Folding Bikes - Gearing on 16" Folders

I like my 16" Citizen Tokyo a lot. It fits in the small space I have in a closet. No-one on the subway has complained about it being in the way. It folds easily. It rides well. I'm having a ball riding again for the first time in years.

But it is also geared too low for the small wheels. Everybody passes me, and forget riding in a group - I can't keep up. It takes me an hour and fifteen minutes or so for about a 10 mile commute. So I'm saving my money for a faster folder.

I like the compactness of my 16" folder, so I probably want to stick with that size. I'm looking at a Dahon Curve or Curve SL, or a Downtube Mini. How is the gearing on these bikes? Can I manage 10 MPH or better on mostly flat terrain (I think I'm averaging 8 on the Tokyo)? Any other bikes I should consider? Brompton or Bike Friday are a bit pricey for me, but I could save up longer, I guess.

Can you share with us the gearing of your Tokyo? Chainring/sprocket tooth counts?

I haven't been on the Curve for ages, but I don't remember it being a particularly speedy example. What you'd want is probably an 8sp SA hub which is a 300% overdrive.

i have a citizen tokyo also and you're right about it being on the slow side as far as gears are concern. i decided to get myself a dahon boardwalk and it's a night and day difference for speed. i also got myself a dahon boardwalk d7 which i am preeping up and upgrading to make into a road bike. i will let you know how it goes. from what i have read, the dahon curve is faster compare to tokyo.

Can you share with us the gearing of your Tokyo? Chainring/sprocket tooth counts?

I haven't been on the Curve for ages, but I don't remember it being a particularly speedy example. What you'd want is probably an 8sp SA hub which is a 300% overdrive.

It is a 48t chainring, 14t sprocket in highest gear (6th). I may yet see what a LBS will charge me to replace the chainring with something bigger. I don't mind raising the lowest gears - 1st is so low that I can walk the bike faster up hills - and have. But in the long run, I think I'll want a better bike, hence the question.

Vic - The idea of going with a 20" folder like your Boardwalk did occur to me. The current Boardwalk available in the US is a S1 - single speed, but very affordable. Most of my commute is flat, but not all of it - every route home has at least one good-sized hill, except the route from the Metro when I do a multi-mode commute. Still, there are some 20" folders in the Dahon and Downtube lines with 7-8 speeds that might do. But as I said, I really like the compact fold of my 16" bike. I borrowed a friend's 20" folder when I was deciding what to buy, and it didn't fit in the closet where I keep the Tokyo - which fits nicely, but barely.

It is a 48t chainring, 14t sprocket in highest gear (6th).

Can that possibly be true? Assuming the Tokyo uses 305 tires rather than 349, that comes out to (http://sheldonbrown.com/gears/) 46.1 gear inches! That's ridiculously slow. With 349, it's 55.1 gear inches, still very slow. You absolutely sure the smallest sprocket is 14t?

Yep, I used to have a 6sp 14-28 freewheel. So it *does* exist.
Ideally, you'd want this:
http://harriscyclery.net/itemdetails.cfm?ID=742
Shimano 11-28 freewheel. But you'll have a better chance of winning the lottery.

Or I guess you could:
- Replace the crank with a 53t, and
- Replace the freewheel with something that starts at 13, or even old suntours with 12
But you'd be spending nearly the price difference to a DT Mini.

I'd go with a Curve D3. With the SA 3-speed Dahons, you can modify the gearing by making your own cogs, preferably out of shimano DX singlespeed cogs. Not sure if this is doable with other hubs.

I had the same problem with my Mission Genie and thought I was being smart getting an SRAM 3x7 hub. But the rim I've bought (I ordered a 16in) is bigger than the existing 16x1.75 I was using. (See the thread I've just started) So, just be careful.... like you, I think I'll just stick to the original plan and change the front chainring to a 53t.

Can that possibly be true? Assuming the Tokyo uses 305 tires rather than 349, that comes out to (http://sheldonbrown.com/gears/) 46.1 gear inches! That's ridiculously slow. With 349, it's 55.1 gear inches, still very slow. You absolutely sure the smallest sprocket is 14t?

Oh yes - I told you it was slow. :(

I may try the chaingear upgrade as a stopgap, but my question stands - are any of the other 16" folders I mentioned any better? I find it hard to believe that the 3-speed Curve is faster, but I'll believe it if someone who owns one says so.

Oh yes - I told you it was slow. :(

I may try the chaingear upgrade as a stopgap, but my question stands - are any of the other 16" folders I mentioned any better? I find it hard to believe that the 3-speed Curve is faster, but I'll believe it if someone who owns one says so.

