Road Bikes Disc Brakes vs Rim Brakes!

[IceCreamMan]

I was thinking about this during my deliberations as well. Your brakes can only work and slow you down as well as the traction/ friction between the tyres and the road surface. So if the road is damp/ wet, how would a higher brake force impacting on a wheel (discs) stop the wheel more quickly and not lose traction, as a good set of Swisstop pads will also easily be able to lock a rim brake? 

 

Until some sort of ABS is invented for bicycles i am happy with rim brakes. I already lock wheels with rim brakes on both front and back (roadbike). 

 

In the wet disks could be vastly superior though.

 

Edit: on thinking bout it disks are more consistent and in the hands of an expert braker (which i am not) would probably result in shorter stopping distances. I think GCN had a video on it on youtube and the differences were marginal but i guess like patch's story 30 cm could be a life saver. 

Edited November 9, 2020 by IceCreamMan

[IceCreamMan]

[Jewbacca]

Everyone uses weight as a metric, but in reality very few of you saying this actually ride at a level where that weight saving actually makes a difference.

 

Oli Munnik got a top 10 at Argus on a Santa Cruz Stigmata. 

 

So, while the 'this vs that' debate rages, train properly, eat properly and once you are beating Pinner consistently, maybe the science starts coming into effect.

 

I'm sorry, but in reality, we are all just hackers who spend too much on our bikes. 

 

So whatever you buy, make sure you think it's rad.

 

The rest doesn't actually matter

[100Tours]

• disc brake set-ups still have 500 - 800 gr weight disadvantage, depending on group set and frame. Yes, disc weights might be coming down slowly but are not yet compatible with rims at the present time.
• The rim brake installation instructions listed the bike frame and brake manufacturers manuals constituted of two pages; i.e. not really required but mentioned it for comparison sake. The disc brake equivalent was more than 20 pages! This included installation and mounting, aligning, filling the oil, bleeding (with some sort of kit and all kinds of special tools required), maintenance and so on. Rim brakes can be installed, change cables, replace pads and adjust within five minutes per brake. I can only guess how long this would take with discs.    who reads the manual.. this is a bit like saying Formula 1 cars take too much engineering. Personally I've been very impressed with how easy it is to bleed the Shimano discs.
• Various considerations to consider when changing a flat/ wheel in a hurry.  I saw the various acts of drama that a number of riders and their mechanics had to go through when replacing a wheel during the recent GT's and classics races. Its great when a spare bike is ready for you when racing but not for us normal riders who have to struggle next to the side of the road. Quick releases rule here.   only assuming you have a mechanic leaning over your shoulder. ask a MTBer - thru axles ride better and they change out just about the same. The problem for the pro team is that the mechanic needs an extra hand to hold the thru axle while he is fitting the wheel. The rest of us will just put it on the floor or hand it to a buddy for a moment.
• This includes the risks of bending the rotor disc when struggling to get the wheel out and the closing of the calipers when a wheel is removed for travelling.  or snapping the end off your QR lever for that matter. this just does not happen often.
• The incessantly annoying squeal of the brakes when being applied.  you've spilt chain lube on your pads maybe? 
• Lastly, the need to change ones existing wheels when changing to discs. I was not prepared to sell five sets to now buy new ones. 

The main 'for' reason for discs is stated to be the improved braking performance. Various comparison tests by a number of publications and bicycle sites have been performed and most agree that there is a slight improvement for carbon wheels in the rain, not so much in the dry. But dare I say that for 99% of us this increased performance is not required, unless you go 2-3 times a year to Europe and race down the various mountain passes in the rain. Even so, the four major WT teams Ineos, Jumbo Visma, UAE and Sunweb are all still choosing to ride with rim brakes. The performance of the newer direct mounts is not that far of that of discs.

Currently the score for the last six Grand Tours is : Rims Brakes 6 - Disc Brakes 0 ! ok, so 2-0 for the weight and the need to replace all existing wheels you may own (assuming they're not already out of date on the 11s/12s cluster issue).

 

Yes, there is a certain visual  'cool' factor with disc brakes but is that enough to fall into the bike/ group set manufacturers marketing trap that something that has worked for decades is suddenly not good enough anymore?

 

I like my rim brake bikes, but I would say that I rode them for years with badly adjusted brakes. I have had pads cut into my tyres, or sit offset, or I've just had the toe in and alignment so far out that they operated at maybe 50% of what they should. When properly adjusted on Alu rims they are on a par to cable discs (carbon rims not so much).

 

Hydraulic discs are an absolute pleasure to ride. Easy on the hands, and confidence inspiring in the corners. But they are perhaps more at home on gravel bikes still. If I was going climbing in the alps I'd swop out the carbon hoops before I switched to discs. A mate of mine has a story he likes to tell about brake fade on the A'Ngliru..

Edited November 9, 2020 by 100Tours

[Andreas_187]

It was an easy decision for me, I had a 2011 Cervelo R3 SL mechanical SRAM Red rim brake weighing 6.3kg.

'Upgrading' to a R65,000 Spez Tarmac SL6 DISC Ultegra mechanical was 8.3kg.

Edited November 9, 2020 by Andreas_187

[Kranswurm]

I still have not warmed up to this disc brake on a road bike thing, but I have accepted that my next road bike will be a disc bike.

