1 gear keeps slipping

[boydj]

Your old Trek would have had a much heavier duty chain.

 

[roodoob]

keep forgetting to ask everyone ...

if it's the CHAIN ...isn't the slipping i describe, going to happen All the Time / All gears ?
compared the 7th cog , w / others during cleaning other day , and Nope,
now, not a fine toothcomb mind ya ,
but , No really obvious wear

thanx

 

[Gasman1440]

I bought a brand new SBC All Road and on the first ride the 3rd smallest gear kept skipping. I checked and checked and checked everything and finally brought it to my LBS. As soon as I told him. The mechanic said, bad cassette. This was sad on a brand new bike mind you, it slipped on the first ride and by the time I brought it to the LBS it had less then 50 miles on it. The give away for me was it wouldn’t slip in the stand but as soon as I took it down and tried to ride it (even across the room) it skipped. New cassette and chain and it works fine. Just my experience....

 

[ColinJ]

Did you get round to checking for chain wear yet...?

Do the 'pulling chain away from big ring' test and take a photo for us?

You could also take a photo of the cassette and let US judge if things look worn, although it often isn't easy to spot.

It might be that the other sprockets are not quite worn enough to slip yet but will do soon.

Slipping usually starts off only on certain gears and when under heavy load. I've had it only happen on one sprocket when trying to go uphill.

If action isn't taken though, eventually the bloody things start slipping all the time.

 

[davidphilips]

If it is the chain and i am sure it is,its that worn that it will have destroyed your cassette, so easy to check and unless you are experienced then wear would not be seen when just looking at it and wear impossible to gauge accurately without some measuring equipment/tool.

The chains i replace all look like new maybe because i keep them well maintained and the fact that some only last about 8 weeks and cassettes are changed with every second chain.

Chain slipping with a worn chain will happen in the most used cogs under load and usually on the smaller sprockets as there are less teeth but slipping wont get better.

Best advice i can offer is watch some utube videos on bike maintenance and learn how to service your own bike or leave it into a lbs as a well looked after bike is safer and more fun.

 

[Ajax Bay]

If it's the CHAIN ...isn't the slipping i describe, going to happen All the Time / All gears ?
compared the 7th cog , w / others during cleaning other day , and Nope,
. . . No really obvious wear

To reiterate (NB see my earlier post):
Your chain is slipping/skating on the second smallest sprocket (8sp cassette), which is the one you have acknowledged is the one you use most.
You have ridden over a thousand miles.
It's NOT the chain alone. You could measure the chain but it'd make no difference.
The chain and the cassette have worn together. Once they wear beyond a certain point (and you can't tell this by looking at the cassette - the wear is not "obvious" - or measuring the chain) when you put power down on the sprocket you use most the chain will jump/slip/skate. This is the sign that both need replacing. No amount of cleaning will then make a difference.
By all means ride on, avoiding the use of that dysfunctional sprocket. In early course another sprocket will start slipping.
If you just change the chain for a new one, most of the sprockets will slip (probably).
Changing the cassette and chain is a quick easy job. You will need a 6-8sp chain the correct length (NB a chain tool to cut it to that length or ask your LBS), a quick link (6-8sp), a new 8sp cassette of similar range (eg 12-28t), a cassette lockring tool, a chain whip and a 10" adjustable spanner.
Send yourself two internal memos for riding your rejuvenated drive train: 'I must try to use my gears more and not sit on one sprocket all the time'. 'I must try to pedal quicker ie rpm and not grind in too high a gear (eg small sprocket) otherwise my 70 year old knees will give up on me quicker.'
HTH

 

[gbb]

Despite the bikes reasonably newness, the free hub might be slipping. When I had my second new Bianchi Via Nirone, it would occasionally slip under load, in a lower gear even when it was quite new. It wasnt often enough to bother me and it stopped without me even realising after maybe 6 months.

 

[Ajax Bay]

Only slipping on a single sprocket, @gbb - the one the OP says they use most of the time.

 

[gbb]

Only slipping on a single sprocket, @gbb - the one the OP says they use most of the time.

I know. I used to find it was always in a low gear, couldnt be sure which but probably one of two.
It is a bit tenuous (my suggestion) tbf but close to what I experienced. The one thing I learned as a machine maintenance mechanic...is never discount anything