Monday, August 27, 2012

Dahon Vitesse X20-TT

It has been quite some time since I last upgraded a folding bike! On my Dahon Boardwalk X20-R, there is practically nothing left for me to upgrade. It is already a 20 speed folding bike with a mix of Shimano Ultegra and 105 components, with fast rolling wheels and tires. Even if I change out the components to even higher end stuff, it may only be marginally lighter and faster, probably not worth the cost involved. In any case, it is already a great bike, and I can find no fault with it.

But my hands are itchy after not upgrading a bike for some time, and the solution is to find another bike to upgrade! I technically have 4 bikes under my stable, with my own Dahon Boardwalk X20-R and Flamingo London S7R, and Bernice's Dahon Vitesse P18-TT and Pacific Cycles Carry Me.

Coincidentally, the Vitesse has been found to be lacking in proper gear ratios at the low end of the gear range. This is due to the custom 9 speed cassette that I previously assembled. You can check out this link for more info on the custom cassette.

12-28T 9 speed cassette, as previously seen on the Boardwalk

This 9 speed cassette has sprockets sizes of 12-13-14-15-16-17-19-23-28. The advantage of this combination is that it has a close spread of high gear ratios (12-17T) for comfortable cruising on flat roads, but also has a low 28T sprocket for those "friendly" slopes.

However, the disadvantage is that the jumps between the lower gears are quite large, as the sprocket size changes quite a lot from 19-23T and 23-28T. This can be a problem when climbing slopes, as the 23T sprocket is too hard, but when changing down to 28T, the difference is too great, and the pedaling momentum is lost.

To solve this issue, the best way is to have one more speed between the 23T and 28T sprocket. But I cannot do that on a 9 speed cassette without sacrificing a sprocket from the higher gear range (12-17T). The solution is to upgrade to 10 speeds!

A lot of people ask why do we want so many speeds? My answer is, it gives you more gear ratios which makes your pedaling more efficient and comfortable. It may not necessarily make you go faster, but you will have more gears to choose from and you will be more likely to find a gear that you can pedal on at a comfortable cadence.

Working from the previous iteration of the Dahon Vitesse P18-TT, the "ingredients" that I need to convert the bike into a 2X10 speed bike are listed as below:

Components needed to upgrade the Vitesse from 18 speeds to 20 speeds:
1) 10 speed road cassette
2) 2x10 speed road shifter
3) 10 speed road front derailleur (FD), double
4) 10 speed road chain

1) KMC MissingLink for 10 speed chains

Shimano Tiagra 4600 12-30T 10 speed cassette.

Why choose this? Wide ratio 12-13-14-15-17-19-21-24-27-30 cassette gives you many climbing gears. The 16T sprocket is sacrificed, but hopefully it is not a problem.

Shimano Tiagra 4600 2x10 speed road shifters

Why choose this? Instead of the higher end road shifters with internal shifter cable routing, I chose these shifters because of the external shifter cable routing. This is better for bullhorn bars to avoid excessive friction in the shifter cables.

Shimano 105 5700 double front derailleur

Why choose this? Because it matches the rear derailleur and crankset!

Shimano 10 speed chain

 KMC Reusable MissingLink for Shimano 10 speed chains

Note that these are not the only components that are needed to upgrade a bike from 9 to 10 speeds! You will also need a 10 speed rear derailleur and a 10 speed crankset. I did not need these for the Vitesse as it already has a Shimano 105 5600 Double Crankset and 105 5600 Rear Derailleur on it, which are both 10 speed components.

Sidetrack: During the upgrading of the cassette, I decided to take the chance to dismantle the rear hub and grease the internal pawl and ratchet mechanism

Rear hub with dirty grease. Still not too bad as it was last serviced at the beginning of this year.

Pawls on the freehub body

A clean ratchet! I just took some toilet paper and wiped away the old grease.

Similarly, the pawls and other parts are also cleaned.

As it says on the cover, you need special freehub grease. It is much lighter than normal grease, but more viscous than oil.

Generously coating the ratchet and pawls with freehub grease

After greasing the internals of the freehub mechanism, the freehub runs smoother and much more quietly. The freehub clicking sound will slowly return to its normal levels as the grease is displaced during normal usage.

