Cervelo Aspero: PRO Vibe Aero Superlight Handlebar and Stem

Building a new gravel bike will require a new set of road handlebar and stem. This is because the previous handlebar and stem cannot be transferred over from the Canyon Endurace, since it is integrated with the frameset. With special headset spacers, 1 1/4 inch steerer tube, special clamping mechanism, it is not common, and it does not make sense to transfer them over to another bike.

Therefore, I have the chance to get a new road handlebar and stem for the Cervelo Aspero. This means that I am free to get anything I want. As I am using Dura-Ace Di2 with hydraulic disc brakes, it will be nice to get a road handlebar where the hydraulic hose and Di2 wire can be routed neatly inside the handlebar.

This narrows down the choice considerably, leaving options such as FSA and PRO. After checking in detail, I found that the routing holes on the FSA handlebar are not in the ideal location for hydraulic hose routing. Therefore, PRO is the choice, since they are actually affiliated with Shimano, and their products would presumably be compatible to Shimano products.

Even though I am building the Cervelo Aspero gravel bike, I will use it as a road bike too, when the Reynolds Assault road wheelset is installed. Therefore, I want to have a proper road handlebar, not a gravel handlebar. Besides, I am not a fan of flared gravel handlebars as they just don't feel comfortable for me.

I chose this PRO Vibe Aero Superlight Handlebar as it is one of the lightest handlebar by PRO. The flat aero sections look to be comfortable for holding as well. Let's take a closer look at the handlebar.

Pro Vibe Aero Superlight Handlebar

Features of this handlebar

Claimed weight is 205 grams, let's see how true it is.

I chose the 40 cm width to ensure it fits like a road bike.

Comes with anti slip paste to put on the contact surface between the handlebar and stem, to ensure no slippage without over tightening the clamp bolts.

Suggested Di2 wire routing through this handlebar. This assumes the usage of a Y split junction like how I did it on the Canyon Endurace.

The guide tubes are already inserted inside the handlebar, if you wish to follow the recommended wire and hose routing.

However, since I will be using my own routing, these guide tubes are useless to me. I appreciate the effort but they are not useful to me. The wire routing that I will use will be similar to that on the Dahon MuSP, where the wireless unit EW-WU111 will be installed inside the handlebar.

With the guide tubes pulled out of the handlebar

400 mm wide, with a compact drop and reach.

Aerodynamic shape on the tops

Integrated with Innegra fibre which is lightweight, vibration absorbing and also strong.

The curved parts of the drops are uniquely shaped, being flattened to make it a bit more aerodynamic.

Flattened drops. Not sure how it would feel when gripping it.

Cable hole near the hoods, to route the hose/cable/wire from the shifter into the handlebar.

Close up of the cable hole

Cable holes under the handlebar, which allows the hose/cable/wire to exit from the handlebar and be routed into the frame.

There is even a hole facing the stem, which allows a Di2 wire to run through the stem, if you want to install the Di2 battery inside the steerer tube.

Weighs 213 grams, just a bit more than the claimed 205 grams.

As for the stem, any stem will do, as long as it is compatible with the steerer tube and the handlebar. I decided to get a PRO stem as well to match the PRO handlebar.

Pro Vibe stem, with the unique V design on the face plate.

90 mm stem length, with a negative 10 degree tilt. It cannot be installed tilted up. Compatible with standard 1 1/8 inch steerer tubes (1 1/4 version also available). Made of aluminium.

For this stem, it is acceptable for the steerer tube to be lower than the surface of the stem clamp, as shown by the minimum fork height line.

Instructions showing how to install the special top cap.

Overall view of the PRO Vibe stem, with the backward facing face plate clamp bolts.

There is a hole near the top of the stem, which allows the Di2 wire to run into the steerer tube, through the stem.

View of the hole from the front of the stem.

Special shaped top cap, with recessed cutouts to allow internal Di2 wire routing.

Shape of the top cap matches the stem. This also means that standard round top caps cannot be used.

This stem weighs 132 grams, which is on the slightly heavy side.

Top cap and bolt weighs 15 grams.

Both the PRO Vibe handlebar and stem are rather special as they have unique features that are not found on other products, as far as I know.

PRO Vibe Aero Superlight Handlebar:
1) Flattened curve area of drops.
2) Many holes for internal routing.
3) Integrated with Innegra fibre.

PRO Vibe Stem:
1) Special face plate design.
2) Reversed face plate clamp bolts.
3) Special top cap.
4) Hole in stem to allow internal Di2 wiring.
5) Steerer tube is not supposed to protrude above the stem clamp.

I can't say that all these features are positive features. For some of them, it feels like it is purposely different for the sake of being different, without making it better.

