Mechanical disc brake choice.

[peetee]

I’ve thinking for my new bike build I might try mechanical (cable) disc brakes. I am halfway through the second winter here and already my wheel rims are in a shocking state due to the highly abrasive grit on the lanes.

Given that I use Tiagra 4600 levers and like a light action, good feel and power enough to match or exceed the ability of Ultegra or Dura-Ace calipers which would you helpful lot chose between Shimano BR-R517, Avid BB7 and TRP Spyre? I do know the Spyres can seize if neglected but if they are significantly better than the rest I would consider them.

[Psamathe]

I can't comment on any you've listed (my new bike not due for a few months will have BB7s) but I would say avoid Hayes. My Croix de Fer (2014) came with CX Expert mechanical disk brakes and the brakes are fine, no issues and I like them. Just getting replacement pads for them is very difficult. The few 3rd party ones generally have bad reviews and UK importer imports the callipers but NOT the pads so I have to order Hayes pads from Germany. Only reason I comment to avoid is pad availability.

Ian

[reohn2]

Providing the cable pull matches your levers BB7's everytime,powerful,good modulation wet or dry,ease of set up and maintenance and calipers can be stripped and rebuilt within 30mins.
Now wait for those who'll tell rim brakes are all you andndiscs aren't necessary,even though you know different

[PH]

I’ve thinking for my new bike build I might try mechanical (cable) disc brakes. I am halfway through the second winter here and already my wheel rims are in a shocking state due to the highly abrasive grit on the lanes.

Given that I use Tiagra 4600 levers and like a light action, good feel and power enough to match or exceed the ability of Ultegra or Dura-Ace calipers which would you helpful lot chose between Shimano BR-R517, Avid BB7 and TRP Spyre? I do know the Spyres can seize if neglected but if they are significantly better than the rest I would consider them.

Of those three, I've tried BB7's and Spyres (Actually Spykes, as they were for straight bars but otherwise identical) I've only used both on flat bars, so others will know more about drop bar compatibility.
It isn't neglect that makes the TRP's unreliable, it's simply use, I don't think there is a way to keep them running well, at least not without frequent strip and rebuild and even then I'm doubtful. If there's any difference in stopping ability, it was too small for me to notice. The TRP's possibly had a slightly nicer feel, though it's minimal.
The Daddy is the Paul's Klamper, which is available with the ideal cable pull for current Shimano levers (I'm unsure if any others are). On straight bars, this doesn't stop any better either, though it has a noticeably nicer feel, maintenance is easy and it looks likely to last a lifetime. Silly money, but I compromised by fitting just one where I'll benefit most.

[Eyebrox]

I've used all three and can find pros and cons for each. I would opt for Spyre based on longer term experience. Both pads are adjustable and once set up with equal space between the pads and the rotor you can compensate for wear by loosening the barrel adjuster on the cable at the caliper. You do have to guard against the pad screws seizing by turning them one way then the other periodically. Some disc brake cleaner or alcohol on the threads can help but just enough to avoid contamination. One thing to look out for is the straightness of the cable run to the rear. I have seen significant improvement in braking performance by changing the outers to good quality compressionless ones from Jagwire. I have also changed the often contrived routing of some cabling to run the outer straight and level along the stays to the caliper, attached with zip ties. The result has been solid braking on a par with the short cable run front brake.

[peetee]

I've used all three and can find pros and cons for each. I would opt for Spyre based on longer term experience.

What road conditions were they subjected to? Is the road debris on the west coast a mix of granite particles as it can be to the east?

[gregoryoftours]

Depending on the frame, fitting a rear pannier rack can be problematic with some cable discs over others. Spyres are lower profile on the outside than many, for example BB7. Personally I'd choose the latter over the former if clearance allows.

[boblo]

I've had Spyres, BB5's, BB7's, Tektro Lyra's and Promax Render's.

I'd forget about the BB5's, Lyra's and Render's. I didn't find them very good.

I found the BB7's a bit heavy and agricultural so changed to Spyres which I have on 3 bikes.

