agmetal

Hey guys, having a minor problem that I can't seem to dial out. The bike shifts fine, and adjusting the derailleurs doesn't seem to make a difference to this rough feeling. The chain isn't skipping, and it isn't visibly rubbing on anything, but when I pedal, especially when going slower, something feels rough through the pedals. The pedals themselves feel fine when spun on their own, and I still get some of the rough feeling when hand-turning the cranks by the crankset itself.

This is on a bike I bought new (but last year's model) about 6 weeks ago, so I'd be surprised if the chain or cassette have gotten worn down significantly in that time, even though I ride it as my primary transportation.

I'll probably stop by the shop at some point and have them take a look, but I wanted to see if anyone here had any thoughts.

fietsbob

Replacement is overdue?

agmetal

On a 6-week-old bike?

cny-bikeman

All gear combos or just some - is it the same when the chain is traveling parallel to the frame, not going in or out between front and rear? Helps to know brand/model, number of cogs on rear.

agmetal

2012 Bianchi Volpe, Shimano Tiagra 3x10. I actually notice this issue most on the middle and large chainrings, and around the middle of the cassette.

Al1943

Take it to the shop where you bought it and ask for help. The first tuneup on a new bike should be free.

FBinNY 

Please consider the source as you read this, but is could simply be a chain oil issue.

Chain drive has a natural vibration designed in. Not intentionally, but it's an unavoidable result of something called Chordal Action. Basically there are tiny speed changes as every tooth goes past the 12 o'clock position. This pulses the chain, and you may or may not feel it depending on speed and load. Usually chordal action is most noticeable when using small sprockets at high load, but it's there on all sprockets and loads.

Chain oil makes a difference, not by changing anything, but by cushioning those tiny little shocks as the chain leaves each tooth.

agmetal

I took it over to the shop a little bit ago...guy took a quick spin on it after making some adjustments, and agreed that the roughness was there. He said it's nothing he'd be too concerned about, though, and to bring it back in a few more weeks when there's more that needs real adjustment, for my free tune-up. He also suggested that I give the chain a wipe down with a rag...I've ridden it in the rain a few times, and have put oil on the chain after a few wet rides, and I guess I overdid it a little. Maybe that could have something to do with it?

SkyDog75

I had a problem that was kinda similar... There was some mild roughness felt through the pedals, only when using the outer chainring (on a double), and only in the middle cogs and outward on the cassette. I took it to the shop since that was a new one for me, but they didn't seem too concerned. *I* knew the bike was normally smoother than that, though, so I tore it down to find the problem. it turns out my cassette lockring wasn't nearly tight enough. I snugged it up and all has been well since.

agmetal

That requires a special tool, though, doesn't it? I have a freewheel puller, but no way to do anything with cassettes.

Looigi

You may have a problem, but I always feel the chain links distinctly when rotating the crank by slowly by hand. Push the rear DR cage forward to make the chain loose and you'll feel it much less. You can remove the chain and verify that the cranks, jockey wheels, and rear wheel all rotate free and easily. Put the chain back on and you'll feel the links.

rydabent

It probably just needs lubed. For years I have noticed that if I dont clean and lube my chains on a regular time frame, I can feel kind of a roughness or rumble. Lubing gets rid of it. BTW I use Mobil 1 oil rather than wax or other exotic chain lubes.

Al1943

Cassettes are easier. All you need is the correct tool for your lockring and an open end wrench or crescent wrench. For removing the cassette you will also need a chain whip to keep the freehub from turning while loosening the lockring.

Cassette lockrings actually require quite a bit of torque. The torque specs are usually shown on the lockring. "Snug" is not enough.

SkyDog75

Like Al1943 pointed out, it takes three tools, but there's a pretty good chance you've got two of them already. You'll need a chain whip (preferably 3/32"), a lockring tool, and a wrench to turn the lockring tool.

You'll need a lockring tool designed for Shimano cassettes, like the Park Tool FR-5. You can find a Park FR-5 for $6 or so online. If you need a chain whip, you can find those in the $10 to $20 range.

These are things you'll need for routine maintenance, and they're inexpensive, so I'd recommend getting 'em anyway. Or with a new bike, you can ask the shop to check for you.

agmetal

Of those, all I have is #3 . All of my previous bikes as an adult have been either IGH or freewheel, this is my first bike with a cassette.

