Bicycle Mechanics - Sad Story

8 yr old Shimano LX crank and BB. Short story, crank arm on crankset side bolt is frozen, LBS said they couldn't get it out. I tried a impact wrench as a last resort and rounded the inside of the bolt. Bolt is harder than any drill I own. Time for a new bike?

No! If nothing else hacksaw the bb spindle off. How did you round the inside of the bolt?

Also, you can crack the bolt head off with a good chisel and hammer. There shouldn't be anything on your bike that a good mechanic can't get off.

Agree with above.

A good mechanic or machinist should be able to drill the head off the bolt with a carbide tipped bit, or tig weld something to to the bolt head and back it out that way.

Bolt is flush-mount allen bolt. Rounded with a electric impact wrench after LBS gave up and said I might as well go for it.

rule number one of fixing anything - there is always a bigger (insert tool here - hammer, drill, wrench, etc)

Sawing the spindle will require purchasing a new crank, so I'd put that as a last resort, drilling out the screw with a better drill is probably first attempt. $ for drill bit << $ for crank.

Is this a self extracting bolt? I can't imagine it is so hard that you can't drill it with a regular drill bit.

Also, this may seem obvious at this point, but that lbs is worthless.

In the future, remember that heat is your friend. Heat does amazing things to stuck hardware.

Az

Tried a new 3/8 bit, it just rattled around the left-over flats of the Allen Head. Tried a new 1/4 bit and barely made a dent. I think its too late for heat now. Maybe it isn't self-extracting the bolts are hard. I'm more familiar with the old style hex-head bolts. God, I'm old. Never had this problem with them. I went to the shop because they "owed me a favor" from a previously botched job. Sounds silly doesn't it?

Is your drill spinning the correct direction? Even if you break or drill off the head of that bolt, you will still need to pull the crank off the spindle. As stated above, heat works well.

Seein as how I don't have a proper vise or drill press, or welding or torch experience, hacksawing is looking better all the time. Thanks for the ideas.

I agree with cuda2k. Purchase a couple good quality drill bits. Drill a smaller pilot hole first, then go after it with the largest drill possible. Do this in a drill press--you'll be able to do it at a much slower speed with lots of feed pressure that way. Keep it lubricated and keep the pressure on, watching the chips rise to the top. Harder materials need to have a chip forced from them. A hand drill will probably not allow enough feed pressure to force a chip. When you purchase the larger drill bit, also purchase an EZ-out sized for the larger hole. After the larger hole is drilled, apply some heat. Insert the EZ-out and carefully back out the bolt. Hopefully this will get the job done. When you install the new bolt, grease it liberally with waterproof grease, such as trailer wheel bearing grease. Let us know how it goes.... OHB

Seein as how I don't have a proper vise or drill press, or welding or torch experience, hacksawing is looking better all the time. Thanks for the ideas.

What are friends for??? Cm'on. You're in Iowa, there's bound to be a farmer around. They know how to remove stubborn bolts.

I am an old farmer, its all these new-fangled allenhead, flushmount bolts that have me confused. Used to be able tackle any bolt with ball-peen hammer and a cold chisel. Either chop the head off the small ones, or hit it at an angle on the biguns to get them loose. Didn't need no high-faluting heat.

I am an old farmer, its all these new-fangled allenhead, flushmount bolts that have me confused. Used to be able tackle any bolt with ball-peen hammer and a cold chisel. Either chop the head off the small ones, or hit it at an angle on the biguns to get them loose. Didn't need no high-faluting heat.

Yup, I've done the same. What about trying the same method with a pointier chisel, like a cape point? I mean, if there's enough bolt head left to get a whack at.
Also, nobody mentioned using a penetrant, which usually helps a bit. PB Blaster is great for bikes. Kroil is darned good too.
Any chance you have another hex that makes a tighter fit than the allen socket? Even a bolt head that can be driven into the allen's recess might give you enough contact to apply some torque.

Penetrant would be great if there were still a bolt head to get a hold of. That thing should be off by now!

likely will end up screwing up the BB with all the drilling. may not be worth all the time and better to just hack off the BB... you may be able to still save the crank by drilling back through the opposite way, when it hits the bold it may dislodge and unscrew. square taper BBs are cheep. 18 bucks CND at the LBS here.

we always do this when we assemble bikes. before installing the crankset, smother the BB spindle with grease. so that as time and harsh weather passes by... corrosion from AL or rust from steel won't fuse these 2 together.

this exact scenario happened to a bike i was working on a few days ago. you need a BOLT EXTRACTOR!. first, you take a small drill bit and drill a hole into the crank bolt. then, take said bolt exctractor and put it into the hole, and turn it with a wrench or a drill. the bolt then comes out as if you were unscrewing it. this is a very useful tool for any bike shop or home mechanic to own. it has saved my life many times.

http://www.irwin.com/irwin/consumer/jhtml/detail.jhtml?prodId=IrwinProd100312

Catatonic just had that problem few weeks ago. I betcha he can tell you the secret!!

edit: I just notified him to check out this thread. He was able to get it off, though. The way he described it, made me think of the game "Twister". :p

My problem was stuck pedals.

I agree with the bolt extractor. That would be the best method.

To have stripped the inside of an allen bolt, either the tool was bad, or the wrong size tool was used. Once the inside is rounded, it's going to be a pain to get it out without an extractor.

