Stuck crankset

[jtr1962]

Two weeks ago I noticed my pedal bearings, especially on the left side, were wearing out. I decided it was time for new pedals. When they came, I just couldn't get the old pedals off. I got the drive side pedal to loosen maybe 1.5 turns with great difficulty but it wouldn't budge after that. The non-drive side pedal wouldn't move at all. I even took the crank arm off, took the pedal off the spindle, clampled the part of the spindle the pedal wrench would go on into a vice, and tried moving the crank arm. No luck.

I decided to just buy a new crankset. Mine was looking a little scuffed, and I wanted a triple anyway:



It's the same type as my old crankset-2 piece.

Now here's the problem. In theory the old crank should slide right out once I take the left arm off. OK, maybe it'll need some taps with a hammer but it should come out fairly easily. No such luck. It moves the first half inch or so easily, meaning the crank shaft isn't rusted frozen to the bearings, but stops after that. I hit it pretty hard with a hammer but it seemed to reach a dead end.

Next step would be to unscrew the bottom bracket cups but guess what? I tried getting the left side cup off. It won't budge.

Basically, I'll be stuck with an unusable bike soon once the left pedal is done wearing out. Can't get the pedals off, can't replace the crankset.

Any ideas? The old crank set is a Truvatic GXP with carbon fiber. Is there anything I'm missing? I've heard all of these two piece cranks should basically slide out once the left crank arm is removed.

 

[chillinn]

crank puller

How to

 

[jtr1962]

I have one of those. It's for a square taper crank set. Mine is a two piece.

 

[turbodog]

Pull seatpost. Pour a "good bit" of penetrating oil/etc down the seat tube. Wait a day. Work back/forth. Patience.

Could take a sawzall and cut the crank out. Then attack the bearings with chemicals/heat/torque.

 

[chillinn]

In theory the old crank should slide right out once I take the left arm off. OK, maybe it'll need some taps with a hammer but it should come out fairly easily. No such luck.

I have one of those. It's for a square taper crank set. Mine is a two piece.

I don't understand why you'd need a hammer, the puller tool should suck that right out.

Could take a sawzall and cut the crank out.

LMAO
Ordnance might be even more fun.

 

[jtr1962]

Pull seatpost. Pour a "good bit" of penetrating oil/etc down the seat tube. Wait a day. Work back/forth. Patience.

Could take a sawzall and cut the crank out. Then attack the bearings with chemicals/heat/torque.

WD-40?

What do you think is causing this? Rust on the part of the shaft between the bearings?

I'll give your suggestion a try. The left pedal should still be useable for at least a few more weeks. Hopefully by then the oil will do its trick.

I don't understand why you'd need a hammer, the puller tool should suck that right out.

Because it's a different type of crank. It's a 2-piece crank, versus the 3-piece which uses crank pullers.

 

[3_gun]

On two sided rotational things one side is often reverse threaded or pinned. Not sure if that could be an issue here

 

[turbodog]

If the crank is corroded inside the BB, then the corrosion is wedging inside the right side bearing race as it goes to slide out.

Maybe there' enough clearance to get a wrench and unscrew the right side bearing. You might have to cut out part of the crank spider to make room.

 

[jtr1962]

On two sided rotational things one side is often reverse threaded or pinned. Not sure if that could be an issue here

The left side BB is normal threaded, the right side is reverse threaded.

If the crank is corroded inside the BB, then the corrosion is wedging inside the right side bearing race as it goes to slide out.

Maybe there' enough clearance to get a wrench and unscrew the right side bearing. You might have to cut out part of the crank spider to make room.

I can get the crank out enough to unscrew the right side BB. Problem is it doesn't budge, either. Granted, all I have is locking pliers. I could order the tool and try again. Maybe with the tool and few taps of the hammer I can get the bottom bracket bearings out. That would at least let me extract the crank set to see what's going on. Yeah, corrosion is my first thought. I've had the bike over 10 years. I bought it second hand on eBay. I think it was made c. 2005. I don't think the crank was ever changed. So basically, 17 or 18 years for corrosion to do its work.

 

[turbodog]

Anytime I've got the frame 'open' I will give it a good shot of spray lube into all the tubes that I can access. Water ALWAYS gets inside... assume that and proceed accordingly.

Maybe someone loctited it back in the day, or simply forgot to grease the threads.

