Brompton P Line: PRO Stealth Saddle

Another modification for the Brompton P Line! This time it would be a straightforward saddle swap, or so I thought. The stock Brompton saddle is quite comfortable, but it is too long and gets in the way when I mount or dismount from the bike.

Stock Brompton saddle, installed with the infamous Pentaclip in the lower position.

Stock saddle is mounted in the lower position, with the round clamp setting.

There are 2 sides to the clamp. The 7 mm side is for round rails, while the 7x9 mm side is oval and meant for carbon saddle rails.

Side by side comparison of the round vs oval clamp area.

Stock Brompton saddle is 276 grams

PRO Stealth Superlight saddle which I wanted to install on the Brompton. It was taken from the Focus Paralane when I dismantled and sold off that bike.

When the Pentaclip is in the lower position, there is almost no clearance between the seat post, clamps and the underside of the PRO Stealth Superlight saddle.

Due to the small clearances and shape of the saddle, a standard Allen key cannot be inserted into the bolt head to tighten the clamp to 10 N.m.

I had to buy a special set of Allen key with extra short head.

All the Allen keys in this special set have short heads, usually for special use cases.

With the extra short head, the Allen key will be able to tighten the clamp as shown above!

Taking off the Pentaclip to weigh it (94 grams). It is infamous because of how many parts it has, and how fiddly it is to assemble and adjust. Still, this is a better version of the original Pentaclip.

The two thick rubber O-rings that come with the stock seat post. I think the purpose is just to stop the Pentaclip from knocking into the seat post clamp when the seat post is lowered.

The Brompton stock seat post is flared at the bottom, so you cannot pull out the seat post from the top. Rather, you need to remove the saddle and Pentaclip, and pull out the seat post from the bottom of the bike.

Stock seat post length is about 55 cm. However, this is without the seat post clamp like on other seat posts, so it is difficult to make a 1:1 comparison in length.

Stock seat post is made of steel, and weighs 394 grams. If the Pentaclip weight of 94 grams is included, the total weight is 488 grams which is quite heavy!

I decided to use a more comfortable saddle instead, the PRO Stealth Off-Road saddle, which has more cushion than the PRO Stealth Superlight.

Comparison of stock Brompton saddle vs PRO Stealth Off-Road saddle. See the difference in length!

PRO Stealth Off-Road saddle on the left, PRO Stealth Superlight saddle on the right. Similar shape, but very different construction, cushioning, weight and price!

The height of the PRO Stealth Off-Road saddle is somehow shorter than the Superlight, despite the thicker cushion.

This is where the problem starts. Due to the size and height of the Pentaclip, I realized that it can interfere with the saddle. Read on to find out what happened!

On the Brompton saddle, the saddle rails are tall enough that the Pentaclip can be mounted in the lower position as shown above. This is the position which the stock saddle came in.

Here is how the Pentaclip looks on the Brompton saddle, when in the lower position.

However, the lower position doesn't fit on the PRO Stealth Off-Road saddle, as the saddle rails are closer to the shell of the saddle.

On the PRO Stealth Superlight saddle, it barely fits. I got the special short Allen keys because I wanted to mount it in this position. However, I won't be using this Superlight saddle for now.

I tried various setups and combinations, and found that there is no way I can mount the Pentaclip in the lower position, when I am using the PRO Stealth Off-Road saddle. Therefore, my only option is to mount the Pentaclip is the higher position, which would theoretically make the folded size taller.

Saddle rails mounted in the higher position of the Pentaclip.

Here is how it looks! PRO Stealth Off-Road saddle on the Pentaclip. It would be neater if the Pentaclip could be tucked under the saddle, but it is physically not possible.

To my surprise, the folded height with the new saddle and higher Pentaclip position is about 60 cm, which is the same as the stock condition.

Stock Brompton saddle with Pentaclip in lower position as shown.

From the comparison of these 2 pictures, I realized why the eventual heights are the same, even though the Pentaclip positions are different. The PRO Stealth Off-Road saddle is shorter than the Brompton saddle, which compensates for the added height from the higher Pentaclip position.

