I recently bought a pair of Qbicle Tangent fenders for my folding bike. The bolt for the derailleur hanger is in the way of the mount:

enter image description here

The fender is supposed to be installed at around this angle: enter image description here

The derailleur hanger looks pretty much like this: enter image description here

And the dropout is just flat (no grooves) with a hole beside it like this: enter image description here

Is that derailleur hanger the only type of hanger that can be used for that kind of dropout?

I could install the fender so that the bolt of the hanger would pass through the fender mount. The fender would be mounted at around 170°; it would just cover the area between the 9 to 11 o'clock positions. Would the fenders be useless at that angle?

  • You could try it out. Nice pictures.
    – paparazzo
    Mar 21, 2017 at 15:24

2 Answers 2


It looks like a tricky problem. When I am faced with such problems I try to exhaust options before altering original parts..

With that in mind, I would look for a button head (rounded top) screw to replace the hex-head that hold on the derailleur hanger to see if the lower profile of the button head gives you the needed room to mount the fender in its designed configuration.

If that does not do the trick I would weigh my options between the fender angles you mention (hard to comment on effectiveness not seeing pictures) and perhaps countersinking the derailleur hanger so a flat head screw can be used to buy you the clearance you need.

Final thoughts... the derailleur hanger hex head looks pretty beefy. I have seen them attached with a couple 2M screws which are quite small. Changing the screw to button or flat head will result in using a smaller hex wrench for tightening. If getting the required torque to tighten it securely is a concern you may want to consider using some medium strength lock-tite as a measure against potential loosening due to vibration.

  • 1
    Yeah, the hanger bolt's head is pretty tall, I might just go find one with a shorter head. That might indeed work since a washer would be sandwiched between the fender mount and the hanger.
    – dork
    Mar 21, 2017 at 18:10

I would replace the bolt holding the hanger on with a counter sunk hex bolt enter image description here.

If you are not confident to countersink the hole in the existing hanger The only precaution I might take is ensuring I can source a replacement hanger just in case.

  • If I were countersunk a hole in the existing hanger, would that weaken it? Yeah, I guess it would be safe to have a replacement if it were damaged.
    – dork
    Mar 22, 2017 at 3:33
  • The bolt is there to hold the hanger on when the wheel is taken off, and locate the hanger so the derailleur is correctly positioned. rotating. Once the QR is done up it holds the hanger. Most (more expensive? ) use counter sunk bolts. There is no reason for the hanger to be particularly strong at that bolt location, the weak spot is below the frame where its no supported.
    – mattnz
    Mar 22, 2017 at 3:54

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