DIY Brompton P Line Weight-Saving: Removing Mudguards & Rear Rack

Daily · Published 10/14/2022 ·

A buddy of mine once said the final stage of Brompton tuning is the secondhand market.

Me, I’d rather not sell mine off — I’m just going for some reasonable, bang-for-the-buck tuning.

Anything with wheels, anything that rolls, is better off light.

This goes for cars, motorcycles, bicycles — all of it, no exceptions.

Some might argue that a bit of heft is actually a good thing, but trust me, lighter is always better.

So… I went ahead and DIY’d the first round of weight-saving work on my Brompton P Line.

Because labor costs for bike servicing and tuning are still ridiculously expensive.

First up, an easy one — taking off the front mudguard.

Nothing to it, really. A few hex wrenches in the right sizes and it’s done. A spanner to hold the nut steady helps too.

Two problems crop up here.

First: the brake cable now interferes with the wheel!

Second: with the E-hook gone, I can’t do a full fold.

I’d anticipated both issues, so I’ll just hold off on full-folding until the parts I ordered arrive.

As for the brake cable interference, I can just ride it carefully until the parts come in, then sort it out.

Moving right along. The tougher job — the rear rack — is still waiting.

Here’s how it looked before I started. From the looks of it, I need to undo the hex bolts holding the stays on both sides.

And then loosen the nut on the center stay.

Luckily I had the right hex wrench at home. One end is a flathead screwdriver, the other a hex wrench.

A bit of loosening and the stay came free.

Same drill on the other side.

Take it slow and work it loose.

Nothing tricky up to this point.

Now the center stay. You’ll need a small spanner, and if you get greedy and crank too hard, you’ll end up scratching the frame.

I went about 45 degrees at a time, over and over.

Gentle does it.

Here’s where things got tricky. Even after loosening the center stay, it wouldn’t come out.

Then I remembered a YouTube video I’d watched on removing the wheel. The brake’s gripping it, so you have to let almost all the air out of the tire.

I deflated the tire and got the rear wheel off.

With just a hex wrench it’s not hard. The chain’s got oil on it, so I wore work gloves for this part.

Here’s the Brompton P Line rear wheel, removed.

It’s a 4-speed external gear setup. Soon I’m planning to swap the 1st gear (the largest diameter) from 18T to 21T.

Once the wheel was off, I removed the mudguard.

The P Line’s stock mudguard was lighter than I expected. But front and rear combined, it’s surely got to be over 100 grams.

I pulled the rear reflector too — I run two taillights anyway, so I don’t need it.

Now I just need to buy and install the front E-hook and an anti-interference part.

It’s my bike anyway, and even if I wreck it I can just bundle everything up, pay the labor, and head to the shop — that’s the mindset I went in with.

It turned out to be a lot easier than I thought.

You’ve got to actually start something before you can see how it turns out. ^^

Contact: bumseok.view [at] gmail [dot] com