Gears / Chain Tension?

Darlophil

I wondered if anyone here could help with a gearing / chain query I have, or at least confirm if it might be a similar issue to what I've found on another thread here.

My road bike is relatively new (couple of months) and while the gearing is smooth througout most of the gears, in the top two gears I can't get a smooth pedal stroke leaving it difficult to get the most out of it speed-wise.

Looking at another thread on here, could it be due to cable tension possibly? Or could it be that the rear deralleur isn't lining up properly with the cog?

Hopefully its a simple fix and I'll do it tonight, if not I may have to bite the bullet and take it in the LBS for a service.

Many thanks

drlodge

in the top two gears I can't get a smooth pedal stroke leaving it difficult to get the most out of it speed-wise

What do you mean by this? Do you mean the chain is skipping or what?

Darlophil

I apologise if I'm being vague, its not intentional, its entirely down to a lack of mechanical empathy.

It feels more like its rubbing of something when I apply the 'power' on the pedal stroke.

Thats leading me to believe that the derailleur isn't lining up properly with the two smallest rear cogs. However searching on here has confused me when I found someone mentioning cable tension.

doug5_10

If it sounds more like rubbing, its most likely your front derailleur that will need it limits re-alligned to stop rubbing against the outer plate when near the outer extreme of the cassette.
A quick look at how to clean, service, set limits and index your gears on Youtube, Park Tools, Sheldon Brown will sort you out. Study and completion should be no more than an hour.

JayKosta

If most cases you're more likely to 'hear' problems than to feel them thru the pedals.
E.g. actual sounds such as 'clicking', 'ticking', metal-on-metal 'rubbing', etc.
Things you are most likely to feel is when the chain is not securely meshing on the chainring or sprocket - and that would feel like the chain is 'jumping' or 'slipping'.

And YES, the highest 2 gears probably are difficult to pedal - they would most likely be used on fast downhills, or by a strong rider on the flat.
If it seems that those 2 gears are 'a lot of work' and 'hard to do', then that's correct!

Jay Kosta
Endwell NY USA

bagz3

As its a relative new bike the cables will have stretched a bit. So by the sounds of it, the tension just needs re-adjusting. A simple fixed, and plenty of tutorials on Youtube.

Record11Ti

Going to be tough to find a cable that is not "pre-streched" - and even in that case, all shifting would be affected across the cassette. If he is crossing the chain - small ring to small cogs - then yes, he could feel some chain line rub (depending on chain stay length and chain line). But, I would have to guess that if he is in the 53x13 or higher, stomping on the bike he could be seeing chain rub due to frame flex.

fenix

Put the bike in the biggest gear and then get off and run the pedals back. Look for anything rubbing. If you have a bike stand or can turn the bike upside down and pedal properly so much the better.

As Jay says though - you're more likely to hear it than feel it.