Help with removal of strange bottom bracket...

danstar10

Hi guys,
Having spent the best part of 5+ hours removing cranks with a hacksaw and drill that had the threads for the extractor tool stripped, I am now faced with a bottom bracket that doesn't want to go anywhere.

I was under the impression that bottom brackets either had the external lockring, or the internal spindle cup that needed removing to loosen it, but this one seems to have both - is that normal? Even a mechanic I showed it to commented that this is odd. See link below for image.

http://imageshack.com/a/img546/2071/6pjk.jpg

I have a tool to remove the inner spindled type cup but it seems like it is pretty stuck in there. Do I need to loosen the outer lockring first maybe? And just to confirm, none driveside BB cup loosens the normal way, drive side is clockwise right?

Cheers

damonlock

Remove the outer lock ring with a c spanner or flat bladded screw driver and hammer if you don't have c spanner then give it another go, might be worth soaking in wd40 or gt85 if it's a bit stuck if that fails heating up but this will more than likey damage you paint or if you have access to an impact gun use the tool on there

nicklouse

Just knock the ring off with a drift if you don't a suitable tool.

http://www.parktool.com/blog/repair-hel ... ervice-bbt

danstar10

Thanks for the advice guys. I managed to get everything out except the inner cup on the none drive side as it is stuck in pretty well.

Just so I know if this is all worth it (As I bought the bike for £20 as a crappy commuter that can get stolen so do not want to invest too much in it!), if I finally get to remove the BB totally, I am planning on replacing it and the crankset with these:

http://www.chainreactioncycles.com/s...t/rp-prod34652

http://www.chainreactioncycles.com/s...t/rp-prod46021

My old chainrings were 38 31 22 or something similar, and these are 44 32 22. Could that cause any problems? Also it is listed as a 9 speed crankset but my bike is 8 speed, assume that will not be an issue...

I measured the bottom bracket shell and axel of the old BB and it was 68mm * 117mm. This BB does not come in 117mm, would 122.5mm axel length be ok to use?


Cheers

cooldad

No. Find 118mm. Like
http://www.chainreactioncycles.com/shim ... -prod71369

Bigger ring might hit the frame, probably won't, but...

raldat

danstar10 wrote:

Thanks for the advice guys. I managed to get everything out except the inner cup on the none drive side as it is stuck in pretty well.

Just so I know if this is all worth it (As I bought the bike for £20 as a crappy commuter that can get stolen so do not want to invest too much in it!), if I finally get to remove the BB totally, I am planning on replacing it and the crankset with these:

http://www.chainreactioncycles.com/s...t/rp-prod34652

http://www.chainreactioncycles.com/s...t/rp-prod46021

My old chainrings were 38 31 22 or something similar, and these are 44 32 22. Could that cause any problems? Also it is listed as a 9 speed crankset but my bike is 8 speed, assume that will not be an issue...

I measured the bottom bracket shell and axel of the old BB and it was 68mm * 117mm. This BB does not come in 117mm, would 122.5mm axel length be ok to use?


Cheers

BB axel length on these is crank specific. I run one of these cranks on my old commuter as well. I had a 122.5 bb on the bike to suit the old crank and had to put a 113 on with this crank to maintain a 50mm chain line. Now that you have hacked the old crank off you won't be able to check the chain line which is measured from the centre of the bb case to the middle ring of a triple, but 50 or there abouts is standard.

cooldad

Good point, but cranks tech docs should state the BB size needed - will be on Shimano website.

danstar10

Ok so I think I have found the techdocs for the M442 crankset:
http://techdocs.shimano.com/media/techd ... 657937.pdf


I have also found a suitable fc131 crankset for 8 speed which is what I am running so this may be a better option:
http://www.woollyhatshop.com/Cranksets/ ... _3149.html

and the techdocs for that:
http://techdocs.shimano.com/media/techd ... 758324.pdf


Man I did not know it was this complicated!
So from what I can derive it looks like the fc131 needs a 122.5mm spindle, but I cant figure what the M442 needs. There is also the (-E) and (-K) prefixes that I know relate to front derailleur type but I don't get - can anyone shine some light on that?
My derailleur is mounted on the bottom bracket.

Cheers