Topic: The Honda CB750 was NOT what you think

[Deltarider]

[...] I’ve learned to ride while keeping an eye on what’s way out front and behind me. The idea is to have enough room to avoid a situation requiring sudden braking or maneuvering. My dual discs (drilled) with stock size MC give me pretty good feel but I don’t want to push it and take unnecessary risks.
When I was 19, perhaps not so much😆

And right you are. I have had the opportunity to receive the same training motorcycle cops get. It was there, that I learned the finesses of braking.
Related to braking and police, here's a dilemma, some may recognise. My usual exit out of town is a dual lane road. On three locations there are traffic lights over the road. You are riding at 70 km/h, the legal speed, and in front of you the lights goes from green to orange. There is time to brake and come to a stop; not much, but you can. In your mirrors you see that commercial van, which was already tailgating, closing in even more on you, like if it wants to persuade you not to stop. What do you do? When you brake, will he brake? In time? In a split second you decide you don't want to risk becoming a casualty and you pass that light that maybe just has turned red the moment you pass it. When there is a camera, you can expect a hefty fine by post some weeks later. I have lived that dilemma quite some times and it is not comfortable. Know that in The Netherlands drivers of commercial vans can behave very irresponsible and even more when the van is the boss his.

[bryanj]

Delta, white van man exists everywhere not just Netherlands!

[PeWe]

That reminds me about Italy in the 2nd half of 80's when I rode my K6 there on vacations.
I think old Jugoslavia had the same traffic culture then.

Several times I did not stop at stop signs. Nobody else did, just drive if there was a gap.
I was sure that the cars behind me should hit me if doing such stupid things as stop for a silly stop sign!

[Don R]

The guy that bought me sandcast new traded in his BSA. His son said he wanted the 750 for the electric start. He wasn't a big guy and had trouble starting the big twin.
  I remember a road test that said you will come out of the bar and be on your way down the road before your buddies even get their bikes started. 

[jlh3rd]

lol
There's no need to get on a forum and boast that vintage hondas' brakes are junk....or the suspension is junk, or the clutch, or whatever, as if it's an expert talking and that's the final word.
yeah, you blast from stoplight to stoplight all the time, or scream into corners trying to emulate the pros on their heavily modified and tuned racing bikes, ...sure, the brakes are gonna fade, the suspension is gonna wobble, and clutch packs are gonna give way. That doesn't make 'em junk.
'cause they weren't.
I think the vintage Commandos are a great looking bike. Power to weight was slightly better than the 750. And, overall, the 1/4 mile time was a few tenths lower than the 750.  But those few tenths, for anyone that has dragged race, can be overcome by the rider's experience. The 750 was only a few mph faster, yes, but in an ad to a 20 something? That sells. Better handling I guess just didn't register.
The other 750 attributes as discussed were icing on the cake. There was lots of icing.
Why didn't the norton outsell? My guess ? Overall, it just wasn't that much better.

what's that joke about harleys? Something like 10 % of all harleys made are in a garage, the other 90% were left on a road somewhere .

[willbird]

lol
There's no need to get on a forum and boast that vintage hondas' brakes are junk....or the suspension is junk, or the clutch, or whatever, as if it's an expert talking and that's the final word.
yeah, you blast from stoplight to stoplight all the time, or scream into corners trying to emulate the pros on their heavily modified and tuned racing bikes, ...sure, the brakes are gonna fade, the suspension is gonna wobble, and clutch packs are gonna give way. That doesn't make 'em junk.
'cause they weren't.
I think the vintage Commandos are a great looking bike. Power to weight was slightly better than the 750. And, overall, the 1/4 mile time was a few tenths lower than the 750.  But those few tenths, for anyone that has dragged race, can be overcome by the rider's experience. The 750 was only a few mph faster, yes, but in an ad to a 20 something? That sells. Better handling I guess just didn't register.
The other 750 attributes as discussed were icing on the cake. There was lots of icing.
Why didn't the norton outsell? My guess ? Overall, it just wasn't that much better.

what's that joke about harleys? Something like 10 % of all harleys made are in a garage, the other 90% were left on a road somewhere .

Growing up in NW Ohio there were several Honda dealers to choose from, not sure if I ever heard of  Norton dealer ;-).

[PeWe]

I got the Swedish Classic Honda Club magazine today.

With CB750 commercial thought to be among the first released in USA.

Upper 2 pictures with strange side cover emblem that might show a preproduction bike.




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[jlh3rd]

yeah, interesting....and how fast is he going? is that 85 mph I see ?
...honda ads and pamphlets were the best. More icing...

[PeWe]

CB is not part of the name there......

[ekpent]

Here is a good picture and description Per of one like you showed (1968 prototype) with the different side covers and other things. https://www.motorcyclespecs.co.za/model/Honda/honda_cb750k_prototype_68.html

[HondaMan]

Here is a good picture and description Per of one like you showed (1968 prototype) with the different side covers and other things. https://www.motorcyclespecs.co.za/model/Honda/honda_cb750k_prototype_68.html

This one shows the blue one that was at the Nevada test, which was their week of flat-out riding between Lighthouse Point and Henderson, back-and-forth, with instructions including "...do not leave the red zone..." regarding the tachs. The clutch housing is different on the right side of those engines, too.

