Foil Disc vs Oltre

[TonyM]

For the descents and the rainy situations disc brakes are the way to go!

They have also some disadvantages which have been mentioned like a slight added weight, serviceability, slightly different handling of the bike, cost,....

but they have also a very important advantages in my eyes (especially if you bike a lot like me in the rain), they are safer than rim brakes! It is like an helmet, you never need one unless you are in a bad situation....and then you will not regret the disadvantages of it.

The best is to have 2 different bikes (rim and disc) and use them depending on the purpose; Like a sun bike and a rain/winter bike bike for example.
Or to live where it is flat und always sunny

[TobinHatesYou]

Living somewhere flat would be the opposite of good.

[zappafile123]

1) Tell me, what more goes wrong with the caliper? I've never had caliper issues.
2) How do you quantify snappiness? Does it come from a stiffer frame or a flexier frame?
3) You know what detracts from my ride quality? Repeated braking from 45-50mph to 20mph on steep descents with hairpins and carbon braketracks having poor thermal conductivity. The lack of initial bite on even the best textured carbon rim braketracks from ENVE, Mavic, Zipp, Campagnolo. The braketrack wear after 3-4 years and a couple million feet climbed/descended. My brands new Campy H11 rotors have brown discoloration on the tynes from heat. You're putting the same energy into a rim brake system, and if your using CFRP rims, you're relying on that heat not melting/delaminating the composite.

1) Thats exactly my point. Air bubbles in brake lines, bleeding, readjusting lever throw, bent rotors, pad contamination - Discs are a pain!
2) Not sure how to respond to this one - the only data I have is subjective feedback from a number of people; I'm certainly not the first person to suggest that discs interfere with ride quality. As for flex/stiffness, its definitely stiffness - the forks and dropouts are reinforced to withstand the higher forces applied to the frame whilst braking. Snappiness/responsiveness is not a property the directly co-varies with stiffness.
3) You're using the phrase 'ride quality' in a completely different sense than the way I've used it so the criticism doesnt apply. But yes, braking is worse for calipers and as you suggest, does have the downside in that it eats up your rims. But with the mini-mountains in Australia, I've had no issues with carbon brake-tracks.

[TobinHatesYou]

1) Thats exactly my point. Air bubbles in brake lines, bleeding, readjusting lever throw, bent rotors, pad contamination - Discs are a pain!
2) Not sure how to respond to this one - the only data I have is subjective feedback from a number of people; I'm certainly not the first person to suggest that discs interfere with ride quality. As for flex/stiffness, its definitely stiffness - the forks and dropouts are reinforced to withstand the higher forces applied to the frame whilst braking. Snappiness/responsiveness is not a property the directly co-varies with stiffness.
3) You're using the phrase 'ride quality' in a completely different sense than the way I've used it so the criticism doesnt apply. But yes, braking is worse for calipers and as you suggest, does have the downside in that it eats up your rims. But with the mini-mountains in Australia, I've had no issues with carbon brake-tracks.

Almost all my centerlock rotors come true or true enough. Bleeding is something I do maybe once every two years. Adjusting lever throw? Really? I consider the contact point adjustment as a plus compared to backing out a barrel adjuster. The reach adjustment on my eTap HRD levers is also better than that of my eTap mechanical levers. On the HRD levers, contact point does not change with reach adjustment. With the mechanical levers, reach adjustment is the same as preloading the lever. That forces you to set up your rim brakes with minimal pad clearance.

Usually if my pads becoming a tiny bit contaminated I can just burn the contamination off by dragging the brake on a descent. It beats having to pick out debris from brake pads before they gouge my rims (alloy or carbon.)

TOUR measured the disc Emonda SLR to be less stiff overall vs the regular Emonda SLR.

When I torque down my disc calipers on the Emonda SLR fork, the legs visibly flex. I'd say there's enough compliance and splay in them.

[pdlpsher1]

When I torque down my disc calipers on the Emonda SLR fork, the legs visibly flex. I'd say there's enough compliance and splay in them.

Light weight and disk forks don't go well together The following are brake-induced fork failures. Notice the break is on the left side of the fork. The last pic shows a recalled Enve 2.0 Road Disk fork. The replacement fork has been beefed up hence adding a lot more weight to the fork.

[TonyM]

WOW scary!

Disc brakes combined with very lightweight forks and frames do really need some investment in terms of R&D from the manufacturers.

If you buy (and use) disc brakes and a lightweight fork/ frame you should really only go with excellent manufacturers who are really having excellent quality products. I am always surprised that some want to buy some cheap chinese frame/ fork from Alibaba etc... and use disc brakes.

