Disc Brake Bikes - What to Consider Before Purchasing

pprendeville

Anyone got advice on buying a disc brake bike? Just looking to find out if there are different types and what is the most common one.

Are they easy to service?

Should I go mechanical or hydraulic?

Do I need to consider tire clearance.

One big requirement is the need to be able to fit full length mudguards.

CramCycle

https://www.boards.ie/discussion/2058333587/disc-brake-bikes-what-to-consider-before-purchasing

Disc brakes will no affect tire clearance, that is a frame issue but typically disc brakes will have far higher clearance than rim brakes as the rim brake callipers might be restrictive..

Go hydraulic, I have both, there is a difference and IMO, properly set up rim brakes are better than mechanical disc brakes but that is just an opinion based on real world experience.

Mud guards have nothing to do with disc brakes, just check does the frame have eyelets, if not you can use raceblades but it is notthing to do with disc brakes.

Servicing is easy and no real difference in terms of ability between types, just different tools.

fat bloke

Consider rim brakes? :)

ARX

Not related to disc brakes, but if you'll want to fly with your bike in a hard case, bear in mind that integrated cable/hose routing (through the head tube) can make it difficult or impossible to get your bike into a standard hard case.

Alanbt

Don’t. That’s my advice!

Fighting Tao

I’d choose hydraulic over mechanical or rim any day. Also, I’d keep away from most SRAM disc brakes due to D.O.T. fluid. It’s highly corrosive, and very dangerous if it gets on skin.

beggars_bush

rim for the win

and I own disc and rim

pprendeville

https://www.boards.ie/discussion/comment/121685723#Comment_121685723

Ha. I’m moving away from them. I forgot to mention I’m told disc brakes have much better stopping power in the wet? Myth or fact?

abmoto

I have 2 bikes, one with Mechanical Disc brakes and the other with Hydraulic Discs. Both have their advantages.

As for your question about if you can fit full-length mudguards, you can on both, as long as the frame allows for it.

pprendeville

Do the mechanical disc brakes rub or does it all depend on how good you are at adjusting them? The only experience I had with them was on my daughters Wiggins bike and they broke my heart as they made the bike so difficult to cycle due to the disc rubbing. No matter how I adjusted them I couldn’t get them right, granted they were not high end. I’d be expecting something more sophisticated on a decent road bike. Am looking at Trek Emondas.

Macy0161

I've bikes with all three, I'd rate braking performance order as Hydraulic Disc, Mechanical Disc, Rim. It's close between the latter two (with aluminium surface) in the dry, but in the wet the mechanical disc win imho. I don't have any more rub issues with mechanical v hydraulic.

In 2024 I wouldn't be buying a bike with mechanical disc though.

eeeee

https://www.boards.ie/discussion/comment/121687042#Comment_121687042

Fact. Have both. Way better breaking performance in wet on the hydro discs. No difference wet or dry. You'll run out of tyre before brake performance.

I'll never go back to rim now bar for tt's.

ted1

https://www.boards.ie/discussion/comment/121686771#Comment_121686771

Rim suck in the rain. And your wheels life is shorter.

id a bad fall due to rim wear on the wheel. Never again will I use rim brakes

dahat

https://www.boards.ie/discussion/comment/121693219#Comment_121693219

Wheel life span is a big plus for disc, once service correctly etc your wheels should last alot longer than rims. I’ve a set of Mavics now 3 years old that roll like new with a yearly service , no fear of brake track wearing out.

Paddigol

On pure stopping power - hydro disc probably wins every time. But the debate is usually skewed by people with a strong preference for one or the other focusing on metrics that suit their argument. How often do you need immediate stopping power, and how likely are you to be able to achieve that without coming down anyway?

I've both - Campy Chorus rim with SwissStop yellow king pads, Campy Veloce rim with SwissStop reacepro bxp pads, Sram Rival Hydro Disc (CX) and Shimano Deore Hydro Disc (MTB).

I prefer rim. Good rim brakes. With top quality brake pads. I've never - not a single time, in that set up, on that bike, had an incident where hydro disc brakes would have made any difference. I don't brake heavily, I've never had wheel rim wear issues. I clean and maintain my brakes regularly.

