King of the Hill 2012: New Drivetrain Setup

In less than a week's time, there will be a major LCSG event, which is the King of the Hill ride. For those who are not in the know, it is a ride which brings you up many of the hills along the southern part of Singapore. Some of the slopes include the NUS campus, Kent Ridge park, Telok Blangah heights, Bukit Chandu and Mount Faber. Usually it will be quite a challenge tackling just a couple of these, but when you try to ride all of them in a single morning, this is where the fun really starts!

Looking back at the blog post I wrote last year regarding the 2011 edition of the King of the Hill, I was surprised at how much my bike has changed since then! Click through the link to see what I did to prepare the bike for the King of the Hill ride last year.

The biggest difference between last year and this year is that I now have a front double system! Which means that I have a 39T chainring to drop into when I climb the slopes. With a 2x10 speed 53/39T and 12-27T drivetrain and 20" wheels, my current gearing is 29" - 88". This is better than what I used last year: 45T front chainring and 12-28T cassette at the rear, with a gearing of 32" - 75".

Even so, I still find the Kent Ridge slope challenging, even with a low gear of 29". I have always wanted to try cycling up the slope on a lower gear, and the King of the Hill ride gives me the perfect chance to try out a different gearing setup.

Since my engine is not that strong, I have decided to modify the bike temporarily to make it easier for me to climb the slopes. I don't like to stand and mash the pedals when I climb slopes, as it puts a lot of stress on the folding joints. This means I will need either stronger legs or lower gears to pedal up steep slopes.

After comtemplating a few options, I realised that the easiest way for me to achieve lower gearing is to use a larger cassette. Other 10 speed cassette options would include the 12-30T Tiagra cassette, or 11-32/11-34T MTB cassettes. In the end, I decided to go all the way and change to a 11-34T MTB cassette, as a 12-30T cassette would not make much of a difference.

Shimano SLX 10 Speed Cassette, HG81-10 (11-34)

Separate parts of the cassette. The largest 3 sprockets are mounted on an aluminium alloy carrier to reduce weight.

 11-13-15-17-19-21-23-26-30-34 10 speed cassette

Technically speaking, a road cassette and MTB cassette are quite similar, as the spacing between each sprocket is similar. Thus there is no problem swapping out my road cassette with this MTB cassette.

However, it is not as straightforward as just changing the cassette! The short cage Ultegra RD cannot be used as it will not reach the large 34T sprocket on the cassette. Also, the chain capacity of a short cage RD will not be sufficient to cater for the difference in gears. Therefore, a different RD is required.

Since I have a road shifter (Shimano 105), it will be best to use a road RD, so that the cable pull ratio is compatible. It is possible to use a MTB RD with a road shifter, but shifting performance will not be ideal as the pull ratios differ a bit.

Shimano Tiagra 10 Speed Long Cage RD

The Shimano Tiagra 10 speed RD was chosen because it is tested to be able to support up to a 32T sprocket. For me, it will be pushing the limits to use it on a 34T sprocket, but I will give it a try. The long cage is needed to absorb the big difference in chain length between the front-top-rear-low and front-low-rear-top gear combination. As I do not plan to use this low gearing setup extensively, there is no need to get more expensive higher end models.

A new 10 speed chain is also required as the chain needs to be longer to cater for the larger 34T sprocket. Either a road or MTB 10 speed chain should work fine.

Installation and Troubleshooting

First thing to do is to remove the current cassette and put on the 11-34T cassette.

The cassette looks really huge compared to the wheels!

A close up of the cassette. There are larger jumps between gears as compared to a road cassette.

As seen when mounted on the bike

The aluminium alloy carrier to reduce the weight of the cassette. Saves about 90 grams as compared to the cheaper version (HG62-10) without alloy carrier.

So far, installation has been pretty straightforward. However, installing and tuning the RD proved to be much tricker (as expected). The main issue comes from the difficulty of reaching the large 34T sprocket, as the RD is not designed to reach such a big sprocket.

In order for the guide pulley to be able to reach the 34T sprocket, the B-tension screw had to be screwed all the way in, so as to pull back the RD all the way to allow the guide pulley to clear the largest sprocket. Don't worry if you don't understand what I just wrote, the key point here is that using a road RD on a large MTB cassette is not recommended!

The B-tension screw (middle of picture) screwed all the way in, in order to rotate the RD backwards

This barely allowed the guide pulley to clear the large 34T sprocket

A long cage RD is used as a chain capacity of >37T is required [(53+34)-(39+11)] = 37T.

With the RD pulled all the way back, this also meant that the gap between the guide pulley and the other sprockets also became quite big. This causes a noticeable drop in shifting performance as the shifting performance is only ideal when the guide pulley and sprocket are about 3mm apart.