[pdlpsher1]

I have no doubt that most disk forks are properly engineered. However due to the extra braking forces the margin of error has been significantly reduced. A little slip in QA or manufacturing tolerance by the fork manufacturer (most forks are designed by the big bike manufacturers but manufactured by third party carbon manufacturers in Asia) you will have catastrophic consequences. One way to combat manufacturing tolerances is to add weight. If you take weight away then you need to beef up QA. But as one can clearly see QA is tricky and not always reliable, as in Enve's case.

Rim brake forks don't have the same issue. The braking forces act up near the crown of the fork.

[zappafile123]

Almost all my centerlock rotors come true or true enough. Bleeding is something I do maybe once every two years.

Lets not quibble over low n's. At the end of the day there is a trade off to be made. As to which side to go for, its up to the consumer. I prefer a racier ride and ease of service over superior braking performance.

Here are two pro reviewers (me being a hyprocrite with low n's haha) who lend support to my claim that disc frames arent as responsive:

https://cyclingtips.com/2017/09/vitus-v ... sc-brakes/

"For those most interested in race performance, I’d recommend the rim-brake version of the Vitesse EVO because it was more agile and energetic than the disc-brake-equipped bike."

https://cyclingtips.com/2017/06/first-l ... ine-slr01/

"It had a definite advantage over the rim-brake bike, and maybe it will help a rider win races, but it wasn’t quite as thrilling to ride."

The same thing can be said for the S-works tarmac (SL5) and Izalco Max

[TobinHatesYou]

Rim brake forks don't have the same issue. The braking forces act up near the crown of the fork.

Since we're instilling irrational fear, uncertainty and doubt...

Delamination of carbon rim braking surfaces is way more common than forks snapping. I don't know anyone who has snapped a fork at the disc caliper personally, but this is my friend's ENVE SES 6.7 front after 26,000mi in the mountains.

[pdlpsher1]

Carbon clinchers and the heat-related damage has been a hot topic for the past several years. Resin technology has improved dramatically in the last few years. The German Tour magazine has covered this topic extensively and they have developed a heat torture test in a laboratory setting. In issue 9 of 2014 they tested a slew of carbon clinchers. Campy and Mavic passed with flying colors. Zipp, Xentis, Reynolds, and DT Swiss had major failures. In issue 8 of 2016 they tested another 19 wheels. Campy, Fulcrum, Mavic, Shimano (AL braking surface), and Zipp passed. DT Swiss and Reynolds had failed. Curiously Enve has declined to participate in all of their wheel tests So no one really knows how Enves compare to Zipp and Campy in regards to heat damage. The Tour torture test is designed to simulate the worst case scenario. The test protocol was detailed in issue 9 of 2014. With that being said I would only buy a wheel that passed the Tour torture test. Based on the pics of your friend's damaged Enve wheels, I suspect they wouldn't pass the Tour test. Riding 26,000 miles in the mountains should show even wear on the brake track. The isolated wear/damage tells me that the wheel couldn't manage the heat well. Did your friend get a replacement wheel from Enve? What did they have to say? Is your friend now on disk wheels or another brand of carbon clincher? You might want to pass on the Tour info. to your friend.

I bought my Boras based on the Tour test. Recently I descended two mountains in the worst possible braking technique, by dragging the brakes down steep switchbacks. The two mountains are Mt. Evans and Pikes Peak. At 14,000 feet there's not much air to create air resistance. Most of my potential energy was dissipated as heat in the rims. During the summer it's high tourist season for both mountains. Cars and minivans jam pack the road. I had no choice but to drag the brakes. I had no trouble in both instances, neither did my friends who own Fulcrum and Zipp carbon clinchers.

[TobinHatesYou]

He got his old 6.7s replaced with brand new 3.4s under warranty. Nobody else comes close to ENVE's 5-year warranty. He also yearns for a disc bike, but it's a big investment to move on from his SuperSix Black Inc. The Scott Foil Disc has been on his mind a lot lately because he can get one on a team deal.

The thing about resin technology is it hasn't really improved. The same resins have been available forever, and manufacturers have to make compromises no matter which one they pick. The heat resistant resins are more brittle. They are more prone to structural failure from impacts and deflection. Companies using these resins have to use more carbon plies and more resin, which itself helps with heat resistance. It does make for a heavier wheel though. I would be curious to see how Mavic's newer, lighter UST wheels do under the same test conditions.

[pdlpsher1]

'Heavy' is a relative term. My Campy Bora 50's came in at 1,470g actual weight, which is under Campy's claim weight, unlike Zipps, Enves, Mavics, and Shimano that always come in higher than the claimed weight.

So yes, light weight and heat resistance can go hand in hand.

[jlok]

when we compare weight of rims/wheel, should we also consider the width as well as the depth of the rim?

(I'm not judging wide vs narrow rim performance)