I had a CBR900 of 1993 vintage, it had a 16" front wheel. I was never comfortable with its feedback from the front end. At Hondas first revision of the CBR900/929 it got the now standard 17" front wheel, I found that a big improvement.
I distinctly recall the vast difference between my 1979 GS1000E with a 19" front and my next bikes- two 1985 GS1150ES's, which had a 16" front wheels. Treacherous, like a bear on cat's paws! A wide but very short contact patch; I dropped the front on that heavy bike on an uphill rainy corner. It was quite a while before I came to trust the "new" 17" rims that we use today.
I never knew why Manx Nortons were so fast, until I rode one and felt what they do when accelerated hard when on a lean. Very few bikes oversteer similarly. It means the acceleration can be much stronger, and there is less lean. With almost any other motor the Manx Featherbed is too light in the front.
Didn't mention anything about steering geometry!!! Castor-angle, trail, rake, etc. Smaller wheel size also gives you a smaller trail and allows for tighter turning for the same lean angle.
All the things you mention were common knowledge back then as well. but experimentation of those things was restricted mostly to racing. Modern times bring it to the consumer market because the market has now matured to demand specific stuff, rather than motorcycles as a mode of transport or at the most spirited riding. What changed permanently was the tire sizes, in an evolutionary way, which even without the altering of Castor-angle, trail, rake, etc. make the motorcycle more proficient at handling.
1920's motorcycles and 23 and 27 Inch wheels. The wheels were an integral part of the suspension back then, when bikes were hard tail with girder forks suspension.
There was indeed a trend for wheels to start dropping in size from 70s 19 inch. There was a phase in the late 80's when the Japanese sports bikes even got down to 16inch wheels, especially on the front. Made for quicker steering, but came at the price of twitchy steering. 17 inch always seemed like the best compromise.
Also a fun thing to note was that due to these larger GYRO's the riders would counter lean without fear of high siding as much as todays riders on modern machines because the power output was lower comparably making them slower to modern motorcycles. Also, they needed much more unsettling forces to throw the weight as ismade clear by the Gyro point.
my dads cb 750f was the first street bike i ever rode when i was 14...loved that bike. my dad rode me around as a kid mainly on a triumph Bonneville but we spent a lot of time on that Honda too ...one thing is for sure, i ride nothing like my dad did. even though he is a trophy winning motocrosser from 1971,2 and 3 he lacked any aggression to his style and just rode the bike like the Fonz where he just kinda sat there and twisted the throttle , not leaning to hard or going to fast but if anyone made a mistake he'd take the trophy
As much for appearance as anything. That is what he was referring to when he spoke of the problem of the small wheel's appearance on the "sit up" superbike compared to the popular look of those same big wheeled Superbikes..Small wheel racing function vs big wheel form...This class was truly a Win on Sunday,Sell on Monday class and the Superbikes were track versions of existing showroom models. These big, naked multis had big tanks and tail pieces and simply looked cooler with big wheels...and went faster with small ones...
Every thing else been equal a smaller 17" wheel has about the same gyroscopic forces as a 19" wheel - although the 17 is lighter it is also spinning faster (rotates more for the same distance covered) at the same road speed. The big difference in the development of the 17" wheels was in tyre development. Low profile and radial construction reduced weight (and gyro forces and sprung suspension performance). Reduced sidewall flexing reduced heat and allowed gripper rubber with as good and better tyre life/mileage. Reduced sidewall flexing also allowed wider tyres and changed tyre profiles which changed the tip in rate and quickened steering inputs. At the same time improvements in overall chassis integrity (stronger frames, stronger large dia forks and axles, dampening control (F&R) etc) allowed the increased performance of the tyre to be exploited. IOW wider low profile tyres on old frames and suspensions would have lead to stability issues.
With a direct-drive wheel (before chain & gear drivetrains became practical), the only way to increase the gear-inches -- and go faster -- was to make the drive wheel bigger.
Quick answer, they didn't. They either had front and rear more or less the same size (19/19, 19/18, 18/18) or a 21-in front for off-road. A large front wheel is more able to cope with uneven and potholed roads. What suits a race bike does not necessarily suit a road bike. Go too small with the wheels and you get handling like a step-through scooter. Whilst a small wheel may suit race speeds, it doesn't really suit slow urban speeds. A bike that turns in fast at high speed might be considered twitchy on the road where a more relaxed ride and straight line stability might be preferred. Also consider that narrow tyres require less lean to get around the same bend as fat ones do. If you look at actual race bikes (e.g. IoM TT bikes), they do not have humongously fat tyres. They are generally 17-in too 120/70-17 front and 190/55-17 rear e.g. Dunlop D212 (road legal).
KC is the reason I subscribed to Cycle World. Great videos, thank you for all your past articles.
Another wonderful engineering/history lesson.
I had a CBR900 of 1993 vintage, it had a 16" front wheel. I was never comfortable with its feedback from the front end. At Hondas first revision of the CBR900/929 it got the now standard 17" front wheel, I found that a big improvement.
I distinctly recall the vast difference between my 1979 GS1000E with a 19" front and my next bikes- two 1985 GS1150ES's, which had a 16" front wheels. Treacherous, like a bear on cat's paws! A wide but very short contact patch; I dropped the front on that heavy bike on an uphill rainy corner. It was quite a while before I came to trust the "new" 17" rims that we use today.
