Any tips for freeing a crank spindle which seems to have welded itself to the BB bearings?

It’s an E13 crank, like so (pic from when it was last out):

Drive side arm has come off fine but the spindle and non drive side crank is well and truly stuck after a year of being in there. Have hit it hard, many, many times but it’s not budged a single mm. Carbon frame too so don’t want to hit it as hard as I possibly can, for obvious reasons!!

Just want to replace the PF 30 mm BB with something with proper sized bearings, even a supposedly weather proof solid oil matrix bearing has got some play now.

You need to hit it harder! Simples!

Sounds like the crank and bearings have cold welded themselves together, so you’re going to need to shock them apart. A willing friend to brace your frame whilst you strike the crank axle will help a lot.

I had to knock a pivot axle out of my frame the other week, I had hit it very hard with a mallet whilst holding the bike upright To no avail. Turns out I needed to hit it very very hard with a proper hammer with the bike on a hard surface, it came out fine in the end.

It’s still there.

It’s had a massive soaking of release spray, for several days, I’ve tried hitting it very hard lots (and lots and lots) of times now it’s cooler in case the crank spindle had expanded in the heat, and I’ve tried hitting it back the other way to see if only one side is stuck and it would start to push out the bearing cups.

Nope.

Even resorted to removing the bearing seals and inners to see if I could start removing the bearings to remove the inner races. Not a chance.

I was going to give the bike a full refresh anyway so I’m now stripping it down, rear linkage has come off and it’ll get stripped to a bare front triangle, I’ll then be able to brace the frame properly against something while trying to hit it again. If not, I’ll be ringing round a couple of bike shops….

One thing is for sure, I ain’t fitting a 30mm crank on it again.

24mm hope press fit with the replaceable bearings and a matching crank.

Should go check my E13 cranks….. The bearings are stupidly small

Would definitely recommend whipping it out, greasing it up and slipping it back in every few months. Would have saved me banging away at it for hours.

One thing is for sure, I ain’t fitting a 30mm crank on it again.

24mm hope press fit with the replaceable bearings and a matching crank.

Guessing this is on your mk2 Jeffsy?

I agree about 30mm, I’ve got some 24mm cranks to go on when I next have to change the bearings.

Having said that, I’ve been running Xcx cranks since 2012 on my enduro bike and only on my 2nd bottom bracket (not too frequently ridden however). They’ve lasted far better than I would have expected

Have you tried filling the spindle with ice? I couldn’t remove a threaded BB cup, used so much force it was destroying the notches. But freed it first time after filling with ice.

I use a spare crank bolt (turn down the OD if needed) (or a plug that fits the crank end perfectly) and an air chisel, walks them straight out. The sharp shock and vibration works a treat (even on ones you have been worried about breaking the frame you have been swinging so hard with a hammer).

Guessing this is on your mk2 Jeffsy?

I agree about 30mm, I’ve got some 24mm cranks to go on when I next have to change the bearings.

Yep, E13 BB lasted 6 months and this one a year.

I use a spare crank bolt (turn down the OD if needed) (or a plug that fits the crank end perfectly) and an air chisel, walks them straight out. The sharp shock and vibration works a treat (even on ones you have been worried about breaking the frame you have been swinging so hard with a hammer).

That’s a good idea, thanks. Same principle as an impact wrench which are a godsend for freeing stuck bolts that you’ve been hanging off. Now to find someone with a power chisel/hammer…. Or maybe even a jackhammer… 😁

Get the whole area really hot with a hairdryer or hot air gun (be careful with hot air gun) then blast area with freeze spray to shock the dissimilar metals, then tap out if lucky. Repeat as necessary. Good luck.

Praise the Lord!!!!

It’s out.

Most of a can of freeze numbing spray with the frame stripped to the front triangle (needed to give it a proper refresh anyway) so I could brace it against a block of wood with some foam and cloth protection, and then twatting it with a rubber mallet very, very hard got it moving a few mm, then after another 2 doses of freeze spray and a good hard twatting, it popped out!

Had a moment of panic as I couldn’t then release the other side but a bit of wood and a quick tap was all it needed. Thank *******!

Frame needs a new lower headset bearing too so will order some parts pronto.

🥳 pure relief!

Don’t think I’ll ever stray away from shimano, 24mm steel running on delrin or whatever those placky things are has been headache free for me, never taken me more than 5 mins to take off, unlike everything else that seems to snap, seize or needs high torque levels.

The hardest part might be finding the bloody spares

The hardest part might be finding the bloody spares

Does seem too bad, hope PF41 24mm BB, Shimano M8100 cranks and unite co chainring all in stock