Crank Puller stripped a thread!

gaffmaster

Hi!

I have an FSA Vero crankset. I decided to check if I had the right tools to remove the cranks and bottom bracket as I'm planning an upgrade soon.

I used my trusty 'Jobsworth' too kit (from Planet X).

I started on the non-drive side crank arm, removing the dust cap without a problem. I used the crank puller tool and having seen advice online, applied plenty of pressure once it reached the biting point. After a few revolutions, a strip of metal came out, along with the tool. When I looked inside, it seemed the tool's protruding piece's head was too big to get through to the square taper BB it was meant to be pushing against.

It's hard to explain but essentially, the tool pushed against the crank itself, stripping the thread a little.

Now I'm wondering, how do I get the crank off the square taper BB? Is there another tool that can be used?

Any help appreciated. I'd rather not have to drop it in to the bike shop.

Cheers.

Kaisr Sose

That's the only tool. Can you post pics?

Are you certain the tool was in all the way onto the crank? It can be that it's not in fully and as soon you tighten the bolt, it works against itself (as you explained)?
Also make sure the bolt is fully back to allow the tool lock onto the crank? If not, it can cause the tool not lock in tight

The shape of the head of the bolt should be tapered enough to get through to the axle and by what you outline, it made contact with something to give the reverse pressure on the tool. Is the crank marked from the head of the removing bolt?

gaffmaster

Kaisr Sose wrote: »

Is the crank marked from the head of the removing bolt?

Yes it seems to be marked. I'll take a few pictures tomorrow if I get the chance.

I'm fearing it might need to be angle grinded (ground?) off!

Canis Lupus

The extractor tool needs to fit through the square hole otherwise yeah it would just push against itself and strip the thread. Must have been hard work to do that? I used one for the first time the other day and there's a fair bit of resistance but nothing crazy. If the pull tool no longer goes on because the thread is f*cked I can't see how you're going to fix without 'drastic' measures.....

Kaisr Sose

gaffmaster wrote: »

Yes it seems to be marked. I'll take a few pictures tomorrow if I get the chance.

I'm fearing it might need to be angle grinded (ground?) off!

Don't grind anything ...

iwillhtfu

oh dear you have the wrong head on the crank puller you need to get a specific head for that one. I usually put a nut in line with the square taper spindle.

Essentially what I think has happened you've hit the inside of the crank arm and pushed against what you're attached to and inevitably the threads stripped.

If you take the tool out I'd be willing to bet there's an indented circle on the inside of the crank arm

gaffmaster

iwillhtfu wrote: »

oh dear you have the wrong head on the crank puller you need to get a specific head for that one. I usually put a nut in line with the square taper spindle.

Essentially what I think has happened you've hit the inside of the crank arm and pushed against what you're attached to and inevitably the threads stripped.

If you take the tool out I'd be willing to bet there's an indented circle on the inside of the crank arm

Yes, this seems to be exactly the case. It was a very quick look I had at it earlier, so I'll have to spend some time seeing if I can get the puller back on any sort of thread. Raging I made this mistake - I was being hasty, and just assumed all crank pullers were the same. Silly really.

I wonder if I could get the other crank off, and the BB out, would the BB cup on the other side be all that was preventing the crank and BB cup from being unscrewed as a unit? In which case, could I unscrew it with something through the BB shell... This was meant to be a quick job!

gaffmaster

If only I had read what Sheldon Brown had to say before diving in...

"Make sure that the "bolt" part will bear on the end of the spindle. Some crank pullers made for spindles with a protruding boss have a pushing surface with is too large to fit into the square hole in the crank. Using one of these vigorously with a bolt-type (hollow) spindle will only strip out the threads in the crank."

iwillhtfu

You could try wrapping the tool threads with ptfe tape (plumbers) and screw it in again you might be lucky.

07Lapierre

gaffmaster wrote: »

Hi!

I have an FSA Vero crankset. I decided to check if I had the right tools to remove the cranks and bottom bracket as I'm planning an upgrade soon.

I used my trusty 'Jobsworth' too kit (from Planet X).

I started on the non-drive side crank arm, removing the dust cap without a problem. I used the crank puller tool and having seen advice online, applied plenty of pressure once it reached the biting point. After a few revolutions, a strip of metal came out, along with the tool. When I looked inside, it seemed the tool's protruding piece's head was too big to get through to the square taper BB it was meant to be pushing against.

It's hard to explain but essentially, the tool pushed against the crank itself, stripping the thread a little.

Now I'm wondering, how do I get the crank off the square taper BB? Is there another tool that can be used?

Any help appreciated. I'd rather not have to drop it in to the bike shop.

Cheers.

Did you remove the bolt that holds the crank onto the Square taper BB?

https://www.youtube.com/watch?v=cPQyQnNdews

gaffmaster

07Lapierre wrote: »

Did you remove the bolt that holds the crank onto the Square taper BB?

https://www.youtube.com/watch?v=cPQyQnNdews

I did yeah - the dust cap and the bolt were one and the same.

I found a couple of solutions on YouTube and Sheldon Brown's website, that recommend using an automotive "Gear Puller". A three pronged contraption that uses the same principle but obviously, not as sure-footed as a dedicated crank puller.

Here's an example of one: http://www.ebay.co.uk/itm/Marksman-75mm-3-Jaw-Gear-Puller-Reversible-Legs-for-External-and-Internal-/382143012036?epid=1043943750&hash=item58f97f9cc4:g:ZdsAAOSw8d5ZU7Zz

07Lapierre

gaffmaster wrote: »

I did yeah - the dust cap and the bolt were one and the same.

I found a couple of solutions on YouTube and Sheldon Brown's website, that recommend using an automotive "Gear Puller". A three pronged contraption that uses the same principle but obviously, not as sure-footed as a dedicated crank puller.

Here's an example of one: http://www.ebay.co.uk/itm/Marksman-75mm-3-Jaw-Gear-Puller-Reversible-Legs-for-External-and-Internal-/382143012036?epid=1043943750&hash=item58f97f9cc4:g:ZdsAAOSw8d5ZU7Zz

Yeah that pullers will do it... assuming it fits that is. Best of luck.

mp31

Sometimes, the end of the crank puller that is supposed to push against the BB actually has a piece that can be removed to reduce the diameter to avoid this sort of thing. I did exactly the same thing as you a few years ago and stripped one thread however the remaining threads were fine.

iwillhtfu

mp31 wrote: »

Sometimes, the end of the crank puller that is supposed to push against the BB actually has a piece that can be removed to reduce the diameter to avoid this sort of thing. I did exactly the same thing as you a few years ago and stripped one thread however the remaining threads were fine.

It's usually still to big as you only remove that piece to fit the adaptor for square taper

Hungrycol

I have done hasty jobs waaay in the past and stripped out a thread or two from the crank arm by not removing the bolt first. I have been lucky and managed to re-thread it with the extractor tool.

gaffmaster

Update!

Thanks for all the input on this one folks.

I finally got around to completing this job. I tried to use that gear puller tool I shared, but the hooked part wouldn't fit between the shoulder of the crank and the frame, so it was a non-starter.

Luckily, there was still one non-stripped thread on the crank, so I put a nut in between the crank puller and the bottom bracket to reduce the diameter of the tool if you like... and it worked. While it worked, it also crushed the nut, and the crank puller tool ended up with a reduced diameter as it bored through the hole on the crank, which meant it was the right size to fit through the opposite crank! Not sure if the crank arm itself survived.

Then the Bottom Bracket was stuck. The LBS removed it for free fair play to them. Got the new BB in and the new cranks on. All working well now.