Disc brakes or not

[spannermonkey]

Disc brakes should have
1-ABS
2-2 rotors & calipers on each wheel NOT just 1

Why? Disc brakes have been functioning perfectly well on MTB for years with one rotor and no ABS.

Cars stopped well without ABS for a long time to
A caliper & rotor on each side for better balance
AND
because I'm a smartass
The local mechanic I'm going to see shortly
Just when I say " disc brakes should have ABS "
Most importantly
Marketing
More " latest tech " to be sold

[P!N20]

Y'know, I was thinking this forum really needed another disc vs rim brakes thread...

[Comedian]

6 inches. That's how far I sit behind the guy ahead. Car's have really good brakes and if they sat 6 inches behind each other there would be lots more crashes. It's about reaction time. Unless people who buy bikes with discs have better reactions??

Cars weigh a shedload more, as in at least 10x more than a portly bloke on a bike, so it's more down to fundamental physics trying to slow that mass than reaction time. Your point is invalid.

Ummm.. reaction time? I can't even apply the brakes in 6 inches if someone jams them on in front of me? Are you serious?

[Comedian]

I'll bite, because you continue to spout incorrect information.

That's the guy who works for a bike shop that wants you to pay him to fix your brakes.

I've said plenty of times before, and will repeat again, 'cos you seem unable to comprehend, rim brakes need MORE maintenance!!!

Comparison of brake service, which I do on a daily basis....
Rim brake bike:
Check pad wear. If low, replace pads. If OK, pick bits of grit out of pads. File pad surface to remove glazing & other finer gritty bits. Check cables for fraying, rusting, excessive friction. If frayed or corroded, replace cables. If OK, lubricate cables. Check caliper pivots for excess friction/binding. Disassemble, clean and lubricate pivots as necessary. Check rims for wear. If bad, advise customer that new rim + rebuild, or new wheel is required. Adjust pad toe-in. Adlust contact height on rim. Adjust cables for proper contact stroke. If new cables, stretch and adjust (section relating to cables equally valid for mechanical discs).

Disc brake (esp. hydro) bike:
Check pad wear. If low, replace pads and push pistons back to reset clearance. If OK, scuff on sandpaper to remove surface glazing. Refit pads. Check rotor wear. If too thin, replace rotors. If good, leave alone. Check caliper alignment over rotor. Check brake pressure, bleed if spongy or if fluid expansion has reduced stroke..



Three lines for disc brake service vs six lines for rim brake. And you tell me disc brakes need more maintenance.

Let's see how long the queue is when disc brake bikes make up more than a tiny fraction of the number of bikes out there.

And you left off the bit where a hydro seal leaks... and it all gets messy.. or you had to change the rear calliper on a bike with internally routed hoses... You left off what happened if the master cylinder needs replacing in the shifter...

All the issues that will start arising when the bikes are more than 12 months old..

[silentC]

Perfect example of why asking the internet for opinions on things is a bad idea!

[djw47]

The technical editor for cycling tips ran a poll recently, and was very surprised that there were so many people who were like me - very happy with rim brakes.

If you go back to the 1800s, people were happy with horses as a means of transport... In a couple of decades, road cyclists will laugh at the notion of using rim brakes, but there will still be some people who have them, same as there are still some people who travel by horse.

[djw47]

That's the guy who works for a bike shop that wants you to pay him to fix your brakes.

I've said plenty of times before, and will repeat again, 'cos you seem unable to comprehend, rim brakes need MORE maintenance!!!

Comparison of brake service, which I do on a daily basis....
Rim brake bike:
Check pad wear. If low, replace pads. If OK, pick bits of grit out of pads. File pad surface to remove glazing & other finer gritty bits. Check cables for fraying, rusting, excessive friction. If frayed or corroded, replace cables. If OK, lubricate cables. Check caliper pivots for excess friction/binding. Disassemble, clean and lubricate pivots as necessary. Check rims for wear. If bad, advise customer that new rim + rebuild, or new wheel is required. Adjust pad toe-in. Adlust contact height on rim. Adjust cables for proper contact stroke. If new cables, stretch and adjust (section relating to cables equally valid for mechanical discs).