 

[jtr1962]

Anytime I've got the frame 'open' I will give it a good shot of spray lube into all the tubes that I can access. Water ALWAYS gets inside... assume that and proceed accordingly.

Good idea. Granted, it's a titanium frame, but not all the components are rustproof obviously.

Maybe someone loctited it back in the day, or simply forgot to grease the threads.

I hate to say it but I was thinking exactly this. They may have loctited both the pedals and bottom bracket bearings. I've worked on my bikes for decades. I never encountered a perfect storm of frozen threads like this.

Good news is that I don't need to take the seat off to spray penetrating oil on the crank axle. There's a water bottle cage screw about 5 inches above the BB with provides perfect access.

I suppose I could hit the axle a lot harder with a hammer but I'm worried about ruining the bearing. That'll make the bike unrideable, perhaps permanently if I can't unscrew the old BB.

To think all this started with just replacing a set of pedals.

 

[jtr1962]

I half-a$$ed it for now. I managed to finally get the right pedal off. Maybe the oil I put on a few days ago finally worked. It looks like the old pedal was cross-threaded when it was installed. That explains why it remained hard to get off even after I started it moving. Anyway, that took care of putting the new pedal on the right side. For the left side I used the crank arm which came with the new crank I just bought. I still want to put the new crank set on, but at least for now the bike has the new pedals. No worries about the old pedal failing in the middle of a ride. I put a nice coating of electrical contact grease on the new pedal threads. That should stop any oxidation.

I'll try penetrating oil on the crank shaft and see if that works.

 

[turbodog]

....

Good news is that I don't need to take the seat off to spray penetrating oil on the crank axle. There's a water bottle cage screw about 5 inches above the BB with provides perfect access.
...

Provided the tube is open to the BB shell. Looking down the seat tube will let you see whether there's an opening or not.

 

[orbital]

+

For any casual readers,

you loosen the left pedal turning to the right.
..Same for bottom bracket cups (on most bikes)

 

[BVH]

Left-hand thread on the Right and Right-hand thread on the left.

 

[KITROBASKIN]

If frame is raw finish wondering if some judicious heat can be applied... Try a different penetrant and give it time?

 

[jtr1962]

Provided the tube is open to the BB shell. Looking down the seat tube will let you see whether there's an opening or not.

I just checked. The tube is open to the BB shell all the way down but the presence of the shell is the problem. Any penetrating lubricant isn't going to go on the axle. Instead, what I'll do is hammer the axle out as far as it goes (about 1/2"), then spray penetrating lubricant in the space between the splines. It should go right on the axle.

If frame is raw finish wondering if some judicious heat can be applied... Try a different penetrant and give it time?

I wouldn't mess with heat. There's a plastic cable guide on the bottom of the bottom bracket housing. Of course, that screw is rusted frozen also, so there's no removing the cable guide.

For now I tried whatever oil I had handy. My brother is going to bring over some the stuff he uses on the car. I think it's called PB Blaster or something similar. I'll spray the axle and the BB cups, let it work for a few days, then try again. No hurry as the bike at least has the new pedals on. If I can at least get the left side BB cup off, I can see what's going on.

 

[bykfixer]

Kroil is the best. PB Blaster is good too.

I've used some stuff called Nano to get rusted parts off but only as a last resort because it has nano particles that can easily soak into your skin.

Upon reassemble any thick petroluem product will act as a bond inhibitor. A little dab'll do ya. Too much allows too much tension to be applied due to lack of friction between the threads. That can cause ridiculous amount of tension to be applied and cause a stretched bolt or really difficult to dissasemble issue.

Actually bees wax type products are what is used assembling bolts on bridges and other big roadway items. Bees wax provides a bond inhibitor and still allows proper friction between threads. Too "wet" or too "dry" threads matters.

And use an inexpensive beam torque wrench when reassembling. Ensures proper tension between items without over tensioning.

 

[turbodog]

I've had good luck w/ kroil and liquid wrench on fertilizer-corroded farm equipment which is pretty extreme.

 

[Poppy]

Penetrating oil, vibration and time work well together. PBblaster is better than WD40, but it stinks. I definitely would NOT use it indoors. Although I was recently told that now, they make PBblaster that doesn't smell too bad. Mine is probably ten years old, so it is certainly the older version.

I'm not familiar with the parts you are trying to remove. Is there a keyway? Could it be that there is a tapered keyway that tightens more as the crank is pulled out?