Folding Bikes - How fast is fast?

Hi all,

I guess this topic could be in a number of fora, but here I am given the fact that my one and only bicycle is a foldie.

The case is that in describing their folding ones, a number of guys, myself among them, speak of them as fast or slow. And I wonder what we mean by that and how we could measure how fast a bicycle is.

Of course, the ideal procedure would be to have a single individual --THE tester-- riding all the bikes on the same circuit under the same conditions.... Of course, the tester should not age, and should keep his physical conditions exactly the same over time... Frankly, not exactly doable.

Any ideas on how to asses this parameter? Hope this raise some interesting brain storm!

15 MPH or more is fast.

Fast is when I’m overtaking roadies on full size bikes.... done it several times and they don’t like it for some strange reason:D

Some hookey playing, half nuts fifteen year old passed me on his mountain bike this morning and challenged me to a race. I obliged him, and after a couple of hundred yards, I passed him when he tired. I got to 23 miles an hour on my Merc and kept it up until he was out of site. As I passed him, I shouted, 'I'll be 60 years old in two years time son. You need to get fitter.' This wasn't the triumph I may be making it sound - he was probably an escaped simpleton.

What is your point behind that figure? I can make 10 m/s on a flat surface, but in vacuum, that does not say much.


15 MPH or more is fast.

What is your point behind that figure? I can make 10 m/s on a flat surface, but in vacuum, that does not say much.

I think it was a joke. It may have been self deprecating irony. That's how I took it.

A significant fraction of the speed of light.

Speedo

A significant fraction of the speed of light.

Speedo

Well, light can travel around the circumference of the Earth 7 1/2 times in one second. I'll take it that a "significant fraction" of that would mean you could travel around the circumference of the Earth once in one second. I doubt that you could do that on a small-wheel folding bike. Maybe on a 700 cm. wheel...

Some hookey playing, half nuts fifteen year old passed me on his mountain bike this morning and challenged me to a race. I obliged him, and after a couple of hundred yards, I passed him when he tired. I got to 23 miles an hour on my Merc and kept it up until he was out of site. As I passed him, I shouted, 'I'll be 60 years old in two years time son. You need to get fitter.' This wasn't the triumph I may be making it sound - he was probably an escaped simpleton.

Hmmm.. I`d like to hear the boy telling HIS story.. :eek::eek::twitchy:

Some hookey playing, half nuts fifteen year old passed me on his mountain bike this morning and challenged me to a race. I obliged him, and after a couple of hundred yards, I passed him when he tired. I got to 23 miles an hour on my Merc and kept it up until he was out of site. As I passed him, I shouted, 'I'll be 60 years old in two years time son. You need to get fitter.' This wasn't the triumph I may be making it sound - he was probably an escaped simpleton.
Sure, on the Merc. I'd like to see you do it on the Strida clone.

The case is that in describing their folding ones, a number of guys, myself among them, speak of them as fast or slow. And I wonder what we mean by that and how we could measure how fast a bicycle is.
Well I have this device strapped to my handlebars that objectively measures how fast my bike is. But it doesn't work very well because when I'm riding with the local geriatric club they notice how fast it is, while riding with the local lycra louts they notice how slow it is. And the latter group has a curious blindness that prevents them from seeing I'm actually in front of them and I'm getting smaller.

Sure, on the Merc. I'd like to see you do it on the Strida clone.



Since I put the wireless speed on on the Strida clone, I once saw 14.3 on the clock while spinning my legs so fast they were a blur. It could be that I've put in too small a wheel circumference and that it was actually 12.3. :lol:

Hi all,

I guess this topic could be in a number of fora, but here I am given the fact that my one and only bicycle is a foldie.

The case is that in describing their folding ones, a number of guys, myself among them, speak of them as fast or slow. And I wonder what we mean by that and how we could measure how fast a bicycle is.

Of course, the ideal procedure would be to have a single individual --THE tester-- riding all the bikes on the same circuit under the same conditions.... Of course, the tester should not age, and should keep his physical conditions exactly the same over time... Frankly, not exactly doable.

