Newbie Gear Changing Problems

smciom

Apologies in advance for the stupid questions & incorrect terminology.

I recently purchased a new Specialised Allez double last week and have enjoyed a couple of rides so far

However I am experiencing problems changing up to the big cog on the front occasionally it won't change. Do you need to be travelling at a certain speed before it will allow you to change up I read on another forum a figure of 15mph (approx) or could it be a problem with the bike ?

Next when I do manage to get it on the big cog on the front and the smallest 2 cogs on the rear there is a strange noise any ideas/suggestions ?

Cheers

Gizmodo

You should be able to change to the big ring at the front at any time, whether your legs have the power to turn such a high gear depends on whether you are going downhill.

You should try to avoid "crossing the chain", that is using the outer front ring with the inner rear cogs and visa versa, the small front ring with the outer rear. Because the chain is at an extreme angle It will rub on the mechanism - chain rub. You can "trim" the gears a little, moving the front mech a small amount, but generally it just wears out your chain and mech more quickly.

For more information see http://sheldonbrown.com/gears.html

grizedaleforest

Sounds like your new bike might need a few adjustments as the brakes and gears bed in. Some bike shops offer this as a free part of their service if you buy a bike from them. Otherwise read the parktool or sheldon brown websites and get stuck in yourself! The noise you describe might just be the chain rubbing on the front derailleur cage. And as Gizmodo says, there's no magic speed at which you have to change up to the big ring - there's just good times to do it and not so good If it's not happening for you occasionally then maybe again something in the front derailleur needs adjusting.

cheers

Gpac65

Agree with previous posts. My wife recently purchased Specialised. After a couple of weeks complained about shifting problems to the big ring.

Was a combination of limit screw adjustment and cable tension. Took about 10 mins and now changes smoothly and without problems. Lots of videos on You tube to help you out. Honest it's not that tricky.

Good Luck

Gizmodo

If you want to do your own adjustments this is a useful site: http://www.parktool.com/blog/repair-help

In your case you need the Front Dérailleur Adjustments section.

smidsy

Although if it is simply cable stretch you should not need to touch the screws on the mech.

The screws limit travel and if they were correct before there should be no reason to adjust them now.

Cable tension is done by barrel adjusters (where fitted) or by physically 'pulling in' or 'letting out' cable having loosened the relevant clamp bolt.

baobei000

You should try to avoid "crossing the chain", that is using the outer front ring with the inner rear cogs and visa versa.

spong

I had this problem too until I started to back off the pressure on the pedals slightly at the moment of changing up. This seems to work for me but is that right? Is that a basic technique that you more experienced guys are taking for granted but us newbies don't cotton on to because people assume that of course we are doing it??

extrusion

spong wrote:

I had this problem too until I started to back off the pressure on the pedals slightly at the moment of changing up. This seems to work for me but is that right? Is that a basic technique that you more experienced guys are taking for granted but us newbies don't cotton on to because people assume that of course we are doing it??

This is correct. At least it's what I've been doing all my life (only recently got a road bike).

I thought the OP might not be aware of the trim function on the left lever. This confused me until I sussed out that it's actually 2 clicks to get to your chosen gear, the first click moves the derailleur a little but doesn't change gear, in order to reduce any chain rub. *

* or you can do one huuuge move with the lever to click twice ... **

** this is how it works in my mind anyway

derbygrimpeur

When changing the chainring it may also be necessary to soft-pedal whilst the chain moves. If you keep the power on it will not shift as easily.