TRP spyres road/gravel 140mm or 160mm discs?

have a Kinesis pro6 CX stylee/drop bar hybrid/aka gravel racer etc
been running BB7’s for a couple of years and are ok but do get fed up with adjusting and coming from mtb prefer a bit more consistent feel to brakes so TRP spyres – great reviews then recalled- now available but with option on disc size (decisions, decisions)- currently running 160mm discs when I look at some of the disc laden road bikes 140mm seems the norm
is this fashion or physics?

140mm lighter (but not much) more discrete so weanie and fashion?
or more importantly less twisting leverage? having had my standard front qr need tightening a couple of times when on a ride I’ll buy a thru axle fork at some point meanwhile appearance is of little concern
so 140mm or 160mm?

edit I don’t race 😕 😐

Just get whichever you can the cheapest.

I run 160mm on a Croix De Fer and TCX at the mo, seems ok.

cheers 160mm would be cheaper as have 2 sets of wheels – one lightish set with 25mm slicks and a set off a cotic x with 32mm tyres so would have to buy a second set of discs, 160mm is OK with me but would 140 be any better?

Note that some of the 140mm discs have extra measures to aid heat dissipation, especially the Shimano ones. With standard discs, I’d stick with the bigger disc. Esp with your choice of calliper… which I presume has a very low volume of oil compared to a full hydro system, and has all that oil closer to the source of the heat.

Such a low volume of oil that in fact it has none at all being cable pull…

160mm is OK with me but would 140 be any better?

I honestly don’t think you will notice. As an aside, there does seem to be more choice of 160mm discs available.

…you could always hedge your bets and have a 160mm up front, and a 140mm on the rear 8)

You do seem to keep buying faux cx bikes Jamie. Aren’t you up to 3 now in a few months? Presumably trying to take. Hora’s title of ‘most fickle’? 🙂

I run 160 front, 140 rear. Works perfectly well. The Spyres are lovely brakes.

Just swapped out some BB7s for Spyres cause after 2 years I was getting sick of the constant fettling they seemed to need, was blown away by how easy the Spyres were to set up. A couple of longish rides and I’m slightly underwhelmed by the braking power and lever throw seems a lot. Probably need to bed in, cable stretch a bit more etc. Anyone have any good set-up tips?

A couple of longish rides and I’m slightly underwhelmed by the braking power and lever throw seems a lot. Probably need to bed in, cable stretch a bit more etc

I have noticed this as well, especially the lever throw. To be honest, if I had my time again, I would probably give the Shimano CX77s a try. The TRPs are ok, but apart from the dual piston design, which seems to give sweet naff all clearance on the front wheel on both bikes, then I am not sure they are as awesome-sauce as has been noted.

Saying that, it is the first version, so going to take time for the design to be refined. But I really think they are a stop gap until road hydro brakes get sorted.

Sorry, I was thinking of the HY/RD, because you said you were fed up of all the adjusting with your current mechanical brakes. Swapping out one set of mechanical for another probably won’t solve anything.

…argh more options but 160front 140 rear makes sense

looked at Shimano cx77’s but as far as I can see they are pretty much same design as bb7’s (single moving pad) but look harder to adjust as don’t have the finger dials so would need to get tool out (ooh..er mrs)for a quick fettle

suspect will go hydraulic at some point as current 9 speed STI’s are starting to get a bit worse for wear but current and probably only options for sometime are all 11speed and that means new rear wheels/getting rear wheels rebuilt as well as mech and cassette which is all a bit hard to justify as quite happy with current set up

I’ve got Spyres with 160mm discs – really like them but they don’t have the stopping power of a basic hydraulic. Speaking to Chris Igleheart at Bespoked yesterday (who as been putting discs on road bikes for 10 years), and he recommended swapping QRs for bolted axles for peace of mind – QRs tended to deform on one side or the other.

I agree that the lever throw seems more than my BB7s.

Anyway, I used 140 rotors front and back for road/CX for a good while without any problems despite being 16+ stone. I’m now on 160mm rotors, for more heat capacity (just in case) and because I got some floating rotors which were 160mm. Though it’s worth noting the floating rotors don’t work with the Spyres.

corroded – Member
…and he recommended swapping QRs for bolted axles for peace of mind – QRs tended to deform on one side or the other.

the front QR issue is possibly a good reason to go to 140mm front as my understanding is smaller disc less leverage?

quite a few of the road bikes sporting discs have gone for bolt thru’s and I’ll def go that way in future – after hearing the tinkling of rotor on caliper on a descent and finding qr had moved a bit I’ve started cranking up the front qr much tighter
I’m pretty light weight (ie short enough to not may weigh much rather than a racing snake) and not an aggressive rider so heat capacity isn’t a huge issue

The Spyre recall was a pain in the arris but the brakes themselves are pretty good IMO. They’ll never be as good as hydros but for commuting they’re spot on. I have 160 front and back but only because that’s all there was. 140 would be fine too I think.

OP, if you’re after extra discs I have a pair of unused 160mm TRP discs which came with my Spyres. I never used them as I already had some Icetechs on there.

OP, if you’re after extra discs I have a pair of unused 160mm TRP discs which came with my Spyres

cheers but will give that a miss – got plenty of 160mm discs and never been sold on the brake specific to disc argument – maybe some small gain for those at the limit – though I may operate at my limits they aren’t near the limits of the kit 😕

I’m running 140mm Ashima rotors with Shimano R505s (about to be replaced with R517s)

I’ve never had a problem with them, they work just perfectly, don’t think I’ve ever adjusted them, despite churning out 1000s of miles on them over some pretty big hills.

That reminds me, I have some BR-R517s I need to put on the classifieds at some point.