Just a photo of tikit

Convenience of a folding bicycle

If you ask me what is it so great about folding bicycles as compared to normal bicycles, here it is:

In fact, two of such bicycles can be folded and stored within the boot of a mid-size sedan (not even MPV or SUV), one on each side of the boot.

What I practically do is to store my bicycle and also squeeze in my son's 14-inch kid bicycle, and we can go to a park to ride our bicycles. This is done without installing any bicycle rack at the back of my car.

Gear Inches

Most people would have the presumption that riding on a bicycle with smaller wheels equates to a "slower" riding experience as compared to one with larger wheels - with the same number of strides when pedaling, the distance travelled on a bicycle with smaller wheels would be less than that on a bicycle that has larger wheels.

This is not entirely true. A bicycle with a smaller 20-inch wheel size may not necessary be slower (or will travel less distance) than a bicycle that has a 26-inch wheel. Wheel size is certainly one of the important factors for cadence, but not the only factor.

What could be the other factor? The answer is gear inches.

From http://en.wikipedia.org/wiki/Gear_inches, gear inches can be expressed in terms of the following equation:

where

gi = gear inches

dwd = drive wheel diameter

fct = number of front chainring teeth

rct = number of rear cassette teeth

As you can see from the equation, the gear inches (gi) can be increased by using any one or all of the below:

1. using a rear cassette with lower teeth count (or decrease rct)
2. using a front chain ring with higher teeth count (or increase fct)
3. using a larger drive wheel (or increase dwd)

The modifications done to my Bike Friday tikit are item (2) and (3) and these make its "vital statistics" to become as follows:

1. the rear cassette has between 11 to 28 teeth (stock, unmodified)
2. the front chain ring has 60 teeth (upgraded from the previous 52 teeth)
3. the drive wheel is 18 inches (upgraded from the previous 16 inches)

My highest gear inch is therefore 18*60/11 = 98.2 and my lowest gear inch is therefore 18*60/28 = 38.6, which is pretty decent and comparable to a fast Tern Verge X20 or Tern Link P9, both having 20-inch wheels. I will have a tougher time climbing up steep slopes when riding at the lowest gear inches though, which I do not anticipate as a reality anyway.

Depending on the material cost that you need to incur, you may opt to use different combination of the above method to modify your gear inches.

MKS Promenade Ezy Pedals

I am using the MKS Promenade Ezy pedals on my Bike Friday tikit and I am loving it! These pedals can be dismantled and kept separately, making the folded bike look more compact. There is however a small issue which is the yellow plastic rings (shown here in the images) that are supposed to prevent the pedals from being dislodged/released accidentally. My bike is primarily black in color and having yellow rings is somewhat a mismatch.

What I have done is simply to remove the rings altogether and I did not have to worry about the pedals getting dislodged when riding (after 3 trips by now); the quick release design is "smart" enough to prevent the normal riding action from dislodging the pedals.

The rings are as shown here

A video showing how the quick release works (you will also appreciate how the yellow rings keep the quick release in check):

Bike Friday tikit

Have been wanting to blog about my Bike Friday tikit ever since I bought it from MyBikeShop in early Mar 2013. Here is a picture of it (click to enlarge) and below is the list of modifications that have been done to it.

1. Upgraded from the stock 16-inch rims with Schwalbe Marathon tyres to the 18-inch WheelSport Magic 355 rims with Schwalbe Kojak tyres.

2. Replaced the stock handle bar (plain old cylindrical) with the ergonomic Biologic - Arx™ Grips with T-Tool as well as replaced the grip shifter with the SRAM trigger-shifter.

3. Zixtro pouch under the bike saddle. (Can be used to keep accessories, including the bike pedals mentioned below) Note that Model-T tikit does not come with a saddle by default, so I got a simple one separately.

4. Upgraded the chain-ring from the stock 53T to the Vuelta 60T, together with a somewhat ugly chain-ring guard (chain-ring guard for 60T is pretty hard to find, so cannnot complain - according to the folks at MyBikeShop)

5. The MKS EZY bike pedal can be dismantled via quick release and then kept inside the saddle pouch - so cool! Bike pedals that are folded are like sore-thumbs sticking out of the folded bike. Having bike pedals that can be dismantled is definitely advantageous. Note that Model-T tikit does not ship with bike pedals by default.

6. Model-T tikit does not come with a kick-stand by default, as such I got a plain and simple one.