Well, Dahon says (http://www.dahon.com/intl/curved3.htm) the Curve D3 is 41" to 77" -- basically its *lowest* gear is the size of the *highest* gear on the Tokyo, assuming my math was right. I still refuse to believe my math was right. But at 41" I wouldn't go up any hills on the D3.

The Curve SL is 31" to 90", a very good range.

The Mini comes in both Capreo and hub forms. I don't know the gear inches, but Downtube could tell you quickly.

My Bike Friday Tikit has gearing from 30 to 77, depending on the actual diameter of the tires. I could stand to have a lower low and a higher high. I might switch to a 9 speed. That would get me lower low, but a higher high is a problem because 11 is pretty much the smallest cog you can get except on the special Shimano Caprio. I could go to a 54 running an 11 30 cassette and end up with a 29 to 78--looking at it, it really isn't worth it.

But, you definitely need to get rid of that 14 as your smallest cog.

Good luck.

The Downtube Mini has a wide 300% range, and an exchangeable chainring so you can fine tune the gearing. Of all choices, it will give you the highest gearing you possibly want. Mine has in excess of 100" at the top. I can go very fast on it.

My Bike Friday Tikit has gearing from 30 to 77, depending on the actual diameter of the tires. I could stand to have a lower low and a higher high. I might switch to a 9 speed. That would get me lower low, but a higher high is a problem because 11 is pretty much the smallest cog you can get except on the special Shimano Caprio. I could go to a 54 running an 11 30 cassette and end up with a 29 to 78--looking at it, it really isn't worth it.

But, you definitely need to get rid of that 14 as your smallest cog.

Good luck.

my dahon boardwalk has 52T chainring and the 7 speeds are 11-30T. so it's basically 35 - 95 (am i right in my calculation).

thanks,
vic

my dahon boardwalk has 52T chainring and the 7 speeds are 11-30T. so it's basically 35 - 95 (am i right in my calculation).

According to Dahon (http://www.dahon.com/intl/boardwalkd7.htm), 34-92. But this is a 20" bike -- why is it being brought up?

I would get a wheel built with a cassette hub so you can use a easy to get cassette with an 11 tooth cog.
maybe look for a big ring from a timetrial bike.
I got a campag 56 tooth ring from ebay for a couple of quid

The Downtube Mini has a wide 300% range, and an exchangeable chainring so you can fine tune the gearing. Of all choices, it will give you the highest gearing you possibly want. Mine has in excess of 100" at the top. I can go very fast on it.

Thanks, Jur, that's the kind of information I'm looking for. Several have suggested upgrades to the Tokyo, and while I may look into a quick, cheap upgrade, I don't want to pour money into this bike - I'd rather save for a better bike. Just trying to figure out what I'm saving for.

According to Dahon (http://www.dahon.com/intl/boardwalkd7.htm), 34-92. But this is a 20" bike -- why is it being brought up?

is there a problem with this post ? is this against the forum's ethics ? the reason i brought this up is to give jcflack some options. we're helping him look for a folder that is speedier than his tokyo. why is it when the tikit's spec was brought up you didn't raise a finger......

is there a problem with this post ? is this against the forum's ethics ? the reason i brought this up is to give jcflack some options. we're helping him look for a folder that is speedier than his tokyo. why is it when the tikit's spec was brought up you didn't raise a finger......

The reason you were questioned about your comment is due to the original poster's following statement: "I like the compactness of my 16" folder, so I probably want to stick with that size." Naturally the person responding to you felt it was redundant to make comparisons with a 20" folder. You were trying to be helpful, and don't believe anyone should be giving you a hard time because of it.

Cheer up :)

Edward Wong III
Qile Duo VSTII 5 Speed 20" Folder

why not just 'copy' the dahon curve?
install a 3 speed internal gear, 14t cog, the original 48T or replace with a 52T, and off you go..
many of us here in indonesia, convert their cheap 16" folders, to a 3 speed hub (around 50 dollars here)
regarding gear inches, if you choose a 48T/14T combo, you will have a slightly lower gear inches than the Curve set up of 46t/13t....

or

if your rear frame spacing permits, install a capreo hub nad sproket (110 dollars here).
then you have a curve csL wannabe...

I may look into a quick, cheap upgrade...

...like a wheel with Shimano, SRAM or Sturmey-Archer 3-speed hub. Even with your existing 48T chainwheel you could achieve something like 36-50-68 gear inches, a useful range.


...I'd rather save for a better bike. Just trying to figure out what I'm saving for.

You're saving for a Brompton, of course!

