Now you can do all these, by mounting a front derailleur on your folding bike! To be more specific, a Dahon folding bike. Dahon does have a few folding bikes with more than 10 speeds, such as the Vitesse P18 (2x9 speeds), MuP24/Speed TR (3x8 speeds), Speed Pro TT (3x9 speeds) or the top of the range Vector X20 (2x10 speeds).
Aftermarket FD Adaptors for Dahon bikes. Adaptor for Speed/Vitesse frames on the left, adaptor for Mu frames on the right.
If you have bought one of these bikes, good for you! These bikes come with either double chainrings or a 3 speed internal hub to offer you lots of gears to suit all terrains. In this case, you don't need much modifications to go touring or climb slopes, since there are already plenty of speeds available.
However, like many of us, if you already own a Dahon folding bike with only 1 chainring upfront, it can be rather tough to get a low enough gearing to go up hills, yet retain a high gearing for downslope pedaling. Technically, it is possible to get a fairly large gear range with only 10 speeds (55T chainring with 11-36T cassette, giving a gear range of 31 to 100 gear inches). This is the setup found on the Dahon Vector X10, with a megarange 11-36T cassette.
However, by dividing the gear range of 31 to 100 among only 10 gears, this means that the jumps between gears can be very big! You will likely find yourself spinning out at a certain gear, yet the next higher gear slows your cadence way too much. Finding the right gear is especially important for long road trips, where maintaining a good, comfortable cadence is important.
Not the cassette found on the Vector X10, but this is a 11-36T cassette. Note the big jump between gears!
Therefore, besides looking at the gear range, the divisions between the gears are important too! To get smaller jumps between gears, and yet have a wide gear range, the easiest way is to have more gears! And this is where having multiple chainrings can be very useful.
However, after encountering the Mount Faber and Kent Ridge slopes, I found that even the lowest gear of 38 gear inches is not low enough for me! I prefer to spin the cranks instead of standing up and mashing the pedals. That was when I decided to get a front derailleur, so that I can switch between the 39T and 53T of my Shimano 105 crankset.
I know that it is possible to have double chainrings without a front derailleur, and change chainrings manually! However I find this quite impractical as it means that I will have to stop and change before a hill, and then change back before I go down the slope. It would be much easier to be able to change it while on the go!
Got the LitePro front derailleur (FD) adaptor, so that I can fix my own FD! Cyclopedia brings in LitePro stuff to Singapore, so it will be possible to check with them regarding the availability of the LitePro front derailleur adaptors. An adaptor is needed because the seat tube outer diameter for Dahon bikes are 40 or 41mm, much larger that the 34.9mm offered by the largest clamp on FD.
Of course it has to be gold in colour! Haha
Cable housing stopper at the bottom
This slot allows you to adjust your FD position forward or backward to suit the curvature of your chainring.
This slot allows the FD to be moved higher or lower. Of course, you can mount the entire adaptor higher or lower on the seat tube too.
Installing the adaptor was not easy at all! On a scale of 1 to 10, with 10 being the most difficult, I would rate this as a 9. Mounting the adaptor is not difficult, but to mount it correctly and tune the FD correctly are the difficult parts! It took me many hours to get it working satisfactorily, as installing the FD is new to me too, thus I was learning as I went along!
I initially tried to mount the LitePro FD (rated for 9 speeds) onto the adaptor, but quickly found that it would not be compatible with my chain (Dura-Ace 10 speed). Because the 10 speed chain is narrower that a 9 speed chain, when the FD cage moves it will not push the chain sufficiently to switch between the two chainrings.
Luckily I had bought a Shimano 105 5700 Front Derailleur, which was what I had planned to use in the first place.
Shimano 105 5700 Front Derailleur (Double, Brazed-on)
The brazed on version is needed to mount the FD onto the LitePro FD adaptor. Mounting the FD correctly with respect to the chainring is important, in order to ensure good shifting performance. Shall not go into the technical stuff here.
Tuning the FD is the difficult and tricky part. Even when the low limit screw of the FD is unscrewed, during the low-low combination (39T chainring with 28T sprocket), the chain will rub the inside of the FD cage. This is largely due the the FD adaptor itself restricting the lower limit of the FD. Luckily, this is not a serious problem as the chain noise is minimal and there seems to be very little drag resulting from the rubbing of the chain.
Pictures of the mounted LitePro FD adaptor and the Shimano 105 Front Derailleur shown below!
Gold adaptor goes well with my black crankset.
Black Shimano 105 FD fits my gold LitePro adaptor perfectly! Note how I clamped the end of the shifter cable to another bolt to prevent it from sticking out.
I used a LitePro Flexible V-Brake noodle at the shifter end, to enable me to adjust the cable tension.
LitePro V-Brake noodles, can be obtained from Cyclopedia.
Cable routing is tricky. Have to route the cable housing under the bottom bracket, and up towards the FD adaptor.
With the front derailleur, I don't need the bashguard to prevent chain drop anymore. This allows a better view of the 105 crankset!
Gold and black themed Boardwalk TT! Now with 18 speeds.
With the double chainrings, now my gear range is increased to 28 to 88 gear inches. Perhaps it does not sound like much, compared to the previous low gear of 38 gear inches. But this 10 gear inches can be very significant, and will determine whether you are able to pedal up the steep hills, or have to stop and push!