83 GS 550E was my first pavement bike. The 16 front end was always great handling and stable....got in lots of trouble with it... 🤣🤣🤣
Awesome as always👍👍
I never knew why Manx Nortons were so fast, until I rode one and felt what they do when accelerated hard when on a lean. Very few bikes oversteer similarly. It means the acceleration can be much stronger, and there is less lean. With almost any other motor the Manx Featherbed is too light in the front.
Didn't mention anything about steering geometry!!! Castor-angle, trail, rake, etc. Smaller wheel size also gives you a smaller trail and allows for tighter turning for the same lean angle.
All the things you mention were common knowledge back then as well. but experimentation of those things was restricted mostly to racing. Modern times bring it to the consumer market because the market has now matured to demand specific stuff, rather than motorcycles as a mode of transport or at the most spirited riding.
What changed permanently was the tire sizes, in an evolutionary way, which even without the altering of Castor-angle, trail, rake, etc. make the motorcycle more proficient at handling.
1920's motorcycles and 23 and 27 Inch wheels. The wheels were an integral part of the suspension back then, when bikes were hard tail with girder forks suspension.
As soon as I saw KC I subscribed and liked THEN I watched the video. WE WANT MORE.
There was indeed a trend for wheels to start dropping in size from 70s 19 inch. There was a phase in the late 80's when the Japanese sports bikes even got down to 16inch wheels, especially on the front. Made for quicker steering, but came at the price of twitchy steering. 17 inch always seemed like the best compromise.
Also a fun thing to note was that due to these larger GYRO's the riders would counter lean without fear of high siding as much as todays riders on modern machines because the power output was lower comparably making them slower to modern motorcycles. Also, they needed much more unsettling forces to throw the weight as ismade clear by the Gyro point.
The music playing in these videos seams so diminutive.
The tunes Kevin
You are a great Man 😎
my dads cb 750f was the first street bike i ever rode when i was 14...loved that bike. my dad rode me around as a kid mainly on a triumph Bonneville but we spent a lot of time on that Honda too ...one thing is for sure, i ride nothing like my dad did. even though he is a trophy winning motocrosser from 1971,2 and 3 he lacked any aggression to his style and just rode the bike like the Fonz where he just kinda sat there and twisted the throttle , not leaning to hard or going to fast but if anyone made a mistake he'd take the trophy
I'll bet his racing line was perfect
Why did those bikes have large front wheels?
Also.
Are there any images of both side by side, I tried to Google them, but I couldn't find.
As much for appearance as anything. That is what he was referring to when he spoke of the problem of the small wheel's appearance on the "sit up" superbike compared to the popular look of those same big wheeled Superbikes..Small wheel racing function vs big wheel form...This class was truly a Win on Sunday,Sell on Monday class and the Superbikes were track versions of existing showroom models. These big, naked multis had big tanks and tail pieces and simply looked cooler with big wheels...and went faster with small ones...
Every thing else been equal a smaller 17" wheel has about the same gyroscopic forces as a 19" wheel - although the 17 is lighter it is also spinning faster (rotates more for the same distance covered) at the same road speed.
The big difference in the development of the 17" wheels was in tyre development. Low profile and radial construction reduced weight (and gyro forces and sprung suspension performance). Reduced sidewall flexing reduced heat and allowed gripper rubber with as good and better tyre life/mileage. Reduced sidewall flexing also allowed wider tyres and changed tyre profiles which changed the tip in rate and quickened steering inputs.
At the same time improvements in overall chassis integrity (stronger frames, stronger large dia forks and axles, dampening control (F&R) etc) allowed the increased performance of the tyre to be exploited. IOW wider low profile tyres on old frames and suspensions would have lead to stability issues.
Why did old timey bicycles have a giant front wheel and tiny rear?
With a direct-drive wheel (before chain & gear drivetrains became practical), the only way to increase the gear-inches -- and go faster -- was to make the drive wheel bigger.
Quick answer, they didn't. They either had front and rear more or less the same size (19/19, 19/18, 18/18) or a 21-in front for off-road. A large front wheel is more able to cope with uneven and potholed roads. What suits a race bike does not necessarily suit a road bike. Go too small with the wheels and you get handling like a step-through scooter. Whilst a small wheel may suit race speeds, it doesn't really suit slow urban speeds. A bike that turns in fast at high speed might be considered twitchy on the road where a more relaxed ride and straight line stability might be preferred.
Also consider that narrow tyres require less lean to get around the same bend as fat ones do. If you look at actual race bikes (e.g. IoM TT bikes), they do not have humongously fat tyres. They are generally 17-in too 120/70-17 front and 190/55-17 rear e.g. Dunlop D212 (road legal).
Mike Brink - haha and the girls would drop their pantaloons
Jeff Slade, read the first comment again, you missed the topic. At least you didn't spend like 30 minutes to write all of that.
Always great instructive videos but the those fucking bells drive you crazy
That’s why I fitted a 10” diameter front wheel to my Ducati superbike...it’s so much easier to park it out front of the hipster cafe
I see a honda comstar in the background...
..Kevin Cameron...awesome....if CW ever lets this guy go...I'll cancel my sub.......he's a 'wizard' in human form...!
I've admired his work for longer than you have.
Great!
I thought it was Charles Manson
Nice!!!
Markos Man and a bit to loud it’s distracting
Agree with the music.You do not need the music.The contact is interesting enough.
Play at 1.25x. You're welcome.
👍
Music is absolutely pathetic in background, this is Kevin Cameron bring respect here.
b.o.r.i.n.g.
No blaring generic metal music, no tattoos, no extraneous hipster talk.
Yeah, I see what you mean.
Irritating Muzak