If I have to haul on the brakes, I've either misjudged the road, the traffic and in any event my wheels are simply going to lock up.

I've yet to get my head around maintaining and adjusting hydro disc brakes.

They are fantastic for off road stuff - CX/ MTB, largely for the better modulation, lack of 'crap' picked up and ease of cleaning. Can't imagine ever going back to non-disc on those terrains.

I just love the aesthetics and simplicity of a good rim brake set up on the road. They are more than adequate - the top pro teams were running them up to a couple of years ago, and probably still would be were it not for pressure from component sponsors. Pros were tearing down Alpine descents in all sorts of weather in them. As a technology, they are 100% absolutely fine.

Being honest, I wouldn't really care, but I'm just bitter that its becoming harder and harder to source compatible bikes/ frames and even rim brakes themselves.

Wishbone Ash

 "I've never had wheel rim wear issues"

@ Paddigol

I'm curious about how you managed that. Do you do very little mileage or only go out in dry weather? The main reason I have to replace wheels is due to rim wear. I've been on several group rides where another rider's rim has blown - the most recent being just last week.

Drake66

https://www.boards.ie/discussion/comment/121697293#Comment_121697293

I had my rear campy zonda do this before Christmas. Even though the braking surface didn't look too bad and the wheel was only 3 years old. Now I'm worried that the front wheel will do the same so I'm probably going to replace it for peace of mind.

Paddigol

https://www.boards.ie/discussion/comment/121697293#Comment_121697293

I'm fastidious about cleaning my bike - wheels, rims and brake blocks/ pads included - during the winter especially. I'm pretty light on the brakes too. Winter/ commuter bike has been Zondas for about 8 years (first wheelset written off in a crash with a van about 4 years ago). Mileage would be mixed - not crazy high but not low either. I've carbon rims on the other bike - will see how they fare over time.

I've nothing to base this on, but my suspicion re blowouts is poor maintenance or (and/ or) heavy brake use?

Or maybe its just been pure luck on my part.

ted1

https://www.boards.ie/discussion/comment/121698713#Comment_121698713

How light are you ? Maybe you don’t carry much momentum or go down steep hills and don’t need as good brakes

Large bottle small glass

https://www.boards.ie/discussion/comment/121698713#Comment_121698713

I've got 40k km out of a set of rims before having to rebuild.

If you ride solo are light on brakes and keep rims clean they will last a long time.

Ride in wet weather a lot with mudguards and don't clean and a blowout is in your future.

I wore the rims of a cx bike gravel in under 3k km.

ARX

https://www.boards.ie/discussion/comment/121699127#Comment_121699127

Do mudguards accelerate rim wear? I've never heard that (I'm not contradicting you, I just want to learn).

Paddigol

https://www.boards.ie/discussion/comment/121698965#Comment_121698965

Fair point. I've been on the lighter end of the scale for most of my years... sliding up the scales now though! Love the hills, but I'm a fluid enough descender.

Anyway, its each to their own. If disc brakes make someone more confident on a bike, that can only be a good thing.

Large bottle small glass

https://www.boards.ie/discussion/comment/121699225#Comment_121699225

Typically mudguards catch moisture and muck which then falls back onto tyre/wheel.

Wheels with proper full mudguards are normally filthy if being used on wet roads/wet weather.

On a long spin that's a lot of braking with filthy rim/pads.

fat bloke

I dunno what yiz are all doing going around braking everywhere! :)

When I go for my spin I brake half way around for the coffee stop and then I pull the brakes again pulling in home. Like lads above, I've never worn out a set of rims. I've a set of mavic slr's that are 12 years old now, ok they haven't had 12 years non-stop use, but they've seen plenty of miles and the rims are fine.

Also, on the braking performance. Yes discs are better in the wet, but that's not to say rims are awful. They world has decades of cycling history on rim brakes and we didn't all go around crashing into walls because of poor braking ability.

I'm kind of intrigued myself, having bought a disc braked winter trainer for myself and used it exclusively all winter, to see how I view the change over to a rim braked summer/race bike in a few months time. But, just as changing to disc brakes wasn't transformative for me, I doubt changing back to rims will be catastrophic either.