The RD fully stretched, when the chain rests on the 53T front chainring and 34T sprocket.

Minimum chain length, when the chain is on the 39T chainring up front and 11T sprocket at the cassette.

As a long cage RD is used, this also means that the cage will hang down quite close to the ground in some gears. This is bad for off road bikes where there are many obstacles on the ground, but it will probably not be a problem when cycling on flat roads.

 RD cage hanging down really low.

The RD cage is only about 5 cm off the ground in the worst case.

 RD cage also goes quite close to the rim and tire

Overall, this new cassette and RD works quite decently, and there are no major issues with this setup. However, it is not recommended for more frequent usage as the gear shifting performance is not the best and the gearing is not suited for long distance road riding due to the gear ratios available.

With this setup, my gear range has been modified to be 23" to 96". At the low end of the gear range, the lowest possible gear ratio has been lowered from 29" to 23", and I reckon this will make a big difference on steep slopes. We will be able to see how well this setup works during the King of the Hill ride!

Comparing the before and after pictures of the rear system:

Ultegra short cage RD with 12-27 road cassette

Tiagra long cage RD with 11-34 MTB cassette

Lezyne Super Drive XL: In Depth Review

Since I got the Lezyne Super Drive XL a few days ago, I have been testing it out quite frequently. Before this, I wrote a short entry about the initial impressions that I had about the front light. This article will be a more in depth write-up about the light. The specifications for the light can be found in the earlier entry.

Battery Life:

As claimed by Lezyne, this light will run for 1.5 hours on high (500 lumens), 2.5 hours on medium (350 lumens) and 5 hours on low (175 lumens) or flash mode (350 lumens). What I did to measure the run time is just to charge the battery to full, and turn it on at high mode, and see how long it lasts.

When the light is on, the button actually glows a different colour, depending on the charge level. Above 70%, the button glows green. Between 50% to 70%, the button is half green half red, and when there is less than 20 mins left, it will glow a steady red. When the battery is about to run out, it will switch to the low mode (175 lumens) and the button will flash red.

Half green half red. This means that it has 50% - 70% battery life left in this mode.

 Steady red glow. According to the manual, it now has less than 20 mins of runtime left.

Actual timeline events during the runtime test, for the prototype:
0 mins  : Test starts in high mode
30 mins: Button glows green/red
65 mins: Button glows a steady red. Supposedly less than 20mins left.
90 mins: Light still going strong!
120 mins: Automatically switches to low mode, button flashes red.

At this point, I ended the runtime test as the light has gone into power saving mode. The medium and high modes are no longer selectable, pressing the button only alternates between low mode and flash mode. I believe that for the prototype, the high mode is actually the normal Enduro mode (350 lumens), and not the Blast mode (500 lumens). That was perhaps why it lasted so far beyond the claimed 1.5 hours duration.

Update:
After I received the production model, I did the runtime test again!

Actual timeline events during the runtime test, for the production model:
0 mins  : Test starts in high mode (500 lumens)
84 mins: Button glows green/red
92 mins: Button glows a steady red.
97 mins:  Light flashes and automatically switches to low mode (175 lumens), button flashes red.
105 mins: Light switches off.

The runtime of 105 mins in the Blast mode is about 15 mins more than the claimed 1.5 hrs for the Blast mode, which is excellent! However, the battery indication was not accurate. The green/red LED is supposed to show when it has about 50% of the battery life left. However, it only appeared after 84 mins, which is way beyond the 50% mark of about 45 mins (half of 1.5 hrs). As such, the LED changed to a steady red (< 20 mins) only 8 mins after the green/red LED came on. Although the overall duration is pretty accurate, the intermediate battery life indication is not.

I suspect that this might be due to the new lithium-ion battery, as the voltage may not be so consistent yet, leading to inaccurate battery life indication. It may get better after a few charge/discharge cycles.

Heat Management:

The exterior of the front light is full aluminium, so it will definitely help to dissipate the heat from the powerful LED. Given that the battery is a 3.7V, 2400mAh Li-ion battery, together with the constant current technology used by Lezyne, a run time of 2 hours means a constant current drain of 1.2 Amperes, which is quite high for a light of this size, proving how powerful the LED is.

Consequently, a lot of heat is generated by the circuitry, which means that the outer casing feels hot after a few minutes. In fact, during the run time test, it became almost as hot as a cup of hot Kopi-O, and I could barely hold it in my hands. It does have some sort of heat protection circuit though. As quoted from the Lezyne manual:
 
"Lezyne thermal protection circuit: Lezyne LED lights are protected by a thermal detection system. If the operating temperature of the light gets too high, the light will automatically change to the lowest setting. After 5 minutes, you will be able to change the light back to the previous mode setting."

