Yet Another Cycling Forum

General Category => The Knowledge => Topic started by: ElyDave on February 24, 2019, 08:07:48 am

Title: square taper bb removal
Post by: ElyDave on February 24, 2019, 08:07:48 am
two questions,

1) lhs is conventional thread, and rhs reverse thread? I'm not going bonkers?
2) best method to wield the tool? I don't have an adjustable that goes wide enough, and my stilsons won't grip. The tool is quite rounded on the corners, not through use, I'm guessing a big socket is best?
Title: Re: square taper bb removal
Post by: Von Broad on February 24, 2019, 08:35:14 am
two questions,

1) lhs is conventional thread, and rhs reverse thread? I'm not going bonkers?

Correct - not bonkers

Quote
2) best method to wield the tool? I don't have an adjustable that goes wide enough, and my stilsons won't grip. The tool is quite rounded on the corners, not through use, I'm guessing a big socket is best?

Well, if you can get a socket on it that gives you a snug fit then that will be fine.

I'm surprised you can't get some stillsons to grip though.

Problem with these tools is that the splines can easily slip off the BB, so what I'll often do is get a large G clamp or grip-clamp [if you have such things] and spread it across the BB from end to end, holding the tool in place as it sits in the BB. Slightly more tricky to do this though if you're going to sue a socket. You don't have to do it up tight just enough to stop the tool from slipping off. A bit of gaffer tape can help with that too. You only need to loosen it then Bob's y'Uncle.
Title: Re: square taper bb removal
Post by: robgul on February 24, 2019, 08:42:09 am
Another solution for the spline tool slipping (but you'll have to source the bolt) is to use a bolt (IIRC it's 8mm 1.0 fine thread) fixed into the end of the BB (i.e. the same size thread as the crank bolt, but longer.  Works a treat to keep the tool on the splines.

The alternative is 5 mins at the LBS - I'd normally do that for free in my shop .. or suggest a packet of biscuits!

Rob
Title: Re: square taper bb removal
Post by: Von Broad on February 24, 2019, 08:51:14 am
Another solution for the spline tool slipping (but you'll have to source the bolt) is to use a bolt (IIRC it's 8mm 1.0 fine thread) fixed into the end of the BB (i.e. the same size thread as the crank bolt, but longer.  Works a treat to keep the tool on the splines.

Watson....had you stood back and thought for a moment, you've have seen that was the obvious way to go :-)
Title: Re: square taper bb removal
Post by: ElyDave on February 24, 2019, 09:02:42 am
Thanks All, will take a look at the crank bolt vs the hole through the tool, might be designed to use that way. 
Title: Re: square taper bb removal
Post by: rr on February 24, 2019, 09:10:42 am
Another solution for the spline tool slipping (but you'll have to source the bolt) is to use a bolt (IIRC it's 8mm 1.0 fine thread) fixed into the end of the BB (i.e. the same size thread as the crank bolt, but longer.  Works a treat to keep the tool on the splines.

Watson....had you stood back and thought for a moment, you've have seen that was the obvious way to go :-)
IRC it is a really obsure size, so don't expect to find one in your local B&Q. I ended up buying one from CRC with a big circular nut on it to hold the tool.

Sent from my moto x4 using Tapatalk

Title: Re: square taper bb removal
Post by: Tim Hall on February 24, 2019, 09:42:25 am
I use a standard crank bolt and a big washer. The washer is slightly harder to source as it needs a big out diameter to cover the hole in the tool and a smaller than usual inner diameter otherwise the bolt head will go straight through. You may have to stack two different sized washers.
Title: Re: square taper bb removal
Post by: Johnny Faro on February 24, 2019, 09:51:20 am
My BB tool can take a 1/2" ratchet straight into the tool so no faffing with slipping sockets or adjustables. Last one I took out was chuffing tight though
Title: Re: square taper bb removal
Post by: Brucey on February 24, 2019, 11:42:11 am
My BB tool can take a 1/2" ratchet straight into the tool so no faffing with slipping sockets or adjustables. Last one I took out was chuffing tight though

the usual slippage is the slippage of the tool out of the BB splines. Bolting the tool to the BB spindle is a good idea, but usually the bolt goes where the 1/2" drive square would sit. Thus you need a big socket.  I think I've used well over 400ftlbs on a (very tight) BB before now.... :o

cheers
Title: Re: square taper bb removal
Post by: Paul on February 24, 2019, 11:47:02 am
I use a standard crank bolt and a big washer. The washer is slightly harder to source as it needs a big out diameter to cover the hole in the tool and a smaller than usual inner diameter otherwise the bolt head will go straight through. You may have to stack two different sized washers.
Cone spanner.
 :thumbsup:
Title: Re: square taper bb removal
Post by: Tim Hall on February 24, 2019, 05:00:34 pm
I use a standard crank bolt and a big washer. The washer is slightly harder to source as it needs a big out diameter to cover the hole in the tool and a smaller than usual inner diameter otherwise the bolt head will go straight through. You may have to stack two different sized washers.
Cone spanner.
 :thumbsup:
Ooh. Filed away under Top Tips for when I lose the specially procured washers.
Title: Re: square taper bb removal
Post by: rr on February 24, 2019, 06:18:30 pm
I use a standard crank bolt and a big washer. The washer is slightly harder to source as it needs a big out diameter to cover the hole in the tool and a smaller than usual inner diameter otherwise the bolt head will go straight through. You may have to stack two different sized washers.
My bolts were too short to do that, you must have a short tool.

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Title: Re: square taper bb removal
Post by: KM on February 24, 2019, 06:29:44 pm
I use a standard crank bolt and a big washer.

Same here.  IIRC my washer was one that had been used to fasten a headboard to a bed base. 

For my particular BB tool I picked up a 32mm Halfords Advanced 1/2” drive socket to go with a Sealey breaker bar. Very satisfying in use.

Title: Re: square taper bb removal
Post by: ElyDave on February 24, 2019, 07:19:16 pm
I found an old wrench in one of mmy inherited toolboxes that had nice flat faces - the stilson were failing to grip because the tool has slightly rounded corners. It needed a bit of fettling itself, a spray of GT85 to free up the mechanism.

Ended up with a big washer against the wrench, then the crankbolt, and a lot of brute force.   Will install the new one tomorrow.
Title: Re: square taper bb removal
Post by: Giropaul on February 24, 2019, 08:23:15 pm
I’m assuming it is a British thread, not Italian?
Title: Re: square taper bb removal
Post by: ElyDave on February 25, 2019, 08:33:00 am
how does the thread affect the size of the wrench used?  I don't get the question.
Title: Re: square taper bb removal
Post by: Brucey on February 25, 2019, 08:48:09 am
Italian uses a RH thread both sides of the BB shell.

cheers
Title: Re: square taper bb removal
Post by: Brucey on February 25, 2019, 08:52:34 am
I use a standard crank bolt and a big washer. The washer is slightly harder to source as it needs a big out diameter to cover the hole in the tool and a smaller than usual inner diameter otherwise the bolt head will go straight through. You may have to stack two different sized washers.
My bolts were too short to do that, you must have a short tool.


Shimano TL-UN74 is shallow enough that a standard crank bolt can normally be used to secure it. You do need a big washer though.

 Provided the washer is smaller than ~36mm dia, then a big socket will fit over it and drive the tool nicely.  I have a 3/4" drive socket and a five foot long breaker bar..... :o

cheers
Title: Re: square taper bb removal
Post by: ElyDave on February 25, 2019, 10:47:40 am
yes, that's the tool I have, I have the big tommy bars, but not the right socket - yet

And, no it's not Italian thread, it's out now.