Discs + wet weather + gravel riding: struggling to swallow the kool-aid

IanEdward wrote:

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I use the cheaper open cut out discs which are a few quid a pair.

Which ones? I've run various rotors including the Magura Storm SL which are more cut-out than rotor! Admittedly that was with different brakes (same bike though), but they didn't do much for the noise.

Still tempted to try sintered pads as I remember them being relatively quiet in the wet on my mountainbike, but I tried sintered pads in some SRAM brakes recently and they were awful, squeeled in the wet AND in the dry!

Also worried about using sintered pads on a rotor that has already been bedded in with resin pads...

Ive had good success with these. https://www.wiggle.co.uk/lifeline-one-piece-stainless-disc-rotor-160mm/?...|sGqMU42pR_dm|mcrid|295292317327|mkw||mmt||mrd|5360597829uk|mslid||&mkwid=sGqMU42pR_dm&pcrid=295292317327&prd=5360597829uk&pgrid=58852352866&ptaid=pla-521629078002&gclid=Cj0KCQjwwODlBRDuARIsAMy_28XW6mJioZtt5e7GV0G0zM1SMuv_ej8m_UGWmDdFI5OS4LEHp9x8gZYaAlP7EALw_wcB

It takes a few times braking with new pads to bed into rotors. I go through a set of pads in a week touring mountains. I put on a new set before a tour and it takes one mountain descent to bed in new pads

hawkinspeter wrote:

@BTBS - I just did a quick search on performance difference between rim and disc brakes and found GCN's testing that concluded that rim brakes are indeed faster. (Summary here: https://www.honeybikes.com/blog/2018/3/25/disc-brake-vs-rim-brake-performance-on-road-bikes)

However, for me the most important difference between rims and discs is the wet weather performance.

That article has cropped up a couple of times now and is ummm - interesting. Aside from the acknowledged looseness in the tests, they've stitched together some of the timing from the GCN video, doubled it up, and concluded that the lighter (rim-braked) bike is faster uphill. Then, on the descents, they found that the heavier (disc-braked) bike was marginally slower downhill in the dry (0.5%) but significantly faster in the wet - enough to better the deficit from climbing - so they said the rim-brake bike had carbon rims and must have been about twice as bad downhill as one with aluminium rims. So they halved the advantage on the heavier bike and tad-dah - the lighter rim-braked bike wins !!! They did at least admit that there are other areas to consider rather than straight 'speed' and I think it's possibly safe to say from the language in the article that it's the answer they might have prefered ...

fukawitribe wrote:

hawkinspeter wrote:

@BTBS - I just did a quick search on performance difference between rim and disc brakes and found GCN's testing that concluded that rim brakes are indeed faster. (Summary here: https://www.honeybikes.com/blog/2018/3/25/disc-brake-vs-rim-brake-performance-on-road-bikes)

However, for me the most important difference between rims and discs is the wet weather performance.

That article has cropped up a couple of times now and is ummm - interesting. Aside from the acknowledged looseness in the tests, they've stitched together some of the timing from the GCN video, doubled it up, and concluded that the lighter (rim-braked) bike is faster uphill. Then, on the descents, they found that the heavier (disc-braked) bike was marginally slower downhill in the dry (0.5%) but significantly faster in the wet - enough to better the deficit from climbing - so they said the rim-brake bike had carbon rims and must have been about twice as bad downhill as one with aluminium rims. So they halved the advantage on the heavier bike and tad-dah - the lighter rim-braked bike wins !!! They did at least admit that there are other areas to consider rather than straight 'speed' and I think it's possibly safe to say from the language in the article that it's the answer they might have prefered ...

It might be flawed, but I didn't see any other direct comparisons of performance between brakes (I didn't spend long looking though). I would have thought that GCN would be more interested in promoting disc brakes, so the bias surprises me.

hawkinspeter wrote:

It might be flawed, but I didn't see any other direct comparisons of performance between brakes (I didn't spend long looking though). I would have thought that GCN would be more interested in promoting disc brakes, so the bias surprises me.

I think a lot of the point is that speed isn't really the be-all and end-all from the GCN videos -  and that article wasn't written by them. The GCN video is remarkably even-handed and interesting, especially in the conclusions and discussion about what could be done more or better.

fukawitribe wrote:

I think a lot of the point is that speed isn't really the be-all and end-all from the GCN videos -  and that article wasn't written by them. The GCN video is remarkably even-handed and interesting, especially in the conclusions and discussion about what could be done more or better.

I didn't watch the video, just read that summary. I'll give the video a go later on when it's convenient to use headphones (I much prefer reading articles than watching a video). But yeah, most people buying disc brakes aren't concerned about a few seconds difference in performance.

Edit: watched the video with subtitles now. Looks like the difference is within experimental error.

hawkinspeter wrote:

fukawitribe wrote:

I think a lot of the point is that speed isn't really the be-all and end-all from the GCN videos -  and that article wasn't written by them. The GCN video is remarkably even-handed and interesting, especially in the conclusions and discussion about what could be done more or better.

I didn't watch the video, just read that summary. I'll give the video a go later on when it's convenient to use headphones (I much prefer reading articles than watching a video). But yeah, most people buying disc brakes aren't concerned about a few seconds difference in performance.

Absolutely, worth watching the video too I reckon, there's a lot of important points missed by the article (plus dubious quoting...)

