Bicycle Mechanics - Loose Bottom Bracket! Ugh!

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View Full Version : Loose Bottom Bracket! Ugh!


zac.stanley
02-13-08, 10:59 AM
I was riding on grizzly peak on sunday when I noticed my cranks starting to shift laterally - inspected the problem and realized the fixed cup was loose - i finger tightened it and limped my way home. This is an early dura ace 7400 BB w/ italian threading.

The lock ring is tight enough that I can't unscrew with my fingers (i don't yet have a wrench) - do i simply need to tighten this or do my problems seem bigger?

thanks in advance!

zac


j0e_bik3
02-13-08, 11:24 AM
I'm pretty sure ALL italian threaded BB's come loose as you ride them, and need constant tightening, as the right side (fixed)cup is not reverse threaded.

per:
http://sheldonbrown.com/harris/bottombrackets.html

(RIP Capt. Bike)

if you use the BLUE* loctite and let it set up overnight, it'll still come loose, but it takes MONTHS instead of weeks or days, I used it on my old ital threaded road bike for years

*blue is medium strength (you can still get it OFF when you want to),..RED is ridiculously strong, and will totally screw up fine aluminum threads upon removal, and should be avoided on aluminum threaded parts (IMO)

[ahhh, grizzly peak,...I lost quite a few brain cells up at "the wall" in my youth :D]

zac.stanley
02-13-08, 11:33 AM
yep - right side is fixed

so i just have to keep tight huh - ok


j0e_bik3
02-13-08, 11:38 AM
yep - right side is fixed

so i just have to keep tight huh - ok

pretty much,..mine was a PITA,..but after the blue loctite it would only loosen up after 3 or 4 months, then you just take it out, clean the threads, re-apply the loctite (I usually serviced the bearings at the same time) and tighten, remembering to LET IT SIT OVERNIGHT before riding.

oh and get a proper lockring wrench (park HCW-5 is one) so you don't fuxor the lockring indents, as you'll be doing this more than most folks.

zac.stanley
02-13-08, 11:48 AM
yeah - it's 85 pinarello that i've maybe ridden 100 miles on. Loctite it is. Thanks for the park tool tip i was just searching their site for it.

cheers,
zac

hhabca
02-13-08, 06:06 PM
My Bianchi has this problem - I use a correct BB wrench and tighten it once a month or so when I'm riding it often. Before I started my once a month routine I had it loosen once when riding - I would get it finger tight but that would last about 2 miles, then I'm off trying to get it tight again. Makes one want to carry some sort of folding BB wrench with them. So, yes, Italian threads are a bit of pain, but at least when you want it to come off, it's already loose!