For example, what is the point of having flattened drops on the handlebar? Once it is wrapped with bar tape, it will be oval shaped anyway and not really aerodynamic.. Not sure if the ergonomics of this flattened area will be good or not. As for the reversed face plate clamp bolts, it looks nice from the front but it is harder to install or adjust.

On hindsight, I might have gotten a standard FSA handlebar and stem, which would probably be cheaper and maybe a bit lighter. In any case, these PRO Vibe handlebar and stem will make this Cervelo Aspero quite unique as I am pretty sure no one else will use the same combination on this bike.

Ultrasonic Cleaning for Chain and Cassette

How often do you clean your bicycle's drivetrain? It is inevitable that it gets dirty through usage, especially if you ride off-road or on wet roads.

Before I converted my Canyon Endurace to a part-time gravel bike, it was a pure road bike which I only rode on roads, and only during good weather. As such, the drivetrain was able to stay clean for a long period of time, before it gets too dirty and needs to be cleaned.

However, ever since I set it up for gravel use, it has seen a lot more off-road usage, which causes the drivetrain to get dirty much more easily and more often. It takes just one wet or sandy ride to generate crunching sounds from the drivetrain, caused by sand and other bits being shifted through the moving parts.

It is the same scenario for the new Cervelo Aspero gravel bike as well. A dirty drivetrain is still usable, just that it will accelerate the wear of the components, such as the cassette, rear derailleur pulleys, chain rings and chain. Therefore, it is a good idea to clean and lube the drivetrain once it gets too dirty. In my case, it is too dirty when the chain looks completely dry with no lube, with lots of gunk around the pulleys.

The drivetrain parts to be cleaned are the cassette sprockets, rear derailleur pulleys, chain rings and chain. I used to clean all these parts, either on or off the bike, by wet tissue or some cleaning agent + rags. It was very time consuming and needed a lot of effort, plus the end result was not very clean.

I decided to try out an ultrasonic cleaner, which uses ultrasonic energy to create lots of tiny cavitation bubbles in the fluid. When the bubbles collapse, it generates high temperature and pressure on a microscopic scale, this is what removes the contaminants on the surface of the material. For more details on ultrasonic cleaning, check out the Wikipedia link.

Small scale ultrasonic cleaners are not expensive, you can get it online or locally from Scootz (in Singapore). I wanted a unit that was big enough to hold a cassette sprocket (ideally the 34T sprocket from the CS-HG800 cassette), to minimize the effort needed to load and unload the ultrasonic cleaner multiple times.

The one that I got has a claimed capacity of 2 litres, which is a good size for most bicycle parts.

Ultrasonic cleaner, with digital settings for the heater and timer.

Close up look at the control panel, where the heater function and timer function can be adjusted and set independently.

Details of the cleaner can be seen at the back. The master on/off switch is here.

Nice smooth stainless steel tank 

Comes with a little basket to hold the items that you want to clean. It has rubber legs to prevent the metal basket from rubbing against the metal tank. 

Here is how the basket fits inside the tank. However, the basket also reduces the usable volume of the tank.

Tested the ultrasonic cleaner for the first time, to see how it works. 

I used a temperature of 60 degrees Celsius for better cleaning effectiveness.

For a start, I tested the cleaning function with some other items, such as the Bike Peddler Take-A-Look mirror that I always use. I added only water and nothing else for this test.

It is quite amazing as once I started the machine, I could see the dirt drifting out from the hidden areas. After the cleaning was complete, it was very clean! It could not have been cleaner even if I had used soap and scrubbed the mirror, as there are many small hidden areas that cannot be reached.

The next step is to try with the chain, as it is very difficult to clean the chain properly even after removing it from the bike. Let's see how effective the ultrasonic cleaner is.

One trick I learnt from reading online guides is to use a ziplock bag, and place the item to be cleaned inside the bag. This prevents the tank from becoming dirty. Make sure to add water around the bag as well, inside the tank.

Using a ziplock bag to hold the dirty chain. I added warm water from the kettle, instead of relying on the built-in heater.

This is with just some hand soap. After 10 seconds this is what you see. 

This is after one cleaning cycle of 10 minutes. Not very effective from what I see...

It seems that the cleaning is not effective, probably because I did not use a proper cleaning agent. Warm water and some hand soap is not strong enough to clean the dirt off the chain.

I went out to get a bottle of degreaser, hoping that it will make the cleaning more effective.

A bottle of expensive degreaser from the nearest bike shop. It came with a spray head that did not even work...

I also found that the ziplock method was not very good, as the chain will rest directly on the bottom of the tank (through the thin walls of the ziplock bag). This caused a lot of vibration, and also scratched the surface of the stainless steel tank.

