I have a set of Middleburns that have been in place for 4+ years. They have cheapy self-extracting bolts that are a baggy fit on the Allen key and have started to round. I know if I give them enough welly to undo the cranks they will go. So, what to do?

My plan is to remove the self-extractors and either fit some decent ones or use a crank extractor.

What should I do?
Are Middleburn bolts the best?
Any tips on removing the knackered self-extractors?
Any tips on removing the cranks with minimum oomph?

Crank extractor, just be careful with the threads. Make sure they’re clean before you start.

Usually a peg-tool to remove the caps yes?

Then std crank extractor. No idea what bolts are best to replace with – I’d use std ones and an extractor myself.

Yep, peg spanner is the proper tool to remove the bolts but I don’t have one and have my doubts about whether it’ll do the trick after they’ve been in there untouched for so long

Spray with a easing spray before hand, preferably overnight. Leverage is your friend. use an old long seattube

If the self extractors are of this variety

Then take your pin spanner and undo the outer sleeve of the self extractor or if you don’t have a pin spanner then use a small pin punch and tap the pin spanner holes gently to turn the alloy sleeve till you get it out.

Either use a quality 8mm hex bit socket with a suitable bar attached to it or use a torx bit, prob a T50 (below) or T55 if is very well rounded off – hammer it into place as this may shock/unlock the head and try and remove with a suitable bar

If this doesn’t work you may need to try a spline such as a M10 (below) and hammer this into place.

Don’t use normal allen/hex keys for this type of work as whilst they are perfectly ok for tightening stem bolts/seatpost clamps etc they are next to useless for this kind of work.

If you have the above tools then it’s an easy job, if you don’t then it may be worth your while to ask around and find a mate that has them otherwise it may cost you a few ££ to buy them.

When it comes to removing the cranks pour boiling water over the crank end taper, the middleburn alloy crank shoulder will expand a minute amount but enough to make removal easier with a suitable crank extractor.

Great stuff. Thanks for the advice

Wow not seen those shimano ones for 20+ years.

My guess is the OP’s are 8mm AK and aluminium caps.

Well, partial success. I got the extractor bolts out using a pin punch and hex key without too much trouble. Drive side crank came off easily enough with a crank extractor tool but the left-hand crank was a complete #$@%* – it was locked solid, the thread stripped and it took three hacksaw blades, two drill bits, a cold chisel, lump hammer and an entire afternoon to get it off.

I guess that’s the price you pay for bottom brackets that last four years…

Next time, I think I’ll take it to a shop

Seems like this may be a little late but in the future hot water on the arm often helps and is a little safer for many than Useing a blow gun

Or if you don’t mind a little damage then a car ball joint splitter works well