[Closed] Which road disc brakes to get with post mount?

I upgraded my Spyres with Juin tech cable hydraulics. Much much better, not able to comment on longevity or how they'd fare on an alpine descent, butvits certainlyva cheaper option.

You could use Shimano MTB calipers with the Tiagra levers, which would be cheaper than Hope. The RX4s are good though.

In the classifieds at the moment there is a advert for gravel bike bits. It has a giant conduct in it for not too much (as well as a decent amount of other bits). It's flat mount by the look of it but postmount calipers are cheap.

I’d consider the Sram Force or maybe Rival, but avoid Apex. The shifters work differently - there’s just one moving shift lever that does both up and down shifts. You tap to go one way and push it more meaningfully to go the other. I loved my Rival 10 speed (rim brake) levers. Hated going back to 105 which is why I eventually went Di2 instead.

Isn’t the RS785 a Di2 lever? Think that’s what I bought to replace my 105 hydraulics which I wasn’t a fan of - di2 cost quite a lot even looking for bargain stuff.
My our other option is buy flat mount levers / calipers and just swap out the calipers. You can buy post mount ones separately for mtb and maybe road? Or there are Hope RX4 which is what I plan to buy when my Shimano caliper seals inevitably fail.

To be honest I'd rather just get hydros than try and bodge it.

Thanks for the heads up r.e. the shimano calipers. Honestly the price difference isn't that great so happy to just get the hopes. I think my confusion is whether or not to keep my 10 speed Tiagra, or whether it's worth upgrading to 11 speed?

@Joebristol, you make the Sram shifters sound really good, especially if you felt 105 was a downgrade in comparison. The RS785 is Di2 which is my only issue. I'd rather not charge things especially as it's a touring bike. They actually have a pair of the shifters and calipers in post mount for £260 which is an absolute bargain, but it's Di2 which is my issue:

https://www.probikekit.co.uk/bicycle-brakes-and-pads/shimano-st-r785-hydraulic-disc-brake-di2-sti-s-pair/11211776.html?affil=thggpsad&switchcurrency=GBP&shippingcountry=GB&variation=11211777&shoppingpid=TOP10_200718_&&thg_ppc_campaign=71700000073341592&gclid=CjwKCAjww5r8BRB6EiwArcckCyGRKP8ppEYSixslmh-jBbee4h5sPC0nCzKmVtuyzuefcz4_cjihqxoChbcQAvD_BwE&gclsrc=aw.ds

I was considering just buying standard Tiagra 4720 10 speed shifter/levers which would work with my existing groupset and just buy Hope RX4 post-mount calipers. I just don't know if it's worth upgrading my current Tiagra 10 speed to something better while I'm at it. There's also the GRX 10 speed levers too which are also around £200.

Di2 is ace and you don’t need to charge it that often - but even with bargains it cost me about £700 all in. At the time there wasn’t any cheap Sram Force 22 about, otherwise I’d probably have got that to save money.

10 speed vs 11 speed I doubt there’s much in it - range isn’t an issue with road bike cassettes I assume? I’m running a 105 11-32 I think (11 speed) and the cassette wasn’t a lot. For you to go 11 speed vs staying 10 speed I guess it’s just an extra cassette / mech and not much else though.

Some people like the Sram, some people don’t. I’d take Di2 over mechanical any day of the week, but after that I’d take Sram doubletap over Shimano non-Di2.

But it comes down to personal preference - I like a very positive / clunky shift where you know it’s shifted (Sram) - other people prefer something a bit silkier smooth and therefore go Shimano. I found 11 speed 105 a bit vague personally.

Just been reading this review of Di2 and RS785 and the author mentions that they managed to get 750 miles for the Di2 battery to come down to 50%. If that's true, I doubt there's any worry of the battery running out. Probably almost certainly won't be serviceable though if something were to happen, like a simple mechanical system.

Honestly at the price it is with the shifters and calipers, it is an absolute bargain and if I was to buy the derailleurs, it would probably cost me the same amount as if I was to buy a standard 11 speed groupset. Might just get them if you'd recommend it and can attest to the battery life comments?

I think I agree, I can't imagine there being much difference between 10 and 11 but people on here are always going on about it.

