So rim brakes on Carbon wheels are better ...

[Thoglette]

but seriously if cars wheels failed catastrophically

What, like this?

Abuse anything hard enough....

[Ross]

I have disc brakes (Shimano hydraulic) on my CX and MTBs and rim brakes (Shimano Ultegra) on my road bikes. I have only done ~3500km on CX and ~3200km on MTB and haven't had to touch the brakes in a maintenance sense. Most of my riding is in dry weather.

Similiarly the only maintenance I've had to do on the brakes of the road bikes (various mileages - ~12000km on one and ~85000km on other) is brake pads once or twice a year and maybe brake cables once a year/18 months. I mostly ride the roadies in the dry as well but sometimes can't avoid getting caught in the rain. Riding in the rfain greatly accellerates brake pad wear. And rim wear. If riding lots in wet weather I will go through a set of rims every 18 months/2 years. Normally front will be badly worn but rear will be not far behind and it's not much dearer to buy a new pair of wheels rather than just buy a single wheel - a new rim only is more than the cost of a complete wheel before cost of rebuilding wheel is even factored in.

A new brake disc is only around $40, compared to ~$650 for a new (alloy Shimano DA C24) wheel. I plan to buy disc brake equipped road bikes in the future.

I find that new for new (new brakes, pads and wheels) the stopping power for both types of brakes is very similiar in the dry, the discs maybe a bit better; in the wet the disc brakes are much better.

[Ross]

And in braking news (or should that be breaking) the other wheel manufacturers have said the test that started this discussion is rubbish..

https://www.bikerumor.com/2017/12/14/en ... rake-test/

Interesting read but I see it as Alto going above and beyond the standard testing procedures. The other manufacturers were calling Alto out for not doing "real world" testing. Maybe it wasn't but wasn't Alto's test harsher so therefore better?

The other manufacturers did have a point about their wheels performing best with certain pads but as Alto pointed out if they had used all the different recommended pads then it wouldn't of been a true comparison.

I think the other manufacturers should procure some Alto rims and perform their own tests using the protocols they claim are better and then publish the results.

[uart]

And in braking news (or should that be breaking) the other wheel manufacturers have said the test that started this discussion is rubbish..

https://www.bikerumor.com/2017/12/14/en ... rake-test/

And I notice that all three of those manufacturers who responded (Mavic Enve and Byod) and made exactly the same point that I made above - that the rims with the smoothest braking surface and the least effective stopping power would have an advantage in this test. They must be reading my posts.

[Lukeyboy]

Must admit those Alto wheels are quite nice As are their disc versions as you might have seen too

So, what would it take in the real world to cause problems to a set of rims?

For example, I'm 100kg, so I'm going to be harder on the brakes than a lot of people. But what sort of speed, hill, braking duration would I need to do to actually cause any damage to a carbon or alloy rim?

I keep reading about "descending the Alps" or "Hotham" but how much braking do I need to do before I get worried?

Well.. I've ridden down the steep side of glorious in the wet (and the dry) with my CF rims and it was fine.

Thing is.. if you're really going to be climbing big mountains why not pop a set of light alloys in? You won't have to worry on the descent, and you'll have a distinct advantage on the climb over your friends with disc brakes and their deep section CF wheels.

Heavier riders have overheated both carbon and alloy rims descending Glorious so your advice against disc brakes doesn't make any sense.

I've also seen the result of a Zipp 404 with a Schwable One blowing out on a lightish rider going into the front side hairpin. If you are going to descend Mt Glorious (its not that much of a descent if you want to be honest really) or any steep descent at speed then learn how to corner and control your braking. Mt Glorious has also claimed many riders eating !! BAN ME NOW FOR SWEARING !! (both motor and non motor bikes) because of poor road craft (I remember telling one group I was in to avoid the edges of the road because if its wet the moss will get you. Needless to say the first proper corner claimed one rider and before I could stop to go back I heard the second corner claiming the second).

Yeah - I've never ridden Glorious or Nebo. I'll make it one of my goals for next year.

Remember to brush the armcos with your shoulders

Enjoy the current kom video. The video on the right (current KOM) was the first time I'd been down it and any other technical road in over 14 months due to a crash on a set of freshly built up HPlusSons Archertypes. The video on the left is returning after a handicap race out near Sommerset Dam on Zipp 404s. Both times I was casually riding along. Damn I'd love to give it a crack in anger. Or even be able to use up the entire road as I reckon I can eeek out another 30 seconds - if not more

[outnabike]

Nothing wrong with a decent tree branch for jambing into the ground under the BB either.

I'd heard of that one but was trying to find a reference from someone who'd actually done it.

I was just being facetious, I mean who would not use the shoe on the top of the back wheel.

[warthog1]

. I have no concerns ripping down Donna Buang, Baw Baw or Hotham at full throttle on the discs, knowing that the chances of anything failing are virtually nil.

Sums it up for me on my carbon clincher Zipps too.
Have carved up a number of disc brake equipped bikes without any concerns and I am no gun.
Just don't drag your brakes whatever you are riding.

[Too Tired]

When I first got my bike (2nd hand) it came with Zipp 303s. Amazing lightweight wheels with tube tyres.

Two issues: easily got punctured and a pain to replace, and the carbon rim brakes were useless. Sounded like a jet engine when braking down a grade and hardly slowed me at all.

I replaced with some 404 clinchers with a metallic braking surface. Much better.

[booge]

If Raoul from Luescher Teknik is calling carbon clinchers a bad design... I'll agree with him.

[Comedian]

I rode down a decently steep descent on boxing day. No euro mountain, but a decent enough descent. Steep, windy, and covered in wet debris so it wasn't like you could let your speed get too high. I was more on the brakes than off. According to strava it was 8km at -5, but there were some 1k sections at -11.

Anyway, at the bottom I made a point to stop and check my Enve braking surface temperature. To the touch it was barely warm.. I could easily leave my fingers on it indefinitely. They have really done an exceptional job of controlling the temps with modern rims and brake pads. All the while they operated progressively and with ample power.

I really don't think this test has any real relevance to anything..

[CKinnard]

I am becoming a greater fan of disc brakes, only because as I get older I am riding wider tires on a CX/gravel grinder, and I haven't found a rim brake to accommodate them.

The additional safety on wet and poor surfaces more than compensates their weight to my mind. And I've never had a flat on a tire >35mm.

I appreciate if Strava times are your priority, then it ain't for you. Though I'd suggest you use a power meter and ride solo if performance is genuinely your motivation.

At some stage, I'll sell both bikes I've got now, and buy one relaxed roadie with disc brakes, and run two sets of wheels/tires, one with 25mm tires, and the other with 42mm. At least one set will be carbon.