Disc brake (esp. hydro) bike:
Check pad wear. If low, replace pads and push pistons back to reset clearance. If OK, scuff on sandpaper to remove surface glazing. Refit pads. Check rotor wear. If too thin, replace rotors. If good, leave alone. Check caliper alignment over rotor. Check brake pressure, bleed if spongy or if fluid expansion has reduced stroke..



Three lines for disc brake service vs six lines for rim brake. And you tell me disc brakes need more maintenance.

Let's see how long the queue is when disc brake bikes make up more than a tiny fraction of the number of bikes out there.

And you left off the bit where a hydro seal leaks... and it all gets messy.. or you had to change the rear calliper on a bike with internally routed hoses... You left off what happened if the master cylinder needs replacing in the shifter...

All the issues that will start arising when the bikes are more than 12 months old..

Changing the hydro fluid for disc brakes is dead easy, no more difficult that re-cabling rim brakes.

A few things I will say that have frustrated me with disc brakes are:
1. the problems with getting dirty pads/dirty rotors resulting in squealing when you apply the brakes - I've cleaned the rotors with industrial disc cleaner, tried sanding/wire brushing the glaze off the pads, even tried burning them over a gas stove to remove all traces of dirt, but it always comes back which means that I've had to replace a few pads in the past few months, which leads me to...
2. the cost of replacement pads - significantly more than buying rim blocks, although you'd expect that price to drop as they become more common which will hopefully address...
3. the lack of a standard for brake pads - there are so many variations out there which probably contributes to problem 2

On the whole, I love my disc brakes, the performance increase is huge, particularly in the wet, and the ability to run carbon rims without fear of grinding them away every time I brake is a huge win. For those complaining about the aesthetics of traditional rim brakes, a lovely, clean, untarnished set of carbon rims is even better looking!

[Comedian]

The technical editor for cycling tips ran a poll recently, and was very surprised that there were so many people who were like me - very happy with rim brakes.

If you go back to the 1800s, people were happy with horses as a means of transport... In a couple of decades, road cyclists will laugh at the notion of using rim brakes, but there will still be some people who have them, same as there are still some people who travel by horse.

That's not valid. The only thing disc brake bikes do better is stop.. and even that isn't always going to be 100% true. They aren't as good as rim braked bikes for going, which is quite a big part of riding a bike.

[Comedian]

I've said plenty of times before, and will repeat again, 'cos you seem unable to comprehend, rim brakes need MORE maintenance!!!

Comparison of brake service, which I do on a daily basis....
Rim brake bike:
Check pad wear. If low, replace pads. If OK, pick bits of grit out of pads. File pad surface to remove glazing & other finer gritty bits. Check cables for fraying, rusting, excessive friction. If frayed or corroded, replace cables. If OK, lubricate cables. Check caliper pivots for excess friction/binding. Disassemble, clean and lubricate pivots as necessary. Check rims for wear. If bad, advise customer that new rim + rebuild, or new wheel is required. Adjust pad toe-in. Adlust contact height on rim. Adjust cables for proper contact stroke. If new cables, stretch and adjust (section relating to cables equally valid for mechanical discs).

Disc brake (esp. hydro) bike:
Check pad wear. If low, replace pads and push pistons back to reset clearance. If OK, scuff on sandpaper to remove surface glazing. Refit pads. Check rotor wear. If too thin, replace rotors. If good, leave alone. Check caliper alignment over rotor. Check brake pressure, bleed if spongy or if fluid expansion has reduced stroke..



Three lines for disc brake service vs six lines for rim brake. And you tell me disc brakes need more maintenance.

Let's see how long the queue is when disc brake bikes make up more than a tiny fraction of the number of bikes out there.

And you left off the bit where a hydro seal leaks... and it all gets messy.. or you had to change the rear calliper on a bike with internally routed hoses... You left off what happened if the master cylinder needs replacing in the shifter...

