Gear Trimming?

[Homervanderlay]

Hi,

So I have the Shimano Claris 2000 8 Speed shift levers which allow for gear trimming.

This is the first time I have owned a bike that allows for gear trimming so was hoping to get some advice.

The trimming function works fine with both levers when in the largest chainring in the front.

However, when I click down to the smallest chainring in the front and use the smaller gear lever for trimming absolutely nothing happens. Is this normal?

I would have thought the smaller lever would allow for some gear trimming in the small front chainring?

Thanks for any input

[Jdsk]

Previous discussion:
https://forum.cyclinguk.org/viewtopic.php?t=124598

User's and Dealer's Manuals:
https://bike.shimano.com/en-EU/product/component/claris-r2000/ST-R2000-R.html

Jonathan

[pwa]

Doesn't shifting from the big ring to the small ring involve going all the way with the left shifter, leaving no further trimming to the left possible? You are at the end of the range of movement with only a trim to the right possible (with the big lever). If you get chain rub while using the small ring and the biggest sprocket you need to adjust the limit screws on the rear mech.

[ElCani]

Doesn't shifting from the big ring to the small ring involve going all the way with the left shifter, leaving no further trimming to the left possible? You are at the end of the range of movement with only a trim to the right possible (with the big lever). If you get chain rub while using the small ring and the biggest sprocket you need to adjust the limit screws on the rear mech.

That’s right. Shifting down from the big ring puts the mech in the inner most position (as set by the limit screw) and from there you can trim the mech cage outwards with the brake/shift lever. From there you can trim inwards again with the small shift lever.

The logic behind this is that you are likely to already be in one of the inner (larger) rear sprockets at the point when you decide to shift down at the front.

[Brucey]

However, when I click down to the smallest chainring in the front and use the smaller gear lever for trimming absolutely nothing happens. Is this normal?

Normal? Sort of.

As I explained in (one or each of) your previous thread(s), in bottom gear the FD position is solely determined by the L adjustment screw. Where a trim click is available this trims to the right. The trim click will only do anything useful if the cable is adjusted correctly.

If you want to resolve your problems you should probably stop making random adjustments and get the FD set up correctly as per the dealer manual. This will save you (not to mention everyone else) a lot of time in the long run.

cheers

[Homervanderlay]

Thanks for the replies folks, a lot of useful information.

[bgnukem]

My guess is the front mech cable is completely slack in the small chainring position (as the mech rests on the stop screw) and the small trimming movement at the shifter is not taking up the slack/moving the mech. You may need to increase the cable tension.

[rmurphy195]

I have the 8 speed claris.

The small lever moves you onto the small chainring (releases the tension on the cable and the springs do the rest), the big lever pushes you onto the big chainring.

I've only ever found trimming necessary on the middle ring. This is when I'm on the smaller rear sprockets. In this instance, unless I change to the big ring then a small push of the big lever will move the front mech outwards slightly, you will hear a faint click from the lever, and the chain will stop touching the outer plate of the front mech.

EDIT: Never had a problem going onto the bigger rear sprockets, maybe cos my technique changing down involes only using the biggest couple of rear sprockets when on the smallest chaninring! When adjusting by the way, I've found that if the front mech is even slightly out of parralel with the chainrings then the change gets a bit unreliable.