Lezyne warns against using it as a flash light, as it can get really hot. However, during normal usage on a moving bike, the air flow will keep it cool easily.

Brightness Comparison with S-Sun 1 Watt and Busch & Muller IXON IQ Front Lights:

Naturally, the all-important question is how bright is it? I did a quick comparison with the two other front lights that I have. The Busch & Muller light uses lux as a measure of brightness, while the Lezyne light uses lumens. There is no way to convert one measurement to another, and so the only way to compare is to shine the lights against the wall.

B&M (40 lux) on top, S-Sun in the middle, Lezyne (350 lumens) at the bottom. All at full brightness, distance about 2 metres. Note the different "whiteness" of the lights.

 B&M (10 lux) on top, S-Sun in the middle, Lezyne (175 lumens) at the bottom.

Lezyne (350 lumens) at left, B&M (40 lux) at right, tiny S-Sun at the bottom.

Lezyne (175 lumens) at left, B&M (10 lux) at right, S-Sun taking a break.

B&M (40 lux) at left, Lezyne (350 lumens) at right. Distance 20 cm.

From these pictures, the general conclusion is that the B&M has a much more concentrated light beam, with a very bright but narrow shape. The Lezyne light is more yellowish, and has a larger spread.

There is another test which I did, but which I have no picture to show. I shone these 2 lights in a large dark room, at a wall about 10 metres away. The B&M light tends to fade off at the edges, and appears much dimmer than the Lezyne light, which maintains a bright and wide beam. To summarize the brightness test, the Lezyne puts out a bit more "light" in total than the B&M.

Below are some pictures showing the actual light beam when mounted on a bike.

Actual usage on the road. Medium mode, 350 lumens. More than bright enough!

Low mode, 175 lumens. Obviously dimmer than the medium mode.

Compatibility with Wireless Speedometers:

Yes this is important! Especially for high powered lights that give out a lot of electromagnetic interference (EMF). I had some problems with the Busch & Muller light, as the light gives out a powerful EMF that drowns out the speedometer signals from the sensor. This happens when I use the high mode of 40 lux, but when I use the low mode of 10 lux, the EMF is weaker and the speedometer is not affected.

For this Lezyne Super Drive XL, I was pleasantly surprised to find that it does not affect my wireless speedometer at all! At all lighting modes, the speedometer worked normally. This works even when I place the Lezyne light right beside the speedometer. This is a plus point that should have been highlighted by Lezyne. Brilliant engineering by Lezyne.

Bike Mounting:

With the mounts provided, you can mount the light on virtually any round bar on the bike. It even has a helmet mount, although I don't think I will mount a light of this size on my helmet? Perhaps necessary for MTB trail night riding.

I chose to mount the light at the front of the bike, using the luggage truss bolts holes to mount the front light. This means that the light does not rotate with my handlebar, and points more or less forward all the time. It also frees up my handlebar for other accessories.

Simple but secure mounting for the light.

This is a really good all purpose light, with the different modes able to adapt to different uses. The low mode of 175 lumens is sufficient for night commuting on lighted roads. In the event that the road is unlit, turn up the front light to its full power and light up your path! The flash mode is a slow flash, and some may prefer this instead of the steady mode.

If you are looking for max lumens in a small package, this could just be the one for you. The smaller sibling of this is the Lezyne Power Drive XL, which is very similar to this, only slightly smaller with a max output of 400 lumens. That may be better in some cases, as the lower power consumption means that it will last a little longer on the same battery.

Lezyne Super Drive XL Front Light: First Impressions

A quick review on the latest gadget from Lezyne, the Super Drive XL Front Light! This is upgraded from the previous version, with a brighter and improved circuit. This is a year 2013 new product, and I am lucky to be one of the first few to get my hands on one of these front lights.

I previously had the prototype version, now I have the actual production version and there are some small differences.

As copied from the CRC website, here are the specifications for this light:

Lezyne Power Drive XL Front Light Features:

• Rechargeable Front light.
• MTB / Road / Commute.
• No wires design, clutter free handlebars.
• Up to 500 genuine lumens output.
• Mode sequence optimized for daily rider. 4 main settings.

