[Shencycle]

So I have this XTR crankarm...the M950 and the damn thing keeps binding to what ever I mount on it....First it was the bottom bracket now it is the Time Atac mounting bolt. I have used Liquid wrench, WD 40, Marvel Mystery Oil, and finally I put a torch to it....still not a budge. I actually bent the allen wrench I was using when I tried to get the pedal off. Same thing when I tried to dismount it from the BB. It looks like I am going to have to cut the BB spindle to get it off the bike.....I have had a few different sets of these cranks with no issues what so ever.....Even the other side is easy to remove.....Can something go wrong with the aluminum alloy... so it actually welds to an unmatched metal????
Any suggestions??
And yes I am turning the wrench the correct way....
Thanks for any positive input....

 

[ChrisKring]

Originally posted by Shencycle

Any suggestions??
And yes I am turning the wrench the correct way....
Thanks for any positive input....

Try putting some grease on the threads next time.

Chris Kring
www.highgearracing.com

 

[Shencycle]

every place grease is warranted, grease is applied, as in all my builds.....
I am looking for productive answers...not jerk off answers.....the obvious has been covered.

 

[ChrisKring]

Actually, it's a galvanic bond

Four Components are Needed for Corrosion…
1 Anode – a metal surface which gives up metal ions (corrodes)
2 Electrolyte – a medium which conducts ionic current between the anode and cathode
3 Cathode – a metal surface that picks up metal ions
4 Metallic bond – a continuous metallic path that allows current to flow from cathode to anode

The grease address #2 by preventing water and salt from entering the joint and #4 is the obvious.

To get it off:
Is it that the crank bolt is stuck in? then drill it out and remove the crank as normal then use an ez-out on the bolt.

If it is crank stuck to the Bottom bracket:
have you tried hiting the crank arm extractor with a rubber mallet?

That usually works.

Chris

 

[Shencycle]

re: the bottom bracket.....I believe the bolt is 'hardened steel'(XTR self extracting) so I think drilling it will be a very difficult task, if possible at all??????. I have even gone as far as using an impact wrench.....to no avail.

re: the pedal....I would like to salvage both the crank arm and the pedal if possible.....at least the pedals since they are only a few months old.....and I do have another XTR crank arm......

My main confusion is why this is happening to this one and only crank arm....all of the others have the same variables connected to them.....it makes me wonder if there is not something amiss with the alloy........worse comes to worse.....I guess the aluminum gets cut.........do you have any other suggestioins???

I have also consulted a "team mechanic" and his suggestion was to cut it off.....I am looking for other possibilities at the moment.....so I figured I question the RM engineers.......
Thanks for your response...

 

[recidivist]

This comes from a conversation about removing stuck seatposts, so YMMV buy quite a bit, but one way to attack aluminum-corrosion is with ammonia.

Of course, in this case, both pedal and BB axles are steel (or ti?), so I don't think this is a case of strict 'cold-welding' ...

See also (particularly #13):

http://www.sheldonbrown.com/stuck_seatposts.html

 

[Kornphlake]

Originally posted by Shencycle
re: the bottom bracket.....I believe the bolt is 'hardened steel'(XTR self extracting) so I think drilling it will be a very difficult task, if possible at all??????. I have even gone as far as using an impact wrench.....to no avail.

re: the pedal....I would like to salvage both the crank arm and the pedal if possible.....at least the pedals since they are only a few months old.....and I do have another XTR crank arm......

I think Chris King is right based on what I know about metals, which is only two materials classes. Sounds like the interface between the bolt and spindle or the interface between the spindle and crank (probabally the latter) has gotten filled up with corrosion.

My only suggestion to remove the thing would be to hack saw the crank wherever is convenient and take it to a shop that has a wire EDM, they should be able to cut around the pedal's spindle to within .00001 inch leaving just a paper thin layer of aluminum that can be scraped off with a toothpick. Many shops use a similar process when very expensive tools break off in a part, or cheap tools break in an expensive part. They'll probabally charge you a bunch though. Burden rate for a wire EDM is going to be at least 35.00/hr. and the process will take an hour or more depending on the machine they have and how competent the operator is.

I think you can salvage the pedal somehow, the crank is probabally toast, the bottom bracket may be too depending on how hard you want to hit it with a hammer. It seems like it is coming down to how bad you really want to remove the crank. I leave mine on until I really have to take it off because I hate banging up my hands on the crank when the stupid thing does go.

