Breaking a Freewheel cog

[splat]

Just got back from a Ride in the Nam with Justbill and Phresh , great ride , but Bill did something I have never seen before. He broke a Freewheel cog , In the process bent 2 others , Made that 9 speed a 6 speed real fast ! Didn't stop us we kept on riding , with Bill Minus a few gears !

[Adam]

I've made regular business out of warping cassettes-If they're Shimano you can ship them back to 'S' for a warranty claim & you'll usually get a new one in return within a week or two. SRAM cassettes have to be returned to the bike shop where purchased for evaluation. Check out Shimano's website for the warranty claim form & return address.
With 3 bikes & year-round riding, I upgraded to a Rohloff Speedhub. It's a high price of entry, but I've done zero drivetrain maintenance in 2 months of frequent all-conditions riding.

-Adam

[Adam]

Oh yeah-an example of my last SRAM cassette. Observe the 34t cog.

[NEMBA_bkr-dude]

once my lbs broke my bike so bad they replaced every part on it and it still didn't work so I assume they bent the frame in some messed up way but hey! they gave me a new bike for free and it was next year's model too :). but then I started breaking parts ever day so I bought my new bike which hasn't had and problems except when I shattered the rear derailleur hanger. (plastic is my enemy). it is funny cause my new specialized is an 02 but my old raleigh m50 is an 03

[C.P.]

Hmmmm. Looks like CLASSIC shifting to a lower gear in a climb, under full pedal load to me, especailly b/c the break is right at the shifting ramp on the broken cog. Seen it many times before. Nowadays, that'll bend/break a cassette real fast, especailly if it's common pedalling practice. Learn to shift under light pedal load, your drivetrain will NEVER have problems, and chain breaks, they'll be a thing of the past as well.

Thats my rear cassette in the first picture. I belive i know what the problem was. I had changed over to my winter wheels(rolf dolomites w/studded nokians) on thanksgiving and adjusted my derailur to shift smooth on the shimano 9. The morning before this ride i switched back to the summer wheels( mavic 521) and never readjusted the derailur for the sram cassette. When i turned hard onto a steep fire road incline and jumped on the pedals the frame flex and poor adjustment led to an auto shift up to a higher gear and i pulled the chain right between the 3rd and 2nd cog.

Always adjust your derailur and breaks when switching wheels

[gungywump]

Hmmmm. Looks like CLASSIC shifting to a lower gear in a climb, under full pedal load to me, especailly b/c the break is right at the shifting ramp on the broken cog. Seen it many times before. Nowadays, that'll bend/break a cassette real fast, especailly if it's common pedalling practice. Learn to shift under light pedal load, your drivetrain will NEVER have problems, and chain breaks, they'll be a thing of the past as well.


First, It's a casette NOT a freewheel.

I gotta go with C.P. he's got it nailed. I see it more on lower end Shimano cassettes than higher end XT & XTR cassettes. SRAMS tend to be fine but again the level of the cassette is a factor.
For chains however SRAM is way better than Shimano in terms of breakage. PC-58 or PC-59 at least. Don't waste time on the PC-48 or PC-49.

[splat]

First, It's a casette NOT a freewheel.



IT IS a Freewheel, it is a cassette freewheel , but it is still a freewheel.

[johnbryanpeters]

IT IS a Freewheel, it is a cassette freewheel , but it is still a freewheel.

What he said, even if he is deluded about operating systems. ::) ;D

J

[C.P.]

If I may, I'm pretty sure Gungy was referring to the difference between the older style "freewheel" and newer style "freehub" with a "cassette" that we typically see nowadays-the difference is big actually. His comment simply referred to the fact that the damage shown in the original photo only affected the cogs on the part known in shopspeak as the "cassette". The repair to this will be to simply replace the CASETTE, and not to even touch the freehub portion of the rear hub. A Freewheel, yeah, maybe in some camps, but were in the "technical" forum, AND your mechanic probably would have corrected you if you brought the wheel in and asked to replace the "freewheel". The wheel shown has a cassette and freeHUB.
Note an older type (5 speed thru 7 speed gear "clusters")freewheel is the combination of cogs AND the ratchet mechanism (they are 1 Part not two), which in shopspeak is known ONLY as a freewheel.
You want to know more as always Sheldon Brown has a great page written.
http://www.sheldonbrown.com/k7.html
Photo credit to sheldon brown.
Freewheel and threaded hub left/Cassette and freehub right.
C.P.