Disc brakes pros and cons

craigus89

What is the general feeling about disc brakes on road bikes these days?
I'm sure this has been discussed at length in various threads but couldn't see one specifically about this recently.

Looking at possible framesets for my 'best bike' build that I'll be doing over the winter for next summer, I find myself immediately discounting a disc brake setup but I'm not sure why. It's not that I'm against them but I think I just assume it's something that I don't need. I'm surprised by how many 2019 bikes are specced with them, it looks like it is heading towards being the standard in a few years time... when you do research on them it seems that there is usually a strong bias one way or the other so thought it would be good to get a few people s opinions.

Main concerns for me are unfamiliarity when it comes to maintenance etc but I assume they are fairly simple.
Do they require less maintenance?
Small weight penalty?
I've never felt like my brakes weren't good enough except occasionally in the wet, are they that much better?

Anyone avoiding them still, and why?

arlowood

Here's my twopenny's worth but I'm sure you're going to prompt responses both pro and con so don't be surprised if you end up still in a dilemma at the end of it all.

If you want to build up a specific winter training bike then you are going to want clearance and the ability to fit mudguards without having to bodge things. On balance disc framsets will generally win out over standard road frames for tyre clearance so you will be able to run 28mm and above and still have the ability to fit mudguards. That's one plus for a disc frame IMHO.

Another is that discs will give you better braking efficiency in the wet over a normal rim brake. Some will argue that the differences are not significant enough to warrant excluding rim brake options.

Disc set ups will generally involve a penalty with the calipers, hubs and rotors adding extra weight over a rim brake set-up. However if it's for a winter trainer rather than a summer race/sportive bike then maybe the weight penalty is moot.

Maintenance issues are a factor but not a biggy. Hydraulic discs are on balance less problematic than mechanical discs but when they do go wrong they can be a bit more of a pain to sort out.

What's the future going to bring. Nobody can tell you with any certainty. Pro-peleton adoption of discs has been sporadic so if the pro's (or their bike sponsors) don't see the need to change then maybe the world will still be riding rim brakes for many years to come.

Just a few thoughts but the final decision is yours'

craigus89

Thanks for that, I've edited my post to clarify that the build I'm thinking about isn't for a winter bike, but a 'best bike' that I'll be building over the winter. Sorry for the lack of clarity.

Maybe I'm reading between the lines of your post but maybe discs are something that are aimed at winter or 'sportive' type bikes for the more casual rider rather than premium stuff? I don't see many people building their 'dream bike' with a disc setup.

fenix

For a best bike I'm sticking with rim brakes - largely because that's what I'm used to.
I've got a couple of sets of wheels that I can swap out if needs be as well. Going disc would mess that up.
I know people who cant get on with discs - their braking was worse than rim brakes. Weird.
I've never thought I needed more braking power than I can get on rims.

Winter bikes at least you can get the bigger clearances you need but thats not an issue on best bikes.

All of this might change in a few years time but this is where I'm at now.

lostboysaint

Pros - more power, better modulation, light years better in shite conditions, no rim wear, simple to set up and reliable (Shimano hydraulic), better tyre clearances (frame dependent, obviously)

Cons - a tiny bit more weight that you'll never notice, the slightly bulky look of the hoods as they have to house the hydraulics.

arlowood

Craigus89 wrote:

Thanks for that, I've edited my post to clarify that the build I'm thinking about isn't for a winter bike, but a 'best bike' that I'll be building over the winter. Sorry for the lack of clarity.

Maybe I'm reading between the lines of your post but maybe discs are something that are aimed at winter or 'sportive' type bikes for the more casual rider rather than premium stuff? I don't see many people building their 'dream bike' with a disc setup.

Tks for the clarfication - I misinterpreted the first sentence of your second paragraph.

For a "best bike" that you will probably be riding exculsively in the summer and in dry weather, then I would echo the comments of @Fenix. Rim brakes will allow you to look at lower weight set-ups and the braking efficiency argument goes out the window.

Only area where you will struggle potentially is getting enough clearance to run more than 25mm tyres if you want extra comfort. Some frames will even baulk at 25's so make sure you check out the clearance issue before you jump in

DeVlaeminck

Don't disc brakes require a stronger fork which may impact ride quality. My steel disc brake bike certainly doesn't have that springy feel I associate with steel frames.