It’s not just shifters and mechs you need to think about. If it’s 2x you’ll need a front junction box A, a mid junction box b, an internal battery and all the cables. That’s usually 6 cables - one each for the mech, 1 for the battery, 1 from junction box B to A and then one fr junction A to each shifter. Junction B can usually be had for about £20 ish, A is nearer £50 for a 3 port (there is a fancy bar end Junction A bit thats more complicated to wire internally in your handlebar - or there’s an XT junction box A with a screen) - and that’s over £100 of cables and £100 for the battery if I remember rightly.

10 speed Di2 gear isn’t compatible with all 11 speed gear either I don’t think. If going Di2 then I’d suggest you go 11 speed. Also measure measure and measure again for cable lengths - I got the rear mech one too short and had to order another, and got lucky with the long front to rear one that I also ordered the inline Bluetooth module - otherwise I ordered too short on that one too.

A lot to think about - but the shifting is epic - the front mech small to big cog is so effortless and smooth vs mechanical shifting.

I like a very positive / clunky shift where you know it’s shifted (Sram)

Not my experience with SRAM! Yes, you know the lever has clicked but whether the rear mech has moved is another matter.

I've got SRAM Force on my CX bike, and definitely wouldn't pay money to swap it on to a bike. The lever action I can take or leave, but I've never had so much trouble trying to keep shifting working reliably. The cable routing on my Force hydros is ridiculous, so it's not surprising it causes issues. I'm not sure if the designers had ever seen a road bike.

Bike24 have Tiagra hydraulics (lever + caliper) for €104 an end, with FM calipers, and a Deore MTB caliper for €25.

The only Shimano stuff I'd avoid is the first generation of 105 hydros (RS505), and that's just based on looks!

I just put grx 1x11 with flat mount callipers on my commuter which has IS mounts. Got adapters from https://www.assolutions.ca/product-category/adapters/. They do post mount adapters too. You need to check the fit (there’s a guide to print out so it’s easy). They come from Canada and I had to pay a little duty on them. Worked a treat for me.

What wheels have you got? Have you checked the free hub will fit an 11 speed road cassette?

I’m asking from semi-bitter experience.

You can avoid the 11s road cassette on a 10s hub problem if you get a 11-34 ultegra or 105 cassette. They are 10s width (so you need a spacer if you want to run them on 11s hub). Assumes you’re happy with 11-34 though.

What sort of touring are you going to be doing? All this talk of road based 2x surely that won't be low enough for 'proper' touring? I recently built up a dedicated touring bike with 3x9 44/34/22 and 11-34 cassette plus Spyres. I don't want to get halfway up something and run out of gears because I chose a 50/34 road chainset or halfway down something and regret going hydraulic as the levers go to the bars...

I've used hydros for years on MTB's and they're ace. They're still not rated for tandems and that should tell you something. For touring, you want reliable, functional, maintainable and if shit comes to bust available hence my choice(s)...

@JoeBristol, thanks for outlining the setup of a Di2 system - something I was very unaware of! For some reason I kind of assumed that it would be plug and play. If I'm honest it sounds not only like a lot of money, but also a lot of work. Part of me just wants to be able to get on the bike as soon as possible! I'm going to be riding it in central London which is the main motivation for getting Hydraulics - my cable brakes are awful and I want to be able to stop as soon as possible. Think I might just put that to the side for now and go with some 10 speed Hydro Levers and Hope RX4s if I can get my LBS to set it up for me.

@pdw, as someone who has no experienced with SRAM (and also very confused by the lineup) that is not very reassuring! I think your suggestion of Tiagra levers is probably the best option and it means full compatibility with my existing drivetrain too. The deal from Bike24 sounds fantastic but not sure if there's any point if I'm going to replace the calipers. But it seems about the same price in the UK without the calipers!

@Oblongbob Given the price of those adaptors it would be the same price to buy Hope RX4s instead! I do like the look of the GRX shifters though, and they have them in 10 speed - the GRX 400s. I wonder how they compare to Tiagra given that the shifter sets are approximately the same price. Shimano seem to state that they're directly compatible with the 10 speed Tiagra road set.

Thanks for the advice r.e. the 11 speed cassette. I'm running a DT 350 rear hub. But will probably end up going with 10 speed just to save time.

@boblo I just find them to be nowhere near the level of braking compared to hydros I've tried out, even when they're set up properly by the LBS. I'm just talking light touring so 2X is more than enough to be honest with you.

