I'm new here, and tried searching/reading before posting. I'm trying to remove the DS crank on my wife's mountain bike, one of the chainrings has broken teeth and causes the chain to skip (unfortunately it's the smallest chainring, so looks like the crank has to come off).

I've disconnected the DS crank from the chainrings, and then removed the 8mm hex crank bolt. I'm using the Park CCP-2 crank puller tool and the cranks are suntour MD320's I think (basic suntour cranks that came with the MTB which uses a Deore setup). I get the first bolt into the crank threads, and then thread the puller portion as far as it will go, but no luck. I tried the same on the other (left) side crank, with the same results. By looking the crank it looks like a regular standard square bottom bracket.

Am I missing something obvious here? I've tried threading the crank puller tool's bolt using a wrench, and still no luck. Perhaps am I using the wrong tool? I'm not sure what type of BB the bike has, but by looking through the crank it looks like a square design. I'm wondering if the cranks are just tight, or if i'm missing something here.

I'd really appreciate any help/tips anyone could give me.

Are you sure the extractor part of it is larger than the bolt that went in?

Also thread that extractor tool into the crankarm as far as it can go before turning the extractor nut. Make sure the extractor nutis not protruding the attatchment nut as well when inserting, so you can ensure full insertion.

Also is the extractor nut going in as far as it can go, or is it just not able to turn at a certain point?

I'll give those ideas a try. I'm using CPP-2 for square-tapered BB, how can I be sure that i'm using the right tool? Is there a way for me to look at the cranks (with the 8mm bolt off) and know if I need a square-tapered tool, or the Octalink/ISIS type tool? When I look through the hole in the crank, I can see the square cutout with a circle inside, so i'm assuming i'm using the right tool, how can I tell for sure?

Can't you tell the difference between the end of a square taper spindle and a round spindle with splines on it?

It kind of sounds like you aren't using the tool as intended.

Screw the larger diameter, with the threads, into the crank arm, until tight. (This is with the inner part turned counter clockwise as far as it will go) Once the outer part is snugged up and has caught good threads, then the inner portion can be turned clockwise against the crank axle. (This will be like a retractable ballpoint pen, as the end is coming out.) This will pull on the crank arm and cause an opposing push on the crank axle.

1. Make sure any washers are removed from the crank arm. The crank puller needs to push against the BB axle. If a washer is left in there, the crank arm won't come off and you could strip the threads of the crank arm.

2. Make sure the puller fits into the square hole of the crank arm. Without the collar threaded into the crank arm, try to insert the tip of the puller. It may be snug, but it should fit. If the tip of the puller is flared out from heavy use, file off the flares.

3. Grease the threads of the puller - the threads on the handle part, not the threads on the collar.

4. Grease the tip of the puller - the part that presses against the BB axle.

Sounds like you haven't removed the washer and the crank puller is pushing against it instead of the axle.
Make sure you remove it before wrenching this puller any stronger, this could damage the crank thread.

You may have to turn the extractor a lot harder than you think. If those cranks were put on really tight when the bike was built, or if there is any corrosion in the joint between the cranks and the spindle, a lot of torque will be required to remove them.

Shimano had an insert that looked like a derby or tophat that had to be used with some of their BB (IIRC the early octalinks) because the hole in the axle was larger than the sq taper hole and the extractor center bolt would not press on the axle. The tophat was dropped in and filled the gap. Sq taper axles will be about 5/8-3/4" diameter where octalink/Isis axles are 3-4mm larger in diameter. Not at home so can't be specific as to measurements.
Steve

There could be some galvanic corrison between the BB spindle and the crank arm. I've had to get rough with some rental crusiers at work because some corrison had frozen the crank to the BB spindle. If you live near the ocean, that is a problem.

If that doesn't work (various suggestions above), try heat. The other day my neighbor was single-speeding an old cannondale. After stripping out the threads in the crank with the crank puller, we applied heat. A couple light taps with a hammer & off it came. He had an oxy-mapp gas torch that did the job; propane should be hot enough too.

try a little heat from a torch, just a little, dont make the steel red, then bear down on the park tool, the arm should come off........29er Rick

Make sure there is not a washer still in there. I have seen people strip out crank extractor threads this way.

Thanks everyone for all your help and advice. Turns out I did have the right tool, and all it needed was some elbow grease

I sprayed it with WD40 last night, still couldn't get it out, tried it again today, and threading the handle with the center bolt was a bit easier, got some resistance, but it was easier to keep turning, and the crank popped off

Chainrings are changed, and the chain is no longer skipping (bent/broken teeth on the old chainring). Thanks so much for all the advice!

Feels great when you do it yourself!

One last tip for when you think the crank should have come off but it didnt- With the tool tight, give a rap on the end of the tool with a hammer. The vibration from the tap typically makes them pop off.

I did have a guy ask for help when he could get a crank arm off. I tried the tool with the same results he got. Then I removed the tool and looked in the crank arm hole. He forgot to take out the bolt!

Now that you've succeeded in getting it off, you realize how tight they're on and how much strength/torque it takes to get it off. Since you're already put it back on, I assume you torqued it down pretty tight. It may be a good idea to check and re-tighten the bolt again after it's been ridden a few times. Same thing with the chainring bolts. Re-tighten them again after a few rides.

Did you lube the ends of the axle before putting it back together? I never have - with square tapers - but some folks always do. Do what you think best.

Oh, and good job!

Next time, take off the large chainring, then you should be able to remove the small chainring. No crank removal required.

10 year old zombie thread

I removed an old crank recently and had to cut out a load of plastic that had stuck on the thread, then clean all the thread out, then grease the thread after which I had to turn the crank puller in with a wrench, once it got past a sticking point it went in/out fairly easily. A lot of crap can build up on the threads.

In my defense........................................D'OH!

Damn, burned again. Sneaky bastids.