How to install geneticbikes.com's chain tug to horizontal dropout with anti-rotational washer and hub gears? I have 8 speed Shimano hub-geared bike. When I place the chain tug by geneticbikes.com, the black tud does not fit into the dropout. According to the thread, here, I can use one chain tug to the right without serrated anti-rotational washer and one anti-rotational washer to the left.


The tud does not fit the dropout. I cannot understand where it should be in some hole but cannot understand the mechanics. What is the tud for?

You can see there the anti-rotational washer, being not round while the chain tug is round.


I am unable to find the right position to the chain tug, apparently the black tud behind in the way. I tested and the tug is of the right size to fit the line but it is very hard to find the right position without tilting the chain tug, not found any position yet (not sure whether I need to round the tud to fit it.



[Update] After filing, how to protect the frame from the tug's screws? Tug on the right (chain's side) and the anti-rotational washer on the other side (recommend on the link below, not sure whether it is enough to stop the hub rolling).



You can see how the screws make bad to the frame, how to protect it?


...and here is the picture on the right side, the anti-rotational washer is on the left side. The right side has no anti-rotational washer -- a problem? The fender screw is on the way to put the tug on a very good position, could the fender be placed on the same screw as the rack?


Further information


same question but with incomplete answers here
moz explaining chain tug here, to protect the soft aluminium frame
chain tug to solve a chain slippage problem here
The extra stud would usually sit in the dropout slot and help align everything, but your dropout runs the wrong way for that so the stud is just an annoyance. File it off and things will work much better.

If the raised/recessed circle on the front of the tug is not big enough to accept the nut on the hub you may have to file that as well. It's visible in the bottom photo above.

update: you will probably be ok with only one antirotation washer, but ideally if you can get the tug in between the frame and hub so you can put the washer on the outside that would be better. Remember that the tug is now taking the force from the chain so the nuts don't need to be done up especially tightly. So you don't need full thread coverage on the nut.