I'm pulling the bottom bracket off an older bike equipped with Shimano Exage cranks. I pulled the non-drive side crank using my handy dandy Park crank pullin' tool, but when I went to pull the drive side, it looks as if there is a more coarse threading on that side. Am I missing something obvious? I've never pulled a Shimano crank, and I know they have some special mojo but I understood that had to do with how the BB was mounted in the shell.

I'd post an image of it but I don't have the requisite 10 posts to be allowed to do that (or links of any kind, apparently). So I've put up a page about it with an image of what I'm seeing.

the7000project.wordpress.com/2017/08/16/crank-thread-difficulties/

Clues for the clueless?

Thanks!

I'm something more than 99% sure that Shimano never used any other crank remover threads. So, I suspect that someone did a DIY rethread at some point.

Your best option is to use an alternate method for removing the arm. My favorite is to use a pair of Jacobs Chuck removal wedges.

Not able ton send macro closeups and/or access a thread pitch Gage?

try walking into a bike shop where it can be seen.. they are the same* .. only if not shimano , or Asian do they stand a chance of not being the same.

1 tpmm RH thread..

Different ones are French.. briefly at premium costs were the Italian ones not..

* Or someone bodged them up, perhaps...






...

That's what I was afraid of. It's a '93 Trek that was handed down from a long line of bike geeks, so it wouldn't surprise me if one got nutty with a tap and die set.

Amazon Prime is my best friend for a reason. Any particular size wedge I should buy for this?

Thank you for the help!

You need No. 6. They're slightly bigger than necessary, but all the others are too small.

You guys are rock stars. <--- Egregious attempt at bumping my post count.

You could replace the NDS crank arm, loosen the bolt/nut on the DS a turn or so. Ride the bike in that condition (stay close to home)until the DS arm comes off of the taper then immediately STOP, walk the bike back and proceed with crank removal.

Tapping a crank where it's removed would be an... interesting task that would require a very... very large tap. I mean that's almost an inch diameter right? Do they even make taps that big or would that require a lathe?

(EDIT apparently they do make taps that big, but almost no-one would have one of them sitting around.)

"More coarse threading": roughly 100% sure that you're looking at dealing with cross-threading or similar damage from a previous removal attempt (i.e., the threads have mostly been torn out). You might have to resort to brute-force methods to remove the crank arm.

Exage used bolts and washers to secure the crank arm to the bottom bracket spindle, if I remember correctly. Too bad you can't go back in time and tell the person who damaged the threads to remove the washer before threading in the crank puller, or else . . .

The list of things I'd do different with a time machine is long, extensive, and mostly legal.

Anyway, #6 Jacobs Chuck Wedges are on order for delivery tomorrow. I'll update you with the results of my efforts.

I have no idea what it would take, or why one would even bother, but there it is.

As far as stuff sitting around, I have 2" sockets, brake pullers for use on Air Force P-15 crash trucks, trap wire links from aircraft carriers, and a whole lot of other stuff with no practical use. No accounting for it!

Something like a tie rod end tool might pop it off, hopefully only taking out the bottom bracket with it.



Also prying with screwdrivers.

Here's a Stronglight crank thread tap:



Bicycle Research made thread chasers for 22mm crank arms:



And there are repair kits that ream and re-tap stripped crank arms to a larger diameter:


Crank thread repair kit VAR Tool, Pro Tap Set Bike

But you're right. Apart from the Bicycle Research thread chasers, none of these are likely to be found in a home mechanic's tool box.

It has been my experience that prying pretty much anything with screwdrivers is the way to busted screwdrivers, madness, or possibly both.

If you resort to violence, don't use the tie rod pickle fork shown above. Instead use a threaded tie rod end puller. You can likely borrow for free at an AutoZone store.

If there's room to get a puller's jaws behind the crank arm, I think I would prefer a small puller over other options. You may stand the most chance of getting the arm off without collateral damage. A puller with an electric impact wrench/gun on the hex head will probably slip that arm right off the spindle. Small pullers can be rented for free from a number of sources that may be local to you (Advance, Auto Zone, etc).

...it's remotely possible that one of the previous owner bike geeks had one of those BR or VAR crank thread repair kits, and rethreaded it using that (which would make it appear both slightly larger and coarser), but then chose not to apply one of the standard repair inserts. If you have the tool, you can use it to pull the cranks without any problems. And the inserts are both a little pricey and often difficult to obtain.

The next guy (you) hasn't got the tool, so you're left with all these other inventive ideas for removal.

To be fair to the last guy, there are a whole lot of tap and die kits out there that aren't bike specific. I've got one kicking around the garage somewhere that I've used for motorcycle frame repair, as well as other miscellaneous tasks not bike related. I won't fault him for the job.

With regards to all these inventive ideas... That's what makes the world such a great place to be! I'm pretty certain I'll need more as I work on this frame.

...for this particular job you need a bottoming tap, which is a little more exotic. And it needs to match up with anything you can cobble together as your puller. But yeah, nothing makes me happier than inventing a way to do something on a bike repair that seems impossible and requires some head scratching.

For instance: if the arm you can't pull is the non drive side, you can pull the drive arm, and with a loose ball BB you can usually slide out the remaining non drive arm, adjustable cup, and the spindle. Then you take it over to a decent bench vise and carefully pound out the spindle with love and hammer, using the vise (and maybe some wood blocking) for support.

That's the name of my next band, mang!

Most of the components are going into the recycler, so my primary concern is not dinging up the frame in any way. If I could pull the entire bottom bracket without taking that arm off, I would.

... best and cleanest way is to sneak the cutting disc in right behind the crank and cut the spindle, but sometimes there's not enough room for safe access without risking a little tic to the BB shell.

You can also just use one to cut some slots in the arm where it goes onto the spindle, and one will usually go through and let you open it up. The aluminum will fill up the disc a litttle, so it's not ideal, and you need to be alert because the aluminum can grab a little. But I've done a few that way and it works.

The stuck on crank arm with stripped threads is a common problem you run into at bike co-ops, where most of what goes through has been around for a while and needs some love.

That thought has crossed my mind on a number of occasions. I think for now I'll go with less drastic measures. If all else fails, I'll grind it off and pray I don't miss.

It's possible a previous owner repaired stripped puller threads with a crank extraction set. I have the Stein version of this tool, but I think Var makes one that does the same thing. It taps the threads to m24 X 1.5.
There are self extractor caps to match the threads and also oversize pullers.

Update! Wedgies arrived today and the crankset is out. I had to improvise a bit, though, as the wedges didn't drive the arm off the BB. So I took the wedges, and drove them between the chainring and the bottom bracket shell until they were locked together, then just used the crank arms to spin it out.

I have to admit that the angle grinder was looking pretty good, though.

Thanks for all the help!