Safety margin bikes and tires

[12VoltInstalls]

because ‘mine’ would probably take 200hrs of work to get to the first ride.. ??

Yours is the twin?

Mine is the four cylinder engineering masterpiece that in race trim in the 1970s they would run at like 16,000rpm. No collector value for some reason but it’s cool. I shortened the blinker stalks, put a low euro bar on it (bmw style, not the low street racer bar), cut the (damaged) tailight bracket down and made a plate for a low Ducati Monster tailight, and painted the tank like the bicolored Nortons. 2HP less than the CB350 because of frictional losses of the additional two cylinders.

 

[Vigo]

Oh no you're right, mine is the twin, i think 73 or 74.. I forgot about the 4cyl one! I watched a video about them once. Never seen one in person..

 

[12VoltInstalls]

Never seen one in person..

They only imported like 10,000.
I own one complete, and two in parts, plus the ?? 1973 CB400F which I need to get functional. That’s a cool motor.

Btw the CB350F is the smallest multi cylinder motor ever put in production. The valves aren’t much bigger than golf tees.

 

[12VoltInstalls]

I bought it for $100 in 2015
It was crashed in 1996.

I fixed it and got it to run, painted it, and was on the road in like three weeks.

 

[Ellcon123]

They only imported like 10,000.
I own one complete, and two in parts, plus the ?? 1973 CB400F which I need to get functional. That’s a cool motor.

Btw the CB350F is the smallest multi cylinder motor ever put in production. The valves aren’t much bigger than golf tees.

FYI, there are 250cc 4 cylinder bikes!

 

[12VoltInstalls]

FYI, there are 250cc 4 cylinder bikes!

Not production. Those were purpose-built racing machines ?

 

[littleharbor2]

Yours is the twin?

Mine is the four cylinder engineering masterpiece that in race trim in the 1970s they would run at like 16,000rpm.

Those have to be some cute little pistons. No wonder you can get such high RPM's

 

[12VoltInstalls]

Those have to be some cute little pistons. No wonder you can get such high RPM's

It’s insane! Like pill bottles. And the cam runs directly in the aluminum head - no bearings. I can’t remember atm and I’m not going outside to look right now but from the factory 10,500rpm red line.
This is the motor and frame Honda put 450cc jugs on and wiped up the 500cc class in the early ‘70s. And again something stupid like 16,000 or 18,000rpm shift points. In like 1973; crazy!

 

[MattiFin]

Not production. Those were purpose-built racing machines ?

Benelli 254 and 304, moto guzzi 254 and honda cbr250f were all production street bikes. Edit: you can add also Suzuki, Yamaha and Kawasaki to list.

Kawasaki even has currently 250cc 4cyl in production but it is aimed for south-east asian market.

 

[Mattb4]

...

I teach automotive students about tires and explain that you really can't trust any tire manufacturer's statements about at what age a tire should be replaced, which in my opinion is at about 5-6 years. If one of them takes the high road and says 'a tire's tractive performance falls off severely after 6 years, therefore you should replace them at that point regardless of tread depth etc' then some other less scrupulous tire manufacturer is going to run an ad saying 'our tires last 70% longer than leading competitors!' just because they 'claim' their tires can go 10 years with no data as to how they come to that conclusion.

...

I just got done this morning ordering 3 new tires for my 1-ton truck due to the age of the old ones. The front two tires are 8.5 years old and the spare has a date code of 1209 (12th week 2009). Seems a shame because the tread is in great shape and no cracks in the rubber. Just a matter of safety based on standard rubber decay rates. Stuff wears out. And the tires were cheap ones when I bought them.

 

[Ellcon123]

Not production. Those were purpose-built racing machines ?

These are road registered but no longer in production. Can only imagine what the internals are like.

Before the ZX-25R — All the Four-Cylinder 250cc Motorcycles

All the four-cylinder 250cc motorcycles of the past — the CBR250RR, ZX-2R, GSX250F, and the FZR250.

motofomo.com

 

[Browneye]

Yours is the twin?

Mine is the four cylinder engineering masterpiece that in race trim in the 1970s they would run at like 16,000rpm. No collector value for some reason but it’s cool. I shortened the blinker stalks, put a low euro bar on it (bmw style, not the low street racer bar), cut the (damaged) tailight bracket down and made a plate for a low Ducati Monster tailight, and painted the tank like the bicolored Nortons. 2HP less than the CB350 because of frictional losses of the additional two cylinders.

I had one of those....back in the seventies. It was my first road bike. Rode bikes for over fifty years - now all history. ?

Oh, and for OP - cuz if you over-volt your solar controller you'll burn it up. It's really quite simple. LOL

 

[12VoltInstalls]

FYI, there are 250cc 4 cylinder bikes!

Time period. Honda designed these for production in ~1971

Not much that happened many moons later is not really relevant to 1971

 

[MattiFin]

Time period. Honda designed these for production in ~1971

Not much that happened many moons later is not really relevant to 1971

”

They only imported like 10,000.
I own one complete, and two in parts, plus the ?? 1973 CB400F which I need to get functional. That’s a cool motor.

Btw the CB350F is the smallest multi cylinder motor ever put in production. The valves aren’t much bigger than golf tees.”

ever put in production before 1970’s or what?

 

[12VoltInstalls]

ever put in production before 1970’s or what?

You could change is to was and add “that was” before put in production

It’s still a fact no matter what glitzmos we have 2020s. I’m not sure what the point is here.

 

[D71]

Not production. Those were purpose-built racing machines ?

