Could I stick some 105 calipers with Tiagra levers without dying?

Equally, could I put Ultegra calipers with 105 levers without dying?

The reason I ask, apart from not being sure, is that the Promax caliper/Tiagra lever combo on the new, winter, road bike are, somewhat,under powered and I was wondering about moving the 105’s down from the CAAD10 and popping Ultegra’s on.

unless you can see the levers beding when you pull them I doubt the Tiagras are actually giving less power than the 105’s.

More likely to be pad compound (or type – are the pads in a shoe) than anything else but I’d look at calipers first.

+1 for changeing the pads first.

AFAIK all the levers/callipers work together. The pull ratio did change (IIRC the same time the gear cable went under the bar tape), but not enough to make a dangerous difference, I run aftermarket brake calipers which I’ve no idea of the pull ratio!

Death is not a risk, it’s inevitable.

From that Merlin website, with regard to Ultegra 6700 calipers –

Must be used in conjunction with ST-7900 or ST-6700 STIs for correct leverage ratio

Or 5700s, basically where the cables run under the bar tape. As TINAS said though, people are mixing and matching and still alive. Not sure I’d test it though myself.

Agree on pads, but also change the cables. I had the cheap stock cables on my Allez which clearly compressed massively when I braked. Replaced with decent Shimano cables and ferrules and the lever feel (and power) are much improved.

Hmm. So 5700 levers with Ultegra calipers should be OK but would 5700 calipers with Tiagra 4600 levers work (well) as the cables don’t run under the bar tape? Sorry to sound such a numpty, I’m a recent road convert.

Hmm. So 5700 levers with Ultegra calipers should be OK but would 5700 calipers with Tiagra 4600 levers work (well) as the cables don’t run under the bar tape? Sorry to sound such a numpty, I’m a recent road convert.

They’ll all work, just some will work better than others. I’d guess the tiagra would have the ‘old’ cable pull.

Have you tried better pads before you buy new brakes? Most of the difference is in the pads.