Tiagra to 105 upgrade query

[robert17]

Dear people,

Could anyone please verify the following;

1. I would like to upgrade my 4600 Tiagra road shifters up to 5700 105's. I believe this is compatible and simple enough. Correct?

Also,

2. My other bike [2007 Ridgeback Voyage tourer] has some very worn 8 speed 2200 shifters on. Could I keep my Tiagras [mentioned above] and keep these as spares for this bike? Can a 10 speed shifter be used on an 8 speed cassette with a little doctoring? Otherwise, I shall try to punt these on.

Thank you.

Robert.

[pete75]

1. Yes.
2. No

[stewartpratt]

The answer to 1 may also be "No". Shimano changed the brake pull on the 5700 series, so in theory you should "need" matching calipers. I'd get onto google and try and find whether people are mixing and matching without too much pain, or whether it's a no-go.

[pete75]

The answer to 1 may also be "No". Shimano changed the brake pull on the 5700 series, so in theory you should "need" matching calipers. I'd get onto google and try and find whether people are mixing and matching without too much pain, or whether it's a no-go.

I'd be astonished if the brakes don't work

[honesty]

They changed the pull slightly, which means that newer levers with older brakes are slightly less powerful. For example 6700 levers with R650 brakes. Its not an issue if you ask me. I think as well that Tiagra 4600 has the new brake cable pull anyway.

[stewartpratt]

I'd be astonished if the brakes don't work

It's not that they won't work, just that the travel and feel at the lever will be different. Either you'll have shorter travel and they'll feel a little more wooden, or you'll have more travel and they'll feel a little more squidgy. Depends which way the leverage changed, which I'm not sure of.

I can't imagine it's a big difference, though. Not as much as the difference between cantis and V-brakes, for instance. So it may be just fine to mix-and-match, depending on which way you do it and how fussy you are. (On MTBs I tend to use canti-compatible levers with V-brakes, I happen to like the extra leverage.)

[Brian73]

The front mech pull is different too I think

"Front mech

At first glance this looks no different from the previous 105 front mech, but closer inspection reveals that the plates are just over 1mm wider apart, they’re shaped differently, and the parallelogram that drives the mech is a new geometry too.

This is because of the revised cable pull from the left shifter, and the revised spacing of the chainrings. The result is a quick and clean shift, but with more room between the plates to allow the chain to run ‘crossed’ – big ring and bigger sprockets, for example, or small ring and smaller sprockets – without rubbing.

Weight: 97g (braze-on, double)"

http://www.bikeradar.com/gear/category/ ... -11-39613/