HTH,
tcs

why not just 'copy' the dahon curve?
install a 3 speed internal gear, 14t cog, the original 48T or replace with a 52T, and off you go..
or
if your rear frame spacing permits, install a capreo hub and sprocket (110 dollars here).
then you have a curve SL wannabe...

Are you all saying that a 3-speed internal gear will be faster than the 48t/14t combo on my current bike? I KNOW that a Capreo would be MUCH faster. Either way, the wheel would need to be rebuilt or replaced, and I don't have the workspace or the mechanical skills to do it - LBS for this. I think replacement is required for the Capreo - my current wheel has 28 spokes, Capreo hubs have 36 holes.

I'm just not sure that I want to spend a lot of money upgrading the Tokyo that I could be saving to buy a Downtube Mini or Curve D3 at just over $500 or a Curve SL for around (gulp!) $850.

Before you give up ,check for loose screws on the web( It is the name of an online seller of bicycle small parts among the "small parts" are front sprockets.I bought a 60 Tooth from them a few years back.) You may simply need a larger front sprocket to make your folder livable.

Are you all saying that a 3-speed internal gear will be faster than the 48t/14t combo on my current bike?

yes; by quite a bit, actually. Your current top speed is 46.1 gear inches; an AW with a 13T cog would get you up to 66.2.
I KNOW that a Capreo would be MUCH faster. Yes, you'd get up to 71.8 inches. A lot better than what you have, but not much better than an AW.


Before you give up ,check for loose screws on the web( It is the name of an online seller of bicycle small parts among the "small parts" are front sprockets.I bought a 60 Tooth from them a few years back.) You may simply need a larger front sprocket to make your folder livable.

No, a 60T chain ring won't do the trick and anyway, it would entail a whole new crank since the Tokyo's chain ring is presumably swaged to the crank arm.

The cheapest solution is to get a used Sturmey Archer AW hub on ebay. The 28-hole variety, which is what you want, can be had for $20 - $30. Rebuild your back wheel with that, and you'll have a tolerable gear range.

The best solution is more expensive, but still way less than a new bike, is to get the new Sturmey Archer X-RF8w hub. Unless you (or your mechanic) is a bit daring, you'll probably need a new rim as well, since the hub is only available with 36 holes. It's an excellent hub, though. This would make your Tokyo very much like a Downtube Mini; better, in fact, if the Mini comes with the older model X-RF8 hub. And you should be able to get the whole thing done for less than half of what a new Mini costs.

A Shimano Nexus inter-4 hub will work, but wouldn't be much better than the SA AW. A Shimano Nexus Inter-7 or Inter-8 will not work unless you get a larger front chain ring, which could get very expensive.

A Rohloff would work, but would be very expensive.

I would get a wheel built with a cassette hub so you can use a easy to get cassette with an 11 tooth cog.
maybe look for a big ring from a timetrial bike.
I got a campag 56 tooth ring from ebay for a couple of quid

Not a good idea if you want to do it on the cheap! Bigger chain ring has to be the cheapest way.
p.s. if you do decide to go the cassette hub way, I have one made up on a 16in rim that you can have for £70 plus postage! All you will need is a 7 sp cassette to go on it. No darn good to me as the rim is too big.

... Bigger chain ring has to be the cheapest way. ...

No, really, it isn't.

If he changes the rear hub to an old SA AW with a 13T cog, he gets 66.3 gear inches.

If he leaves his existing rear wheel, he has to get a 69T chain ring to get the same ratio. And that's not going to be cheap.

The best solution is more expensive, but still way less than a new bike, is to get the new Sturmey Archer X-RF8w hub. Unless you (or your mechanic) is a bit daring, you'll probably need a new rim as well, since the hub is only available with 36 holes. It's an excellent hub, though.

My new Sturmey-Archer X-RK8(W) hub lasted maybe 250 miles before 3rd and 4th gears turned into great big neutrals. I've been waiting two weeks for a response from Sturmey about this problem.

The older design Sturmey 8 has a well earned reputation for early demise as well.

tcs

PS - FWIW, the X-RF8(W) model IHW8FXDSSAA1 has 28 spoke holes and a 120mm OLD.

The cheapest solution is to get a used Sturmey Archer AW hub on ebay. The 28-hole variety, which is what you want, can be had for $20 - $30. Rebuild your back wheel with that, and you'll have a tolerable gear range.

If you get one off ebay, make sure it comes complete with everything you need. Running down the extra small parts can really add up!

A brand new 28 spoke hole Sturmey AW three speed - with the improved NIG internal mechanism - is just $78 from biketoolsetc.com. This includes the hub, cable, shifter, guides, nuts, anti-rotation washers, band straps and mounts.

tcs

No connection to biketoolsetc other than I've been their customer.