I had been reading at the Bikeforums about replacing the stock roller wheels with either the Easy Wheels (expensive) or roller blade wheels. The stock Brompton wheels are not that useful for rolling the bikes and have the negative benefit of getting caught in your shoes when pedalling. I’ve developed an inside out stroke to compensate for this so my shoes don’t get caught anymore. If your shoes get caught it could be dangerous if you happen to be in the middle of the street or you could take a sideways tumble if you’re stationary with your foot caught. 
It took me a while to do this upgrade because I didn’t want to spend too much for roller blade wheels. Thrift shops carry donated roller blade skates, but they don’t want to sell individual blade shoes (a roller blade skate has 4 wheels and I only need 2). I finally came across some new wheels that cost me $3. Also, make sure your roller wheels come with bearings.
The upgrade was straightforward and pretty simple. I used the screws from the Brompton roller wheels. The wheels protrude sideways the same length as the old Brompton wheels, but they do make a difference in getting your shoes caught. Or rather NOT getting your foot caught.
There was no benefit of being able to roll the bike on the new wheels, though. I thought you could roll the bike like luggage at a 45 degree angle by pulling the saddle as a handle. It’s just not possible. The suspension “nipple” protrudes and you periodically get snagged while rolling it. Maybe a larger diameter wheel can solve this (I used a 72mm wheel). I don’t know, though.
Here’s my bottom line for this upgrade:
Pros:
1) No more shoes caught on the wheels (!)
2) Very low cost
Negatives:
1) Can’t roll the bike at an angle
This is a definite “must do” upgrade for your M3L because it’s so inexpensive.
It took me a while to do this upgrade because I didn’t want to spend too much for roller blade wheels. Thrift shops carry donated roller blade skates, but they don’t want to sell individual blade shoes (a roller blade skate has 4 wheels and I only need 2). I finally came across some new wheels that cost me $3. Also, make sure your roller wheels come with bearings.
The upgrade was straightforward and pretty simple. I used the screws from the Brompton roller wheels. The wheels protrude sideways the same length as the old Brompton wheels, but they do make a difference in getting your shoes caught. Or rather NOT getting your foot caught.
There was no benefit of being able to roll the bike on the new wheels, though. I thought you could roll the bike like luggage at a 45 degree angle by pulling the saddle as a handle. It’s just not possible. The suspension “nipple” protrudes and you periodically get snagged while rolling it. Maybe a larger diameter wheel can solve this (I used a 72mm wheel). I don’t know, though.
Here’s my bottom line for this upgrade:
Pros:
1) No more shoes caught on the wheels (!)
2) Very low cost
Negatives:
1) Can’t roll the bike at an angle
This is a definite “must do” upgrade for your M3L because it’s so inexpensive.