Back to the Vitesse upgrade!

Sparkling new 10 speed cassette!

Go on, count it. You know you want to.

Tiagra 10 speed road shifters. Great shifters at an affordable price.

New Shimano 105 5700 FD with the older series Shimano 105 5600 53/39T crankset

Shimano 105 5600 series RD

I love the gleaming look of a clean drivetrain!

New bar tape in Bianchi Green! Definitely eye-catching.

Overall view of the Dahon Vitesse X20-TT

I have brought the bike out for a few test rides, and it rides awesomely well! In fact, sometimes I feel that it rides better than my own Boardwalk. With the new 12-30T cassette, the gear range is now 26"-88". Great for climbing, ready to tackle any slopes! The shifting is also buttery smooth, you got to try it to believe it. Personally, I feel that the shifting is at the Dura-Ace level, smooth, light and precise, especially for the front shifting.

It was a fun and great upgrade. Definitely worth the time, money and effort spent!


  1. Just read this n think of fixing same spec. Where can this setup be done n at what budget. Thanks

    1. it really depends a lot on what you currently have. from there, i can give u an estimate based on the same specs as this.

      MyBikeShop would be a good place to upgrade folding bikes.

  2. I have a polygon 16" .Just put on 53 teeth crank . Going to 20" seen OrI , Drake. Help to shorten my learning curve. Thanks

  3. I don't quite understand what you mean
    which bike model do you want to upgrade?

    1. Hi Steve, pls advise which 20" foldable to get new and with shimano tiagra or 105. I saw some of these foldable at the last ocbc event passIng at over 30kmh and intend to get one if possible. Tks

    2. Hi Steve, pls advise which 20" foldable to get new and with shimano tiagra or 105. I saw some of these foldable at the last ocbc event passIng at over 30kmh and intend to get one if possible. Tks

  4. Hi Steve, Im Pierre also ride quite often on LCSG Sunday ride the pass 2months, in this upgrade do you still need the spacer between the BB since now the cassette is a 10 spd, will the double chain ring havno problem of rubbing the FD right.

    Is there any problem shifting throught out the gear ranges? I intend to further zhng my Vittesse D7, but now already 10spd version to a 20speed version.

    Im buying a FD adaptor from ThorUSA instead of Litepro now awaiting for the part shipment.

    1. BB spacers are still there, the 10 speed cassette has a similar chainline to a 9 speed cassette. whether your bike will need spacer at the BB also depends on the crankset that you use. from what I know, in the newer series (6700, 5700), the crankset was improved to reduce chain rubbing when in the front-low rear-top gear combination.

      All gears can shift well, just cannot cross chain (front-low, rear at 9th or 10th speed). really depends a lot on the frame and component set up. but no major issue.

  5. hello steve.
    i plan to put my vitesse d7 a new crankset shimano 105 52/29t. will remove the 39t and will be installing 10 speed sprocket. a 1 x 10 set-up

    question, since i am not putting fd and 105 cranks do not have chain guides, is there a possibility that the chain will fall off the crank teeth if i shift to the biggest sprocket or smallest sprocket?

    do i need to put spacers on the BB's?

    1. you should continue using the inner chain guard that comes with the bike. this prevents the chain from dropping off on the inside of the chainring.

      You will also need a bashguard on the chainring, to prevent the chain from dropping off the outside. If you don't use a chainguard then there is quite a high possibility for the chain to drop off.

      There is no need for spacers on the BB since you are not installing an FD, the chainline is not that important.

  6. Hello Steve, posted this on another stream but it seems relevant here.
    I have a Dahon Helios SL with a Kinetix Comp on the back, the freewheel was waggling about a bit and occasionally binding, which would throw off the chain.
    I took it to my LBS to service and tighten, apparently they did that and packed it with grease, however it is now much worse. Is the freehub body replaceable? Am I in 'new wheel' territory? Should it be serviceable?

    1. Hi Marco i already replied in the other post. It takes a while for the comments to show up as I will need to approve them first.

  7. Hi would like to check do you still need to insert the spacer in the crankset to prevent the chain line rubbing the chain ring?

    1. I still added the spacer, but it only minimizes the rubbing, and does not completely eliminate the rubbing.