Author Topic: Square Taper Bottom Bracket replacement woes (tools)  (Read 517 times)

Square Taper Bottom Bracket replacement woes (tools)
« on: July 28, 2020, 08:04:48 am »
Hi All.

Decided to replace the BB in my Surly as it felt rough and knackered. (13,500km old). I found out what it came with and ordered a like for like replacement from Stronglight.

I've not touched an 'old' style BB like this before (all my other bikes have press-fit *shudders* ) so a colleague gave me a crank extractor and a splined BB tool. Upon trying to remove the NDS BB collar, the tool slipped and ripped half the plastic collar off. I was able to slowy remove the BB from the DS but it was very awkward, if i turned with any sort of angle the tool would roll out of the cup. 

When installing the replacement (having cleaned and greased the threads), first thing i noticed was how much resistance there was. It was engaged alright, but i needed the tool to wind it in. An instructional  video i had watched showed him winding it in by hand with ease. It was a bit of a struggle, again the tool slipping.

Putting the NDS collar in, it was even tighter and the tool kept slipping, to the degree that little bits of plastic started appearing on the floor below. I stopped at this point, because something isn't right.

The tool I have is:

 'BBT-2'. I notice online that this doesn't exist anymore, replaced by BBT-22?

The difference seems to be the newer ones don't have the chamfer on the splines. I get the feeling a square ended spline would have proper engagement and stop it rolling out/stripping the teeth in the cups.

I'm minded to, if i can get the appropriate tool, remove the new one while the grease on the threads is still fresh and chuck it as the teeth are so mangled. It'd be impossible to remove another few years down the line.

Any advice/suggestions? Where have I gone wrong?

Cheers

Peat


LittleWheelsandBig

  • Whimsy Rider
Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #1 on: July 28, 2020, 08:39:27 am »
The problem is that your frame needs to have the threads cleaned out with a tap. Then you need to keep the tool aligned while you are applying some effort.

The first needs an expensive tool that you don’t have (go to a bike shop, it only needs to be done once) and the second needs some mechanical sympathy and ideally a tool that you can clamp in place.

https://www.bike24.com/p2275889.html is a BB tap.

https://www.wiggle.co.uk/shimano-bottom-bracket-removal-tool can be prevented from slipping with a big washer and the crank bolt.
Wheel meet again, don't know where, don't know when...

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #2 on: July 28, 2020, 08:40:33 am »
some comments

a) the chamfer on the tool is not ideal if it restricts engagement between the tool and the parts
b) that the cups are stiff to go in is probably due to two things; first the frame threads probably need to be chased n'faced and second
c) the driveside part should be at least half a turn away from fully home when the NDS cup is wound in. The final half turn on the DS should be followed by the final turn on the NDS.
d) if the tool tends to 'cam out' (*), the tool should be secured to the BB parts using something through the middle. Pedros make a tool for this purpose, but it is often possible to improvise.

(*) when the tool cams out this is usually in part to do with the technique used and partly to do with the extension bar/spanner used to drive the tool.  If a swivel-headed breaker bar or slightly cranked spanner is used such that the handle is in the same vertical plane as the splines themselves, there is no cam-out force and a well-practiced hand can install/remove even the most obstinate assembly.

BTW you don't have to live with a  plastic NDS cup; some BB models come with an aluminium cup and even if not an aluminium cup can be bought separately and used.  Just make sure that the ID of the cup matches the bearing cartridge; they vary.

cheers

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #3 on: July 28, 2020, 09:25:13 am »
I have chasing and facing tools if you're near Swindon.  They go in pretty smoothly when the threads are good.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

zigzag

  • unfuckwithable
Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #4 on: July 28, 2020, 12:24:29 pm »
the tool needed to be secured to the axle with a washer and bolt - otherwise it slips (or has very high tendency to).

lbs may have an old knackered bb with a metal cup, which could be scavenged.

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #5 on: July 28, 2020, 12:27:59 pm »
My Park tool has more tendency to cam out than a cheapie one I also have.  Its bulk and weight don't help.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

robgul

  • Cycle:End-to-End webmaster
  • . . cyclist, Cytech accredited
    • Cycle:End-to-End
Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #6 on: July 28, 2020, 12:46:49 pm »
Cleaning the threads with the proper tool is a good idea BUT give it a try with a small wire brush and some WD40 .... running the brush "round the threads" rather than across them.  That usually gets them a bit better for accepting the new BB - and some grease as you screw in the BB & cup.

The other thing to look for is whether the BB cartridge has a ridge around it that fouls the non-drive cup (I used to come across that quite often when i ran an LBS) - either find another cup or file/grind it down a bit shorter.

Rob

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #7 on: July 28, 2020, 01:50:31 pm »
the tool needed to be secured to the axle with a washer and bolt - otherwise it slips (or has very high tendency to).
I'm a fan of the Pedro's tool for that. I know not everyone agrees.

LMT

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #8 on: July 28, 2020, 01:54:46 pm »
Take it to your lbs. Might want to ring and check before hand but back in the day these were fitted with a two handled wrench. Went on much easier than trying to fit with a locknut.

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #9 on: July 28, 2020, 07:48:51 pm »
I once ended up with the BB tool in a vice and the bike frame horizontal sans wheels and it seemed like a giant steering wheel, moving it round bit by bit. Happy days.

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #10 on: July 28, 2020, 09:23:26 pm »
I think that may be the way that one of my two vice breakages happened...

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #11 on: July 28, 2020, 09:31:15 pm »
I broke the splines of a Shimano tool doing that!  In the end the LBS got it out.  They have Hagrid's brother chained up in the back yard.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #12 on: July 28, 2020, 09:43:43 pm »
I think that may be the way that one of my two vice breakages happened...

Small vice then?

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #13 on: July 28, 2020, 10:03:21 pm »
Not especially. A fairly standard Record one.

I broke a Shimano tool too.

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #14 on: July 29, 2020, 01:15:02 pm »
I don't think I have not seen at least one broken UN-type BB tool of every common make, so none of them are entirely proof against breakage. However some of them are broken when they slip out and others are broken when the tool is slogged with a hammer; if neither thing happens the chances of breakage are very much reduced.

FWIW I have used up to about 600-700ftlbs on a shimano tool (driving it using a 6' bar and a 3/4" drive socket) and to my considerable surprise the tool didn't break.

cheers

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #15 on: July 29, 2020, 01:31:34 pm »
So, I borrowed a different BB tool with square ends and removed the new, mangled plastic one.

I have since aquired a Shimano BB (ally cups) and LBS kindly loaned me a tap/chasing tool. First go and the shell wasn't readily accepting of the tap, so i'm not going to force it.

I'll ponder this avo.

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #16 on: July 29, 2020, 01:40:55 pm »
Make sure you have the taps in the correct side.  Cyclus taps are labelled BSA-L and BSA-R.  This refers to the handedness of the thread, NOT the side they go in!
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #17 on: July 29, 2020, 01:50:13 pm »
 :facepalm:You're right.

I've swapped the L & R and it whistles in!

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #18 on: July 29, 2020, 03:54:27 pm »
All done.

Threads cleaned up nicely, new BB spun it's way in easily and the original tool I was using engaged properly throughout.

Thanks for the advice.

Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #19 on: July 29, 2020, 03:59:21 pm »
<applauds>   Glad you got this sorted.
Rust never sleeps

LittleWheelsandBig

  • Whimsy Rider
Re: Square Taper Bottom Bracket replacement woes (tools)
« Reply #20 on: July 29, 2020, 05:10:30 pm »
Thanks. I’ll have a pint...
Wheel meet again, don't know where, don't know when...