All the issues that will start arising when the bikes are more than 12 months old..

Changing the hydro fluid for disc brakes is dead easy, no more difficult that re-cabling rim brakes.

A few things I will say that have frustrated me with disc brakes are:
1. the problems with getting dirty pads/dirty rotors resulting in squealing when you apply the brakes - I've cleaned the rotors with industrial disc cleaner, tried sanding/wire brushing the glaze off the pads, even tried burning them over a gas stove to remove all traces of dirt, but it always comes back which means that I've had to replace a few pads in the past few months, which leads me to...
2. the cost of replacement pads - significantly more than buying rim blocks, although you'd expect that price to drop as they become more common which will hopefully address...
3. the lack of a standard for brake pads - there are so many variations out there which probably contributes to problem 2

On the whole, I love my disc brakes, the performance increase is huge, particularly in the wet, and the ability to run carbon rims without fear of grinding them away every time I brake is a huge win. For those complaining about the aesthetics of traditional rim brakes, a lovely, clean, untarnished set of carbon rims is even better looking!

Really? Would you mind popping over to help me with my MTB brakes? I'm told you might have to do this procedure a few times and it may or may not work. So I pay my LBS to do it. I think it's $140 a go. Or maybe that was $140 with pads...

http://www.bikeradar.com/au/gear/articl ... kes-21800/

[bychosis]

Perfect example of why asking the internet for opinions on things is a bad idea!

I think we've doen enoguh to scare the OP off. He's probably sitting rocking in the corner of a Toyota dealer about to sign up for a new landcruiser.

[bychosis]

The only thing disc brake bikes do better is stop..

Funny, I thought that was what they were supposed to do.

[silentC]

What Comedian is implying is that there is a weight and aero penalty which means that your disc-braked bike will be slower. The irony is that when the same argument is used in support of CF frames, it suddenly seems not to matter so much. But you come to expect such inconsistencies

[biker jk]

The technical editor for cycling tips ran a poll recently, and was very surprised that there were so many people who were like me - very happy with rim brakes.

If you go back to the 1800s, people were happy with horses as a means of transport... In a couple of decades, road cyclists will laugh at the notion of using rim brakes, but there will still be some people who have them, same as there are still some people who travel by horse.

That's not valid. The only thing disc brake bikes do better is stop.. and even that isn't always going to be 100% true. They aren't as good as rim braked bikes for going, which is quite a big part of riding a bike.

Apart from braking, the other things that disc brake bikes do better is allow the fitting of wider tyres (which are indeed faster at the same pressure), keeping the aerodynamics of front wheels by allowing wider rims to match a wider tyre (again, helps you go faster) and preserving your rims.

[silentC]

And also allow rim designs to ignore braking surfaces.

[madmacca]

If you go back to the 1800s, people were happy with horses as a means of transport... In a couple of decades, road cyclists will laugh at the notion of using rim brakes, but there will still be some people who have them, same as there are still some people who travel by horse.

That's not valid. The only thing disc brake bikes do better is stop.. and even that isn't always going to be 100% true. They aren't as good as rim braked bikes for going, which is quite a big part of riding a bike.

Apart from braking, the other things that disc brake bikes do better is allow the fitting of wider tyres (which are indeed faster at the same pressure), keeping the aerodynamics of front wheels by allowing wider rims to match a wider tyre (again, helps you go faster) and preserving your rims.

And this is why my next bike will be disc-braked, even though I prefer the rim brake aesthetic - I want it to be gravel-capable with clearance for 32mm tyres. I currently run 28mm Conti's and clearance is so tight that even with the brakes fully released, still need to deflate the tyre to take the wheel off. Of course tyre clearance is about frame design as much as removing brake calipers, but the tendency towards larger frame clearances has gone hand-in-hand with the availability of disk brakes - removing the requirement for a brake bridge, and the additional stiffness of through axles allows frame designers more flexibility.

PS. I'm not sure that wider tyres are faster at the same pressure. It is more that you can run wider tyres at a lower pressure, which is faster.