Instead of using a thin ziplock bag, I changed to a plastic takeaway container, which fitted well inside the tank. This will prevent the parts from scratching the walls of the tank, and also makes it easier to rinse and clean the parts.

Added some degreaser to the warm water, with the chain inside. Remember to add water on the outside of the container!

Much better this time. This is after cleaning the second time with degreaser. 

However, the areas between the links and under the rollers still have quite a bit of dirt.

It seems that during cleaning, the solution may get saturated, or the degreaser may have been used up, which makes it difficult for any more dirt to be removed from the chain. Therefore, the only way is to empty the used solution and to put in fresh water and more degreaser, and repeat the cleaning process.

Finally, after 4 times of ultrasonic cleaning! Duration is 10 minutes each time. The first time probably doesn't count as degreaser was not used. 

Even the hidden areas between the rollers and links are cleaned, which will normally take a lot of brushing with strong cleaning agents.

Next up will be the cassette, which also gets very dirty with usage. Other than the chain and cassette, the rear derailleur pulleys and chain rings also need to be cleaned. For the pulleys, I am not sure if it is a good idea to clean with the ultrasonic cleaner, as it may damage the plastic surface.

As for the chain rings, it obviously does not fit inside the tank. The 34T inner chain ring (Dura-Ace R9100) might fit, but it might damage the chrome surface finishing on it.

Cassette is very dirty as can be seen here. 

This is after I wiped the cassette sprockets with a wet tissue, but before using the ultrasonic cleaner.

After running it for 2 cycles (5 minutes each), this is the result! Perfectly clean, much better than what I can do by hand. Takes much lesser effort as well.

Same for the smaller sprockets. Takes 2 cycles to get them really clean. 

The bigger sprockets does not fit completely into the tank, so you have to rotate it to clean the entire surface. Left side is before cleaning, right side is after.

Super clean cassette! Even a brand new cassette is not so clean. 

Super clean chain, before applying new chain lube. 

Super clean drivetrain!

I am really pleased with the effectiveness of the ultrasonic cleaner. It takes me much less effort to clean them, and yet is much more effective.

Dura-Ace CS-R9100 11-30T 11 Speed Cassette also cleaned! 

Even the spaces between the sprockets are very clean. It is difficult to clean these areas properly even with a brush.

Points to take note:
1) Isolate the ultrasonic cleaning machine in a room, such as the storeroom, to prevent hearing damage from continued exposure.
2) Degreaser and warm water is very effective for cleaning the cassette and chain.
3) Do not put anything flammable into the tank as it will heat up during usage.
4) It may remove pad printing or other surface treatment from the parts to be cleaned. If in doubt, test it out first.
5) As the parts will come into contact with water, try to dry and lube it as soon as possible, to prevent rusting after cleaning. Unless you are using high end parts that are very rust resistant.

Cervelo Aspero: 700C vs 650B Wheel Size Comparison - Part 1

Before I tried gravel riding, there was no need to consider wheel size or tire width. Basically, a road bike setup means using a 700C x 25 or 28 mm tire. The tire diameter or width is just what it is, there is no concern if the tire ends up a bit wider or narrower than claimed, or even a bit bigger or smaller in diameter.

However, when I first used a gravel setup on the Canyon Endurace, I found that depending on the tire width, the tire diameter will also be affected significantly, especially if the tire width differs a lot. This can be a problem, as a bike is designed around a nominal wheel size, with only a small variance allowed. If the wheel size differs too much, it affects the geometry of the bike.

Crank clearance with the ground will be reduced if the tire diameter is smaller. Also, the trail of the bike will be reduced with a smaller wheel size, which can cause instability.

If the tire diameter is larger, the usual problem is frame or fork clearance, but the bigger issue is a slower handling bike due to larger trail from the larger tire size. This may be good or bad depending on your desired purpose.

In this case, it is difficult for the bike frame designer to optimize for a single wheel size, if it needs to accommodate a wide range of tire diameters, from small 700C x 23 to large 700C x 43 mm, for example.

Which is why the Cervelo Aspero has a Trail Mixer on the fork which allows the trail value of the bike to be adjusted, depending on the wheel size and also your preference for a more agile or more stable bike.

I will not go through the explanation again on why I chose 650B wheels and tires, you can read about it in my previous posts.

DT Swiss G 1800 Spline DB 25 Wheelset
Panaracer GravelKing SK 700C x 32 Tires

Hunt 650B Adventure Carbon Disc Wheelset
Panaracer GravelKing SK 650B x 43 Tires

Before I compare the new 650B wheelset, I will compare the wheels used previously on the Canyon Endurace. That would be the Reynolds Assault carbon wheelset for the road setup, and the DT Swiss G 1800 wheelset for the gravel setup. Both are 700C wheels.

