Flash

Didn't know threads were compressed on non-drive side of this Univega Supra Sport until I began to take apart crankset today. I can't thread my crank puller due to the compressed threads on non-drive side. See pic, any ideas on how to remove apart from brute hammer force. Clearly the previous owner beat this up a bit. Thanks.

dabac

The left crank is easily removed using a standard 2-armed bearing/gear puller.
Slightly more violent methods include the use of a so-called pickle fork used to split steering linkages on cars.
Or FBs recurring recommendation of chuck wedges.

Flash

thanks, would the one pictured below do the trick?

hueyhoolihan

because the crank is essentially ruined or at least not to be used again in the near future, i assume, there is nothing to be lost by using what would normally be considered potentially destructive removal techniques.

like for instance, gently tapping your hardened steel crank puller into the decidedly softer aluminum alloy threads (squarely of course) and essentially forging the steel puller threads into what could prove to be usable thread beyond those that have been butchered by abuse.

one potential outcome is that in addition to removing the crank arm, the process could in fact result in a DIY thread chaser/tap that could make threads reusable and thus saving the crank arm.

if it were me, i know i would give it a try at lease, especially if i planned on discarding the crank altogether.

SlowJoeCrow

If you want to reuse the crank the most elegant solution is to use a crank arm repair kit like the ones made by Stein or VAR. These use a special tap to cut an oversize extractor thread which is used to install a lock ring that converts your crank arm to a self extracting style. This would be a bike shop type deal since the kit costs way more than a cheap crank arm or complete crankset to replace one you remove destructively. BTW this is also a convenient fix for old French cranksets with oddball extractor threads

sch

Gear puller pictured may work IF the crank has enough gap between crank arm and frame to get the puller into place and is not rounded adjacent to the frame
which appears to be the case from your pix. I was thinking you could just forcibly thread the crank puller into place but close exam of your pix shows essentially
no threads at all so not likely to work. Another option: remove R side crank and the BB bearing shell on R, get 2x6 and drill hole ~3/4-1" in size, place frame on its
side with BB shell on 2x6 and axle in hole and with a large dowel and BFH hit the axle end on the L side to knock it out of crank. Another option is to just go out and
ride the bike up a few hills and at some point the crank will loosen up. Worked for me when I rebuilt a bike over a month or so and forgot to reinstall the crank bolt
and the crank came off just after a 12% grade 200yds long. Had to one leg it for 8 miles back to car, but was ~20 miles into the ride at that point.

ThermionicScott 

I can't tell how "compressed" the threads are from the pic (but thanks for posting it anyway, I like pics) so before resorting to the more destructive methods, see if you can clean out the first couple of threads using a very sharp nail. If you can get the puller started, then it can tap the remaining threads and you may be able to pull the crank normally in the future.

FBinNY 

Yes, though you might have to grind away some of the hook if it's too thick to get behind the crank. (be sure to grind from the back, not the part that goes against the crank. Also, you might need to put the bolt back in loosely for the pusher to push against so it doesn't damage the threads in the spindle.

I prefer using Jacob's chuck removal wedges.

They're cheap, easy to use and very reliable. They do the job so nicely that you can reuse the crank with confidence even if the original removal threads are toast.

Just be sure to buy the right size.

Flash

This worked!! Thanks for the tip. Took several aggressive "taps" to get the puller embedded, but once it dug in I was able to thread it. At the moment the crank puller is attached to the NDS crank, I'll get it separated soon. Thanks again for the various responses. I really appreciate people taking the time to help.

cale

If you can't get the extractor off the crank arm, I recommend cutting it out with an angle grinder. Very satisfying. Be careful not to cut the tool or hurt yourself. Wear goggles.

JohnDThompson 

The arms are pretty far apart on that one; it might be difficult to get them to grasp the crank arm securely. I got this 2-arm puller at Harbor Freight that has worked well for me:



Otherwise, if the threads in the arm aren't completely stripped, you may be able to chase them out and use a standard crank puller.



Bike Tools Etc. - 1000's of bicycle tools and parts for the home mechanic!

Gresp15C

@FBinNY, do you worry about damaging the BB bearings when using those wedges?

I'll look into that little Harbor Fright puller. I've still got a stubborn one, albeit on a BB that doesn't seem like it urgently needs servicing.

As for cleaning the threads, an old machinist once suggested, for a non-bike use, finding a small tap with the same thread pitch and using it as a scraper.

FBinNY 

Not at all. In theory you could damage a bearing by beating on it with a heavy hammer. But these wedges have a very shallow ramp angle, so you can remove cranks with pretty gentle tapping. If you're worried (I'm not) you can temper the blow by using a piece of wood between the hammer and wedge.

BTW- these wedges are designed and made for removing taper fit chucks on pretty expensive precision machinery. These machines have spindle speeds up to a few thousand rpm, far faster than a high cadence of 100 or so rpm. So if anyone had a reason to worry about bearing damage, it wouldn't be the bike mechanic.

Keep in mind, that though we sometimes speak of brinelling in bearing races, especially at the headset, the reality is that this is rare in the real world. What's called brinelling is usually false brinelling, or fretting, which is a totally different process that produces similar looking effect.

dabac

I don't know about that.
There was a guy called Carl Fogel who got cross-posted to cyclingforums.com(together with Jobst Brandt).
He bought a department store bike for winter riding which eventually morphed into some kind of rolling laboratory.
And while the sample size was admittedly small (one), he didn't have any problem indenting the BB races by pounding at it.
I loaned a bike to a heavyset guy, and it came back with a bent axle and an indented cone.
So, to me, which of the two that is the rare occurrence in quite an open question.

shelbyfv

I have a TA crank that I want to remove. I wonder if the chuck wedge would be appropriate? I once had a TA puller but I'm unable to find it and hate to buy another for a one time use.

FBinNY 

A long as there's about 4mm (or more) clearance between crank arm and BB face, it'll work.

shelbyfv

Thanks!

Rubato

I prefer using Jacob's chuck removal wedges.

They're cheap, easy to use and very reliable. They do the job so nicely that you can reuse the crank with confidence even if the original removal threads are toast.

Just be sure to buy the right size.[/QUOTE]

Rubato

I prefer using Jacob's chuck removal wedges.

They're cheap, easy to use and very reliable. They do the job so nicely that you can reuse the crank with confidence even if the original removal threads are toast.

Just be sure to buy the right size.[/QUOTE]

Jacobs Chuck removers For Sale-size #1 .