We tried for hours to get the rear wheel off this bike using wrenches and hammers. Then I noticed this screw that looks like it attaches straight to the rear axle. Do we need to undo this screw? screw in rear hub

Its probably just rusty but before we break something I thought I would check.

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    A clean and well-lit photo of your bike might provide a bit more info than this generic stock photo.
    – Criggie
    Commented Nov 30, 2017 at 19:22
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    @Criggie, you're right. This was my friend's bike in another city that I was trying to fix a flat for over the holiday. I was really just wondering what that random screw was for since I had never seen it on a bike before. She also rides a flip flop bike so I figured it was just some fixed gear bike thing I had never seen. This photo does the job though! The screw is very clear in the photo. It was bothering me so much that I decided to post a question on the forum in case I saw it on another bike in the future.
    – daniella
    Commented Nov 30, 2017 at 21:33

2 Answers 2


As @Nate Wengert says that screw is for adjusting chain tension. It pokes into the axle slot and prevents the axle from moving forward. It does not attach the axle or hub to the frame in any way.

It sounds like you just need a bit more torque to get the axle nuts undone. If you cannot apply enough torque with a full size wrench, a short length of approximately 1" diameter sturdy metal pipe that can be slipped over a wrench handle to extend it for more leverage - sometimes known as a 'breaker bar' - is the usual tool of choice.

Apply WD-40 or similar to help loosen the nuts before attempting to undo them.

It's best to use a box-end wrench if you can. Avoid an adjustable wrench if possible because there is a greater chance of rounding the flats on the nuts.

Also, you want to be really, really sure you are loosening not tightening (we've all done this at some time), especially if you use a breaker bar as you may end up rounding the flats on the nuts or stripping the threads.

  • Word of warning. Axle torque should be about 260–390 inch pound. Nothing that cannot be undone easily with a 10" spanner or socket handle (I need a breaker bar to get 3000inch pound-not on my bike :) ) . If you need a breaker bar on a bike, things are ceased, assembled wrong, or over tightened. I would use penetrating oil before reaching for a breaker bar.
    – mattnz
    Commented Nov 30, 2017 at 19:35
  • @mattn I was assuming OP in fact has seized axle nuts. Agree on using caution with a breaker bar Commented Nov 30, 2017 at 19:54
  • Thank you! That's what I figured but wasn't sure. Obviously the photo I used is not the actual bike. The actual bike was a bit rusty so we'll just have to get something with a bit more torque!
    – daniella
    Commented Nov 30, 2017 at 21:21
  • Threads are "siezed" meaning they will not slide when rotated. Rust could totally cause this. "Ceased" means "stopped"
    – Criggie
    Commented Dec 1, 2017 at 2:02
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    @Criggie, I think you mean "seized"?
    – daniella
    Commented Dec 11, 2017 at 19:16

enter image description here

The nut in the orange circle is what you need to remove on either side of the hub, there should be no use for a hammer in this application. Simply use an adjustable wrench on either side and remove counter clockwise.

The yellowish green arrow points to a tensioner screw, which helps to tension the chain and properly space the axle in the dropout so that it is equal distance on either side.

The blue oval is an issue, your chain should not be doing this and i'm not sure how that happened. Is the chain off the front chainring so that it is loose i assume? I would roll the wheel forward and fix this chain hang up before removing the wheel so that your not fighting it when you try and slide the axle back and out of the dropouts,

  • The chainring is visible through the pedal -- with no chain as you thought
    – Chris H
    Commented Nov 30, 2017 at 16:56
  • The bolt to which the greenish arrow points looks like an Allen bolt to me.
    – Carel
    Commented Nov 30, 2017 at 17:33
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    @Nate Wengert That's not the OP's bike, pic is from the Pure Cycles website page in swapping out rear sprockets: purecycles.com/blogs/bicycle-news/148888903-swap-that-cog (found via Google image search). The wound up chain is to act as a chainwhip. I'd expect the OP's bike is heavily corroded, hence their problem. Commented Nov 30, 2017 at 18:47
  • FYI: "either side of the hub" that means both sides in this case.
    Commented Nov 30, 2017 at 20:40
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    That makes a whole lot of sense.. haha but yeah, hit it with some pb blaster let it soak and go at it again, with a little more leverage or a breaker bar if need be just be careful with a breaker bar not to twist the axle in half if it is seized. PB blaster will do wonders to seized parts though
    – Nate W
    Commented Nov 30, 2017 at 21:42

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