Folders tend to have small wheels and upright seating. Their obvious attraction, for some anyway, is their ability to fold for carrying onto mass transit or storing. However, I'm curious, would those of you who ride folders be willing to ride the same bike even if it didn't fold? In other words, is the bike size/shape attractive enough to you to consider it for commuting whether or not it folded (for those of you who don't need it to fold)?

Some people do, because there are in fact bikes out there that have the same form factor and appearance as folding bikes, but do not actually fold up.

Hi,

I agree that many folding bikes are often non-standard sizes and more upright positions (as they come). First, with some modifications, this issue can be greatly ameliorated. Second, some manufactures (Bike Friday, for example) try hard to make bikes that are sized to fit as a regular road bike would.

The folding bike I'm putting together now will fit me almost identically as my regular bike (although right now it is geared higher than my regular bike; I'm trying to fix that now).

For many people commuting, folders make a lot of sense. If it doesn't appeal to you, then don't get one.

Cheers,
Charles

Actually, I'm intrigued by them, especially some of those (photographed here) with front and rear racks, they look like great touring bikes. But, if I am to consider one of these, I certainly don't anticipate a need for folding which is why I asked.

No, not for me. I ride the folder because it can fold to a relatively small size (mine has 16" wheels), but if it didn't have the fold feature I would never have purchased it.

Rick / OCRR

people commonly tour them over here because you can bring them on the high speed (330kph/205mph) trains, whereas you can't do that with non-folding bikes.

No. in my opinion a full-size diamond frame bike is across the board superior to the small wheel folder (Dahon Speed P8) that i sometimes ride, with the sole exception that my small wheel folder can fold up real small. that convenience is the sole reason why i own such a bike.

in my opinion: bigger wheels = better ride.

Absolutely. If I could justify the cost, a Moulton TSR9 would be my primary bike. Quite frankly I find large wheels to be cumbersome. If I want to ride a bike with big hoops, I still have my Flying Pigeon PA-02 (635 hoops) for that experience.

+1. Even though my present folders are a one size fits all deal, I have them adjusted to suit my riding style... most notably flat bars set 2" below the top of my Brooks saddle. The Bike Friday that is being built for me at this time will fit me more like my favorite big wheeled road bike which has the same ergo's as my folders aside from a slightly extended reach (2.5") from saddle to bars.

The same applies to bottle generators... the smaller wheel spins faster and so does the dyno.

My new Moulton has very small wheels and a Shimano generator wired to a Halogen lamp... even at low speed the output is exceptional on what is typically used as a higher speed light.

I commute on a Brompton and Spez Tricross. If the Brompton does not fold, I don't think I would ever ride it :-)
The ride quality for me is better on the Tricross. The Brompton shape is OK, but it would not be enough to sway me to get one.

Hi,

No, it doesn't.

The output of a generator depends on how quickly it is being turned. If you have a hub generator and small wheels, the RPM of the wheel is higher and therefore your generator will be turning faster with a 20" wheel than a 799c wheel.

For bottle generators, it is how fast the tire is moving past the bottle that matters. So, at 10 mph, the outer edge of the tire is moving 10 MPH (relative to the fork) with 20" wheels and 700c wheels*. So, the bottle dynamo spins at the same rate regardless of the wheel size.

Cheers,
Charles

* If one wants to get nit-picky about this, since the dynamo runs on the sidewall and not the edge of the tire, it's almost certainly the case that the dynamo runs more slowly on the 20" wheel than 700c wheels as, say, 1/2" from the outer radius of a 20" wheel is a bigger change than 1/2" from the outer radius from a 700c wheel. But this is not a large effect.

+1.
To help illustrate, if you have two wheels, one with a 40" circumference and one with an 80" circumference (just for arguments sake and to simplify the explanation) the smaller wheel will have to turn twice to cover the same distance as the larger wheel, that being 80" of linear travel . A bottle dynamo will only sense a total of about 80" of travel in either case whereas a hub generator will sense two revolutions with the small wheel as opposed to one revolution with the larger wheel for the same distance traveled.

I had trouble at first, but my kids were doing it on their folders so I knew it could be done. So, I started practicing and whalla! It can be done and is useful n getting up and over hills etc.

Incorrect.

Your arguement is actually self defeating as if you state the the hub is spinning faster on a smaller wheel, then the smaller wheel is also moving at a higher rpm for a given speed than a larger wheel.

Comparing actual wheel sizes here...

A 406 mm wheel turns at 168 rpm at 10 miles per hour, a 622 turns at 123 rpm, at 30mph the 406 turns at 504 rpm and the 622 wheel turns at 368 rpm.