Any ideas on how to asses this parameter? Hope this raise some interesting brain storm!

It's a fictitious parameter. IMO, you can't think of a bicycle like a car with a human engine because a human being doesn't produce power like an engine does. I think it's better to think of a bicycle as a human amplifier and while one amplifier may best match a certain human, I believe, a different amplifier will match another.

A significant fraction of the speed of light.

Speedo

Well, light can travel around the circumference of the Earth 7 1/2 times in one second. I'll take it that a "significant fraction" of that would mean you could travel around the circumference of the Earth once in one second. I doubt that you could do that on a small-wheel folding bike. Maybe on a 700 wheel...

When I go out for a ride I try to ride fast enough to get a measurable time dilation between the clock on my odometer and the clock in my house. I can usually succeed to the tune of a couple of minutes.

One time I went for a long ride on my titanium road bike, and got home only to find that the time dilation was big enough to leave my wife with a head full of gray hair and lots of wrinkles. Man was she PO'ed. I had to go out and do the ride in reverse to get back to my original time.

Speedo

When I go out for a ride I try to ride fast enough to get a measurable time dilation between the clock on my odometer and the clock in my house. I can usually succeed to the tune of a couple of minutes.

One time I went for a long ride on my titanium road bike, and got home only to find that the time dilation was big enough to leave my wife with a head full of gray hair and lots of wrinkles. Man was she PO'ed. I had to go out and do the ride in reverse to get back to my original time.

Speedo

No wonder your BF name is Speedo!

When I go out for a ride I try to ride fast enough to get a measurable time dilation between the clock on my odometer and the clock in my house. I can usually succeed to the tune of a couple of minutes.

One time I went for a long ride on my titanium road bike, and got home only to find that the time dilation was big enough to leave my wife with a head full of gray hair and lots of wrinkles. Man was she PO'ed. I had to go out and do the ride in reverse to get back to my original time.

SpeedoHmmm... I'm not yet ready to believe this story... so far, we know that time can't be shifted backwards. It can only go forwards slower or faster.

My own efforts on the Swift have resulted in a very accurate measurement of time flow rate of 1s/s. There are reports that a titanium bike may result in a different result, but never a negative value. So check your data and your own hair color again.

Hmmm... I'm not yet ready to believe this story... so far, we know that time can't be shifted backwards. It can only go forwards slower or faster.


You know it's funny, my wife denies having any recollection of me running in the house, hugging her, and showering her with kisses. But that makes sense because it was the future. However, I live in a neighborhood of identical houses, and for the last couple of months the old lady who lives next door has shrieked, then run into her house and locked the door behind her whenever she sees me.

Speedo

It seems we all are versed on the Special Relativity and on its applications to speeds well below c/10^6 ....

Anyway, although I know the average speed depends both on the rider and on the terrain, I think this value could give some idea of how fast a bicycle is. Let's not forget that the bicycle speed is mainly the final result of the friction it offers to both the air --aerodynamics-- and the ground --the tire factor--.

On my Giant MR4-R, my average speeds rages from 17.5 to 21.0 km/h (between 5 and 6 m/s), over distances between 10 and 40 km.

Iosepus

Hmmm. How to determine "fast" without a wind tunnel. Add weight inside the tubing until a selection of foldies weight the same. Add little parachutes to the rear of each one, drop them out of an airplane and see which hits a lake first ( I do assume you want them back). Better yet add a tracking GPS unit to each and see which accelerate faster and which have a higher terminal velocity. Problem solved.

my joey is the more fastest folding bike there is
specially cuz i ride it!
my GF believes her NWT is faster, but she only races me when i dont know about it.

Fast bikes seem to be efficient. Swap knobbly tyres for skinny racing tyres, and the bike feels much faster - just because it is more efficient. So factors such as wind resistance, rolling resistance, frame stiffness (and flex in the right place) affect the efficiency and therefore the speed of the bike.

I'm sorry, I appear to have posted something relatively sensible. I'll just pop back and change it, I'll be back before I left!

