xbartx

Newbie Bike mechanic here! I just replaced the chain, chainrings and rear cassette on my bike, the new cassette and chain rings are the exact model that they replaced.
The trouble I’m having is with my front derailleur, a Shimano 105 10 sp. I can’t get the the chain not to touch the left side of the derailleur cage when in the largest gear in the back wheel or the right side of the derailleur cage when in the smallest gear in the back wheel. It seems like it could only be cause by the rear cassette being wider or the chain being wider or am I missing something? I'm not talking about moving from one front chainring to another this without any front chainring movement.
It doesn't look like the cage is bent and I even took the cassette apart to see that it wasn’t seated properly and also measured it to see that it looks to be the same width as the old one.
When I look at online videos they mention the chain being 1 or 2 mm from the cage. I can’t set it any better than barley touching both sides when on either end of the small and large rear gears.
The clearance is a little better in the larger chainring that the small chainring.
Any ideas?

dsbrantjr

Did you change the chainrings themselves or the entire crankset/chainset? If chainrings, are they oriented correctly, that is not flipped over? How does the outside width of your new chain compare with the old one? I believe that your 105 front shifter has a trim function. are you using it/is it working correctly?

Unca_Sam

You didn't state that you used a 10 speed chain. Did you? Also, please clarify if you're using a 10 gear cassette, or a 5 gear freewheel.
@dsbrantjr is right about the trim too. Sometimes the shifter overshifts to push the chain or pull the chain quickly into the desired gear. You'll need a slight adjustment back to prevent rubbing the chain on the cage.

xbartx

I did check the chain width and it is correct ( it is a Shimano 10 sp chain) and I changed just the chainrings and did check the orientation. Would the chainrings or the trim have any effect on my problem? I don't see it having to do with the trim on the front derailleur because it doesn't involve shifting from one chain ring to another, it is that the chain touches the inner part of the derailleur cage when the rear cassette is on the largest gear and with the same front derailleur position when I shift the rear to the smallest gear the chain touches the outer part of the derailleur cage. Like the cage isn't wide enough or the rear cassette has to much outward/inward travel.
Hopefully I'm explaining it right, but I can't get any gap between the cage and the chain when I'm at the extremes of my rear gears (the smallest and largest gears). The chain will touch either side of the cage depending on if I'm in the smallest or largest rear gear.

dsbrantjr

That is what the front trim function does.
https://si.shimano.com/pdfs/dm/DM-RAFD001-04-ENG.pdf
Front derailleur how-to: shifting and trim

xbartx

Yes, it is a 10 speed here is what I purchased- SHIMANO Ultegra CN-6701 Chain compatible with 10-speed drivetrains and the cassette is a-shimano cs-5700 105 10-speed

Andrew R Stewart 

I've had customers who on having worn out drivetrain replaced with same new stuff state the same thing, chain rub when in near crossover combos. When asked about the use of the shifter's trim function the reply is, sadly, often "what are you talking about" … So for years they never knew about their shifter's full features. That they didn't complain with the old stuff might be explained by looser tolerances on the original parts, proper adjustment when the new were installed, the rider's changing way of using their gearing or other possibilities. Andy

xbartx

I have had this bike for 4 years and ride 3-5 days a week, 15-30 miles a ride. To be honest I hadn't been involved with the mechanics much other than replacing the chain a couple times and going through several tires and many tubes. It could be very well the case that it has always been like this and I never noticed till I replaced these components and tried going through the adjustments I found online. I thought I understood the trim function, maybe I don't fully understand it.

Andrew R Stewart 

xbartz- I got the email of your delated post. The description of chain rub in the combos your op states are not the result of a too tight/loose cable as they are opposing results WRT cable tension. Both might be the case if the trim functions weren't being used as they are intended to be. Make sure the shifter is all the way to the lowest ring click spot to check the inner ring and large rear cog combo. Accordingly make sure the shift lever has swung all the way inwards to unsure it's clicked to the furthest outward position when on the large ring and smallest rear cog. Of course the limit screws are assumed to be correct in that they are not limiting the cage's travel. For and rub between the lowest combo and the highest gear combo the trim functions are used.

BTW it's time to check your shift cables as they enter the lever's cable spool, just beyond where it's easy to see them if the casing was pulled back/out of the lever's seat. A fraying (and Shimano shifters are very well known for this wear point) will inhibit the fine movements of the cables, as in the trim functions. Andy

TakingMyTime

That happened to me once and it took me way too long to figure out what the problem was. It's now one of the first things I check. Actually, the cabling is the first thing I look at. See if all the ferules are seated properly etc. Then I start working on the problem.

xbartx

Andy, Thanks for your replies!
I'm thinking that my bike doesn't have Shimano shifters and the trim function I see talked about. The only trim for the front derailleur that I was aware of is on the top tube of the frame. I'll look at it again.