 

[12VoltInstalls]

These are road registered but no longer in production. Can only imagine what the internals are like.

Before the ZX-25R — All the Four-Cylinder 250cc Motorcycles

All the four-cylinder 250cc motorcycles of the past — the CBR250RR, ZX-2R, GSX250F, and the FZR250.

motofomo.com

The link says, “There are however some disadvantages to owning an older four-cylinder 250cc bike like the below.”

“Older?” Those are newer bikes to me, the total metamorphosis that occurred 1979 or so and continues in that tradition to today.

From the link: those are 1980+ and that is like comparing Star Trek to the moon landing.

From wikipedia: “At the time, the CB350F was the smallest capacity four cylinder motorcycle ever to enter into full-scale production. There were no changes to the 1973 model, but Honda designated the 1974 bike the CB350F1”

All its contemporaries in the 250-400cc range were not road bikes but rather were amazing purpose-built contrivances like the 1960s 250cc six cylinder which is one of the most quintessential sounds emitted from a motorcycle ever.

 

[D71]

The link says, “There are however some disadvantages to owning an older four-cylinder 250cc bike like the below.”

“Older?” Those are newer bikes to me, the total metamorphosis that occurred 1979 or so and continues in that tradition to today.

From the link: those are 1980+ and that is like comparing Star Trek to the moon landing.

From wikipedia: “At the time, the CB350F was the smallest capacity four cylinder motorcycle ever to enter into full-scale production. There were no changes to the 1973 model, but Honda designated the 1974 bike the CB350F1”

All its contemporaries in the 250-400cc range were not road bikes but rather were amazing purpose-built contrivances like the 1960s 250cc six cylinder which is one of the most quintessential sounds emitted from a motorcycle ever.

Go ride an old Kawasaki 2 stroke 500cc triple. Then know Kawasaki made a 2 stroke 750 triple. The Yamaha rd350 - rd400 2 strokes were legend. The brakes tires and handling were the hold backs. They were very fun to ride. Never got to ride 750 kawasaki.... but everyone said it was much faster then 500. Sometimes you can still find 500 triple.

if you step way back there was the Vincent Black Shadow.

 

[12VoltInstalls]

These are road registered but no longer in production. Can only imagine what the internals are like.

Before the ZX-25R — All the Four-Cylinder 250cc Motorcycles

All the four-cylinder 250cc motorcycles of the past — the CBR250RR, ZX-2R, GSX250F, and the FZR250.

motofomo.com

The link says, “There are however some disadvantages to owning an older four-cylinder 250cc bike like the below.”

“Older?” Those are newer bikes to me, the total metamorphosis that occurred 1979 or so and continues in that tradition to today.

From the link: those are 1980+ and that is like comparing Star Trek to the moon landing.

From wikipedia: “At the time, the CB350F was the smallest capacity four cylinder motorcycle ever to enter into full-scale production. There were no changes to the 1973 model, but Honda designated the 1974 bike the CB350F1”

All its contemporaries in the 250-400cc range were not road bikes but rather were amazing purpose-built contrivances

 

[D71]

I don't remember many 4 cylinder small displacement bikes .... most were parallel and V twins. Thumpers too.
Believe it or not a 400cc motorcycle was a big bike or thought of that way for a while. The Honda 350 four and 750 four changed a lot. The Kawasaki took the crown with their 900. I had an old honda 305 scrambler. Twin.. it was fun to ride. The roads were not real good back then either.
The old Japanese motorcycles are hard to get parts when restoring..... lot of the fasteners were junk too. They strip...or would break....Dissimilar metal corrosion for fasteners and such. Steel fasteners in aluminum does weird things..dissimilar metals. I think the Japanese never meant for them to be disassembled and maybe even considered motorcycles disposable with affordable future replacements.
I was also a big fan of 2 stroke Yamaha. Have ridden motorcycles for long time. Had several version of 750 four to include 812 yoshimura engine kit. Pops Yoshimura was involved in a lot of racing designs. My last crotch rocket was the 1983 Honda V45 interceptor the power delivery was incredible like 2 bikes in 1. Ridden some of the new ones but never owned one. A 600cc crotch rocket is real fast now compared to old.

Racing has been a driving factor for developments. Tires were a biggie for development.

The zero motorcycle and other electric bikes seem interesting. With tesla car it can toast most super car. Are there any electric bikes that can do the same to gas power crotch rocket motorcycles?
Think this bike is crazy expensive and seen it on youtube about year ago.

ALL the current parallel twin motorcycles being developed and sold again is very interesting.
The Triumph Rocket would be a blast to ride - 3 cylinder engine with wheels - monster torque.

got any pictures of your bikes? i don't have many pictures left most were damaged ruined over the years never digitized.

This is my Harley clone that built .... interesting to wheelie on a big bike. This is a torque monster and dyno right at 100hp with 6 speed. paint is actually polished buffed powder coat.
Over the years noticed ppl that rode mostly at warp speed are not around anymore.

 

[12VoltInstalls]

This was apparently before I melded in the Ducati monster tailight but after the euro-style bars. And before it got run over in a parking lot and totaled - thankfully without me on it. The tank was a fun paint job.

As I bought it, crashed:

 

[Batvette]

Every motorcycle I owned, in order:

 

[Batvette]

The last, FJ1100, was the most well balanced, comfortable yet still fast, machine of its era. The CX500TC was a steaming pile of poop.

 

[12VoltInstalls]

FJ1100, was the most well balanced, comfortable yet still fast, machine

That is definitely in the top ten bikes of all time. 2nd gear failure rate was the only negative. Maybe top five at any price or age?