Triple dropping straight to small ring?

[mrandmrspoves]

It is quite usual on some set ups to have slack in the cable when in the small ring on a triple, as long as the 'low' stop is set correctly it isn't a problem.

That is correct - (but only if the cable is tight enough to pull the FD up to the middle and large chainrings correctly)

 

[Ajax Bay]

What has been discussed is that stainless steel cables do not stretch at all.

All materials stretch when a strain is induced therein. A cable stretches every time it is operated and returns to its original dimension when the lever is released (removing the tension). Which is why I said: "they stretch the same amount every time (the same amount of) tension is applied". Take your point about the outers grooving, which is why it's prudent to change outers at the same time one changes the inner.

 

[mythste]

All materials stretch when a strain is induced therein. A cable stretches every time it is operated and returns to its original dimension when the lever is released (removing the tension). Which is why I said: "they stretch the same amount every time (the same amount of) tension is applied". Take your point about the outers grooving, which is why it's prudent to change outers at the same time one changes the inner.

Not sure I agree on this (though I suppose it's irrelevant to the OP but I find these topics interesting!)

So you're suggesting that stainless steel shows elastic properties under the loads that a derailleur requires? I'm sceptical. Be curious to see what @Yellow Saddle thinks.

 

[Ajax Bay]

Yes. Young's Modulus for stainless steel is circa 200 GPa, so 10 kg wt (force) would stretch the cable 2 nanometres (if the cable was 1m long (say)), if I've got my assumptions and maths right. And then return to its original length when the tension is released. You may accuse me of splitting hairs: but this is in quite a different league!

 

[Blue Hills]

It is a lot easier to set up a triple set up correctly with an inline adjuster in place

View attachment 152919

Been looking for one, though managed last time to, by mistake, buy a thing which slots into a downtube cable stop, which I don't have.

Can you recommend such a thing? with link if possible?

I have heard some folk criticise them though? Introducing an extra complication/somewhere for muck and water to enter the system maybe?

 

[User6179]

Been looking for one, though managed last time to, by mistake, buy a thing which slots into a downtube cable stop, which I don't have.

Can you recommend such a thing? with link if possible?

I have heard some folk criticise them though? Introducing an extra complication/somewhere for muck and water to enter the system maybe?

I just used one off a brake at the downtube stop .

 

[Blue Hills]

I just used one off a brake at the downtube stop .

sorry, don't understand this. That pic looks like something totally in-line, no stop.

 

[User6179]

sorry, don't understand this. That pic looks like something totally in-line, no stop.

Sorry ,that was just a pic off google search for the OP , not mine , I just used a brake adjuster on the downtube stop.

 

[User6179]

sorry, don't understand this. That pic looks like something totally in-line, no stop.

Google shimano sm-ca70

 

[Blue Hills]

thanks eddy

 

[Tommy2]

To revisit this, this video show me clicking the shifter to the big ring then clicking down just once but as I release the downshift it clicks again and releases all tension on the cable as if something is worn or broken in the shifter and is not engaging in the middle ring postion like it's skipping over a worn stop.

View: https://youtu.be/FOpT-PuIEWs

 

[Crackle]

As said, adjust the cable tension but also check the height and the angle. if it's never worked from the beginning, it may not have been set up right.

http://www.parktool.com/blog/repair-help/front-derailleur-adjustment#article-section-7