What to consider? - Well it all depends on the bike. A top shelf rim bike will beat the pants off a mid-tier disc bike and vice versa. Rim bikes still have the advantage though in terms of purchase cost - second hand at least you can buy a bona fide pro level superbike in rim guise for the cost of a mid to lower end disc braked bike.

ARX

https://www.boards.ie/discussion/comment/121699509#Comment_121699509

Good point, my bike has mudguards and yes, the wheels get manky. I do clean them before every spin, maybe I need to start cleaning them at the coffee stop 🤔

07Lapierre

Regardless of how light you are or how lightly you apply the brakes, rims will wear out eventually. In my view, the wear indicators are very conservative and if you were to replace your wheels once the indicators had disappeared, i would be replacing wheel twice as often as i currently do!

I have a set of Zondas and and the rim on the rear wheel is concave in shape (wear indicators wore away over a year ago) I've a new set on order as i don't want to wait until the rim actually fails.

07Lapierre

Regarding Disc Brakes..

Winter bike: Disc Brakes - better in every way except how they look!

Summer Bike: Rim brake - but if buying a top end summer bike, best of luck finding a rim brake version!

Wishbone Ash

https://www.boards.ie/discussion/comment/121699576#Comment_121699576

So you don't slow down/stop when approaching red lights, junctions, sharp bends, steep technical descents, heavy traffic, school wardens etc.?

Regarding the other comments about being fastidious with cleaning preventing rim wear, that doesn't make any sense to me as the bike will get very dirty within minutes in some conditions. No matter how fussy you are, if you do a 12 hour ride on a sh!tty day, the bike is going to be dirty for 99% of the ride. I seriously doubt that anyone cleans on the go.

MangleBadger

I presume it is due to only getting into cycling recently but I must be the only person who prefers the look of a disc brake bike. I don't like rim brake calipers, and I don't like exposed cables.

Paddigol

https://www.boards.ie/discussion/comment/121703238#Comment_121703238

As I said, I don't really care about the rim v disc debate. I'd just like to be able to buy rim versions rather than be forced down the disc route. I've given up hoping on that front though. Someone mentioned wheel degeneration (of course all parts wear out eventually, and by their nature rim brakes will wear a wheel out faster, but then everything is relative...) and I simply noted that it had never been an issue for me. Someone then wondered why, and I simply suggested that maybe it was to do with keeping my rims well cleaned and maintained. Whatever about the rim v disc debate, I've even less interest in debating what effect a well maintained and cleaned wheelset will have on lifespan 😄

I think we're in danger of veering off topic at this stage, so apologies to the OP!

ednwireland

worst thing on shimano road bikes. is the 2mm Allen key on theplastic bleed bolt in the lever. what a joke.

lucky if it lasts one go

pprendeville

https://www.boards.ie/discussion/comment/121686711#Comment_121686711

Not too worried as it won’t be going anywhere. Thanks though.

pprendeville

https://www.boards.ie/discussion/comment/121693828#Comment_121693828

That’s excellent advice. I’ve never actually though of changing to Swiss Style brake pads.

i’ve never fallen thank God but the stopping power on my rear brakes is awful in the wet. I’ve stuck with the Shimano pads so maybe that’s my issue.

Large bottle small glass

https://www.boards.ie/discussion/comment/121704523#Comment_121704523

Good pads and clean rims with well adjusted calipers give very good braking.

Irrespective of technology most cyclist would benefit greatly from

1. Improving braking technique

2. Learning to descend better

3. Learn how to anticipate when you'll need to brake.

If an average cyclist did all that they would gain more than any gear upgrade after giving someone 23 digits

ednwireland

I always found cleaning aluminium slurry off my bike with rim brakes. a pain to clean off.

pprendeville

One last Q aimed at the rim brakers. If you accidentally get something like chain lube (GT-85 for example) on the rim, what do you use to wash it off. I usually give the chain a shot of this post-washing and then wet or dry lube.

and sometimes the PTFE spray (GT-85) drips onto the wheel rim which probably doesn’t help braking.

just seeing CRC no longer ship to Ireland. Anywhere in Ireland sell Swiss Stop pads?

