Finally! Fixed the annoying rubbing between rear wheel and fender

So I got a renewed M6L C line, everything is great after some minor adjustments. One thing that kept bothering me, which seems to be a common issue, is that the rear wheel rubs inside of the fender, near the caliper mount. I decided to take the fender apart and finally solved it. What I did:

• Remove the long seat stay screw that holds brake caliper, fender, reflector and fold lock together. Also remove the screws on both sides that hold the 3 spokes for fender support

• Bend the plastic fender so it’s more “curve” around the mount point. I bend it to a level there is a little bit visible “fold” near edge, but not noticeable unless you look for it.

• Straighten the mounting metal clip on the fender as much as I can, so that the lower piece is as straight as possible. Be very careful not to apply force on the plastic. Only on the metal clip.

• I used a dremel bit to enlarge the mounting hole on the clip towards lower, maybe 0.5-1mm, so I can mount it a little bit higher.

• When reinstalling, stuck the front edge of the rear fender behind, not in front of, that horizontal bar. This makes the fender more like a circle shape overall. There is another reason I want to do this — I am considering buying an after market fold block which allows folding to remain locked when the seat post is only half way down, making it a bit easier to push. That requires the fender to be pushed behind.

After all these steps, the rubbing is completely gone. I did a test by sticking a foam block of 3mm thickness with tape on the wheel and let it spin thru the fender. Before adjustment, the caliper mounting area used to destroy the tape and foam as there was no space at all. Now, it passes with light rub, even easier than the 2 other screw areas on the fender. Overall I think I got ~2.5mm clearance against a fully inflated tire (70psi).

Tried to fold the bike and let it sit on the fender. Does not bring back the rubbing, which is good. Once fender is properly adjusted, it’s really the spokes that are supporting the weight of the bike.

I do notice that the screws holding the fender spoke on the fender is a bit long, sticking out on the inside. So far it’s not bothering me as my foam block test shows sufficient clearance. But if it bothers you on your bike, it’s always an option to use a dremel to file down the tip of the screw a bit.