 

[Thylacine]

Yup, sounds like classic galvanic corrosion to me. Next time, grease or ti prep the threads beforehand...oh you said you did use grease, well, obviously not enough/frequently enough. Maybe a big tin of ti prep is in your future?

Hrmm...ammonia.....never tried it, but it sounds interesting. Can't hurt, so give it a go perhaps. Otherwise, have you tried extending the lever arm of whatever it is you're using to get both the bolts undone? I know a couple of times, we've just found a long piece of pipe to stick on the end of the allen key or socket wrench does the trick. Its amazing how many people don't think of this. Theres also soaking the thing in petrol or wd40, but in my experience this often does nothing except stink up the place. Not that ammonia will be any different, but if Sheldon B suggests it, it might actually work

Other than that, you're screwed basically :devil: Most of us have learned this lesson - I sacrificed a Syncros post in my old slingshot frame because of galvanic corrosion...and boy was it stuck. We ended up just trying to see what lengths we would have to go to to remove the sucker. All I can say is it wasnt pretty, and the post and frame are now on the scrap heap.

Good luck!

 

[Shencycle]

the crank arm/BB spindle/pedal connecting bolt where very well greased.

I had the cranks off of the bike about 2months ago. I do not ride in very wet conditions.....
I will try the ammonia experiment and see how it goes..I also am going to see if I can get my hands on something to freeze it ...and see if the different rates of contraction may free it ....IMHO trememdous torque was applied to the bolts....I had a jack handle approximately 18" that I slid over the allen wrench for some mechanical advantage.....I can not believe I did not just strip the bolt right out of the threads....(actually bent the allen wrench)
....It is still puzzling how this is only happening to one crank arm .....and at both junction points!!!!!!

I think my lesson in this is to use anti-seize.


If and when I solve the problem...I will post the method of solution.......unfortunately I am seeing some type of blade involved..:devil:

Thanks everyone

 

[recidivist]

Originally posted by Shencycle
I also am going to see if I can get my hands on something to freeze it ...and see if the different rates of contraction may free it

I think that Sheldon Brown link I posted discusses this a little bit. Be careful with the heating/freezing solutions. The aluminum expands/contracts twice as fast as steel (so sayeth Sheldon). Since both the (steel) BB and (steel) crank are _inside_ the (aluminum) crank, I think you're going to get in trouble with freezing.

Heating, on the other hand? Maybe you can expand the crank enough to loosen it...

Of course, I'll let you try it first...

 

[ChrisKring]

Originally posted by Shencycle
..I also am going to see if I can get my hands on something to freeze it ...and see if the different rates of contraction may free it ....

I don't think you want to freeze it. Just the opposite, you want to heat it up. The aluminum will expand more than the steel and should allow you to get the bolt out. However, even though I have never heard of the amonia trick, I would try that first because there is a smaller chance of really screwing something up.

Chris

 

[Shencycle]

Originally posted by ChrisKring

However, even though I have never heard of the amonia trick, I would try that first because there is a smaller chance of really screwing something up.

Chris

LOL........ABSOLUTELY ...it certainly does sound like the lesser of the 2 evils :devil: ....I have already had it 'red hot' with a torch....still not a budge....I can try it again....but I think I will be kissing both the pedal and crank goodbye....

Thanks...

Alright I am the guinea pig

 

[oldfart]

Can't help you remove the parts. All I can think of is big levers. But if the crank bolt is stuck, it can't be galvanic corrosion because its a steel bolt in a steel spindle. However, the bits of the self extractor are aluminum. Could it be that that's what's frozen? And if so maybe dig out the self extracting components and see what happens?

I wonder how its only one side. Is it related to transporting the bike on the back of the car with the one crank close to hot exhaust? Melted out the grease? Maybe you drove somewhere where the roads had salt on them and one side was sprayed. I dunno I'm just throwing things out here.

And even the best grease won't stay in there forever. It does need to be redone periodically. But I think you know that. Anti seize seems to stay longer in my experience.

 

[Shencycle]

I just had to do it:devil:

Anywhoooo, I use a roof rack..both sides get same exposure......interesting thoughts though.....
The little "self extracting caps" come off with ease......


so I guess the ammonia trick won't work(if they are both steel) ....aaaaahhhhhhh....

I was trying to find out what the spindle threads were made of....all I saw listed was 'billet'....that can be either steel or aluminun.....no??

 

[johnbryanpeters]

The bolt's steel, the spindle's steel, bolt's stuck in spindle. Two target reasons would be rust or buggered threads from cross-threading or crap in threads.

So what happened, did you saw it off?

J