[Thoglette]

the other things that disc brake bikes do better is allow the fitting of wider tyres

Bullsh:t. Horse puckey. Utter rot and nonsense.

This is complete and utter lie, deliberately peddled by certain marketing departments.

People have been running wide tyres (38mm and beyond) for the best part of 100 years. And with brifter compatible brakes ever since we settled on the psuedo standard for road brake pull somewhere in the '70s. Hell, the old "road standard" was 27 x 1 1/4 - that's 32mm.

I present the (mid reach) Shimano R451 as exhibit A and the Mafac centre pull (since the '50s and still effectively available from Compass) as exhibit B. I'll ignore the dozens of cyclocross bikes running 32mm (UCI limit) tyres or all the 2" tyres on MTBs and the 35mm "city bikes". And every touring bike ever made. Because cantilever brakes apparently don't exist either.

What that limits tyre width on most road bikes is the frame design, not brakes. Which is what drove the 650B tyre revival.

[biker jk]

the other things that disc brake bikes do better is allow the fitting of wider tyres

Bullsh:t. Horse puckey. Utter rot and nonsense.

This is complete and utter lie, deliberately peddled by certain marketing departments.

People have been running wide tyres (38mm and beyond) for the best part of 100 years. And with brifter compatible brakes ever since we settled on the psuedo standard for road brake pull somewhere in the '70s. Hell, the old "road standard" was 27 x 1 1/4 - that's 32mm.

I present the (mid reach) Shimano R451 as exhibit A and the Mafac centre pull (since the '50s and still effectively available from Compass) as exhibit B. I'll ignore the dozens of cyclocross bikes running 32mm (UCI limit) tyres or all the 2" tyres on MTBs and the 35mm "city bikes". And every touring bike ever made. Because cantilever brakes apparently don't exist either.

What that limits tyre width on most road bikes is the frame design, not brakes. Which is what drove the 650B tyre revival.

The op is not looking for a cyclocross bike, mtb, city or touring bike. My Lynskey road bike with standard rim brakes won't fit any tyre wider than 25mm. My disc brake road bike can take 32mm wide tyres.

[Thoglette]

My Lynskey road bike with standard rim brakes won't fit any tyre wider than 25mm. My disc brake road bike can take 32mm wide tyres.

Which, and let me be absolutely clear, has NOTHING to do with the brake type. It is a decision the frame designer took.

F'example the two current Rivendell "road' frames both use mid-reach caliper brakes and both fit 32mm tyres.

You'll be further amazed to discover that bikes with both disc and rim brake mounts (e.g. Velo-Orange Polyvalent) only specify one maximum tyre width (ok, two - one with fenders, one without ).

[djw47]

The technical editor for cycling tips ran a poll recently, and was very surprised that there were so many people who were like me - very happy with rim brakes.

If you go back to the 1800s, people were happy with horses as a means of transport... In a couple of decades, road cyclists will laugh at the notion of using rim brakes, but there will still be some people who have them, same as there are still some people who travel by horse.

That's not valid. The only thing disc brake bikes do better is stop.. and even that isn't always going to be 100% true. They aren't as good as rim braked bikes for going, which is quite a big part of riding a bike.

Brakes are kind of designed to make you stop though! and discs do it better. I'm not sure how rim brakes make you "go" better, if you're brakes are slowing you down, they need adjusted, I've had brake rub more often with rims than I've ever had with discs - it only takes a wheel to be a tiny bit out of true to get persistent rim brake rubbing.

[Comedian]

What Comedian is implying is that there is a weight and aero penalty which means that your disc-braked bike will be slower. The irony is that when the same argument is used in support of CF frames, it suddenly seems not to matter so much. But you come to expect such inconsistencies

I thought the irony with that was that when I said "why not wear a 200 gram penalty and go with a near indestructible Ti frame" you all said "NO! It's unthinkable! Never! We can't possibly bear the thought of a bike that's 200 grams heavier".

