jxpowers

Hi everyone, so im having problems with my shifting.

Background info:
I have a 9 year old road bike, with a sora groupset.
I had it fully serviced recently by a bike mechanic, all new inner cables, new cassette, new chain, all bearings lubes, gears indexed and brakes adjusted wheels true, bearings greased etc etc, kept the front chain rings as is.

Now heres the problem the chain tends to jump between 2 sprockets ( usually the 2nd and 3rd largest sprocket ). Okay so i adjust the barrel adjustor to fix the problem, those gears then work perfectly, then the problem happens further down the cassette for example it starts jumping between the 5th and 6th sprocket. Confused. I adjusted it again to fix the problem.

I start from the largest sprocket and try the gears again, it happens again between the 2nd and 3rd sprocket.
I thought maybe its cause of a worn freehub, i swap my cassette on a new wheel and try it on my bike, the problem persists.

i thought maybe its the mech hanger is bent, i bought a brand new mech hanger, still dosent fix the problem.

Now im thinking maybe its the derailleur? If i get a brand new mech will it fix the problem? If it dosent can anyone else suggest what i can do, ive essential bought a brand new groupset at this point and getting worried about how much im spending. The parts ive bought are now worth more then the frame itself!

Steve B.

You mention "new inner cables", but don't mention cable housings. I hope the mechanic replaced those as well, because dirt in the housing is often the reason for lag and poor shifts.

masi61

Just replacing the mech hanger is not sufficient. You now have to have the new mech hanger checked for alignment since it could still be mis-aligned.

Iride01 

When I once had the issues you described it was the cable binding randomly at times. When I finally found the cause a couple weeks later, it turned out to be the cables cutting into the steel of my BB shell where they ran bare around it as many did in the vintage days. A cable guide solved it. Perhaps your cable guide on the BB is worn out.

For sure I'd go back and inquire with the mechanic as to what else they recommend. Besides you, they know the most about your specific bicycle and what was done to it.

Jheitt

More often then not anything mid cassette is an alignment problem. As said above even a new hanger needs to be squared to your bike. Just because the hanger is strait doesn't mean its square to the cassette. good old manufacturing and paint tolerance.

GhostRider62

Went thru this myself recently. The derailleur hanger was loose. After tightening, still some shifting issues. I checked the hanger alignment and sure enough it was off. Bent it. Readjusted the etap and bingo, back in business. Sounds like you have a hanger issue

jxpowers

Also, its worth nothing that i have crashed my bike before and landed on the rear mech, could this have totally damaged the mech to a point where its easier just to replace it?

delbiker1 

If the bike was like that immediately after the tune up, take it back to the mechanic and tell them the issue. They should take at least take a look at it with no charge. If it is a minor thing like straightening the hanger, again, there should be no charge. That is my opinion, and I know the shops I have done business with in my area would handle it that way. If they did not replace the housing, pretty sure they will not do that just for the price of the housing, but I would certainly be looking for a bit of a break on the cost. Of course, if you did not want the housing replaced, and it turns out that is the problem, that is on you.

SpedFast

I like throwing parts at problems only because I enjoy tinkering on my bikes. If the cable housings weren't replaced with the cables, I'd start there. Then the BB guide, and then the hanger alignment. Good luck.

BCRider

If I'm reading this right the bike is older, the problem is with the most commonly used middle speed cogs on the cogset and the trouble stayed on the new wheel but with the original cogset. And the new hanger didn't fix anything either.

The others mentioned that new cables might not run smoothly in old housings. That's valid.

Some mentioned that the new hanger might not be the issue if the mounting point on the frame that takes the hanger is where there is a bend. The hanger might be fine but the hanger mount on the frame might be tweaked.

And finally the elephant in the room to me..... It's quite possible that the middle speed cogs are badly worn and that is why it doesn't want to shift through those cogs smoothly but it does shift smoothly on the cogs to either side of the most used cogs. This may or may not be coupled with a badly worn "stretched" chain. Did you check the chain with a ruler or stretch gauge for wear?

Freehub play is also easily felt and compared. It's normal to have a slight bit of play in the freehub bearings. But it will be minimal and barely feelable on a good freehub. If the freehubs on the old and new wheels both felt pretty well the same then it isn't the freehub.

MudPie

OP said new cassette and chain installed.

Crankycrank

Possibly. Check the pivot points that may have some road rash on them. This can deform the parts that move and sometimes causes friction in the pivot action. Also maybe it may have caused some sloppiness in the derailleur in other ways. Also, any new hanger should be checked for alignment after mounting. Tolerances for the dropout-hanger interface are not super tight for many bikes so need to be checked.

cxwrench

No. Problems (noise) that start mid or larger cassettes and get worse as you shift to larger cogs are a hanger alignment problem. Noises that only happen in the middle cogs are more often wear related or problems w/ cables/housing. If the hanger is bent in as it would be from a fall the noise can only get worse as you move to larger cogs.

Jheitt

I have 10-51 on 3 different bikes. when a hanger is out ( or derailleur cage rivets for that matter ) its always 2-3 cogs mid cassette that act up, just as the OP described i can move it around with cable tension. it doesn't get worse the higher you go. Up high and down low the limit screws keep things in check. I've ruined cages and not had a hanger bend enough that it would act as you have described. Hanger alignment issues for me have always been more of a twist then a bend.

Tawraste666

Hanger alignment is such an easy and quick check to do, and 90% of the time that's what it is.
Once the hanger is aligned, the barrel adjusting bit takes 10 seconds to do and you wonder why you didn't align it first of all.
One of the most useful tools I have ever bought for the bike.

cxwrench

Read my post again and think about this. If a hanger has been bent because the bike fell over on the derailleur and is bent towards the wheel (like 99% of bent hangers) the chain will make more and more noise til it starts to jump to the next cog. It can ONLY happen this way. It won't make noise in the middle cogs and then 'fix' itself and not make noise in the large cogs. Not possible. It's a basic geometry issue. If the hanger isn't bent the pulley cage and cogs are perfectly parallel. If the hanger is bent the cage basically becomes the hypotenuse of a triangle. Eventually it will run into the line described by the cogs. It will happen at some point as the cogs get larger and will get worse as they get bigger. It won't straighten itself out and get less noisy. Impossible.
If you still don't get this I'll provide a drawing.

Jheitt

I completely understand everything you are saying. My point is hanger problems are not generally in or out, they are side to side in my experience so the hanger sites toed out or in so to speak.

cxwrench

In/out, side to side...same thing. Nearly all hanger problems are a result of crashing or dropping the bike on the derailleur side. This naturally pushes the derailleur towards the wheel. Even if this results in the derailleur being 'twisted' a bit the same is still true. The problem can only get worse as you shift to larger cogs. Trust me, I fix this problem every damn day. My most used specialty tool is my HAG by a long shot.

jxpowers

I bought a HAG just for this very problem and it turns out the hanger is aligned, im stumped to why else this is happening