With the PRO Stealth Off-Road saddle installed, it is now using the same saddle as a few of my other bikes. This makes for a consistent sitting experience across different bikes.

Specialized Aethos: Assembly with new Frameset

In the previous post, I wrote about the replacement Specialized Aethos frameset, in Maroon colour. With the replacement frameset, there are actually a few options for me.

1) Sell the new frameset and buy another frameset to build up. Cannondale? Trek? Etc.

2) Sell the new frameset, and also the components that I removed from the Aethos.

3) Rebuild the bike using the new frameset and the same components.

Option 1 sounded tempting, as I could get a new frameset from another brand. However, the value of the Aethos frameset was not really good even when brand new, as the prices have dropped a lot since I first got it. In fact I think there is now excessive stock which the shops are trying to sell off.

Option 2 means having no road bike to ride, as the Aethos is my only road bike after selling away the Focus Paralane earlier. Although I do get back some cash if I sell the road bike, I think I still want to keep one road bike for the occasional fast road ride.

That means I eventually decided to go with Option 3, which is to rebuild the Aethos using the same components but the new Maroon frameset. Since I was going to rebuild the Aethos from scratch, I decided to take the opportunity to change some components as well.

I bought a new PRO Vibe superlight carbon handlebar, which is a new generation that is even lighter than the previous version! The previous version weighs 198 grams, which is already lightweight but there are a few others that are even lighter.

This time, the new handlebar is going to weigh even less, check out the actual weight below!

New PRO Vibe superlight carbon handlebar, now lighter than the previous version!

In my preferred width of 400 mm

Just 2 holes at the bottom for the hydraulic brake hoses, instead of 4 in the previous version. It is assumed that you will be using wireless road shifters.

Hole near the drops for routing the hydraulic hose internally from the road shifters to the middle of the handlebar.

Oval hole at the back of the handlebar enables Di2 wires to be routed into the stem, if necessary.

Side view shows a short reach and a standard drop shape, with a flat horizontal end.

See how thin the walls of the carbon handlebar are! Good manufacturing and quality control is needed to ensure that the wall thickness is consistent and fulfils the minimum requirement. It's a delicate balance between weight and strength.

Handlebar is really lightweight at just 160 grams! 38 grams lighter than the previous handlebar.

Inclusive of the Specialized S-Works SL Stem, the stem + handlebar combo weighs just 275 grams! Lighter than many integrated carbon stem + handlebar combo.

Although the new handlebar saves 38 grams of weight, the new Maroon Aethos frameset weighs 56 grams more than the old frame, so there is a net increase of 18 grams. Although it is nice to keep the weight low, I have realized that adding a little bit of weight here and there is not going to matter at all.

Since the components have been completely removed from the bike, I took the chance to clean up the Dura-Ace R9200 cassette as well. Once again, I used the Ultrasonic cleaner to make sure that the cassette is as clean as can be, with minimal effort from me.

Dura-Ace R9200 cassette to be installed onto the Shimano Road L2 spline freehub body, on the Dura-Ace R9270 C50 wheelset.

Shiny cassette after cleaning, looks as good as new!

As the new frameset came with a new fork as well, this means having to cut the fork steerer tube to the correct length again. Since my home workshop is pretty comprehensive, with all the right tools that are commonly used, I was able to do this job at home.

Marking the section to cut, after fitting on the stem for confirmation.

Using the table clamp to hold onto the Topeak Saw Guide, and cutting with the carbon blade on the Park Tool Hack Saw.

After cutting, the fork weighs only 286 grams! 16 grams was removed by cutting it to my required length. This is one of the lightest forks you will ever see.

Specialized S-Works SL Stem installed, with the lightweight expander slightly recessed as per instructions.

Front part of the frameset is ready, with the fork, headset and stem installed.

Glittery Maroon paint job! Looks awesome in sunlight, much like the Cervelo Aspero.

The Maroon colour looks better and better by the day!

