DOUBLE AND TRIPLE SHIFTERS !!!!

simz720

Hi there, i just recently bought a pair of shimano sora 7 speed sti shifters for my road bike with a shimano 105 rear mech of ebay.
the shifters arrived arrived and the one for the rear gears was excellent, but the seller did not specify whether the left hand shifter was for a double or a triple, i checked the left hand shifter and it turned out to be a triple, which is the problem as i have a double chain-set, but i wanted to know whether a triple shifter can work on a double chain-set, I have heard rumours of people managing to get a triple to work on double. I wanted to know whether this is possible and if anyone has any tips on this as i am installing the shifters my self.

Mike67

It's perfectly feasible, I have a Sora triple STI on my double set up on my cross bike.

The way I did it (though others may say different ) is limit the front derailleur movement using the high limit screw so in effect you're using just the first click on the shifter.

The high limit screw then stops you applying the second click on the shifter (this would move it onto the outer chainring if you had a triple set up).

Hope that makes sense.

simz720

thanks for the help mate

desweller

Personally I would do it the other way round, so the two highest positions on the shifter are used for the gears, and the lowest is redundant (and avoided by suitably adjusting the low limit screw).

The reason I say this is because shifting to low gears is handled by the derailleur spring, so you can't overstress the shifter. Shifting to high gears is powered by your hand, so you could overload the shifter against the limit screw.

Not very likely, I admit, and probably more of a problem with the famously fragile 105 shifter.

John.T

I had 7sp shifters on my bike in 1998. I think that at that time they were all (except maybe Dura-ace) double or triple. My bike came with a double but I fitted a triple later. No problems. When it was on a double the final click was just locked out by the limit screw. This from new and worked fine.

Mike67

DesWeller wrote:

Personally I would do it the other way round, so the two highest positions on the shifter are used for the gears, and the lowest is redundant (and avoided by suitably adjusting the low limit screw).

The reason I say this is because shifting to low gears is handled by the derailleur spring, so you can't overstress the shifter. Shifting to high gears is powered by your hand, so you could overload the shifter against the limit screw.

Not very likely, I admit, and probably more of a problem with the famously fragile 105 shifter.

Yup!!!!

That's the other way
I always thought there was risk of having loose cable in the shifter though as you can still use the last click (releasing tension in the cable) even though the derailleur doesn't move.

I'm also very rarely tempted to try and change up from my 50 ring....haven't got the legs for it

c0ugars

ive got a tripple on my double chainring and it work no problem. just use the limit screws and it will work no problem.

simz720

thank you everyone for the help , the shifters are now installed and gear changes are as smooth as silk !