ashsimmonds

removing the cranks on my CRX4, the left one came off alright, then thought i was going alright on the right crank and then the tool popped out and i noticed instead of pushing it off the crank, it had actually completely stripped out the thread of the crank arm.

now what? i'm replacing the crank arms anyhoo, but how the hell do i get it off?

Wil Davis

Sorry to hear it.

Rules:

(1) make sure threads on crank and extractor are clean and lubricated.
(2) make sure extractor is screwed fully into the crank
(3) use search function to find all threads dealing with similar problem (there has been at least one here on BF in the past month)

Hope this helps -

- Wil

ashsimmonds

ok, first two rules are moot :/

i'll look around then...

ashsimmonds

ok, most of what i can find is just about proper procedure for removal, apart from lubing up everything i did was right, it just totally shredded the inside thread.

only thread i can find on borked threads is this https://www.bikeforums.net/mountain-biking/284087-crank-question.html where someone recommends a heli-coil thingorama.

Little Darwin

You may be able to get it off with a gear puller, available at auto parts stores etc. They aren't too expensive.

An LBS or garage may have one to save you the purchase and could pop it off for a couple of bucks.

Wil Davis

There was one recently in which a poster suggested the use of a regular gear-puller, which led to a discussion of exactly how that might be done. Someone even suggested using a wedge and a hammer.

- Wil

filtersweep

This happened to me on an old bike I was rehabbing--- and the spider was bent anyway, so I had no reason to save the crank. I ended up using a dremel to cut it off. It took forever.

Wil Davis

Here you go! (post #38 has good advice…)

- Wil

MudPie

If you have a square taper spindle, see Park Tool's advice:

https://www.parktool.com/repair/readhowto.asp?id=136

tellyho

There are 4-5 posts on this. On guy is fond of the "put the right sized socket into the crankarm hole, lay your bike on a concrete floor, and knock the crankarm off around the socket" method.

Looking at that sentence, I've concluded that there's no easy way to summarize. Do the search. Also the gear puller, as above.

maddmaxx 

I know its too late to help but by any chance was the washer from the crank bolt still in the bottom of the hole. If so the crank removal tool will push on the washer not on the bottom bracket.

The idea of laying the bike down on a cement floor with a socket small enough to fit through the crank but pushing on the bottom bracket shaft and then GENTLY tap the crank off with a hammer. Use a socket extension or small pipe to reach through from the top of the frame.

BSLeVan

I saw an old mechanic in a bike shop (must have been in is 80s) about 20 years ago use a gear puller on a crank with stripped threads. He had no problems, but worked very slowly. He placed the three arms of the gear puller behind the crank, turned the extractor bolt till it was snug. Checked the placement of the arms, did a full turn of the extractor, checked the arm placement again, and repeated until the crank was off. According to him the biggest risk of using the gear puller is having the arms slip off the back of the crank while working. Given the metal is pretty soft, it can gouge it pretty good. Good luck.

peripatetic

If the bolt is off, you can go ride the bike. That'll back the crank off.

top506

That would be my plan 'A'.
Plan 'B' would be a ball-joint fork.
Top

Deanster04

I made one using bolts, and industrial grade washers to brace the crankextractor. I had to drill the crank arms for the bolts. It worked quite well and allowed me to save the expensive bottom bracket. I will try and gather the thing together and post a picture.

Grand Bois

There is a special tool for this:

https://www.biketoolsetc.com/index.cg..._id=VR-PE11000

Maybe you can find a shop that has the tool and a mechanic that knows how to use it.

BikeManDan

If I was a shop I could maybe see dropping $160 (and then writing it off) but for the average joe, wow. Id go with some of the other methods first.

justinb

I've used the automotive gear puller as well. I backed the crank with a couple pieces of 1/8 steel plate that were laying around. As mentioned above, it's difficult to get purchase on the crank and pull evenly from all sides- work slowly, continually checking the interface of gear puller arms and crank.

The spider still bent, but considering that the threads were stripped, it was headed for the trash bin anyway.

DannoXYZ 

I've used motorcycle tyre-irons before. Just wedge the tip between the crankarm and BB-cup. Pry a little >POP<, the crank comes off. Takes all of 5-seconds .

Grand Bois

Nobody suggested that he buy the tool.

San Rensho 

Find a socket that just fits inside the square of the crank arm.

Put the socket on a cement floor.

Place the bike over the socket so the socket is inside the square of the crank arm. Have someone hold the bike.

With a flat punch and a BFH (big f@cking hammer), hammer on the crank arm as close as you can to the bottom bracket. Put a big flat washer between the punch and the crank arm to protect the soft metal.

dbs

Never worked on this issue before but things similar.

A little heat does wonders for loosing these things up. I'd expect the arms are aluminum and the crank shaft is steel. Aluminum will expand faster than steel so just a little heat and it may fall off.

powers2b

Just ride around town with no nut onthe spindle.
Trust me, the crank will come off when it is ready.

DMF 

Not only do I not believe that, you shouldn't believe it either.

And while I'm on my soap box, why don't you give us enough information to help you? No clue as the type of crank retention mechanism you're dealing with! Are we supposed to guess? Put out some effort!

JunkYardBike

I found what I think is a tie rod remover at a garage sale yesterday. Adjustable arms on pivots, and it has two claw sizes if you flip the arms. Worked like a charm on an old crankarm-attached-to-spindle I had. Took quite a bit of torque to remove, and the pop scared the ***** out of me.