Monday, May 28, 2012

Journey of the Boardwalk: Part 24 - New Kojak Tires

It has been almost 2 months since I last blogged about my Dahon Boardwalk! The truth is, there isn't much more I can upgrade and write about, since I have already upgraded everything on the bike.

While browsing through some older photos of my Boardwalk, I realised that the Kojak tires have been on my bike for quite a while. Looking at the date on the photos, it has been 21 months since I first installed this pair of Kojak tires! Now, there are a few components on a bike that can be considered consumables, meaning that they will wear out and eventually have to be replaced. Here is a short list of these components:

1) Tires. Depending on the brand and type of tires, can typically last at least 2000km.
2) Brake Pads. Wear rate is very dependent on weather conditions and riding conditions, not so much on mileage. Brake pads wear much faster in the rain and in the city where braking is done more often.
3) Chain. Can usually last thousands of miles before stretching too much, but they are usually changed out earlier due to rust or bike upgrades.
4) Cassette & Chainring. They will eventually wear out, but it takes a lot of mileage to wear them out. The teeth will become sharp as the chain wears down the gear teeth.

Of course, actual wear rate and lifespan of these components depend a lot on riding conditions and frequency of maintenance.

For me, the cassette and chainring wear is not a problem since I have been upgrading my bike, and the Shimano Ultegra crankset and 105 cassette are relatively new. Same for the chain, switching from 7/8 to 9 and now 10 speed Dura-Ace 7901 chain. The brake pads are not so new, but the wear rate can be easily seen, and they look fine so far. Plenty of thickness and life left.

As for the Kojak tires, it is not so easy to detect wear. Unless you really use your tires until the rubber wears out and the carcass of the tire is seen, it is hard to tell that your tires are worn, especially if you are using slick tires with no treads.

My rough estimate puts the mileage of the Kojak tires at 3000+ km, probably close to 4000km. No problems with the tires so far, apart from being tight on the rims, making it a PITA to remove from the rims. This is partly due to the wire bead type of Kojak that I am using.

On the surface of the tires, I can actually see many small dots on the tires, much like the surface of a sponge cake. It is hard to estimate the remaining lifespan of the tires, but this is probably an excuse for me to change to new tires!

Besides the Schwalbe Kojaks, the other tires that I have considered are the Duranos, which are narrower and faster tires. The Duranos are 1.1" wide, compared to 1.35" width of the Kojaks. It is excellent if you are looking for pure speed, but since I do carry stuff and do some light touring with my Boardwalk, I felt that the Kojaks are still the best tires that suit my purpose. Narrow and slick enough for fast riding, and yet wide and cushy enough to handle some load and less than perfect roads. Lower tire pressure is required, which makes it less prone to punctures. In this case, there is no good reason to change to another type of tires, since the Kojaks work so well.

Small holes on the tires, a result of normal wear and tear

New Kojak tires!!! Love the smell of fresh rubber

The new Kojak tires has the words and logo printed with reflective paint, brilliant for side visibility at night.

The new Kojak logo design, compared to the older Kojak tire.

Comparing the surface of the new and old tires.

I got the Kojak tires with a Kevlar bead, which means that the tires can be folded, and the flexible bead also makes it easier to install and remove the tire from the rims. Moreover, the Kevlar version is lighter at 230g each, compared to 290g each for the wire bead version.

Together with the super light Schwalbe tubes (SV 6A), the tires and tubes weigh less than 600g in total, down from around 800g. Probably too little to feel while carrying the bike, but since these are rotating mass at the edge of the wheels, it might just make a little difference.

New tube and tire, ready to go onto the rim

Nice contrast, especially with a brand new tire!

Love the reflective words!

 Close up look at the Kojak logo and the Wheelsport logo

The rear wheel also gets a new tire

 I'm sure you can tell that I really like the glowing logo!

Cycled 20+ km on the new tires today, no problems at all. Feels the same, not faster or slower. Pleased with the new rubber on the bike, the tires are ready to roll for another 4000 to 5000km!


  1. Hi Steve,

    What is your recommend tire pressure to be used for your kind of riding profile

    1. For me I use about 80 PSI, max I use is 85

  2. Hi Steve,

    I enjoyed reading your blog so much! I think I already got poisoned by the journey of your boardwalk. Now I am starting to upgrade my Tern. If you dont mind, where did you get the kevlar bead kojak and tube and how much?



    1. Thanks for your support! I got them at Mybikeshop at I think $50-60 each.

    2. Thanks Steve and more power to your blog!

  3. Hey steve,

    I was wondering how much it cost for all upgrades from start to finish? What the total cost.

    1. not cheap la. you can find my list of components and find prices online to get an estimate. can't paste the link from my phone but the list is at the bottom of the Boardwalk X20 tab.

  4. Hi steve. Sorry but need some advice from u again. Wats ur view on this kojak tyres when lets say u travel on wet rd.

    As these kojak r slick tyres will it slip easily when u travel on wet rd?

    Thx again

    1. slick tires for cars will slip on wet roads, because the car tires have a flat profile that tends to trap water underneath during high speed and cause aquaplaning.

      bicycle tires are different. they have a rounded profile, similar to the hull of a boat that displaces water. bicycles also travel much slower, thus they don't really trap water and cause slippage.

      all tires, including slicks or knobblies, will slip on slippery surfaces such as algae, metal grilles or wet tiles. knobblies only have superior grip on uneven surfaces such as during off road.

      don't worry about using slick tires. there is sufficient grip on normal tarmac roads even when it is wet. it is the metal grilles and painted lines you have to worry about. even if you use tires with deep treads, you will still slip on wet metal surfaces.

  5. Ok I gt it. Thx for ur kind explanation. Will go ahead 4 e kojak

  6. Hi

    Can I check what r the options I have to upgrade from 9 speed to 10 speed on my P9?
    I was told P9 cannot upgrade the speed by one of the LBS I checked with

    1. If you want to go 10 speeds, you will need a rear derailleur adaptor. However the Tern bikes currently do not have a rear derailleur adaptor, as the stock Neos derailleur uses a non-standard mounting method. Technically speaking the Neos derailleur can also be used for 10 speeds, but the performance may not be very good.

  7. Hi,

    is it possible to mount a 1.35" width tyre on a 1.5" rim? Any implications?

  8. hi!

    glad to come accross your blog. it really is helpful to those looking to upgrade their foldies.

    i currently have a vert v8 (stock parts) and i'm considering to upgrade my wheelset & tires to wheelsport (preferrably black color) with kojack or durano tires. i intend to make my bike faster and hopefully shed a few grams off of it too.

    hope to get your views on my upgrade and any suggestion is much appreciated.


    - percy

    1. Hi Percy what is your question?

    2. hi steve!

      i would just like to get some advice with regards to my intended upgrade (wheelset & tires). any suggestion on how i could achieve a faster ride is appreciated as well.

    3. The Wheelsport wheels and Kojak tires are good and will definitely allow you to go faster. Changing to stiffer road cranksets will also help.

    4. thanks!
      i'll start to scout for a good deal for these components. hope i can get it ready by end Sep.