My trick for picky crank bolts/pedals is to remove the seatpost, put the wrench in the desired spot....in your case an allen key with a thin pipe over it for leverage, and while standing over the frame, legs bracing it....push in the proper direction with all you got.

For pedals, you need a shorter second pedal wrench wrench (I have a cheapo I got from performance bike for that task) to keep one crank pushing against the ground. In your case you might want to do that as well, just to add to leverage.

You don't need air tools on a bike, ever. actually I would refrain for power tools at all for bolts or nuts of any variety on a bike. Not so much about curmudegeonery as much as it is about the low torque levels required for these parts. I suck at upper body strength, and I still overtorque stuff.

As a final resort, maybe supergluing a nut to the bolt and using a hex wrench might do it for you. Just be careful to not superglue it to the cranks!

Good luck!

Once again I thank you guys for the input. As I think about it more calmly, I tend to think I'm in deep s___. Given the history that before I rounded the Allen head with an electric impact wrench I first couldn't move it with a 6" allen wrench. I then purchased a 8mm 3/8" socket to put on the end of a 12" socket wrench. It wouldn't move. I then went to the LBS and all king's horses and all the king's men gave up. I question as to whether any of the solutions will allow me to put more torque on the bolt than I already have. Again, I appreciate the input, but doubt the effectiveness.

Hmm, sounds like you need to deep freeze it a few times.

Either instant chiller, or go buy some canned air, put the tube on the can, filp it upside down, and spray that sucker until it has ice on the outside. Then heat it up quickly (I used rags soaked in boiling hot water...of course wearing protective gloves...the rags still freeze within seconds, so keep the tub of boiling water nearby.), and repeat a few times. this can often break any bonds that may have formed through material expansion/contraction.

this sounds like aluminum oxide.
when aluminum and steel (crank arm and cro-mo spindle) come in contact aluminum oxide forms. this chemically bonds the two metals toegther. depending on how long it has been there, it can be broken with a firm tug or not. use AMMONIA. this is the exact situation that happens with stuck alu seatposts in steel frames or vice versa. spray down the spindle and whatever else with ammonia every chance you pass by it (or~10 times a day) for a week. then go at it again and it will be free :)

this sounds like aluminum oxide.
when aluminum and steel (crank arm and cro-mo spindle) come in contact aluminum oxide forms. this chemically bonds the two metals toegther. depending on how long it has been there, it can be broken with a firm tug or not. use AMMONIA. this is the exact situation that happens with stuck alu seatposts in steel frames or vice versa. spray down the spindle and whatever else with ammonia every chance you pass by it (or~10 times a day) for a week. then go at it again and it will be free :)

The bolt and BB are steel the crank is aluminum! He can't get thye bolt out not a problem removing crankarm.

Do you have access to a tig/mig welder? Put the allen wrench back in, weld it to bolt, take bolt out with wrench. Discard bolt/wrench

The bolt and BB are steel the crank is aluminum! He can't get thye bolt out not a problem removing crankarm.

Do you have access to a tig/mig welder? Put the allen wrench back in, weld it to bolt, take bolt out with wrench. Discard bolt/wrench


On a self extracting bolt, that is the problem. The crank is stuck and the bolt won't turn because for it to turn, it has to pull off the crank.

get an ez-out/bolt extractor. a welded allen wrench can snap, but the ez-out uses a tap handle that is stronger and allows you to get 2 hands on it. I used one last week on a suspension that had aluminum bolts going onto steel studs. These were bigger than crank bolts and I sheared the head clean off.

Going to try the ez out. Studied the crankset and BB last night, and found that there isn't enough clearance to use a hacksaw if I wanted. The granny gear bosses are in the way and the clearance between the crankset and BB shell is LESS than the thickness of a saw blade. ALSO, I was wrong about it being self-extracting. Just a bolt with the plastic flange around the head. I took the bolt out of the other crankarm. I can't believe a bolt that small is in so tight. Its going to take a small ez out. There is also NO WAY any penetrating oil will get past the plastic and the bolt head flange. The s___ is getting deeper and deeper.

good. lay the bike down flat and put a lot of weight into the ez-out.

Take it to your local tool and diemaker shop. They will get it out for you.

No, I'm done. After all the torque I used previously, I decided the ez out still wouldn't let me put enough torque to loosen it. Decided to drill out the bolt. Two $7.95 cobalt drills later all I'm doing is polishing the bottom of the hole. I'm out of money and patience for this project. The bicycle will be a parts bike just because of a trashed bottom bracket. Shame too, because I really liked the bike. Poor,Poor Pitiful Me.

Instead of throwing a pity party, find a good shop with a drill press. This isn't a heart and lung transplant.

You could probably remove the BB with the arm still attached. If it is the old cup style this is simple as there will be flat spots. If it is a cartridge which it sounds like it might be then take the channel locks or a large pair of vice grips to it. remove chain rings first so you have room to work. remove the opposite cup too of course. I'm sure at this point you are not too concerned about chewing up the BB. Put ammonia or penetrating oil down the seat tube if it is stubborn.. Remember drive side is clockwise to loosen.

I can't even believe what I'm reading here. Just hacksaw or crack the cranks with a chisel at the spindle.

mcoine - see above where he states that there is no room to get a hacksaw blade in between the crank and the BB shell. I agree there has to be somewhere to get the bolt drilled out and the thing off.