 

Not because I want discs, but because that is all you can buy.

 

There aren't many rim brake bikes available in SA, unless you want to go entry level.

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[Ozzie NL]

I've heard it said that the pro's are exactly the wrong users for disc brakes on road bikes, unless it's raining

 

all the drawbacks that you'll find for discs are directly applicable to mountain bikes too, apart from the rapid wheels changes in a road race, so not really all. I'm not sure how many mtbers out there wish for rim brakes... perhaps do a poll?

 

personally, i think i bike looks nicer with discs, esp those with hidden cables. YMMV, and as long as your mileage makes you smile, it doesn't matter to me how you stop.

Not quite....mud clogs up rim brakes when dirt jockeying...not likely to encounter that scenario on tar

[Jonathan S]

I would say disk brakes on MTB and gravel bike as the additional NM stopping power pairs better with larger tyres that also have more grip. Off raod bikes are also more likely to go through wet patches and mud. For a road race bike with 25mm to 28mm tyres, rim brakes just make more sense to me at the moment.

[Thomo]

Probably could have killed two birds with one stone and added "road tubeless" to the conversation...

[sirmoun10goat]

I would say disk brakes on MTB and gravel bike as the additional NM stopping power pairs better with larger tyres that also have more grip. Off raod bikes are also more likely to go through wet patches and mud. For a road race bike with 25mm to 28mm tyres, rim brakes just make more sense to me at the moment.

But there is more grip on tar than on dirt/grave, so when you refer to additional grip, then disks make more sense on road bikes.

Edited November 10, 2020 by sirmoun10goat

[TNT1]

the differences were marginal but i guess like patch's story 30 cm could be a life saver. 

Except no-one dieded in his story did they? I didn't read it as that or that even anyone got hurt? Maybe I misread.

 

All this anecdotal evidence doesn't mean much anyway. There would have been many other factors at play to account for the perceived stopping distances in that story.

[Patchelicious]

Except no-one dieded in his story did they? I didn't read it as that or that even anyone got hurt? Maybe I misread.

 

All this anecdotal evidence doesn't mean much anyway. There would have been many other factors at play to account for the perceived stopping distances in that story.

The fact that nobody got hurt was the entire point.

 

You can discard my story if that pleases you, I have zero desire in convincing you or anybody else to buy a disc bike.

[TNT1]

The fact that nobody got hurt was the entire point.

 

You can discard my story if that pleases you, I have zero desire in convincing you or anybody else to buy a disc bike.

In the context of the brake vs brake thread that this is, both fared equally well in your story. Even steven. is what I took away from it.

[Jewbacca]

OP, if you aren't racing at the tippy top of the field with 4% body fat and years of conditioning, all of the options you mentioned are just as good as each other.

 

Honestly. 

 

Marginal gains only come into effect when there are no more gains to be had. 

 

Any new, light bike with a good groupo will far out perform you, whatever brake type you buy.

 

This isn't an 'us vs them' scenario guys, they are bikes. The Geo, fit, comfort etc will outweigh any 500g weight advantage or brake type for a weekend bodger.

 

FYI I regard 99.99% of all roadies in SA 'weekend bodgers'. 

 

So in reality, your metrics for 'performance potential' should look beyond weight, and venture into fit, trail, geo and other basic, but hugely influential aspects of bicycle design. 

 

Also, if the bike stirs your nether regions, buy it. It will be the best bike. Bettererer than the one that weighs less but doesn't make your panties wet

[The Ouzo]

buy what makes you happy

for me, personally, the last time I had any confidence with rim brakes was in the 90's, having discs now has brought back that braking confidence. And I dont even have a decent hydraulic setup with the giant using giants hybrid hydraulic system.

[Jehosefat]

1. Aligning calipers on a rime brake.  Easy.  On a disc brake.....LIVING HELL!  The tolerances are MUCH smaller on road bikes and it takes time to get it perfect.  Replacing your brake pads will $$**($ up the alignment all over again and the re-centering starts all over again.  Or you can give it to your bike shop and they will smile all the way to the bank.
2. Replacing cables on a rim brake....easy.  On a disc brake (bleeding) .....time consuming and if you don't do it yourself, expensive.  Each time your brakes does not feel 100% the bike shop will tell you "It needs a bleed".  Do you bleed it a lot?  No.  But replacing brake pads is a schlep as the calipers does NOT retract as the marketing BS tells you it does.  It takes a couple of rides to get the brakes not to drag anymore. 

 

Can't say it's ever taken me more than 10 minutes to align a caliper on any of the 4 bikes I have that have disc brakes (my 2 mtbs, my gf's mtb and my road bike). Either take an old credit card and pop a bit of it between the disc and the pads on both sides then tighten the bolts on the caliper or squeeze the lever and slowly and evenly tighten both bolts holding the caliper. 90% of the time it works every time 

 

Yeah, when you replace pads you need to open the bleed port at the lever and gently squeeze the pistons back into the caliper using either a dedicated tool like the parktool one or just a plastic tyre lever. Can get a bit messy if you don't have a bleed funnel. I've never had an issue of new pads rubbing after following his approach.

 

But again, each to his own. I like working on my bikes so the bit of extra time it takes with discs isn't an issue for me and I've not had to take a bike in to the shop to get the brakes sorted yet (all shimano: XT on the MTBs and Ultegra on the road).