[PeWe]

Here is a good picture and description Per of one like you showed (1968 prototype) with the different side covers and other things. https://www.motorcyclespecs.co.za/model/Honda/honda_cb750k_prototype_68.html

This one shows the blue one that was at the Nevada test, which was their week of flat-out riding between Lighthouse Point and Henderson, back-and-forth, with instructions including "...do not leave the red zone..." regarding the tachs. The clutch housing is different on the right side of those engines, too.

Very interesting. Same bike.
Carbs look different too.
I wounder wich type?

[pekingduck]

Brakes on the SOHC bikes were not as "good" as the other discs of the period, as on Triumph, Norton, and most Ducati 750s, as they used a cast iron rotors (although triumph chrome-plated some of theirs).  At that time, Honda used very hard pad compound for long wear life. 

During that period, we found that changing to dual discs greatly lowered the lever pressures making the lever travel greater and the feel and control much better.  When smaller master cylinders from the CB350F, CB350G and CB360s came out, their smaller (1/2" compared to 14mm) pistons made a big difference with single discs.

I just looked at my box of '70-'78 round cap master cylinders and none had any markings that identified their size except a couple of '78 CB750K that were marked 14mm.  My recollection was that there were some marked 1/2", but I will continue my research.

[jlh3rd]

the 1969 Norton commando did not have disc brakes. That's the original topic of the OP. Everyone tries to play catchup after the fact.

[rotortiller]

Yup, when bike discs came out they were experimental by nature and drum brakes could still perform. So back to my point, stock SOHC brakes have always been weak contrary to what the video stated, back in the day they were not a vast improvement as suggested, that took some time and never happened much during the SOHC production run although they did double up on the discs and try different calipers. That poor progress seems to get people's underwear up into knots, something I enjoy no end lol. Other brands were in the same boat with poor experimental and underdeveloped new production disc brakes, in a nutshell. Carpy sells a bolt on lol.   Wonder how it works? https://carpyscaferacers.com/shop/shop-our-store/motorcycle-parts-accessories/honda-cb500-cb550-cb750-parts-upgrades/beringer-classic-caliper/

[pekingduck]

I agree, only the Honda had a viable hydraulic disc brake in 1969-1971, and all manufacturers were worried that the great braking power could toss a rider over the bars, or lock up the front brake easily, so high lever pressures were dictated by all. 

The Beringer caliper is not necessarily far superior, it just has 2 pistons that allow a stock master cylinder to operate with less lever pressure.  The right master cylinder size could allow the stock caliper to improve its results.

A friend of mine was the parts guy at a Honda dealer in Marina Del Rey, not too far from Honda in Gardena.  He says that back in 1967 or 1968, a pre-production Honda 750 four test bike stopped at the shop.  It was tested with a CB450 drum front wheel.

[seanbarney41]

 think Peking Duck has nailed it...as I have noticed on Kawasaki's too, but especially Honda's.  Don't worry about the caliper's and rotors, just get rid of that damn master cylinder

[Don R]

 I agree the discs were a revolution but still could have been better.

[PeWe]

Which master cylinder to buy then?
CB750 look or close.
If there is a new aftermarket version.

[scottly]

The Beringer caliper is not necessarily far superior, it just has 2 pistons that allow a stock master cylinder to operate with less lever pressure.

A caliper with 2 opposed pistons does NOT increase the clamping force over a single piston caliper with the same size piston, regardless of the master size. Just how big is the $600 Beringer caliper? I see the required 296mm rotor, which is the same diameter as stock, costs $660, but I didn't bother checking the price of the Beringer master.
I'm now using a Honda 32mm two piston caliper (both pistons on the same side, so the equivalent of 1 45+ mm piston) with a 320mm Ducati rotor and a stock K7 master. This combo is just as effective, if not more so, as 2 iron rotors with 38mm calipers, and is less than half the weight. The caliper cost about $25 from Bob's junkyard, and I bought two Duc rotors from a member here for $75.  

[Deltarider]

Honda has always been very prudent with brakes. I remember the days that almost all motorcycle manufacturers already had drilled disks, except Honda. I also remember BMW owners in particular did have to have their teared disks replaced under waranty by other ones. When Honda models came with drilled disks, they were good from the start.

[gearsoup]

A caliper with 2 opposed pistons does NOT increase the clamping force over a single piston caliper with the same size piston, regardless of the master size. Just how big is the $600 Beringer caliper? I see the required 296mm rotor, which is the same diameter as stock, costs $660, but I didn't bother checking the price of the Beringer master.
I'm now using a Honda 32mm two piston caliper (both pistons on the same side, so the equivalent of 1 45+ mm piston) with a 320mm Ducati rotor and a stock K7 master. This combo is just as effective, if not more so, as 2 iron rotors with 38mm calipers, and is less than half the weight. The caliper cost about $25 from Bob's junkyard, and I bought two Duc rotors from a member here for $75.

What did the Honda caliper come off of, as well as the Ducati disk? I'm tearing into my K8 this winter and looking to improve anything I can along the way (it's a hobby, I've got running bikes to ride if this takes longer than expected)

[ekpent]

Suzuki GT750 was the first in 1973 with dual discs up front. The 1972 4 shoe drum is sought out by vintage racers. OK- back to Honda stuff 

[rotortiller]

Curious pekingduck, did you personally ride the Beringer brake? ekpent, The GT750 had poor front brakes too.

[pekingduck]

No, I didn't try that Beringer caliper.