veronese68

Personally the pros far outweigh the cons, obviously I can only speak from personal experience. I bought my Kinesis with disc brakes about 5 years ago. When I first had it I fitted BB7 cable calipers, about the best available at the time. Irritations were that they needed regular adjustment for pad wear, after a while I was getting a slight pulsing on the rear brake from a very slightly warped disc. I bought an ex-demo TRP Parabox hydraulic convertor. This was a pain to fit, mainly because it had been removed by a poorly trained gorilla. Since getting it sorted it's been great, probably 3 years now. The pulsing from the rear brake has gone although the disc is the same, there's a small amount of self centring with hydraulics which is enough to cope with a tiny wobble. I've never had to adjust for wear, wore a set of pads right down due to forgetting to check them however. Braking is better in all conditions for me, I've not had the latest fanciest rim brakes so am talking about my experience. I've not had full hydraulics with drop bars, but without doubt my next new bike will do. I expect them to be even better than what I have but it's not enough of a reason to change. I have had two MTB's with full hydraulics and they are phenomenal.
However, if you are a small light rider and only using it in good weather the advantages will be minimal and personal preference should guide you. In those circumstances if you prefer rim brakes stick with them.
A lot of the problems people have are user error. There are a few things to be wary of. Avoid pulling the brake lever with hydraulics if the wheel is off, pushes the pads out and you can't get the wheel back in. Some people have trouble with brake alignment after removing a wheel, I think this is mainly with QR wheels as mine is avoid this by fastening the QR's with the bike on it's wheels so the wheels are fully located. Keep chemicals away from the discs and pads, for a thorough clean I take the pads out. It only takes a moment to remove them and avoids contamination. Just remember not to pull the lever.
Hope that helps, I'm sure many will disagree with me.

apreading

Bear in mind that for a 'best bike', you will probably have 'best wheels' on it too. If you have rim brakes then these expensive wheels will wear out. If you have disc brakes then they wont.

Disc brakes are just better, not because you can brake harder and lock your wheels but because they work immediately when you press the lever, regardless of whether its wet or mucky etc. Meaning you start losing speed sooner which is important in emergency situations. They also dont lose their power when its wet. Lever throw is much lighter, with 1 finger braking easy from the hoods or drops and very easy to modulate to just the right amount of power.

They dont have problems if your wheel goes out of true because you hit a bump or break a spoke. Over the years I have seen on a number of occasions where someone had to detach their rim brakes because of a problem with the wheel and finish the ride with brakes only at one end. When I broke a spoke with discs, I just snapped it off and carried on riding till the end of the day and got it fixed then (was a bit wobbly by the end though!).

They have more clearance and dont need adjusting as they wear. They dont need you to deflate a tyre to get the wheel in or out.

What I would say though is that you should only consider hydraulic discs. If you get cables or hybrid they are often a pain to adjust and you lose alot of the advantages.

The only downside I have found is that earlier versions could overheat on long alpine descents. But nowadays the pads are finned and the Shimano ice-tec rotors seem to cool better and resist warping and you can get finned rotors if you have centre lock too. This doesnt seem to be a problem any more.

flight147z

To me the major disadvantage of disc brakes is that unless you have deep rims (>50mm) they look terrible

For some reason they look ok on aero bikes, but I think they spoil the look of a lot of bikes they are fitted to

kingrollo

I could be wrong - but IMO discs are the future. I tend to keep by bikes a good few years (9-10) - so my next purchase will be hydro discs (cable discs no - prefer decent v'')

The only downside - is because of the 'dash to disc' is that u can get some cracking deals on rim bike bikes and wheels !

I was watching a GCN vid where they rode a descent with rim brakes and disc brakes - wet and dry - the surprising conclusion was that disc brakes were only very marginally better in the wet - but what they guy said was that the feel of hydro discs was much easier to use - its a different feel - which you either like or not.

lakesluddite

If I were to get a new 'best bike' (I'm not by the way), then it would be hydro discs all the way. I think these days the weight penalty is coming down (at least if you're prepared to pay for it) with some carbon/disc bikes coming in at not much more than rim braked bikes of similar spec. My winter/wet weather bike is hydro disc, but is heavy - mainly because it's a steel frame with middling group-set and components, but the feel and reliability of the brakes just inspires more confidence than my rim braked 'bestie'.
If I could get a featherweight carbon frame, deep section carbon rims and lightweight finishing kit/groupset, I would certainly have discs. And as you imply, it does seem that the industry is going in this direction - you just need to look at the ads in cycling mags for new bikes, I bet 70% of them will be disc equipped.

ricky_h-2

Here's a thought, go for a high end hydraulic disc equipped bike as your sole bike and save £££'s. You can still brake powerfully with discs on carbon hoops in poor weather, can get 28mm tyres on and yes your chainset will suffer over winter but replacing it for the summer months is way cheaper than two bikes.
That way you get to enjoy your ride year round and save money

CitizenLee

flight147z wrote:

To me the major disadvantage of disc brakes is that unless you have deep rims (>50mm) they look terrible

For some reason they look ok on aero bikes, but I think they spoil the look of a lot of bikes they are fitted to

That's not really a disadvantage, just a subjective opinion.


Personally I wouldn't buy/own any bike without disc brakes, but then I come from a MTB background where rim brakes thankfully died decades ago. As for maintenance, I haven't bled my brakes in over 2 years, and they still work like new (pads have been changed a few times obviously).

