Press fit bottom bracket tool

rliu

Über Member
Hi I posted a thread about this 3/4 weeks ago and can't find it again, but basically I'm trying to remove a Shimano BB91-41 using one of the cheap tools sold by Burton Bikes off ebay:
1579958486677.png


It doesn't actually sit snug in between the cups and the bearings for me, so it rests at an angle. This means I've been hitting it on and off for probably a good hour and budged it a couple of mm at most. Anyone else used their tool before or have any general tips?
 
Location
Loch side.
https://www.cyclechat.net/threads/press-fit-bb-tool-recommendation.256258/

I haven't used one of those tools before, however, it sounds like you re doing something wrong. You are trying to hit it from the inside, out, are you?

Firstly, to prevent the skewness or, having it at an angle, have a helper hold the tool for you. Insert it, and have the helper pull on the small end, The helper will then assure that the tool seats perfectly on the bearing. You then position your punch and hit hard and squarely. Don't tap-tap. Hit.

If the tool is not held squarely against the bearing, you will damage the frame. But once it is square, hit it hard. Don't fool around.

The helper will prevent the tool and bearing from coming flying out.
 
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OP
R

rliu

Über Member
https://www.cyclechat.net/threads/press-fit-bb-tool-recommendation.256258/

I haven't used one of those tools before, however, it sounds like you re doing something wrong. You are trying to hit it from the inside, out, are you?

Firstly, to prevent the skewness or, having it at an angle, have a helper hold the tool for you. Insert it, and have the helper pull on the small end, The helper will then assure that the tool seats perfectly on the bearing. You then position your punch and hit hard and squarely. Don't tap-tap. Hit.

If the tool is not held squarely against the bearing, you will damage the frame. But once it is square, hit it hard. Don't fool around.

The helper will prevent the tool and bearing from coming flying out.
Thanks for the link and advice. Basically you position the tool in the groove between the cup and bearing, where it's supposed to sit square, and then hit it out with a screwdriver pressed against the groove in the flat section on top.

If hitting it while slanted is futile and potentially damaging, I may be better off getting a different removal tool
 
Location
Loch side.
Thanks for the link and advice. Basically you position the tool in the groove between the cup and bearing, where it's supposed to sit square, and then hit it out with a screwdriver pressed against the groove in the flat section on top.

If hitting it while slanted is futile and potentially damaging, I may be better off getting a different removal tool
The fact that you're using a screwdriver already tells me you're gonna screw this up.

That flat section on top doesn't house a groove. It is a centering hole for a suitable drift. You need a sturdy drift, at least 20mm in dia.

There's nothing wrong with the tool. Blame something/one else.

Don't forget that the frame needs support whilst doing this, preferable not in a stand, but in someone else's arms.

Interference fit components require some skill. Have someone show you how rather than botch the job.
 
OP
R

rliu

Über Member
The screwdriver tip is actually something they print on a piece of paper sent with the tool. Anyway I've gone for one of the other tools that are built around a central rod now and going to return this one, as I one don't wanna do any damage and two don't want to keep spending time getting nowhere.
 

CXRAndy

Guru
Location
Lincs
Finally got it off 10 minutes ago with a different tool,

View: https://www.amazon.co.uk/gp/product/B009T6DBJI/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
(will give them a plug out of relief mixed with gratitude)
Now if anyone could just remind me of any other bits to watch out for while fitting the new BB - I should avoid lithium grease altogether or apply just a thin layer?
You could apply holding loctite to bond the BB or go with a smear of grease to try eliminate BB creak
 
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