Edit : I owe the article writers an apology, they didn't halve the descent time - that was my mis-reading of their discussion about compensating for carbon rims - the bent of the article was still mis-leading  even without that IMO.

hawkinspeter wrote:

@BTBS - I just did a quick search on performance difference between rim and disc brakes and found GCN's testing that concluded that rim brakes are indeed faster. (Summary here: https://www.honeybikes.com/blog/2018/3/25/disc-brake-vs-rim-brake-performance-on-road-bikes)

However, for me the most important difference between rims and discs is the wet weather performance. In traffic I really like my brakes to start slowing me down as soon as I activate them and I've found that rim brakes make me a lot more nervous in the wet (I have to ride slower in case cars pull out on me etc). Disc brakes feel a lot nicer to use (just a finger will do with complete control) but it's definitely the reliability factor for me.

Given the choice, I'd go for hydraulic discs every time. (I've clearly fallen for the capitalist propaganda)

I've never not had enough braking in the wet, one adapts to the conditions no matter what you use, the pros have managed on carbon rims in the wet, they've managed with far flexier stirrups/calipers and worse pad compunds too. The restricting factor is the tyres and a persons ability to ride to the conditions, has been for a very long time, more so in the wet.

I'm probably not far off 200,000 miles over 35 years of being on the road, not a massive number compared to some but a decent amount, I started off with chrome steel rims as a teenager, had a few self induced offs along the way but none down to braking efficiency or lack of power and non of the motorist caused incidents would more powerful brakes have helped either.

I've said elsewhere that having more powerful brakes simply induces you to take greater risks, to go in deeper/faster on approach, you cut down thinking time should the worst occur. For me there's too many downsides to discs for a tiny amount of improvement in braking in wet conditions when really you should be going at a speed that gives you the distance to stop no matter what brakes you have.

Similar to my first race bike, my first car had drum brakes all round, 12" wheels with probably some horrible tyres, somehow never managed to crash it, nor run someone over. We've got to a point were the next step has taken us to a point that serves no real purpose for road bikes, even adventure/gravel bikes, has increased bulk, weight, increased ugliness IMO but also has the unintended consequence of reducing thinking time and coplacency particularly in emergencies because one becomes accustomed to the apparent power. Similar thing with motors when disc brakes and ABS became common place, stopping distance restricted by tyres and people still crashed at the same rate because they kept braking later and from higher speeds.

Each to their own but for road bikes in any guise discs are more hassle then they're worth at any level from pootler to pro.

BehindTheBikesheds wrote:

Simplifying frame design, lol, it was simple before, have you any idea how much more complex a disc brake frame is compared to a rim brake, you've seen all the extra add on bits that are needed so that you can fit discs right, all the additional 'beefing up' and huge changes in frame design?

The excuse about carbon clinchers melting was feeble, a small number of people, mainly people who have no business descending in the mountains at high speed on carbon clinchers, and that was back in the early days with poorer compounds, Corima carbons have been fantastic for over a decade amngst others. Maybe those wannabe's should learn how to ride descents or simply not cane it when there's no need to or just bring along alu rims if they aren't that great on descents and are worried about their cheap carbn rims!

I'm a mini V user on my tourer/audax/winter racer, it'll take up to 55mm tyres, easily 45s with guards, Specialized made in my opinion the ultimate do it all bike in the Sirrus Pro Ltd, full carbon, room for 40mm tyres plus rack and guard mounts, std 68mm BSC BB and V pegs. Currently running it with Avid 7s but have TRP mini Vs if I decide to convert to drops.

Most of the offerings for gravel/adventure are fat bloaters, even the high end full carbon jobs are heavier than my Sirrus, all are disc brake offerings so for me none are of interest. If Tom Pidcock can win a Worlds junior cyclocross on cantilevers then it's good enough for the rest of us!

For a benefit to a very, very small number of people in a very small fraction of situations were a well set up disc brake will do better than a rim brake, it's just not worth the extra cost/weight and numerous downsides that most disc brake users experience.

 

I can't disagree with most of what you write, even when it contradicts my previous post. I realise I'm only parroting all the industry lines.

'Simplified frame design' was the wrong choice of words, hands up. I realise there has had to be massive strengthening to manage forces around and due to the calipers that I am sure was really complicated to design. Simplified and cleaner shapes with less junctions better? Due to the industry push, you can only conclude that when road bike disc brake design & manufacture matures the frames will be cheaper to produce. Same with wheels. Otherwise, what's your reason why the industry is totally abandoning rim brakes?

Oh and when Pidcock won worlds everyone else was on canti's too - you know that!

Like it or not within a couple of years you're not gonna have much of a choice If you want a new bike

IanEdward wrote:

...... The usual advice, but they're as well bedded in and as well looked after as a set of brakes could hope for. Anyway, I thought disc brakes were supposed to be low maintenance? 

Mine are.  In fact they are as near as dammit no maintenance.  And, although I've used discs from four of the major manufacturers, I've never suffered from noise.  Not once, wet or dry.  And I've tried, really tried.  Although I sometimes spend excessive amounts on genuine replacement pads, I've often bought the cheapest too, but still my brakes are silent.

 What is the secret?  Well, I could be wrong, but I think it's to do with aligning the pads parallel to, and equidistant from, the disc.  That way there's no vibration when you press the lever and consequently, no noise.  I occasionally loosen the calliper, then press and hold the lever to centralise everything whilst tightening it all up again.  It could be a waste of time but, as I said, it works for me.

Best of luck.

IanEdward wrote:

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Metathesiaphobia

Nope, but kudos for googling a clever word to be dismissive with 

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Bed them in properly, quick clean now & again, and they are fine.

The usual advice, but they're as well bedded in and as well looked after as a set of brakes could hope for. Anyway, I thought disc brakes were supposed to be low maintenance? 

Low maintenance, not no maintenance.