greenlight149

also posted this on the mechanics forum, figured i might get more answers here

two problems

1: there is significantly more noise in the drivetrain when the chain is directly inline with the front chainring, but not when i shift up or down a gear. the noise is not a grinding noise, but sounds more like the chain rolling....if that makes any sense.

2: when im pedaling hard and trying to shift into the 11t cog, it makes a grinding noise, when i let up a bit it'll shift, it also shifts fine when im hand pedaling. as i understand, the lower half of the chain is not under tension when im pedaling hard, so why is it not shifting to the small cog?
i have adjusted the cable tension, the limit screws, and everything works fine when im just hand pedaling.

any help would be much appreciated.

ColtJ

I'd say check for anything that could/would affect the cable.

Had the same problem, changed the cable and housing and it went away.

deacon mark

need more I information. Did you recently change anything? First action would be to go back a fine tune the drive train for shifting. Google how to do this if you do not know. IF the cogs all shift correct then the noise would need to be heard to figure out. Is this a 10 spd or 11 spd, shimano or sram, and first thing is to make sure the chain is clean and well lubed. Report back on the find.

greenlight149

ok heres more information

11sp drivetrain
FD, RD, cassette: ultegra
shifters: 105 5800 (including cables, housing all brand new, just put everything on a few weeks ago)
crankset: rotor 3df
chain: kmc
wheels: fulcrum racing quattro

everything is lubed with dry lube

i know how to tune everything, it doesnt happen with my other bike which is 10sp, but aluminum.

this bike hasn't even seen pavement, bought it just before the winter and its used indoors ever since.

Carbonfiberboy 

Another vote for recabling. Oh . . .and make sure you didn't use any brake housing by mistake.

greenlight149

maybe it wasnt apparent in my previous post, but i said all cables and housing are new when i put the 105 shifters on a few weeks ago.

Carbonfiberboy 

well . . . I've had just this problem when I had a bend in a relatively new cable from turning the bars too far. Bent right where it passes into the HT cable guide. Also, I have used a piece of brake housing by mistake, with similar results. These are easy things to check.

rpenmanparker 

How's your b-screw adjustment? That is important, particularly at the extreme ends of the range. You didn't mention it.

bt

did you check the cables?

Stucky

Exactly what I was thinking....

greenlight149

I adjusted the b screw so that at the biggest cog, the derailleur is close but not touching the cog, the noise isn't there on any cogs except when the chain is on the big chainring and the cog directly in line with the big chainring, the noise is gone if I shift up or down a gear so that the chain isn't perfectly straight.

And ya I checked the cables and housing, I didn't mix them up, and the housing isn't bent. The housing doesn't do big loops either, it goes from the right shifter into the down tube that's also on the right side.

Stucky

Could you have a worn or damaged cog in your cassette?

Has any work been done to the bike just before this started happening?

greenlight149

I would be highly surprised if the cog is worn already, the bike is a few months old and never ridden outside, only on rollers.

The noise might have been there before I changed the shifters, cable and housing, but I don't remember. I might just notice it now because I expect the shifting to be better with the new shifters. Old shifters were microshift bar ends.

Stucky

Microshift bar-ends? Just what kind of bike is this?

greenlight149

ridley dean rs, came with clip on aero bars which had bar ends.

TrojanHorse

depending on the size of your largest cog, you may be adjusting the B screw on the wrong side of the cassette. In any case, make sure the RD has enough clearance when you're in the smallest cog.

Stucky

Oooo, nice bike!

Probably not an issue...but just to be safe: If you shift into the big ring and the big cog, does the RD still have a little bend at the jockey wheels (i.e. not pulled out completely straight)?

And when shifted to small/small, is the RD still pulling some tension on the chain?

greenlight149

thanks! got last years model with a big discount ($1700 off)

just checked, big ring big cog there is still bend in the RD, and small ring big cog theres tension in the chain. i thought the chain might have been too lose, but there's tension so im not sure.

deacon mark

What does this noise sound like? If it does not sound like a gear that this not tuned exact then you have to figure it is nothing to do with shifting as such. When you get into the noisy gear you need to play around and see what makes it stop. Shifting a gear and it stops then you have some shifting issue. Need to be more specific on the noise problem.

greenlight149

the noise is not the same as when the indexing is off (grinding), it sounds like the inherent noise of the chain becomes louder. it doesnt make you feel like you need to adjust the RD, but rather the chain is lose, thats the best way i can describe it, ill get on the bike today and see if i can come up with a better description.

i have checked the alignment of the RD in respect to the cassette and it looks straight.