Kimmo

Chordal action can be distinguished from a dirty chain by the chordal phenomenon's relatively low-frequency throbbing compared to the random, higher frequency grittiness of a dirty chain.

Was this a consideration when you developed Chain-L #5 ? Because that stuff damps it better than anything else I've used

I was going to suggest that perhaps the bike came with a cheap non-Shimano cassette and maybe it'd wear in after a bit, but I'd say this is more likely... when cleaning your chain, don't spray degreaser at it; put it on a rag and wipe the chain clean. Then when you lube it, just put a single drop on each pivot and wipe it as dry as you can get it. The cogs and rings don't need lube on them, but excess chain lube causes a horrible gungy buildup to accumulate everywhere, quite possibly accelerating chain contamination.

Unfortunately there's actually no way to completely clean a chain that isn't utterly insane, so just do your best and remember in future to do what you can to prevent it getting too filthy.

Sheldon's serious article on the subject may be of help.

Engine oils aren't recommended since many of them contain detergents which totally kills their ability to withstand riding in the wet.

I haven't found a better chain lube than FB's stuff, myself. Quietens the drivetrain, lasts ages. Hard to see a shiny chain through it, though... it tends to make the chain black despite wiping it dry.

FBinNY 

Yes, chordal action, the "jumping off the tip" that a stretched chain does as it comes off the rear sprocket, and the effects of misaligned sprockets are three reasons I paid particular attention to impact dampening.

It's also because I like a quiet drivetrain so I gave quietness extra emphasis.

agmetal

I stopped by a shop this morning that often lets me use a stand and tools, and check the cassette lock ring. It was able to be tightened a bit, but that didn't solve the issue. Definitely confused now!

CycleCoder

I had a similar problem about two weeks ago on my bike 2 days later one of the links in the chain snapped, replaced the link and everything has been perfect since. Had me puzzled until the bike finally told me what was wrong.

FBinNY 

I just looked at your post again and noticed this which IMO is a game changer. You wouldn't usually feel any chain related issues, such as chordal action or poor chainlube when there's no load.

So slip the chain off over the pedal and pull it back at the FD cage so the crank is free. Now see if you still feel any roughness when turning the cranks. Id so, you've isolated the issue to the BB bearings. Possibly wet weather riding got to them, or maybe they're preloaded too tight, or that's just the ay they are.

If you don't feel any roughness turning by hand, try standing on the pedals with the bike near a wall you can brace against and rotate the cranks while standing with your full weight on the pedals. If it's smooth, you know the BB is fine, and it's back to a chain drive issue, but probably not one to worry about.

RubeRad

Chain lube was what I was going to suggest too. I finally got around to switching my MTB to Chain-L; on my last ride it was so 'crunchy' I thought the drivetrain might have sand all in it. Quick clean with garden hose, wipe down with paper towel, apply Chain-L (and remove, clean, grease, and replace the RD pulleys), and my MTB is now as silent as a ninja.

So OP, I'm not quite sure from what you've told us, did we already eliminate the issue of chain lube? Because even a new bike, if you ride it a good lot for six weeks, could need re-lubing, if using mere mortal light-oil chain lubes.

You might also consider cleaning and greasing RD pulleys, but unless you rode through a lot of mud or something, I wouldn't think those would get fouled up in only six weeks. Other than that, I got nothin.

tahoeeddie

i'm not sure i understand what you mean when you say "rough"? two things came to my mind. either that there is or are a few stiff links, in which case, lube or some just bending of the links will free them up, unless you have something like a burr caught in a joint. The other thing that came to mind if the roughness was from rubbing in the derailleur either front or rear. if that's the case, then adjusting the derailleur should address that. if that doesn't do it, you may have a bent derailleur hanger.
those are the top things that came to my mind.

agmetal

I'll give this a try when I have some free time, maybe tomorrow after work.

I don't think it's a lube issue, but I could be wrong. I've been using Phil Wood Tenacious Oil, and I've gotten the impression from people who've seen it in person that I've possibly over-oiled it.

It's a really difficult issue to describe...it's not consistent, either. It's a new thing that I only started noticing about a week and a half ago, and I've noticed that sometimes when I'll be in the gears where it's most noticeable, it won't be there at all when I either start a ride, or haven't been in that particular combination in a few minutes.

Kimmo

Tried this yet?

Kotts

Small correction: You don't need a chain whip to TIGHTEN the cassette lockring. You will to loosen it, though.