Originally Posted by
Eusam
I strongly suggest your first upgrade be adding a front brake. I overheated the band brake on one of these bikes on a moderate hill, and I'm pretty light. You should also be able to install a rear caliper brake. I have a 3-speed Dahon of about the same age, and it uses a centerpull brake with a really long straddle cable. The brake is mounted above the chainstays, and the straddle cable goes all the way around the seat tube. You could probably use a similar setup, you would just need to find a place to mount a cable stop inside the front frame "triangle". I was never able to find a sidepull that worked on the rear, since it would have to fit between the crank arms.
Upgrading the gearing could be tricky. I've seen one with a 7-speed freewheel. Because the chainstays are short you couldn't actually use the outermost cog. The chainline was too extreme, and the chain would pop off of the front chainring. You might be able to get 7 speed to work if you shift the front sprocket outwards or re-dish the wheel, but getting anything with more speeds would be a stretch. If you try to use a freewheel with anything larger than a 28t cog, you may need to swap out the derailleur, which could cause derailleur ground clearance problems. An internally geared hub would be a good option, if you are up for building a wheel.
The 2nd thing I added was a front brake (see photo). The first was a kickstand. I also tried adding fenders and brought the bike to the co-op to help with making sure they would fit. I found a pair that were black anodized aluminum and the front fit, even with the brake, but the clearance was too tight under the fork crown and the tire would rub with any weight on the bike. I couldn't find a way to mount the rear. Besides the fenders, I picked up two brake levers (the original is worn and wobbly), one run of brake cable, a pair of blinkies, a rear kickstand and a six speed 13/28 rear freewheel all for $20 at the bike co-op...all used, or barely used except for the brake cable which was new. I already had some cable housings at home from the last project.
Having read about and personally experienced the ineffectiveness of Dahon's old band brakes, I planned on replacing the rear with a rim brake. Thanks for the tip I will use a center pull brake. However, for right now the rear band brakes works surprisingly well, and must have been refurbished at some point, because I have not encountered one on an old Dahon for sale that worked with any effectiveness.
I had thought about an internally geared hub, but wheel building is out of my realm of expertise, and the budget for this project won't allow for much more than used parts and me doing the work. If this bike with the upgraded gears is practical for commuting (It is currently too slow) then I may buy a new or newer 16-inch bike.
I also mounted an AIrZound Air horn like all my other commuters.
In the meantime, my next step is to clean and repack the rear hub, put on a new chain and install that 13/28 6 speed to see how that goes before getting the 11/28. Also, fenders that fit, if I am to use this bike for commuting.
