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How much gap should be between the crank arm and bottom bracket

I recently decided to restore an old bike I had lying around so that I could ride with my son. I'm installing a shimano MC 361 Acera crankset on a UN55 68/122.5 bottom bracket. After attaching the left crank arm I noticed a rather large gap between the arm and the bracket.


Is this normal. Looking at another bike I am using for reference the gap appears to be less than 1/4 inch. On the one with the new parts it is 1/2" or more. I have included a picture. This is my first project and just want to make sure I have missed anything.

Thanks for the Help.
for a casual rider, this gap does not really matter as long as the arm clears the chain stay, the other side is more important as you need to maintain a good chain line, which you need to check visually after assembly and by making sure all gears can be obtained smoothly.
If the bolt retaining the crank arm on the BB is correctly torqued (usually 305-391 in-lbs), and you don't feel any play in the crank, the gap should be OK
Thanks for the replies.
I got a hex socket for my torque wrench and put them at 360 inch/lbs. They seem solid with no play.
Guess it's just my OCD that's bothered by the gap.

You did install it in the correct direction? (hey, just asking... though I guess that many BBs have the threads of one side fixed to the cartridge, so it should not be possible... I guess)
As far as I know I did...the drive side is considered the Right side correct? I inserted the BB in with the arrow pointing to the R on the drive side.

Quote:As far as I know I did...the drive side is considered the Right side correct?

Sounds about right to me.

Also, the gap looks OK, similar to the one on my square-taper BB and cranks. A couple of mm here or there doesn't matter much, as said before, provided the peddle end is clear of the chain stay and the chain line is OK.
If you look at the pedal distance on both sides you will see they are both away from the BB on one side the gear cluster. IF the pedal was a lot closer to the BB it would not clear the chain stay. Rotate the pedals back and look how much clearance they have.
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