Don’t forget it’s CA$ so “only” £23.50 a piece, which is probably 1/3 of the price of the hopes isn’t it? Still a stupid price for what they are. Postage wasn’t too bad.

Was tempted by hopes but was reluctant to have a set of callipers leftover. I think I had to pay £10ish of duty and post office fees too, which was a minor pain.

The grx shifters are really nice. Replaced some old ultegra 10s and bb7/Spyre set up. I never got the cable disks to work that well despite lots of faffing - hydros are great on the same old discs. I got the 1x grx 800 shifters and brakes from Merlin for a hefty discount (almost 50% iirc), but even then still quite pricey.

If I was going touring, as you suggest, I'd be sticking with cable plus STIs or even bar end shifters.

The TRPs can be serviced if they've stopped working well - there is a there's on here about it.

Also make sure your TRPs have the little plastic cover that protects from dirt and is held on by the pad retaining pin. (On mine, one had this, one didn't and the one that didn't went pretty shitty after a few muddy rides).

You can get it from Triton, Upgrade, etc about 6.99. Annoying but useful.

If you're looking at spending 300 quid plus, have you got everything you need to make your touring enjoyable? Good rack, panniers/luggage, sleeping kit?

No way I would swap Shimano + TRP calipers for SRAM hydros unless I got a bargain on Rival or above. And even then I would wonder what I was doing.

Shimano MTB post mount calipers work with their hydro road STIs, as mentioned. Dig about for the correct info re hoses/olives. Or you can still find the post mount road calipers some places. The calipers are really cheap compared to the levers.

Also re availability, in most developed countries, 10 vs 11 speed kit is similarly easy to find and often 11 speed stuff is cheaper for the same group (e.g. 10 spd 105 vs 11 speed). If it's Tiagra 4700, 11 speed mechs are compatible.

The price of the GRX shifters are equal to the Tiagras, but wasn't too sure what the major differences were. Will just get the GRXs I think.

@sb88

Thanks for the advice r.e. touring and the TRPs! I adjusted them myself and took them to LBS to get them to replace the cables but they said they're working as best as they probably will, and it's not sharp enough for me to be honest, so just going to get the Hydros.

I'm not touring anytime soon - that's for the summer! But will be doing a few long rides probably.

Since the opinion on here doesn't seem to favour SRAM, will give it a miss. Are they that bad?

Just going to get the GRX 10 speed shifters and Hope RX4 calipers. I saw the Shimano ones but the Hopes look better to be honest, and I'm happy to pay the extra.

The deal from Bike24 sounds fantastic but not sure if there’s any point if I’m going to replace the calipers. But it seems about the same price in the UK without the calipers!

Well, brand new but second hand FM calipers should sell for a few quid. People upgrade frames, and Shimano don't sell spares so there should be a strong market for them. Even just the pads included in the kit are about £16 a pair in the UK.

The other reason is that the kit also includes hoses and fittings and if you make sure that you buy PM calipers with a bolt on fitting rather than a banjo fitting, the hoses will swap straight over. Spare hoses are surprisingly expensive, and if you buy GRX levers without calipers, they don't come with the necessary bolt to attach the hose, and the bolts are £7 a pop. I'm not sure if the same is true of the Tiagras but I think it might well be. Buy a kit and you'll definitely have the right bolt.

Even if you don't sell the calipers, it may well work out cheaper overall.

I have just upgraded my first generation R785 calipers with XT M8000 and it is a lot better . Shifters are DI2 . They are a few years old but were Ultegra level .

With DI2 what matters are the derailleurs . Keep front and rear same model . The rear derailleur dictates if 10 or 11 speed .

I am on 10 speed Ultegra , enough for me .

Once you go DI2 , you dont go back to cables . I have TX DI2 on a Orbea Rallon and looking to upgrade the hardtails .
About 2000 km before it needs charging .

In the time it took for my Shand to go from order to delivery (!) in 2017, the world of road discs switched from post to flat mount.

My solution was to use the then brand-new-model Ultegra R8020 11-speed shifters with "old" R785 post mount calipers. I researched a lot at the time and am confident most of the Shimano MTB calipers are compatible if needs be in the future.

I've been using this setup for 3 years and they work brilliantly.

I got my flat to post adaptor from here

http://www.spokeydokeybikes.co.uk/