Clicking Gears and Unsmooth Gear Changes!

[hpratvfrk]

Hey All!

Just recently bought a used 2012 DeVinci Milano (loving it!) and I'm having some trouble with the gears! I usually use my left shift in gear 2, and right shift in gear 1-7 depending on the hills/speed (I also heard that there are gear combinations that should never be used, is that true?!).

So when I'm on LS2 and RS6, 5, or 4, and I use a bit of strength to pedal, the bike kind of 'misses a beat', and feels like the chain missed a gear tooth. This only happens when I accelerate though, but doesn't when I'm at a steady speed.

What do you guys think? Is there something I need to replace? Is it something I can hold off to replace, if I go gently on those gears? I just recently got into riding, please excuse me for my lack of biking diction!



Thanks!
-Rich

 

[vspa]

hi and welcome, first things first: from their website i see a triple chainring in front so you should avoid, using your clever code system, LS1 plus RS7 & LS3 plus RS1 commonly known as big/big (big chainring and big rear sprocket) and small/small (smallest chainring and small rear sprocket). The reason is that chain acquires a cross or bent position which could make it jump out while riding or even brake down in the long run second: the gears where you miss a beat or miss a gear while applying pressure or force is not acceptable, it could be one of two things, the chain and the rear sprockets are worn out, which we can dismiss as the bike is a 2012 model, and the gears needs to be adjusted and aligned, which is a very common and straight forward job in your favourite bike store or even as a DIY project, hope this helps

 

[hpratvfrk]

This is great info, thanks vspa! I'll definitely keep that in mind. How much does it cost typically to have the gears adjusted/aligned/replaced?


Thanks again in advance!

 

[swampy1970]

This should give you a good idea of how to adjust the rear gears:

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Nexave/SI_R670B/SI-R670B-001-ENG_v1_m56577569830679415.pdf

Look at section 4.


Basically, you're changing from 2nd to 3rd gear. The shift should be smooth. If it has to 'try' for a second or two to change gear then you need to adjust the 'adjustment bolt'. Make the change (one rotation) and try again. If the change is now smooth then put it back in the 2nd gear. The change down should be smooth. If it is not then adjust the 'adjustment bolt' half a rotation the opposite way you made the change.

As long as the rear derailleur hanger is straight and all the parts are fairly clean and well lubricated, it's all about the cable tension.

This page on the Shimano website is a wealth of information:

http://bike.shimano.com/publish/content/global_cycle/en/us/index/tech_support/tech_tips.html

 

[alfeng]

Originally Posted by hpratvfrk .

Hey All!

Just recently bought a used 2012 DeVinci Milano (loving it!) and I'm having some trouble with the gears! I usually use my left shift in gear 2, and right shift in gear 1-7 depending on the hills/speed (I also heard that there are gear combinations that should never be used, is that true?!).

So when I'm on LS2 and RS6, 5, or 4, and I use a bit of strength to pedal, the bike kind of 'misses a beat', and feels like the chain missed a gear tooth. This only happens when I accelerate though, but doesn't when I'm at a steady speed.

What do you guys think? Is there something I need to replace? Is it something I can hold off to replace, if I go gently on those gears? I just recently got into riding, please excuse me for my lack of biking diction!



Thanks!
-Rich

In addition to the preceding ...

With YOU off of the bike ... rotate the crank backwards & see if there is a hiccup anywhere in the chain ... if there is, then look at the chain at the particular connection & with the CHAIN TOOL which every rider should own, tweak the pin so that it doesn't stand proud of the link's plate ... try 1/4 turn ... test & observe ... repeat as necessary.

This is a DIY fix ...

Your cost is the cost of a chain tool.

 

[dhk2]

I'd start by checking the wear on the chain. Your chain has a 1/2" pitch, or pin-to-pin length, so that the pin centers always come out on the half or whole inch marks on a ruler. When the chain wears, the links seem to "stretch". A chain worn "1%" then will measure 10.1 inches over 10 links, instead of the nominal 10 inches. If the chain is worn to this 1% or more, it's time to change.

The rear cassette cogs tend to wear with the chain, ie, as the chain "stretches", the cog profile changes slightly to accommodate the "longer" chain. If the chain wear is higher than the 1%, say 2-3%, the cassette will likely need replacement too. The normal way this kind of wear is detected is that the chain skips cogs under heavy load, just as you're experiencing.

Don't know how many miles are on your bike, or whether the chain has been kept clean and lubed. With a well-lubed chain, I get around 5K miles on a chain before it hits the replacement limit. I've found that I need to replace the cassette with every second chain, ie, around 10K miles ( if not, I get skipping under load with the new chain). If you ride a lot, this is just routine maintenance, like changing tires.

Bottomline, if the chain hasn't been kept lubed on your bike, the chain and cassette gears could now need replacement. Suggest you measure the chain yourself, then take it to a mechanic to confirm and do the replacements as needed. You can learn to do this yourself if you want to take the time. Easy way to learn is to watch the mechanic. The LBS will be happy to sell you the tool needed to remove/replace the cassette, as well as the chain tool needed to shorten and reconnect the chain on your drivetrain.

 

[vspa]

This is great info, thanks vspa! I'll definitely keep that in mind. How much does it cost typically to have the gears adjusted/aligned/replaced? Thanks again in advance!

20, 25 usd. tops (not a replace, just the adjusting)

 

[doctorold]

I learned to adjust my rear derailleur by watching some youtube videos. Sounds like yours needs an adjustment. Give it a whirl. If you don't get it, make a visit to your LBS.

 

[hpratvfrk]

Thank you everyone!