Bicycle Tutor

Hi, guys/gals. I posted on here a while back about a chronic problem that I have with my two-month old Bianchi 24-gear touring bike. I had received some replies, but I don't think my question was posed correctly. Please allow me to try again, and I hope some of you experts can help me. I ride my bike 99% of the time with the left gear shift on number 3 and the right shift on number 7 (I'm explaining this as easily as I know how as a non-mechanic). The chain is lined up straight on both derailures [sic?]. The only time I down shift from 3 to 2 is when I come to a stop sign or have to adjust for traffic, etc. Ok, my problem is that in both positions, especially in the 3/7 gear, my sprocket will skip, especially if heavy torque is applied, but it will do so with normal pedaling(14mph). It sounds and feels like the chain rips across the teeth of the sprocket, but I know that is not the problem, so it has to be internal. I can't tell if it is the front sprocket or the rear. All I know is that it does it it with enough frequency to irritate me. I mean, this bike is two months old. Can anybody enlighten me? I will take it it back to the shop, but I am hoping that somebody can explain what may be going on so I will be able to talk intelligently with the bike mechanic. Thank you!!...for your time.

If I understand you correctly, you have the chain on the outermost chainring in the front and 1 in from the innermost cog in the rear. If so, this is not an ideal gear combination. This is called cross-chaining when you have the chain from outside to inside or vice versa. You should be able to achieve the same gear ratio running in roughly the middle of the front and rear.

Now, cross chaining is a little hard on your drive train and will wear it out faster, but it should not cause skipping. I don't know what the problem is, but thought it was worth pointing out that it sounds like you're using less than ideal gear settings.

Beyond that, skipping is usually caused by either worn cassette and chain or by out of adjustment/bent/damaged derailleurs. But it's going to be hard to diagnose these just from your descriptions.

If the bike's two months old, can you take it back to the shop? This would definitely be warranty, part of the normal adjustments they would do on any new bike.

(Oct 28, 2012 08:29 PM)DaveM Wrote:  If I understand you correctly, you have the chain on the outermost chainring in the front and 1 in from the innermost cog in the rear. If so, this is not an ideal gear combination. This is called cross-chaining when you have the chain from outside to inside or vice versa. You should be able to achieve the same gear ratio running in roughly the middle of the front and rear.

Now, cross chaining is a little hard on your drive train and will wear it out faster, but it should not cause skipping. I don't know what the problem is, but thought it was worth pointing out that it sounds like you're using less than ideal gear settings.

Beyond that, skipping is usually caused by either worn cassette and chain or by out of adjustment/bent/damaged derailleurs. But it's going to be hard to diagnose these just from your descriptions.




If the bike's two months old, can you take it back to the shop? This would definitely be warranty, part of the normal adjustments they would do on any new bike.

Hi, Dave, yes, the chain is on the outside sprocket in front and on a next to last low sprocket in back....the chain is straight as an arrow...no cross-chaining at all....so, that can't be it......the bike tech even said it was a good position....it is an 8 speed....it's got to be internal.....somewhere...is still under warranty.....thank you for your reply.

Got it - misunderstood your description. It could be just a shifter adjustment or a faulty freehub. Very typical for the shifter cables to stretch a little early on and this will knock your shifters out of adjustment. Very unlikely it is skipping in the front unless the chain actually falls off the front chainring. Most common cause of this is a worn cassette & chain. They should not get that worn in two months unless you're doing something very unusual, but this kind of skipping is fairly common. Probably tough to say much else without touching the bike.

Side note - Some don't bother, but I'd recommend playing with different gears a little more. I'm sure you'll never use all 24 combinations, but you should probably use more than 2. You'll be faster and use less energy if you adjust the gears so you can pedal at your desired effort level while keeping a pace of around 70-90 revolutions per minute on the pedals. YMMV