Crank bolt stuck/rusted/ not moving. Any advice to remedy this that wont just round off the bolt and

[Cyclopathic]

necessitate drilling or other dramatic measures.

To clarify it is the bolt that holds the crank in place on the side without the chain wheel. It is a bolt type, not a nut and it is not the allen key type but one that requires a 14mm socket. I've given it as much force as I think is ok without risking slippage and rounding. Currently it is steeped in wd40 awaiting my return.

 

[Mugshot]

Have you tried to tighten it? Try that first if you can, a little bit of a turn will often break the seal, so to speak, and you should then find it much easier to undo

 

[Cyclopathic]

^^^I'll give it a go, thanks.

 

[GrumpyGregry]

have you got a decent 14mm hex socket, rather than the sort of socket that fits a head 12 ways and have you got the bike in a stand? Both can make a huge difference ime.

 

[Robson3022]

Try and leave it 24 hours with plenty of WD40 if you can. Or heat it up if possible?

 

[Cyclopathic]

I've got a bike stand. I'm just using a regular 14mm socket from a socket set with a long arm attached. Is there a better option? Just looked properly and the socket os the 6 sided rather than 12 point one.

 

[green1]

Always use a 6 point socket on a seized nut, cant round it off then.

 

[Mugshot]

Or heat it up if possible?

Just about to post this, if you can get some heat on the thing this should allow your chosen lubricant to penetrate further into the thread.

 

[Sheffield_Tiger]

I have a large copper headed mallet - heavy as (well, as heavy as a large copper headed mallet) that does wonders when striking the end of an 18" long breaker bar

 

[GrumpyGregry]

I've got a bike stand. I'm just using a regular 14mm socket from a socket set with a long arm attached. Is there a better option? Just looked properly and the socket os the 6 sided rather than 12 point one.

Have you got it off yet and how much brute force had to be applied?

 

[Sheffield_Tiger]

It should withstand more force than can be reasonably applied on a stand. Have you tried sitting the frame on the ground (on a sheet, bit of old carpet etc) upright, bottom bracket on the ground, seat post upright, with crank arm sat along the ground, leaning on the frame to keep it pushed down on the floor and standing on a breaker bar with a 14mm socket?

The bolts are usually pretty hard unless it's a *really* naff B/B axle with dull silver coloured bolts - I've never managed to round one off

 

[HovR]

It's not so much rounding the bolt head off that I'd be concerned about, but shearing the head off the bolt if it is really rusted in. Think I'd be tempted to try soaking it in penetrating fluid first, then applying heat, then brute force..

Worst case scenario is the head shears off or you have to drill it out, then you'd have to buy a new BB (about £15) so not too bad.

 

[Cyclopathic]

I have decided to leave the bloody thing where it is. It will have to come off one day but it will probably have to be sawed and or drilled. I've been at it with wd40, a blow lamp and a 2 and a half foot crank for taking car wheel nuts off. The amount of play at the end of the crank is absolutely tiny so I'm leaving it until it absolutely has to come off.
Thanks for all the tips.

 

[Cyclopathic]

Have you got it off yet and how much brute force had to be applied?

It is equal to and better than all the brute force I have applied. See above. Fortunately the chainwheel side came off quite easily so I can get in there and give it all a good clean up.

 

[screenman]

If you have the use of a quality impact gun that should do the rick, if not nip it to a local garage and let them do it for you, most will be only to happy to show you how clever they are. Nice thing about the impact gun over a long bar is that is will not flex the frame.

Now if you do use the long bar method make sure the bottom bracket is well supported by placing it on maybe an axle stand or suchlike.

I am only 60 miles from you so if you are ever on a ride out towards sunny Skeg drop in on your way and I will do it for you.