So if a bottle generator on a 700c wheel needs to have the bike rolling at 10 mph to bring it up to full power, the smaller wheel only has to be turning at 6.5 mph to spin the bottle generator at the same speed as this is where the rotational speeds of the wheels match.

Whether it is a hub generator or bottle dynamo, a smaller wheel does not have to turn as fast to deliver the same output as a larger wheel

In your math, you forgot to put the radius back into the equation for the bottle dynamo. It is the edge of the tire that turns the dynamo, so it's rotational speed times radius, which is just the linear speed.

I'm sorry, but you're simply wrong here. If you don't get the math, try it in real life.

"I can't tell you what works best but I can assure you that tires like the Maxxis Hookworm with a wrap around tread are far from ideal. I had to machine a wheel of vulcanized rubber and adhere it to the metal contact wheel on the bottle generator. It's larger diameter dealt with the tread much better and also reduced the tire diameter/generator ratio to reduce the drag a little and keep the voltage of the generator down to acceptable levels when running 406s at speed. I run DIY LED head/tail lights so I also had to include an ICVR (https://www.radioshack.com/product/in...ductId=2062599) (up to 35v in, 5v out), just in case, to keep my LEDs from burning out. Keep in mind that bottle generators are normally intended for use on larger wheels."

I believe that a bottle generators input and output are affected by angular speed / rpm as it is the sidewall that drives the generator and if that sidewall is passing at 168 rpm on a 20 inch wheel and 135 rpm on a 622 at the same linear speed of 10 mph that this does affect the input and output.

In practice it just means that a small wheel will deliver power differently than a larger wheel at the same speed... after you get up to a normal speed the output should be pretty much the same and then at higher speeds one might have to worry about lesser generators over-powering the lights and possibly burning them out.

I have not done any scientific testing but have observed that bottle generators on smaller wheels do seem to light up more brightly on smaller sized wheels at slightly lower speeds and like you found that they do seem to come with more drag.

The same thing happens when you use a standard hub generator on a smaller wheel and why Son makes a hub generator for 20 inch and smaller wheels that does not work properly with larger wheels due to low speed voltage issues.

Hi,

Please read what we are reading (BassNotBass did a pretty good job here). For hub generators, you are correct - it is angular speed (rotations per minute) that matter. For bottle generators, it is linear speed. It really is.

If you need to, work out how much the bottle generator wheel moves (assume it has a radius of 1/2 inch) against a 20" wheel that has rolled 5 feet and a 700 c wheel that has rolled 5 feet. You'll see that the bottle generator has turned the same number of times. If both wheels make it turn the same amount in the same distance, than both wheels will make it turn the same rotational speed if they are going the same linear speed.

None of this affects how well a folder works for commuting, so hopefully we can get back to the issue at hand. If you have questions, feel free to PM me.

Cheers,
Charles

Hey boys, take this somewhere else. We'd like to learn more about folders here.

Sixty Fiver, you failed to either read or acknowledge a later post where I admitted to having made a wrongful assumption (the one you quoted). My explanation above points out what I should have recognized in the first place and was pointed out by cplager, or at least I think it was him. Old dogs can learn new tricks as long as they're receptive to it instead of being adamant about being right... (that's directed towards myself).

Sorry...

So, folders are really cool. Go get a folder.

Bike Friday, for example, does a good job of making folding bicycles that are fit much more closely to a standard bicycle. And if the fit is the same, you'll be able to stand up the same. And even for other folders, there are things you can do to make them sized more appropriately to make standing up more practical.

i can stand and pedal on my Dahon Speed P8, but i'm careful not to get too aggressive with it because the long telescoping handle post stem certainly doesn't instill the same level of confidence as the headset/stem combo of a regular bike.

Yes... folders / small wheeled bicycles are awesome.

I have a somewhat modified Dahon Speed D7 with drop bars and my 13 mile commute on it is nearly identical to the commute on my two full size road bikes. I don't really hammer on any of my bikes, but I do ride a decent pace, and the folder compares quite favorably in terms of speed to the full size road bikes. I am sure that if you were racing, this would not be the case, but commuting is not racing for me, anyway.

I have a GreenZone steel folder. It was quite cheap new at $200 including a bag. I only use this bike when I have to go on the bus or other public transport method. I find folders because of the short wheel base to be "nimble" or "twitchy". Also the gearing ratio is not as good as my regular commuter (a 1980's Sears "Free Spirit") so I have a work a bit harder. this is just the nature of the folder beast. However it is so convenient to take on public transport or to store at home.