I’d like to replace my tektro calipers on my Defy with a sale set of 105 calipers. Thing is, they come with a warning about leverage ratio at the lever – so can I use 105 calipers with Sora 3800 (I think – the 2013 sora which is paddle only) STI’s?

I think you need to give the model numbers and hope MisterP comes along and supplies an answer.

Even within the 105 range different model years had differing leverage ratios.

I ran the opposite, new levers with old callipers and got a quite on / off feel with short lever travel. I would imagine using new callipers with older levers would give the opposite.

IIRC, 5800 calipers with 3800 Soras should work. It’s the x800 thing that matters.

I can’t find the sora model number. It’s 2013, paddles only so no thumb button, and 9 speed – anyone know?

There is no 3800 Sora, current model is 3500 which is “old” cable pull and is 9 speed with two levers rather than the little thumb knob.

You won’t die using this combination.