The OE pads are rubbish to start with and improve when broken in. I also use Avid G3 discs rather than OE as they improve braking. The braking is good with Shimano 105, Sora or SRAM Force levers, can't say for others. I'm reasonably pernickety about cleaning and maintenance so haven't found any issues with seizing etc (yet). I wash my bikes down after salty/winter rides and dry them indoors. Obv if the OP doesn't or commutes etc, this may affect reliability.

Last point, I use sintered pads once the OE ones are finished. This usually improves the braking.

I'd buy Spyres again.

[slowster]

Bedtime reading for you:

TRP Spyre Vs Avid BB7 mechanical disc brakes

Quick check - servicing TRP Spyre mechanical cable disc

Anatomy of BB5 and BB7 brake calipers

TRP Spyre/HyRd and Shimano brake pulls

TRP Spyre Disc Brakes - Not Impressed.

[Eyebrox]

Not much granite on road surfaces. The damage tends to be done by road salt in the winter. In that regard the BB7s were more resilient with their hand adjuster (or spanner flat) pad control. The Spyre pads are adjusted with a 3mm torque key, the receiving end often getting chewed up by a combination of adjusting and wear and tear from road grit. Coming at the inner pad from an angle (through the spokes) doesn't help either.

[Brucey]

I’ve thinking for my new bike build I might try mechanical (cable) disc brakes. I am halfway through the second winter here and already my wheel rims are in a shocking state due to the highly abrasive grit on the lanes.

lots of hills and different muck on the roads can make for a differently rim-shredding environment. You may also find that whatever brake blocks you used to use are not the best ones for where you are now. If you have not tried disc brakes on a road bike then there is only one way to find out if they suit you or not. However the whole bike will be different from what you are used to; it definitely won't be 'the same bike feel but with different brakes'.

Given that I use Tiagra 4600 levers and like a light action, good feel and power enough to match or exceed the ability of Ultegra or Dura-Ace calipers which would you helpful lot chose between Shimano BR-R517, Avid BB7 and TRP Spyre? I do know the Spyres can seize if neglected but if they are significantly better than the rest I would consider them.

ST-4600 have NSSLR cable pull which means that they are not going to be a perfect match for BB7 'road' calipers because they were designed for the previous generation of brake levers. Spyres are a good match for the levers; the problems with those brakes are that the pad adjuster screws start to move around by themselves after a while and that the weather gets into the thrust bearings and wrecks them. The shimano BR-R517 calipers are also a better match for the levers. In any event good or bad pads will make a big difference here too.

FWIW I can understand why you might want to re-use some extant STIs but if you are building a whole (mostly new) bike it may be a false economy to allow them to dictate the bike's specification? If you are thinking of disc brakes then this means a new frameset and a new wheelset, and no going back once the die is cast. If you want a light brake action and good power/modulation then a full hydro system may feel the best. It won't come without other things that you may or may not like though.

If wearing rims out is the only reason for wanting to try disc brakes there are other ways of addressing this issue; for example if you are like most cyclists then you will do most of the mucky miles on one bike, and that bike can have cheap rims that you don't mind wearing out (because they are cheap to replace) or hardfaced rims which don't wear out so quickly.

If you just want to try disc brakes on the road, an easy way of doing this is to take a cheap bike (eg a hybrid or MTB-ish bike with disc brakes eg a Carrera subway), fit drops and road tyres to it, (eg using Tektro brake levers for dropped bars which use MTB cable pull) and to use that as a 'winter beater' for a while. It might prove that disc brakes are just the job for where you are now, or it might help stop you from spending a lot of time and money on a new road bike that may not really suit you. The donor bike oughtn't cost more than about £100 to buy and the conversion cost will be about the same again (assuming that you have a few bits and pieces squirrelled away). Worth a go? It'd be an interesting lockdown project anyway...?

cheers

[peetee]

