I’ve two dropped bar bikes with cable discs on. One with 105 10sp which works really well, one with Tiagra 10sp/Sora LH shifter (it’s 1×10) which works less well.

I’m assuming the difference in braking feel/power is due to some different pull ration of the 105 brakes compared with the others but can someone confirm before I invest in some new bits please?

Thanks!

Yes, but not enough that they’re really incompatible.

IIRC if you use new callipers with older levers (pre 2007 ish) you end up with more leverage (i.e. the lever moves a bit more but you also have more power but the pads sit closer to the rim), using new levers with old callipers had the opposite effect, the brakes felt a bit wooden as the lever doesn’t move as much.

But none of the aftermarket brake people have changed AFAIK which shows how little effect it really had (there aren’t two variations of BB7’s, Spyres, HY-RD, V-Twin, Juin Tech etc).

It’s not like V’s versus road pull which is almost double.

If you’ve got a marked difference then I’d look at the cables and pads.

So if I understand correctly the new levers pull a bit more so less movement for the same effect. If so that’s what I thought and it seems to translate to better disc braking with the new levers.

So 105 10sp with BB5/shimano thing is better than Tiagra+Sora (old) with BB7 IME. And I think it’s the levers.

Thanks!

If you stick up what model it would help (eg 4700 etc)

Are the disc calipers road rather than MTB?

Pad compound and disc size makes a difference as well.

Have you had a look at the shimano compatibility charts?

Shimano keep tweaking cable pull, SLR, SLR EV, Super SLR etc

Before you change anything, check that they are set up right – are the discs being deflected before they are clamped by the pads? This can make a big difference to the feel.

Silly question maybe, but there isn’t any chance the 105 bike has compressionless outers and the Tiagra bike doesn’t, is there?

Ok, more detail.

Tiagra is probably pre 4700 – it’s one with the exposed gear cable with an adjuster on it. Sora is old, probably 2010 vintage. Both these are paired with road BB7 with compressionless outers, set up correctly with avid pads (sintered I think but have tried a few different ones without noticing a significant difference). They work fine but just don’t feel good as the following:

105, 10 speed, probably 2015 with a shimano caliper, probably a CX77 or similar on the front and road BB5 on the back. Normal cables and outers, in fact front cable outer is two separate pieces to make up the length! Significantly more ‘solid’ feeling and effective. It just feels like the cable pull is more with the 105 levers.