Removing a crank... Crank removed; huzzah. Now for the Bottom Bracket.

[Andy in Germany]

I've finally found a frame that I can restore to make a 28" wheel touring bike, and we're having trouble removing the old components. In particular the chainwheel screw thread , were we would normally insert the removal tool, is completely gone.

The frame is from VSF Fahrradmanufaktur and is a rare early butted example, made from Chromoly, so it's worth fighting for.

How would others on the does anyone have a recommendation how to remove the chainwheel? I can get the outer two gears off from the outside, but the inner is inaccessible. I'm open to all suggestions, up to and including using a disc cutter to cut through the crank itself.

 

[ivegotabike]

google showed me this video, could it help?


View: https://www.youtube.com/watch?v=jrpIoXxVyTs

 

[fossyant]

Angry grinder or even a Dremmel

 

[Punkawallah]

Angry grinder or even a Dremmel

If you have a replacement for the square taper spindle, and don’t need the crankset, a grinder cut across the offending part of the crank will do the trick. Otherwise, R J is your man.
Good luck!

 

[ivegotabike]

google showed me this video, could it help?


View: https://www.youtube.com/watch?v=jrpIoXxVyTs

Amazon has quite a selection of "three leg bearing pullers" or "three jaw gear extractors" etc.

This listing has various sizes that start at £7.55. I have no idea if any of them is suitable, but they look a bit like the one in the video

https://www.amazon.co.uk/dp/B01AGKYL30

 

[MontyVeda]

I'm open to all suggestions, up to and including using a disc cutter to cut through the crank itself.

If the bike is ridable then just ride it and the crank will drop off. They're bolted on for a reason. Leave a loose(ish) bolt in if you don't want it to drop off completely.

 

[Gunk]

I would try a bearing puller, I’ve removed one with a stripped thread using one

 

[Punkawallah]

I would try a bearing puller, I’ve removed one with a stripped thread using one

I’ve never tried that. Was the crank set stuck?

 

[Andy in Germany]

If you have a replacement for the square taper spindle, and don’t need the crankset, a grinder cut across the offending part of the crank will do the trick. Otherwise, R J is your man.
Good luck!

I've wondered about that, as the crank is now only held on by tension and rust, so cutting into the crank will remove the tension.

 

[Andy in Germany]

The bearing puller looks like the way to go: I'll have a look at the crank today, remove everything that can be removed and see what will fit.

Of course, there's a fair chance the BB will be rusted solid, but we'll take it a step at a time...

 

[Venod]

A length flat bar or round plate, drill and tap the centre of the bar/plate with a suitable hole for a substantial available bolt, drill two suitable holes to bolt the bar/plate to the crank, thread the bolt into the bar/plate and tighten.

 

[lenfield]

If you know any DIY car mechanics then you could always use a ball-joint splitter.

 

[biggs682]

Bearing puller

 

[Tenkaykev]

The local Tarmac Plant used to borrow our " Big Red 'Uns " if they had an intransigent motor coupling. The legs stood over a metre tall, and the bar that operated the screw thread mechanism was bent out of shape due to the use of a length of scaffold pole used as a " torque converter ". We'd rest the legs on railway sleepers to bring them to the correct height and parallel with the motor shaft, get a couple of big propane torches blasting the coupling and heave away. Having them probably helped when they were looking to renew the maintenance contract.

 

[Gunk]

I’ve never tried that. Was the crank set stuck?

Yes, loads of Plusgas and then a three prong puller and a lump hammer