But when it comes to carrying .5 - 1kg extra for disc brakes it's all good. It's worth it!

[P!N20]

So Froomie's on the juice? Who woulda thought...

[/attempted distraction]

[Comedian]

My Lynskey road bike with standard rim brakes won't fit any tyre wider than 25mm. My disc brake road bike can take 32mm wide tyres.

Which, and let me be absolutely clear, has NOTHING to do with the brake type. It is a decision the frame designer took.

F'example the two current Rivendell "road' frames both use mid-reach caliper brakes and both fit 32mm tyres.

You'll be further amazed to discover that bikes with both disc and rim brake mounts (e.g. Velo-Orange Polyvalent) only specify one maximum tyre width (ok, two - one with fenders, one without ).

Exactly! My lynsey won't fit any bigger either.. but it's purely the location of the chainstay and the brake bridge.

[biker jk]

My Lynskey road bike with standard rim brakes won't fit any tyre wider than 25mm. My disc brake road bike can take 32mm wide tyres.

Which, and let me be absolutely clear, has NOTHING to do with the brake type. It is a decision the frame designer took.

F'example the two current Rivendell "road' frames both use mid-reach caliper brakes and both fit 32mm tyres.

You'll be further amazed to discover that bikes with both disc and rim brake mounts (e.g. Velo-Orange Polyvalent) only specify one maximum tyre width (ok, two - one with fenders, one without ).

Exactly! My lynsey won't fit any bigger either.. but it's purely the location of the chainstay and the brake bridge.

Not really.

From Thoglette's link.

Brakes and design determine usefulness.

Modern racing bikes use short-reach brakes. Combined with modern road forks, those brakes limit you to 25mm tires, or maybe----if you're lucky----28mm. The Roadeo uses the old "standard reach" brakes, made by either Shimano or Tektro. There's no visual difference between standard and short-reach brakes; most people can't tell the 1cm difference in reach. But the extra centimeter under the caliper works wonders at making a bike more useful. Because of the Roadeo's standard-reach brakes and fork design you can ride 28mm tires with fenders or 35s without; and that's what we did with the Roadeo.

If the brake bridge is higher then you need longer reach brakes (so the type of brake does matter. Longer calipers flex more. You don't need a brake bridge with disc brakes).

Some discussion here that it's the tyre height that matters on the front as well.

When we talk of clearance we use the language of tire widths, because that's how people buy tires, and the listed size--35mm or whatever--is right there on the tire. But talking about tire width in the context of top-of-the-tire clearance is a scientifically and mathematically dumb way to do it, because what usually impedes the tire, and always on a ROADEO, is the HEIGHT. But nobody knows "height language," so we (who know better) drift back into the width language. But height is where it's at.

https://www.rivbike.com/collections/fra ... cts/roadeo

[Thoglette]

If the brake bridge is higher then you need longer reach brakes.

Actually, that's back to front: you'll need a higher bridge if your short reach calipers have tyre "height" issues. (And the new ones seem worse than the older ones). But I get your point.

The trouble is you also need to move the seat post forward (by having longer chain stays) to fit the taller tyres. Toe overlap becomes more of a problem. Your head tube becomes shorter (or your handle bars go up). And you still need to spread (or dimple) the chainstays; seatstays and forks to clear the taller (ok, wider) tyres. Your wheelbase just got longer too.

Note that cantis and centrepulls don't need brake bridges. So in the claim that "discs allow wider tyres" it turns out that brake bridges are just another straw man: the problem remains the frame design.

[familyguy]

I could fit 42s on my Fuji Tread (disc brakes). Do I need to? No. 35 is plenty.

I could fit 35s on some of my steel frame roadies (rim brakes). Do I need to? No. 28 is plenty.

Horses for courses. Adapt and overcome. That's how most of this stuff happened in the first place.

Disc brakes are good, but I have really only encountered one situation where I have thought "lucky I had discs otherwise I would have run into something/someone". Was that enough to make me change all my stuff to disc? Nup. But discs are increasingly popular and increasingly available.

Jim