Lezyne Power Drive XL Front Light Specifications:

• Race Mode: Access to toggle between Blast and Enduro settings.
• Simple to re-charge: Micro USB charging cable included (common EU standard).
• Easy to fit: No tools required, hard mount Composite Matrix bracket with angle adjust.
• Quality materials: Fully CNC sculpted alloy body.
• Highly water resistant: O-ring sealed to FL1 standard.
• Side visibility design improves safety.
• Uniform beam pattern: Even distribution of light optimized for cycling.
• High Quality Lezyne Lithium Ion Battery (Interchangeable) LIR18650.
• Battery indicator: Traffic light style intelligent power button when riding.
• Battery check: With light off, charge level can be checked with quick press of button.
• Compact: 33mm diameter x 102mm.
• Lightweight: 149g with handlebar bracket.

Lezyne Power Drive XL Front Light Settings:

1. Enduro (Medium): 350 lumens / 2.5hrs
2. Blast (High): 500 lumens / 1.5hrs
3. Economy (Low): 175 lumens / 5hrs
4. Flash: 350 lumens / 5hrs

The set that I have is the "Loaded" version, which means that besides the light and standard bracket mounting, it also comes with an extra battery and the helmet mount.

Clean packaging

Top of box with CNC marks. Are the plastic boxes CNC milled at the top?

The manual with clear instructions and glorious full colour.

Unboxing! The stuff that comes with the "Loaded" version of the Lezyne Super Drive XL.

Besides the light and the standard bracket mount, it also has the extra battery and the helmet mount.

Overall look of the light. Sleek and clean design.

Super big and powerful LED, magnified by the lens.

 

Micro USB port at the bottom for charging. Protected by a rubber cover.

The extra rechargeable battery with the casing, exactly the same as the one in the light. Will need to insert the battery in the light for charging.

The helmet mount, with a ball joint for angle adjustment.

Two different sized clamps are available. With the rubber shims, they can fit pretty much any handlebar.

Before I got this Lezyne front light, I actually already have another powerful front light, the Busch & Muller IXON IQ front light. You can read more about it at the review here.

Comparing the size. The Lezyne light is much slimmer, at about half the diameter of the Busch & Muller light.

  Comparing the weights of the lights, including the clamps.

From the weighing scale (my new digital weighing scale! Only $12!), we can see that the B&M light is about 60 grams heavier. But it is also because the B&M light has 4xAA batteries inside it, which means it has a much longer runtime. 5 hrs in high mode, 20 hours in low mode.

Of course, there is no point comparing the size and weight of the lights, if the light is not bright enough! I haven't had time to test out the lights on the road yet, but I can say the the Lezyne light is really very bright! Even on the Economy mode of 175 lumens, it is more than sufficient for lighting up the path on an unlit road. The Enduro and Blast modes of 350 and 500 lumens are even brighter.

With 2 fully charged batteries, the light can last for 3 hours on Blast mode, and 10 hours on Economy or Flash mode. For extended night rides, it will be best to have at least two batteries in order to last the whole night. But for short night rides of a few hours, the runtime of 1.5-5 hours will be sufficient. With USB charging, it is easy to just plug the light into any micro USB plug to charge the light.

This is only the first part of the review, will follow it up with the review of the actual light usage!

The second part of the review is now up! Click here to see the in depth review.

Double Layer Rim Tape

An old problem on my wheels have resurfaced recently. The inner tube will spontaneously get punctured and of course the tire will be flat. This always happens when the bike is sitting at home, not while I'm out riding, which in some sense is probably lucky for me.

From what I can deduce, the problem seems to be that the tube bulges through the rim tape and into the spoke holes. Apparently this stretches the tube too much, or it gets cut by the edge of the spoke holes, causing the puncture. There is no way to patch this kind of punctures as the cut on the tube is too big to patch.

To try to remedy this, I have placed 2 layers of rim tape this time, to try and prevent the same problem from occuring again. Wide rim tape cannot be used, as this will fill up too much of the space on the rim, making it very difficult to fit the tires onto the rim.

Without rim tape

First layer of rim tape. This is the new rim tape I got from MyBikeShop.

The original Wheelsport rim tape. It is not too bad, but can't seem to withstand high pressure very well. This goes on as the second layer of rim tape.

Another reason for this might be the tubes that I am using. For the Wheelsport wheels, which have a 30mm profile, I need a tube with a longer valve, in order to pump the tubes. The Kenda tubes seem tougher/thicker but has a valve that is too short. The Schwalbe ones have a longer valve which is more suitable for these wheels. However, the Schwalbe tubes that I got from MyBikeShop are the Extra Light SV6A, which are the only ones that they have, and they seem to be thinner and lighter than the Kenda ones. Maybe that is why these thin tubes are more prone to punctures?

Anyway, with the double layer of rim tape, it seems unlikely that the same problem will occur again. The rim tapes that I used are rather narrow and thus do not affect the seating of the tire onto the rim. Shall monitor the situation for a few days and hopefully nothing happens!