........ while riding with the local lycra louts they notice how slow it is. And the latter group has a curious blindness that prevents them from seeing I'm actually in front of them and I'm getting smaller.

.......you know, Jur, the invitation is still open to come up here with your Swift for my Sat morning "lycra lout" ride, you'd enjoy it.....fast paceline, breakaway attacks, uphill sprints and more attacks.
Not meaning to be offensive, but remember, there are pseudo "lycra louts" and there are real "lycra louts" ;)

:) Lycra louts is purely tongue-in-cheek, of course. Just this morning I switched to lycra lout mode myself. ;) (Only my legs felt like lead from a hard week of commuting, no sprints for me, just sedate cruising. :D

And I'd love to come over some day, perhaps we can make a definite date? Just not today, 46degC! :eek: Highest ever! :eek: :eek:

It seems we all are versed on the Special Relativity and on its applications to speeds well below c/10^6 ....

I just want to know what you guys are using to supercool your bottom brackets, because mine always melts.

I just want to know what you guys are using to supercool your bottom brackets, because mine always melts.

I've had this trouble on the Merc, but I found that filling it with liquid Nitrogen was only a short term solution as the gas boils off too quickly. Instead, I have welded cooling fins onto the BB, the front sprocket, and the SRF-3 hub. The chain survives because it gets a chance to cool on the bottom run. The rear sprocket is cooled by conduction via the driver into the finned hub.

Oh, good idea.

And Pedro's Superlubinal, right?

No problem here - I have an unobtanium BB.

Oh, good idea.

And Pedro's Superlubinal, right?
You must be thinking of White Lightning.

I find White Lightning separates into its components at speed.

rbrain - yes, correct. Bicycles are, in and of themselves, neither fast or slow. The parameter is efficiency.

tcs

I just want to know what you guys are using to supercool your bottom brackets, because mine always melts.

Dilithium crystals.

Speedo

I find White Lightning separates into its components at speed.Oh, that's twice now. Good, very good. :roflmao2:

My folder has the ability to slow and even stop the flow of time...

Hi all,


Of course, the ideal procedure would be to have a single individual --THE tester-- riding all the bikes on the same circuit under the same conditions.... Of course, the tester should not age, and should keep his physical conditions exactly the same over time... Frankly, not exactly doable.

Any ideas on how to asses this parameter? Hope this raise some interesting brain storm!

My addiction forces me to go through bikes like Dixie cups :twitchy:
My borish, unscientific non-quantifiable observations:
Here in inclinally challenged FL, 20+/- mph average is normal for my 10 mile commute.
My folder will do 27mph sprinting on the 80", 9th gear as judged by the police depts
'SLOW DOWN' lite-up box. This is about 2 mph faster than the MTB on the same section
and about 2mph slower than my 27" wheeled roadie. I think then it becomes a question
of effort Vs. distance.....The MTB will cease to be 'fast', quickly because pushing big weight
and tires becomes ponderous. The road bike will maintain a higher speed, longer due to less
rolling resistance and momentum in the larger wheels....the Folder, being very easy to pedal
but requiring a little more spinning because of the 20" tires is pretty close to the road bike in
overall efficient(?) type speed. So I guess if "fast" means being able to make it to your destination
based on time and energy spent in that time, my Folder is fast. Yes, I regularly pass roadies on A1A :)

To answer the question seriously - some folding bikes are faster than others. The more upright your seating posture, the more wind resistance you create, so a bike like a Friday or a Swift and some others that duplicate road bike geometry and allow you to tilt your torso forward, are faster than Bromptons or some Dahons where you sit bolt upright. As well, skinny, hard tires make a big difference, so slick tires in the 1"/25mm width range are faster than softer fat tires or knobby ones. And your top speed also depends on gearing, so a bike with a higher top gear will have a higher top speed.

I did the kessel run on my Brompton on 12 parsecs.

Dilithium crystals.

Speedo

Be sure to bring spares.

The more I read this thread, the more I don't understand why it's gotten this far... :)

My neighbours complain of my sonic boom.