Hydraulic is not an option. I want neither the expense nor the hassle of another indexing system in my fleet. My current winter bike has an eclectic mix of bits which I am very happy with that, with the exception of the brakes, would be passed over to the new steed.
The issue of having a bike that rides differently to what I am used to is a consideration but I was hoping I could offset that with a change from my usual 25mm tyres to 28mm. I was looking at a caliper brake equipped steel Audax frame and found Spa Cycles had a viable product. From there I strayed towards the titanium frames then disc brake fitted ones. The steel framed, disc ready Spa Elan gets favourable write-ups with regard to comfort. Titanium is tempting but I don’t want a carbon fork - steel is an option but matching it to a titanium main frame seems a bit contrary.
I went into this being pretty certain what was right for me but now I rather feel like the child in the sweet shop that can’t make his mind up which jar.

[slowster]

The steel framed, disc ready Spa Elan gets favourable write-ups with regard to comfort. Titanium is tempting but I don’t want a carbon fork - steel is an option but matching it to a titanium main frame seems a bit contrary.

Spa's Ti Tourer has a steel fork, and my only concern about buying a titanium Elan with the steel fork would be if the head tube required a headset larger than 1 1/8" (1 1/2" head tubes look odd paired with a relatively slim fork). The titanium Elan has the added advantage of not being susceptible to corrosion, which would be a consideration for me for riding on gritted winter roads and/or if living close to the coast.

With regard to future proofing, I think the inexorable trend is for disc braked road and 'do anything' bikes like the Elan to switch to thru-axles. I think Shimano have stopped making the benchmark M756 XT quick release disc hubs, but Spa still have some in stock, so that might be a consideration.

(I think most/all of Shimano's current range of disc hubs are Centre Lock instead of six bolt, but I vaguely recall reading that some or all of the Centre Lock discs are not suitable for use with brakes like BB7 which have a single moving piston and consequently bend the disc slightly when actuated, i.e. because some or all of the Centre Lock discs are not just steel: they have an aluminium core.)

If you don't want everything to be the latest current kit, it can be a bit of a headache deciding which technologies you want and ensuring that what you want is all compatible, and that you have sufficient spares if it looks like what you want to use has been (or shortly will be) discontinued.

[Stevek76]

You definitely get solid steel centrelock rotors and shimano's own mechanical brakes are single moving piston also.

between Shimano BR-R517, Avid BB7 and TRP Spyre?

I've got some CX77s same as r517 but lighter (they were going super cheap - rrp increase is not worth the few grams imo) and BB7s (road version).

Both work fine for me, but a few things differ
Shimano pros:
-Easier to set up to wear the pads 'straight'
-Perhaps a slightly wider range of aftermarket pad options

Cons:
-The moving pad adjustment is fiddly (2.5mm hex and it can be tricky to access on the rear depending on caliper placement and any racks/guards) and the range of adjustment for that pad is barely sufficient
-Even the fixed pad adjustment is a 3mm hex rather than by hand

Avid pros:
-Far easier by hand adjustment on both pads (though the fixed pad adjustment was incredibly stiff on mine initially but this can be solved by taking the plastic adjuster off and bending it out slightly so it engages with the detents less enthusiastically)

Cons:
The 'tri-align' mounting mostly just seems to result it in being more askew. I'm not sure why as the same system with the loosen bolts, engage brakes and tighten method has worked fine on various mtb hydraulics I've had but not on these, might just be that bike
They're quite wide and the combination of chainstay rear caliper and my toe heavy cycling position meant I was gradually tightening the pad adjuster as I pedalled with my heel - I ended up removing the plastic knob which solved that.



I'm not sure I'd say either were particularly 'light' on road levers, at least from hoods, but then many rim brakes aren't either, neither seem to be particularly better than the other. Quality compressionless cable outers make a big difference on mechanical discs I find, even over the relatively short distance to the front.

[Si]

I've BB7s and Spyres for a few years. Both have been reliable and easy to maintain. The stock pads on the Spyres are rubbish. The ones on the BB7s were fine.
BB7s offer more power on my bikes. However, part of this will be down to rotor, cables, levers, etc.