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.
