stripped notches on external BB cups

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22camels
Posts: 302
Joined: 21 Sep 2013, 8:15pm

stripped notches on external BB cups

Post by 22camels »

I installed a new shimano external BB today and as I was tightening the cups using the Lifeline Performance External Bottom Bracket Wrench, I noticed that the tool had started to strip some of the thread i.e. the notches on the cups. The wrench never slipped off to the side and was aligned with the notches. Picture:
bb-6626.JPG


Is this: a) bad tool, b) bad cups, c) user error e.g. trying to tighten too much (recommended torque is 35-50 Nm which I took to mean as tight as I can reasonably go without straining too much) ?

Reason I ask is that the same thing happened on the previous BB upon installation and when I tried to remove it, perhaps it was more seized up than when it had been installed due to dirt or whatever, but anyway, the notches had already been stripped a little, and basically I couldn't get it off, and applying more force (yes in the right direction) I stripped the notches even more, so much that I had to take it to the LBS and was pretty lucky there was still some notches left for them to remove the BB. I am trying to avoid the same thing happening again.

Thanks!
Valbrona
Posts: 2696
Joined: 7 Feb 2011, 4:49pm

Re: stripped notches on external BB cups

Post by Valbrona »

What cups are we talking? They now come in three flavours each requiring a specific tool:-

Sixteen notch/39mm - Dura-Ace BB-9000.
Sixteen notch/41mm - Ultegra 11 speed.
Sixteen notch/44mm - HollowTech II, Power/Ultra-Torque, Stronglight ActivLink, MICHE EvoMax, Chris King, etc.
I should coco.
tim-b
Posts: 2093
Joined: 10 Oct 2009, 8:20am

Re: stripped notches on external BB cups

Post by tim-b »

Hi
I prefer to use a socket-type tool such as this one from Park Tool to give a little more surface area. As has been said they now come in several sizes and other manufacturers are available (mine is Pedro's version)
Regards
tim-b
~~~~¯\(ツ)/¯~~~~
22camels
Posts: 302
Joined: 21 Sep 2013, 8:15pm

Re: stripped notches on external BB cups

Post by 22camels »

Hollow tech II, the Tiagra BB4600, sorry should have specified.

Yes Shimano does specify a specific Shimano tool TL-FC32/36 in the spec for this BB, but I thought I could use others too, as they all looked similar and I think I checked the lifeline performance one for hollow tech compatibility. Should I stick with the Shimano tool? What does 39/41/44mm refer to?

I noticed the park tools one (bbt-9) goes all the way round so that would perhaps give better grip.
beardy
Posts: 3382
Joined: 23 Feb 2010, 4:10pm

Re: stripped notches on external BB cups

Post by beardy »

This gives me confidence when fitting or removing external bottom brackets.

http://www.chainreactioncycles.com/pedr ... -prod26744

Nice and secure fitting if you ever need to apply lots of force, which I never have had to do.
Samuel D
Posts: 3088
Joined: 8 Mar 2015, 11:05pm
Location: Paris
Contact:

Re: stripped notches on external BB cups

Post by Samuel D »

Why is the Lifeline Performance tool, and the Shimano TL-FC32 for that matter (but not the TL-FC36), open-ended? That does not inspire confidence.

The Pedro’s socket-type tool looks much better and would allow use of a torque wrench.
Brucey
Posts: 44521
Joined: 4 Jan 2012, 6:25pm

Re: stripped notches on external BB cups

Post by Brucey »

22camels wrote:
a) bad tool,

b) bad cups,

c) user error e.g. trying to tighten too much (recommended torque is 35-50 Nm which I took to mean as tight as I can reasonably go without straining too much) ?



a) there are better tools than that. e.g. I have a 'fat spanner' socket which has loads of engagement.

b) unlikely.

c) I think you should get a torque wrench. If the spanner is about 1' long then most people should be able to 'reasonably' get to about 100ftlbs quite easily, which is about three times as much as you need for this job....

Fat spanner socket tool;
Image
http://www.fatspanneruk.com/product_details.aspx?Product=X-Type-Socket-BB-Tool
you can see the nice deep splines in the socket... what you can't see is that on the back of it there is a 1/2" square drive fitting so that you can use a torque wrench on it.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
pwa
Posts: 17371
Joined: 2 Oct 2011, 8:55pm

Re: stripped notches on external BB cups

Post by pwa »

Do these cups loosen if you underdo the tightening?
22camels
Posts: 302
Joined: 21 Sep 2013, 8:15pm

Re: stripped notches on external BB cups

Post by 22camels »

Thanks for the suggestions, yeah the pedro's tool looks the biz.

"Do these cups loosen if you underdo the tightening?" - not sure, but it doesn't feel like I'm tightening them excessively, before the stripping starts.
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Erudin
Posts: 646
Joined: 17 Sep 2009, 3:39am
Location: Cornwall

Re: stripped notches on external BB cups

Post by Erudin »

I'd guess the tool is not a good enough fit.

I tighten/loosen mine with a Hollowtech socket tool and a 32mm spanner. The tool can be held securely to the cup using a quick release skewer. I also have a Park BBT-9 which is a good fit, but not as good as the socket tool.
Attachments
HT2 Socket Tool held by QR Skewer (600 x 355).jpg
Last edited by Erudin on 22 Apr 2015, 1:54pm, edited 1 time in total.
Brucey
Posts: 44521
Joined: 4 Jan 2012, 6:25pm

Re: stripped notches on external BB cups

Post by Brucey »

22camels wrote:Thanks for the suggestions, yeah the pedro's tool looks the biz.


FWIW I think the fat spanner tool is better than the Pedros one (it has a deeper socket which is necessary with some BB types, and it comes with a handle as well as a 1/2" square drive) and it can be had for less as well eg;

http://www.discountcyclesdirect.co.uk/catalog/product.php?CI_ID=8030&Item='Fat%20Spanner%20X-Type%20Socket%20Bottom%20Bracket%20Tool'

"Do these cups loosen if you underdo the tightening?" - not sure, but it doesn't feel like I'm tightening them excessively, before the stripping starts.


They should self-tighten (like pedal threads) in service; they do seem tighter during removal even having been in a fairly short while... Regarding the torque required; you may be right on the money but you may be overdoing it.... which is why you should be thinking about using a torque wrench.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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