problem changing gears

gabriel959

Hello buddies,

I have noticed that on my Giant SCR2 sometimes I change gear (on the rear cassette) but it doesn't change, instead it will "jump" after cycling a bit longer. This is very annoying as I might be riding change gear and may be 30 seconds later the change will apply.

Anyone knows how to fix this?

Cheers

Frank the tank

Sounds like you need to tweak your indexing on the back end of the rear mech.

airborne_warrior

I agree. Where the gear cable inserts into the mech itself there will be a black plastic adjusting nut (usually black anyway) which can be turned clock or anti-clockwise. Just move it half a turn at a time until your shifting is smooth. You may have to try it one way first (clockwise) then try again the other way (anti-clockwise).

Fru T Bunn

Righty tighty, lefty loosey

Diogenes

gabriel959 wrote:

Hello buddies,

I have noticed that on my Giant SCR2 sometimes I change gear (on the rear cassette) but it doesn't change, instead it will "jump" after cycling a bit longer. This is very annoying as I might be riding change gear and may be 30 seconds later the change will apply.

Anyone knows how to fix this?

Cheers

Hi,

How old is the bike and have you had the cables adjusted since new?

There are a number of potential causes, an obvious one not to overlook is cable tension / cleanliness. After riding for a while it is not unusual for cables to stretch a little, this does not normally not affect going from a larger cog to a smaller but if going the other way you have to pick up slack before moving the mech.

Another common cause is a sticking cable, usually corrosion products, salt, or general crap in the cable sheath and this generally affects the change when going from larger cog to smaller, the spring tries to bring the mech in but the cable is reluctant to budge. Often after riding a while it will jump as the cable moves.

If it has been changing sweetly until now then cables is where I would start looking. Try to work out which way it is jumping, adjust the tension if necessary and clean ./ change the cables if required.

Kinked or trapped cables are also a possibility.

Also try a drop of lube into the moving parts of the mech, sometimes they stick, especially in this weather.

D

oldwelshman

Cable tension needs adjusting

STEFANOS4784

Fru T Bunn wrote:

Righty tighty, lefty loosey

Apart from pedals

(almost killed myself trying to get one off and turning it the wroong way :oops: )

a_n_t

STEFANOS4784 wrote:

Fru T Bunn wrote:

Righty tighty, lefty loosey

Apart from pedals

(almost killed myself trying to get one off and turning it the wroong way :oops: )

well one pedal

STEFANOS4784

Ah yes

gabriel959

Thanks for the help guys,

I hadn't used the bike all winter, had an accident with it, then my wife had a baby, then weather was shit so it means the bike has been doing nothing for about 3 months!

The bike is less than a year old, I bought it April 2008

I will try adjusting the cable tension as suggested. Which lube do you use to do this? Do you use normal chain lube?

shmo

If you crashed it check the rear mech hanger isn't bent. The chain line through the rear mech should be in line with the sprockets on the cassette ie. not leaning in towards the wheel.

gabriel959

I took it to the bike shop and he fixed everything. The bike ran fine afterwards (tried for a few rides)

thanks for the comments though