ARX

https://www.boards.ie/discussion/comment/121704669#Comment_121704669

Brake cleaner (comes in an aerosol, spray it on a rag and wipe the rims, do it outdoors as it's highly volatile). You can get it at any motor factor or online from Germany. I don't know about Swiss Stop pads in Ireland, I get mine from Germany. I find that they don't fit well into Shimano pad holders so I just got the full set, when the pads are worn you can get replacement pads.

SwissStop Full Flash Pro Original Black Brake Shoes Racingbike Brake Pads | Bike-Discount

SwissStop Flash Pro Original Black Brake Pads Road Brake Pads | Bike-Discount

They come in blue and black, apparently the black is easier on the rims but the blue is better in the wet. I don't notice any difference so I'll go back to black when the blues are worn out.

pprendeville

https://www.boards.ie/discussion/comment/121704726#Comment_121704726

Cheers. The Kool Kool Stop Dura 2s seem to get good reviews also. Both links avove are for aluminium rims, correct?

Edit: I see they’re listed for aluminium so all good there.

07Lapierre

https://www.boards.ie/discussion/comment/121704669#Comment_121704669

I pick up a set of Swiss stop pads in Cyclesuperstore recently.

MojoMaker

Quality brake pads for sure a brilliant upgrade from the stock Shimano pads.

Don't last anywhere near as long though (as you'd expect).

DeepBlue

Should I go mechanical or hydraulic?

On long twisty descents where you have to break to control speed coming into blind bends and the like then hydraulic disc brakes are great. When your colleagues with rim brakes get to the bottom they can well be massaging their wrists and arms to relieve the effort of holding the brakes for so long while you are fine as you only needed to lightly apply pressure with a couple of fingers.

Paddigol

https://www.boards.ie/discussion/comment/121706553#Comment_121706553

Again, not my experience with properly set up, mid-to-high end rim brakes. Take my Campy Chorus on carbon rims - they're set up so minimal clearance between pads and rims... and pads are sufficiently good that relatively little force is needed to achieve braking power. As with everything, you can have great kit but if it's not set up properly you're not going to get the benefit of it. The hydro disc brakes on my CX bike need recalibration as they're way too spongy now after a couple of seasons' use.

Nothing worse than the feeling of crap rim brakes in the wet on a descent, granted. Heart-in-mouth stuff!

Large bottle small glass

https://www.boards.ie/discussion/comment/121706553#Comment_121706553

I'd be more concerned with the weak ass wrists than brake type if it was me

Wishbone Ash

https://www.boards.ie/discussion/comment/121706553#Comment_121706553

....and red hot wheels from excessive braking.

07Lapierre

If your wrists /hands are sore from braking your descending too slow. ;)

DeepBlue

https://www.boards.ie/discussion/comment/121707414#Comment_121707414

Not everyone does 30k kms a year and is suitably conditioned. There is a definite difference in fatigue in wrists and arms when switching from rim brake to hydraulic.

ednwireland

oh remember burning my hands fixing a puncture at the Bottom of a greek mountain bike descent. backing rim brake mtb days

Peterx

If getting discs - If at all possible go for hydraulic disc. Mechanical disc can very often be difficult to keep from rubbing. I had a couple of bikes with mechanical discs and it felt like I was nearly constantly having to fiddle with them.

I have had a few CX bikes - both SRAM and Shimano hydraulic disc and the mineral oil shimano set up is much simpler and nicer to work on. 2 bikes with SRAM rival hydraulic fitted have had leaking nasty DOT5.1 from a brake lever.

07Lapierre

Chill out…it was a joke! Geez!

saccades

It's like stepping into a thread from +20 years ago on a MTB forum...

The only mechanical discs that are consistently rated are BB7s, but you can get hydros (which self adjust clearance) at the same cost so why wouldn't you?

CramCycle

https://www.boards.ie/discussion/comment/121715204#Comment_121715204

I have BB7s and I wouldn't rate them tremendously, hydraulic brakes all the way.