Folding Bikes - conversion of Dahon Vitesse to single-speed

I have a Dahon Vitesse D7 that I want to convert to a single speed (with coasting ability.) Could anyone recommend a good resource on how to do that? Would converting a Dahon be similar to any bikes, or is that specific things that I should look out for?

I`ve converted a 2007 Vitesse to single speed. The vitesse has a 110 over-locknut distance, as such a single speed BMX wheel works perfectly. Once you remove the shifter and cable you will need new grips as well. Depending on whether your Vitesse has a derailleur, you may need to shorten the chain.

Hace fun with your single speed!

The only folder-specific issue would be gearing. The "conventional" singlespeed gearing is about 68"-72". On a 20"-wheeled folder with a 16t BMX freewheel, this means fitting a 60" chainring.

2007 D7 (non HG) should be 130mm rear.
the easiest way to do it, is to buy a single speed kit and use that, as the rear wheel is a regular freehub style formula hub for shimano 7sp cassettes.

the first part to figure out is if you have a freewheel, or a freehub rear wheel.

if you have a freewheel, you would have to respace and redish the wheel, then it's all a matter of putting on a SS freewheel that is commonly available as the threads for it are most likely 1.375".

First of all what Vitesse model do you have? The HG has horizontal dropouts so you won't need a chain tensioner on that model.

The only folder-specific issue would be gearing. The "conventional" singlespeed gearing is about 68"-72". On a 20"-wheeled folder with a 16t BMX freewheel, this means fitting a 60" chainring.

??? There are 13T freewheels too.

Yeah but that means building a new wheel... a Vitesse D7 rear hub is the regular 1 3/8" threaded type IIRC, won't take a 13T FW.

thanks all for a lot of info but I am confused by the apparently contradictory info. My model is vitesse D7 2007, as in this link.

http://www.dahon.com/archive/2007/us/vitessed7.htm

My motive of changing to a single speed is to shave weight. I have recurring wrist pain and lifting the bike on and off commuter trains is not a pleasant experience. I would like to minimize the weight of the cassette, remove the derailleur assembly but need to keep the freewheel. Not sure how much weight I could save. If the total weight exceeds 1 pound, it could be worth it.

that's the exact one I have, it uses a shimano spline suntour cassette. 7sp width freehub 28h formula wheel
You will need a single speed conversion kit like this one: http://www.nashbar.com/bikes/Product_10053_10052_175492_-1_200300_200276_200429

btw, the cranks and bottom bracket in that thing is pretty heavy.

What else have you done to get the weight down? The rack alone weighs over a kilo. On my 2007 Vitesse D5 the best weight-saving upgrade I made was to switch the seatpost and saddle for a second-hand SDG I-beam model, cutting about half a kilo.

There are cheap & decent non-folding pedals that would cut 220 grams or so.

ditch the steel rack it comes stock with and use one of the aluminum arc racks.
you can also chop down the bars so they are a bit narrower.
if you upgrade the wheels and use the schwalbe durano mango or conti GP tyres, that can also save weight.


but my mods are more utilitarian rather than weight savings.

The handlebar on my vitesse was oddly heavy (238g), don't understand why Dahon would use components like that. I saved 100 grams switching it.

If you keep the seat post but remove the pump you'll shed 200 grams.

The front fender weights 126g.

Kickstand: 178g

thanks for all the weight saving tips. I don't know why, but my mind was so fixated on the gears that I actually never thought about changing the other parts! I will definitely look into these other components!

If I use a single speed conversion kit, I suppose using the tensioner is the only way to make sure the chain is taut? (assuming my frame has a vertical dropout) Do all tensioners work the same (I see some are "spring-loaded" and some aren't) and would backpedalling action derail the chain?

if the chain line is straight, it won't fall off.
you might have to play around with the tensioner as the dahon RD does not fit onto the frame like a normal derailer does and it has vertical drop outs.