With a new frameset, the excitement of building a new bike is here again. At the same time, there is the reassuring thought that I have done this before, and all the components have already been tried and tested to fit this frameset. In fact, even the chain can be reused as it is still in good condition and of the correct length.

For a detailed part by part analysis of the Specialized Aethos, check out the original series where the Champagne Pink frameset was first assembled!

Specialized Aethos: PRO Stealth Team Saddle + Camera Mount

A new saddle is needed for the Specialized Aethos, as it is an additional bike to my bike stable. Normally if I am replacing a bike, I will just transfer the saddle from the existing bike over to the new bike.

As you may already know, I am very comfortable with the PRO Stealth series of saddles, ever since I did a proper bike fitting at LOUE Bicycles. In fact, I bought many PRO Stealth saddles to replace most of my existing saddles.

The first Stealth saddle that I got was the PRO Stealth Superlight, which is found on the Focus Paralane all-weather commuting bike. Subsequently I also changed to the PRO Stealth Off-Road saddle on the Cervelo Aspero gravel bike and also the Fnhon DB11/12 folding bike.

Although there are many other saddles that are lighter than the PRO Stealth series, comfort and compatibility is more important. I would not want a superlight saddle that looks good but is not as comfortable. Therefore there was no doubt that I would get another PRO Stealth saddle for the Specialized Aethos.

Some additions to the PRO Stealth saddle lineup included the Stealth Team saddle, which is also a lightweight saddle that is different from the original Superlight model. This new model looks more appealing to me as it costs less, although it does weigh a little bit more. Check out the differences below and also at this link.

New PRO Stealth Team saddle, with an edgier appearance. This is the version with 142 mm width.

Specialized Aethos: S-Works SL Stem and PRO Vibe Superlight Handlebar

In the earlier posts about the Specialized Aethos, I have shared some information about the frame, fork and other small parts that come with the frameset.

As the Aethos is designed to use a standard stem and handlebar, with no integrated cable routing at the front, it means that I am free to choose a stem and handlebar to use. I like it this way as I am not a fan of integrated cockpits. Although it looks very neat and clean, it takes a lot of effort to assemble this kind of integrated cockpits. If you leave this job to the experienced bike mechanics at the shop, it is not an issue for you. However, if you prefer to work on your own bikes, I would definitely prefer to have a non-integrated front end that I can work on easily.

For a lightweight build, the weight of every part needs to be considered carefully, as every gram counts. I have considered using super lightweight parts from Darimo, but the price is just too high for me to accept, at $750 for a handlebar and $650 for a stem. An alternative is to use Specialized own stem, which is pretty lightweight. It also matches the S-Works frameset which is a nice touch as well.

Specialized S-Works SL Stem, ordered online from the Singapore Specialized store.

I was surprised to see how moldy it is straight out of the box!

Cervelo Aspero: PRO PLT Carbon Road Handlebar

On the Cervelo Aspero gravel bike, I have been using the PRO Vibe Aero Superlight handlebar since the beginning. At that time, the plan was for the Aspero to serve as a dual purpose road and gravel bike, as seen from the two wheelsets that I had.

Later on, after I got the Focus Paralane as a road bike, the Cervelo Aspero was converted to be a dedicated gravel bike with a front single drivetrain. One of the more recent change was to GRX Di2 shifters which work really well for gravel riding.

All the while, the handlebar used was the PRO Vibe Aero Superlight handlebar, which is OK for road riding but not really ideal for gravel. I have some issues with the design of the PRO Vibe handlebar, such as the teardrop bar shape in the drops, and the non-compatibility with standard Garmin computer mounts.

Therefore, after much consideration, I decided to change the handlebar to a more conventional round type, to improve the ergonomics and avoid all the downsides of the PRO Vibe Aero handlebar.

At the same time, I wanted to avoid or minimize the internal routing needed, as it takes more work to route hydraulic hoses and Di2 cables through the handlebar.

Finally I chose the PRO PLT Carbon Handlebar, which is relatively lightweight, with less internal routing and a normal round clamp section on top.

New PRO PLT Carbon Handlebar