The Reynolds Assault wheelset is equipped with Continental GP4000 700C x 28 tires, but the actual tire width is almost 32 mm. This is due to the relatively wide internal rim width of 21 mm.

The DT Swiss G 1800 wheelset is equipped with Panaracer GravelKing SK 700C x 32 tires, with an actual tire width of 35 mm. This rim has an internal width of 24 mm.

Rim diameter looks almost similar, with the gravel wheelset being just a little big larger.

Close up look at the different tire tread patterns.

Tire diameter is very similar.

In this case, if the tire diameter is almost the same, swapping between the wheelsets will not cause significant differences in ride geometry. This was the case on the Canyon Endurace.

Moving on to the new Hunt 650B wheelset, the rim diameter is smaller, but the tire will add back some of the diameter by having a taller sidewall. A 700C rim has an outer diameter of 622 mm, while a 650B rim has an outer diameter of 584 mm. This is a difference of 38 mm, which means 19 mm on either side. If a 650B tire is to have the same outer diameter as a 700C tire, the side wall needs to be 19 mm taller, which is a huge difference.

650B x 43 mm tire on the left, 700C x 32C tire (actual 35 mm) on the right. The diameter difference is quite obvious.

The 650B wheelset on the right has a smaller diameter, as seen from the difference in axle height. This will also be the difference in bottom bracket or crank arm clearance.

Another view showing the difference in tire diameter.

Using a long thru axle to align the centre of the hubs, the difference in radius can be measured more accurately.

650B tire has a gap with the ground. Multiply this gap by 2 and you get the diameter difference.

Using a 10 mm Allen key as a gauge, there is still a tiny bit of clearance. I would say that the gap is about 11 mm.

Other than the diameter difference, there is a big tire width difference as well. The wider 650B tire on the right has 5 rows of small knobs instead of 3.

43 mm width on the left, versus 35 mm (actual) width on the right. This 8 mm width difference is quite obvious.

There is some difference in sidewall height, as the 650B tire on the left will have a taller side wall as it is wider. The height of the brown sidewall area is about the same, but the black sidewall area is much taller on the 650B tire.

Finally, let's also compare the 700C road wheelset with the new 650B gravel wheelset. These are the two wheelsets that I will use on the Cervelo Aspero. I will explain more about the road and gravel setup in a later post.

Hunt 650B wheelset on the left, for gravel riding. Reynolds Assault 700C wheelset on the right for road riding.

Significant difference in tire diameter between these two wheelsets.

Another view of the different tire diameter. Despite the wider tire width, the 650B tire does not add enough tire height to come close to the 700C tire diameter.

Difference in axle height, which is about 8 mm.

Big difference in tire width and tread pattern. 32 mm tire width vs 43 mm tire width.

Comparison of the tire sidewall height. The 650B tire is taller with much more volume, but not enough to make up for the smaller rim diameter.

In summary, here are the tire diameters as measured, and also the difference in BB to ground distance (which is calculated as half the difference in tire diameter).

Continental GP4000 700C x 28 (actual 32): 695 mm diameter
Panaracer GravelKing SK 700C x 32 (actual 35): 699 mm diameter
Panaracer GravelKing SK 650B x 43: 677 mm diameter

On Cervelo Aspero (Size 51)
BB to ground distance for Continental GP4000 (700C x 28): 268 mm
BB to ground distance for GravelKing SK (700C x 32): 270 mm
BB to ground distance for GravelKing SK (650B x 43): 259 mm

The differences between the 700C road and 700C gravel tires are small, while there is a big difference between the 700C road and 650B gravel tire. What does this mean?

Swapping from the 700C road wheelset to the 650B gravel wheelset will lower the bike by about 9 mm. That is 9 mm less crank arm clearance. Not sure if pedal strike will be an issue, as it has even lesser ground clearance compared to my other bikes.

On the plus side, a lower centre of gravity will help in cornering and descending at speed. A smaller tire diameter also means a lower trail value, which increases agility. Is increased agility good or bad for a gravel bike? This is up for debate, as increased agility can allow you to tackle twisty trails more easily, but also make a speedy descent less stable.

Regardless, the proof of the ride quality will require actual riding. Whether good or not, I will have to use the tires to see if it is suitable for my usage.

From left to right: GP4000 28 mm, GravelKing 43 mm, GravelKing 32 mm

The 650B wheelset is the junior here, having a smaller diameter than the other two.

This concludes the first part of this comparison, which is between these three tires. Later on, in Part 2, there will be an additional tire added to this comparison, stay tuned!