View Full Version : bb question

Johnny Law
03-25-2009, 03:44 PM
why is it that when i'm in the seat and pedaling, continuous spin for the most part, that only then that it feels as if the bb is grinding? i looked down at the front derailuer and it poosibly could've been rubbing ( 53x 12 ) as i noticed the chain on the crank move a hair outward toward the drailuer but when out of the saddle and not really bouncing ( i can control that for the most part) but rather with the wieght of my body more so on the front side of the spin/crank that i can't feel any grind?

i think i know the answer, adjust the derailuer slightly but does that negate that the bb may be wearing out?

i know, take her to a shop but i can't just yet so i figured i'd ask you all.

tm 2.53.15, 16.1 av, 46.58 miles, 53 x 12 on the way out averaging 17.3 but 53 x 14 in with headwind for exactly the half ride back. and strong wind too which is when i get out of the seat. not a fan of down gearing but rather get out of seat and ride like it's a fixed gear. and that's when i noticed that i wasn't receiving any grind while standing and running in the pedals.

i thought the ride in the rain yesteday may have contributed but when i got home yesterday and cleaned her off, i checked her and there wasn't any out of normal play/flex in the crank. and there isn't now either.

slightly desperate because i can't afford a new crank or serioss service just yet. thanks.

03-25-2009, 04:17 PM
i looked down at the front derailuer and it poosibly could've been rubbing ( 53x 12 ) I'd first check to make sure your cable hasn't stretched a little making it easier for the chain to rub the front derailleur when you stand and flex the frame more than normal.

Johnny Law
03-25-2009, 07:32 PM
i forgot that i've only used the 39 once, for about 2 minutes on a local 'experienced' store ride recently and until that day and from about the entire previous two entire months of ownership was unable to get to the 39 as she wouldn't shift outta 53 at all. not a big deal to me but i thought after awhile (2 months!! :) that i may just be needing it seeing as how my plans are to start inner city riding and so i got it worked on at the store in the morning previous of this local 'experienced' ride. derailuer = working, then and now but it did slip back inwards a bit, resulting in and obviously causing the grinding.

but i just didn't feel like what a chain has felt like to me with this grind as it had on my mtn bike and on the cross or even on the old dirt jumper but that's exactly what it is, this time and for now. first road bike so go figure.

goOd. I wasn't looking forward to a goOd 70 -100 miles constant 'grinding' tomorrow. fsa mega exo is seeminlgy spinning like a set of swiss bearings.