:) Lycra louts is purely tongue-in-cheek, of course. Just this morning I switched to lycra lout mode myself. ;) (Only my legs felt like lead from a hard week of commuting, no sprints for me, just sedate cruising. :D

And I'd love to come over some day, perhaps we can make a definite date? Just not today, 46degC! :eek: Highest ever! :eek: :eek:


Sorry for not replying sooner, been helping a mate who lost part of his house in the fires. He lost a few sheds with valuable equipment, many trees as well, he lives on a semi rural green belt property. Our fire is believed to have been started by an mindless idiot flicking a smoke butt out the car window. Close to 100 houses lost and two people died. Scum bag looters have been arrested, so one night we were on security duty armed with a wooden handle from a wood splitter.......didn't get to use it :(

As for meeting up, let me heal up from the cracked ribs fron a MTB crash and get some training in, then we'll talk.

Sorry for not replying sooner, been helping a mate who lost part of his house in the fires. He lost a few sheds with valuable equipment, many trees as well, he lives on a semi rural green belt property. Our fire is believed to have been started by an mindless idiot flicking a smoke butt out the car window. Close to 100 houses lost and two people died. Scum bag looters have been arrested, so one night we were on security duty armed with a wooden handle from a wood splitter.......didn't get to use it :(

As for meeting up, let me heal up from the cracked ribs fron a MTB crash and get some training in, then we'll talk.Glad to hear you're OK, Steve.

^ ^^ Watching those horrific Victoria fires in the news here in NZ. So tragic. I've also just received an email from a good friend over there, fire got to about a km of his house. Apparently all of his mates survived, but they have all lost their homes! :(

Glad you guys are OK...

.

Workmate of mine lives in St Andrews... his house is OK but he has lost 2 friends and about 10 more of his mates are missing presumed dead.

The tales are heart-wrenching... like a father who raced into Kinglake town with his 2 kids to bring them to safety, returned to his bush home to save it, only to learn later his kids died when the entire town was razed to the ground.

Sorry to high jack the thread, but....

Sad news tonight of the unconfirmed deaths of another 142 people found today, bringing the total to 323...so far. This is beyond understanding. Very, very sad.
Some may think my son, a friend and I were foolish or foolhardy to disobey the police's roadblock and break through to our mate's house to help, we could only think of our mate, we wanted to help. We got through just after the main fire front went through so we were running through small ground fires, not that dangerous. Houses had been razed, everything was black, it was very hot, but we got there. Just to see our mate alive was worth the risk, he was pleased to see us. He is one of the fortunate ones to not lose everything. He is a very experienced fire fighter and says he's never seen anything like this.
Such was the intensity of the heat from the fire that a plastic water pipe buried 1 ft underground was melted, windscreens from work vehicles were melted like wax, anything made from alloy was melted into streams.
I learnt that you can lose your house but it can be rebuilt, cars can be lost but you can buy another, even valuable much loved possessions are not that important, but it takes years to build a family and that is nigh on impossible to replace.
I felt little, if any emotion while helping these past few days, we had a job to do and that was that, but today when my wife asked me if I was afraid, it hit home hard...all I could think about was helping my mate and my concern for his welfare, today I wept.

^ Not to worry... what's there to high jack about this thread anyway?

What get's me is the uncanny coincidence about the title of this thread. I saw a news clip showing a portion of the fire front traveling at speed over a mountain ridge. I might've heard it wrong, but I think I heard the report say the fire was advancing at about 90 kph! It certainly looked it! No wonder so many people got caught out and lost their lives.

Yeah... how fast is fast, alright!

.

Back in 1983 with the Ash Wednesday fires in Victoria, I heard of a motorcycle policeman fleeing the fires on the Great Ocean Road, he was traveling at those sort of speeds and could barely keep ahead of the fire front, I think he survived.

On Saturday we went around to my friend's house to collect our dogs as we had just returned home from a holiday. He was very quiet and distant in deep thought, when I quizzed him about it he said that the extreme heat and wind reminded him of Ash Wednesday, fires he bravely fought. We returned home only to hear of our fire a few hours later....makes you think, doesn't it.