If there was ever a motorcycle that changed the history of motorcycling, it is without a doubt the Honda CB750. In the October edition of Auto Motor Klassiek we have published a nice report about the restoration of this legendary machine, which has left its mark in the sands of time. Yes, this is the rare 'sandcast' version.
Why the 'Sandcast' Honda CB750 is so special
In the late 60s, Soichiro Honda presented its new four-cylinder to the world, a move that was seen as a bold and prophetic master plan. The Honda CB750 'sandcast' wasn't just any motorcycle; it was a phenomenon. With a displacement of 750 cc and a price tag of 6.500 guilders, it set the tone for the first superbike era and changed the perception of motorcycles as a means of transportation. The engine brand was not yet sure whether the engine would start, which is why the first production was delivered with sand-cast crankcases. That is a lot cheaper than having casting molds made.
Rare components, irreplaceable experiences
A “nut and bolt” restoration of a motorcycle can quickly entail costs of € 15.000 and higher. That makes the Honda CB750 'sandcast' edition, with its rare parts and nostalgic value, a pricey but rewarding venture. The Internet is a godsend for collectors and restorers, giving them access to those elusive components that were once cast in sand.
Twelve years of dedication
The story behind the 'barn find' in Groesbeek to the final restoration process is nothing less than an adventurous journey. The motorcycle had an original Dutch registration from January 1969, which was unusual as this model was not officially delivered to Dutch dealers. With plenty of extra parts included in the purchase, it was a ride full of surprises and near misses.
A timeline of change
The Honda CB750 underwent numerous changes over the years, from the first versions to the later K and F series. The K2, one of the best-selling models, is a great alternative for those who want to own a historic motorcycle without spending a fortune on a 'sandcast'.
Warning for adventurers
For those thinking of purchasing a Honda CB750 'sandcast', be warned: it may be a lengthy, costly experience, but ultimately it will yield a piece of motorcycle history worth its weight in gold.
Specifications that defy time
With its 67 hp at 8000 rpm and a top speed of 200 km/h, the CB750 was a technological marvel for its time. The specs may no longer matter, but the impact this motorcycle has had on the industry is undeniable.
Whether you are a motorcycle enthusiast, a collector or simply an admirer of technical innovation, the article of the Honda CB750 “sandcast” in Auto Motor Klassiek is a must read.
I had a CB750 four F1 from 77, I had it for 28 years and had no problem with the crankcase. They probably tightened the oil pan screw too much, a friend of mine's oil pan cracked at the thread, I solved this by welding it to aluminum and never had any problems again. If the bike had been standing still for a year due to illness, for example, it just took a few kicks and it started running. Had a nice machine.
In our club, someone switched from his Harley 69cc side valve to a Honda 750 in 750 and it was almost as expensive as a new Harley at the time. Only he rode everyone on a Harley snot in front of their eyes and never had to do any tinkering that we regularly had to do to keep riding. Top speed and power didn't count for us, but the fact that that thing was always running was enviable.
Jaap,
"Rare" …..? I have the idea that quite a few of them were sold in 69, so I bought a Laverda S from Raymakers that was immediately delivered with 2 of those Sandcast Hondas intended for 2 sons of a well-known herbalist at the time. Also had several acquaintances near Rotterdam who had one, but they were notorious for breaking the primary (I thought) chain. At the company where I worked, an old aluminum welder worked there and I had the broken crankcase welded for several acquaintances (at least if they had still been able to find the debris). The man always did it, but was anything but happy with it, it was gear for welding, the material was full of dirt. No idea what happened to the crankcases that could no longer be repaired, perhaps repaired with a more modern injection molded example.
The top speed also depends on the air resistance and certainly also on the ratios in the gearbox and the transmission. It is almost impossible to calculate the correct speeds purely theoretically without taking this into account.
The aerodynamics and predictions are sufficiently familiar to me. How do you sit on the machine? Upright like a tree or with its nose on the instrument shop. But you can still trust that every manufacturer, if he does not suffer from masochism, will conduct experiments with a streamlined person who sits on the machine as aerodynamically as possible to obtain the best possible values. Predictions are fun, but 'the proof of the pudding is the eating' and so they are ridden with it until the maximum scored value can be given as a statement. And that's why it goes. Is a value of 197 kmh with 67 hp realistic? I can't imagine that it concerns a calculated top speed. These are determined by measurements
What always surprises me is the specification of top speed in relation to power. Here again 200 km/h with 67 hp. Just looking it up, I found 2km/h less as a value, so yes. For comparison, we look at a BMW R1150R, which is stated to have 85 hp and a top speed of 197 km/h. So I'm not so sure whether the Japanese data really has any real value. Especially because I haven't driven a 69er CB750 myself. What I do know for certain, however, is that the R1150R fully lives up to its stated performance. Who can tell me more about his/her experiences with the performance of a CB750? It's just a sincere question.
It was not so much its power and top speed that impressed, many English and Italian beauties did the same, but its reliability.
Where others leaked or did so over time, the Honda remained dry.
While others were long overdue for an overhaul due to their outdated technology, the Honda just kept going and going... mileage of over a tonne is the rule rather than the exception.
That was the power of the Japanese stuff; Don't worry about whether you came home without complaints.