Whatever you do, definitely avoid Avid BB5s and BB7s unless you enjoy pointless fettling.

thegreatdivide

Always good to see the 'I bought a disc bike' justification squad out in force. Keep fighting the good fight boys.

CitizenLee

thegreatdivide wrote:

Always good to see the 'I bought a disc bike' justification squad out in force. Keep fighting the good fight boys.

You mean the people who have used disc equipped brakes and are trying to be helpful/provide their opinion as per the whole point of this thread? Yeah, what a bunch of dicks! :roll:

Take the stick out of your ar$e

craigus89

thegreatdivide wrote:

Always good to see the 'I bought a disc bike' justification squad out in force. Keep fighting the good fight boys.

You are obviously not a fan, could you explain why? It would be more helpful than trying to derail this into a slaging match. I'm not trying to be a dick btw.

vegas76

Personally I find that I ride holding the handles, rather than the dropped bars. Getting the purchase to brake hard when doing this is much harder. IMO rim brakes work well if you are dropped but much less so when holding the gear shifter housings.

turbo_hamster

"I bought a disc bike" after consulting a few club-mates. There was no concensus, but a lot of interesting and useful comments. I don't want to repeat any of the points made above. However, some unexpected (but not insurmountable) outcomes have been:
1. thru-axles (instead of the quick-release on my other bikes) means I can't immediately use the new bike with my old Tacx Flow Turbo trainer. For £29, one can buy a replacement thru-axle that fits the turbo trainer. (I still can't use it, forgot that my new bike also has 650c wheels instead of standard size).
2. thru-axles means I can't put my new bike on my beam-type workshop stand, which holds the bike on the bottom bracket, fixed with a QR to either drop-out.
3. disc means the new bike does not sit comfortably on the type of floor stand I use for the other bikes, as there is not enough space between seat-stay and disc.

Now that I have a collection of bikes that range from 9 to 11 cogs on the cassette, swapping rear wheels was out of the question anyway, but it is a pity I can't swap front wheels.

ayjaycee

I really don't want to encourage any further arguments on this and, owning both, I am fully aware of the pros and cons of hydraulic disc and rim brakes and believe that both have their place. However, I would really be interested in opinions of hydraulic - v - mechanical disc systems. I ask as I thought that I had made mind on rim brakes for my forthcoming project to put together a winter bike based upon a latest generation Kinesis 4S frameset but am now considering mechanical disc (although rim brakes are winning pro tem). My thinking is that mechanical discs would only need a new set of wheels plus, of course, the calipers (as opposed to a new pair of shifters as well). Obvious candidates are either Shimano CX77 or TRP Spyre but TRP Hy/RD might also need to come into the equation.

Has anybody used any or all of these and in a position to provide opinions based upon real world experience?

shirley_basso

The problem is they just look so damn gopping.

I am lucky that I am fairly lightweight and now mostly ride on the flat so don't really have the need for discs.

I was considering a disc braked fork for my commuter to run front disc and rim braked rear, but then left London, and also realised that even in the wet, braking quality was fine enough.

Also people who have expensive rim braked bikes/wheels then need to sort out swapping them all over which is expensive if the rims can't be rebuilt.

Otherwise, they do make a lot of sense for all the reasons mentioned previously, but it's been a long time since anyone I know made a cycling related purchase which made sense.

whyamihere

ayjaycee wrote:

I really don't want to encourage any further arguments on this and, owning both, I am fully aware of the pros and cons of hydraulic disc and rim brakes and believe that both have their place. However, I would really be interested in opinions of hydraulic - v - mechanical disc systems. I ask as I thought that I had made mind on rim brakes for my forthcoming project to put together a winter bike based upon a latest generation Kinesis 4S frameset but am now considering mechanical disc (although rim brakes are winning pro tem). My thinking is that mechanical discs would only need a new set of wheels plus, of course, the calipers (as opposed to a new pair of shifters as well). Obvious candidates are either Shimano CX77 or TRP Spyre but TRP Hy/RD might also need to come into the equation.

Has anybody used any or all of these and in a position to provide opinions based upon real world experience?

I've got Spyres, JuinTech R1s (hydraulic calipers but cable activated), Sram Apex and Sram Force. The JuinTechs and both Sram sets are in current usage, the Spyres are sat in the shed. The big advantage of the hydro discs is the feel of them, especially if you have sub-optimal cable routing options. The hydro discs feel nicer, and have less force needed to get them moving. They're also a bit less picky about maintenance. With the hydro sets, you fit them and then ignore them until the pads are worn out. The Spyres require adjustment to make sure the pads are hitting the rotor correctly and to accommodate pad wear. The JuinTechs are in the middle. I did have traditional single sided mechanical discs years ago, and would recommend pretending that they don't exist - Most people who've used a variety will wish they didn't ever exist.

