very few can keep up with one, with a few simple mods on the basically stock bike. I've seen my streetable bikes beat F -750 and Super Vintage bikes that had bigger engines, disc brakes and racing frames. And my bikes were very low tech and used easily sourced 1970s parts from junkyards. At the old original Laconia track and at NHIS , real old time racers and fans saw what a Commando could do. They thought the bikes just show ponies but the Commandos showed them what they were made of. To see Jerry Wood, Greg Nichols and Yvon Duhamel and all the others ride my Commandos was like watching a Willy Shoemaker ride a stallion like Man O' War. My bike ridden by Jerry Wood even took an FIM #1 plate by beating a 1000cc Guzzi with dual disc brakes in Heavy weight Super Vintage. Great racers gravitate to great bikes and can-do great things on them!
What I have found in general working on Japanese bikes is they are built like a watchCome on, both bikes have their maintenance foibles. My CB750 has 45,000 miles on it and the primary chain(s) is original and still in spec on its automatic tensioner. Same for the cam chain.
It took me 5 minutes to change the Honda main drive sprocket. How does that compare
No isolastics to renew, it doesn't vibrate. Undo and slide out the one piece axle and the rear wheel rolls out on the centre stand. The tank is 1 minute to remove: unlock seat and hinge up (stays up); ease clip off single fuel tap and pull off the fuel pipe; roll rubber retainer off rear of tank; slide tank off. Also, the horn is easy reach. A great disappointment though, only one oil (serving engine, gearbox and primary / clutch together) to argue about!
But, it has 4 carbs to clean and balance! Although, in fact that's not that tricky, access is easy and the gantry is nicely made and it slots together nice. And the carbs aren't Amals!
I've had the engine out for my restoration. A previous owner had taken off the cylinder head cover with a chisel and irreparably damaged the gasket surfaces. It leaked badly. It was a simple step by step exercise (using the very clear Honda workshop manual) to remove the engine and replace the head and cover (the bores were measured and honed by a local firm and I put new rings in, whilst I was there). I also stripped everything down for the frame etc. to be blasted and powder coated. Parts availability is fine. Ease of process must be good, for me to be able to do it. My rubber band push rod holders remained in the Commando drawer. Everything went back together like a jigsaw puzzle, even the 4 exhausts, which I was dreading. I did find my mechanical cam chain tensioner was seized. Emery cloth and Autosol on the plunger sorted it.
Tickover is even and free of chain slap above 1250rpm. So, that's where I set it. I change the oil 500 miles earlier than the Commando, but otherwise it's as easy to keep on top of as the Norton and just as nice to work on. Haven't found a Whitworth thread yet. I was tempted to put one on a bracket somewhere, to confuse a future owner.![]()
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I did my very modified XS1100 primary drive chain after 36,000 miles of merciless beating.What I have found in general working on Japanese bikes is they are built like a watch
They come apart like a watch and go back together like a watch
I've not often needed a special tool or had to force one apart or back together
I replaced the primary chain on my fj1200 just because I couldn't stand the jangling and snatching but it did have an extremely high mileage
It was a dead easy job to strip the engine and wrap the chain around the crank
I had an 1100 tooI did my very modified XS1100 primary drive chain after 36,000 miles of merciless beating.
Split the cases.