Chain and gears slipping - advice for bike shop visit

james22b2

Hi
My bike chain keeps slipping and I drop gears when it is under high tension - for example riding up a very steep hill - how much of a fuss should I be making at the bike shop and what can they do to fix this?
The bike (a Giant) is only a few months old, under guarantee and has had this slipping issue since I got it, but now it feels worse. I don't really trust the gears when I am tackling really steep, loose hills anymore, for example, and have had a couple of scary moments where the chain has slipped at very inopportune points in a climb and I am basically left with no power on a steep bank etc. I am not changing gears on the hills, either.
Thanks.

penguin_of_death

Did it come with a free checkup after 6 weeks or so? Barring something being damaged then it could be cable tensions gettng slack so that the gears aren't fully engaging - if you think you can do it yourself look into 'indexing gears'

paul.skibum

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19733931#p19733931]james22b2[/url] wrote:

Hi
My bike chain keeps slipping and I drop gears when it is under high tension - for example riding up a very steep hill - how much of a fuss should I be making at the bike shop and what can they do to fix this?
The bike (a Giant) is only a few months old, under guarantee and has had this slipping issue since I got it, but now it feels worse. I don't really trust the gears when I am tackling really steep, loose hills anymore, for example, and have had a couple of scary moments where the chain has slipped at very inopportune points in a climb and I am basically left with no power on a steep bank etc. I am not changing gears on the hills, either.
Thanks.

Gears shouldn't slip. This could be (as Penguin mentions) cable tension or mech indexing being out. Definitely things the shop can assist with or you can attend to yourself. As we are in the beginners section though I will just ask about how you are using your gears.

Do you use big to big chainring to rear cassette? Do you use small to small in the same way? Are you hauling away at an inappropriate gear to get up something rather than actually using the gears to assist you?

james22b2

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19734004#p19734004]paul.skibum[/url] wrote:

Gears shouldn't slip. This could be (as Penguin mentions) cable tension or mech indexing being out. Definitely things the shop can assist with or you can attend to yourself. As we are in the beginners section though I will just ask about how you are using your gears.

Do you use big to big chainring to rear cassette? Do you use small to small in the same way? Are you hauling away at an inappropriate gear to get up something rather than actually using the gears to assist you?

Thanks for the feedback. The bike has 2x10 gears. To be honest I only ever use the use the large rear cassette.
The slips tend to happen in one of two scenarios:
1. When I am charging up a hill in a high gear at 30kmh+, and then the large cassette tends to slip into another gear.
2. When I am grinding up a hill in one of the lowest gears, and then the small cassette often seems to slip (leaving me flailing and then eventually settling into a lower gear at the front)
Thanks..

brianbee

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19734063#p19734063]james22b2[/url] wrote:

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19734004#p19734004]paul.skibum[/url] wrote:

Gears shouldn't slip. This could be (as Penguin mentions) cable tension or mech indexing being out. Definitely things the shop can assist with or you can attend to yourself. As we are in the beginners section though I will just ask about how you are using your gears.

Do you use big to big chainring to rear cassette? Do you use small to small in the same way? Are you hauling away at an inappropriate gear to get up something rather than actually using the gears to assist you?

Thanks for the feedback. The bike has 2x10 gears. To be honest I only ever use the use the large rear cassette.
The slips tend to happen in one of two scenarios:
1. When I am charging up a hill in a high gear at 30kmh+, and then the large cassette tends to slip into another gear.
2. When I am grinding up a hill in one of the lowest gears, and then the small cassette often seems to slip (leaving me flailing and then eventually settling into a lower gear at the front)
Thanks..

By ''large cassette'' do you mean the chain wheel where the pedals are ?

It sounds like a simple index problem on both front and back derailer. Take it back and ask them to sort it out, it should take them about half an hour, well it would take me half an hour, they may do it quicker

cooldad

30kmh up hill in a high gear?

Surely Superman doesn't ride a bicycle?

paul.skibum

I am not sure what you mean by large and small cassette but you have to give the gears a little assistance - if you just keep it in the big ring at the front and run it all the way up to the big ring at the back you are doing what is known as cross chaining - which puts stress on the chain and mech and causes excessive wear.

Try to use the big ring at the front with the smallest 5 (or6) gears on the cassette and then switch to the smaller chainring before using the rest of the cassette.

I like a good old fashioned out of the saddle pedal mash as much as the next man from time to time but changing gear under power is also a good recipe for a) heavy wear on your gears and b) snapping a chain and c) slipping gears resulting in nuts to crossbar/stem or pedal to shin.

MilesUK

It sounds as though your lowest gear on your cassette that the rear mech limit screw needs to be loosened off slightly. If you put your bike into first gear i.e. the lowest/biggest ring at the cassette can you pedal backwards without the chain dropping to the second gear? does it take a big push on the shifter to get into first gear?

If this is the case and also that your chain is not staying in the bigger chain ring at on the crankset then it is a simple case of gear cable tension which can be adjusted easily at the shifter by turning the adjuster anticlockwise.

This is why most bike shops offer a free first service as the cables will stretch after a few rides. Some shops do pre stretch the cable as much as possible which will lessen the feeling when used.