Edit: As you can probably tell from the number of sets I have, I'm a big fan of discs. The only bike I own which still uses rim brakes is permanently set up on the turbo. The summer bike with Force discs is just a bit above 7kg with some fairly heavy other bits on, so it's not impossible to make a light bike.

veronese68

ayjaycee wrote:

However, I would really be interested in opinions of hydraulic - v - mechanical disc systems.

Mechanical require regular, although minor, adjustments to keep them working. But for a winter bike I'd rather have mechanical discs than rim brakes.

kingrollo

ayjaycee wrote:

I really don't want to encourage any further arguments on this and, owning both, I am fully aware of the pros and cons of hydraulic disc and rim brakes and believe that both have their place. However, I would really be interested in opinions of hydraulic - v - mechanical disc systems. I ask as I thought that I had made mind on rim brakes for my forthcoming project to put together a winter bike based upon a latest generation Kinesis 4S frameset but am now considering mechanical disc (although rim brakes are winning pro tem). My thinking is that mechanical discs would only need a new set of wheels plus, of course, the calipers (as opposed to a new pair of shifters as well). Obvious candidates are either Shimano CX77 or TRP Spyre but TRP Hy/RD might also need to come into the equation.

Has anybody used any or all of these and in a position to provide opinions based upon real world experience?

I have cable discs on my MTB - pain in the neck - would prefer rim brakes, you have to keep adjusting them - if you don't then the braking power has no advantage over rim brakes.

Something like ultegra rim brakes is superior to cable discs - even in the wet IMO.

ayjaycee

Rollo, It's Ultegra (and modern 105) rim brakes that play a large part in persuading me personally that I'm OK without discs on my road bikes. For my Kinesis, I was thinking of Shimano R650s which I have seen advertised as either the Ultegra or 105 version of long drop calipers (depending on where you look!). I've got both in short / 47mm on other bikes and they are great. The Kinesis needs long drops and I also need to get full mudguards under them.

keef66

I'm relatively light and most of my riding is on quiet, gently undulating roads where I don't do much braking at all. I ride year round, but still have life left in some 11 year old rims, so I'm clearly not wearing out wheels prematurely. So rim brakes are perfectly adequate for me. And I'm not about to get rid of either rim braked bike just to be on trend.

However, if I was in the position of buying or building up a new bike today I would probably go for hydro discs, mainly for the bigger tyre clearances they allow.

If I was a heavier rider, lived in a properly hilly area, doing loaded touring, or commuting daily in all weathers with lots of stops and sharing the road with unpredictable traffic / cyclists / peds I'd definitely have hydro discs for the better / quicker braking in the wet.

flight147z

CitizenLee wrote:

flight147z wrote:

To me the major disadvantage of disc brakes is that unless you have deep rims (>50mm) they look terrible

For some reason they look ok on aero bikes, but I think they spoil the look of a lot of bikes they are fitted to

That's not really a disadvantage, just a subjective opinion.

Do you think disc brakes look good on road bikes?

CitizenLee

flight147z wrote:

CitizenLee wrote:

flight147z wrote:

To me the major disadvantage of disc brakes is that unless you have deep rims (>50mm) they look terrible

For some reason they look ok on aero bikes, but I think they spoil the look of a lot of bikes they are fitted to

That's not really a disadvantage, just a subjective opinion.

Do you think disc brakes look good on road bikes?

In all honesty bicycle brake aesthetics have never been a major concern for me.

sloppyschleckonds

kingrollo wrote:

I was watching a GCN vid where they rode a descent with rim brakes and disc brakes - wet and dry - the surprising conclusion was that disc brakes were only very marginally better in the wet

So those posters who've said braking in the wet is much improved must be mistaken?

shirley_basso

CitizenLee wrote:

flight147z wrote:

CitizenLee wrote:

flight147z wrote:

To me the major disadvantage of disc brakes is that unless you have deep rims (>50mm) they look terrible

For some reason they look ok on aero bikes, but I think they spoil the look of a lot of bikes they are fitted to

That's not really a disadvantage, just a subjective opinion.

Do you think disc brakes look good on road bikes?

In all honesty bicycle brake aesthetics have never been a major concern for me.

Lifetime ban

BikerGroveish

The biggest pro is that they reduce rim wear. The cons of using them on a road bike are so numerous it makes it a bad idea. People bang on about how much more effective they are than rim brakes in poor conditions but if you get your rim brake pad compound right for the given conditions this really isn’t necessarily the case. If you’re using thru axles rather than Q.R. skewers it makes any wheel off repairs more of a pain than it needs to be ( especially if your out in the dark ). There are lots of other disadvantages as well. This is only really applicable to a disc brake set up on a road bike. Disc brakes are a great idea on a MTB or cross bike.