Tour Mag. disc brake vs. rim brake test

[Imaking20]

Most road frames fit up to 28mm tires now, also on wide rims, so 40mm real clearance. This should be enough even for heavy riders on really bad roads.

For gravel you need more and disc will help on loose ground (but with long reach calipers this could also be possible with rim brakes).

Yeah, the extra clearance afforded by direct mount brakes is pretty awesome. I keep wanting to have a bike that comfortably clears 27-28mm tires* - even though I never end up actually riding them, including gravel. I've done gravel on 28c clinchers (~18mm ID) twice at different pressures and never ran such a large tire again as I just found the ride so bouncy. My best times on several gravel segments have come on 25mm tires. For sure, that's a little less fun on really chunky stuff and if I was spending 50+ miles on gravel in one shot - I may sing a different tune.

By no means am I trying to challenge you specifically with this anecdote - I just think it's worthwhile to actually type out somewhere on the internet that 28mm+ tires aren't required to ride gravel. Forums and product sites everywhere seem to make this some sort of rule - I think it's really only driven by the desire to sell more product* (need specialized tires, rims, and frames, and brakes for every type of ride!)

I've had the front tyre blow out on two occasions on steep decents, almost certainly because of overheating.

In your case you either get disc rub or the above. Your choice.

Can't choose alloy clinchers or carbon tubulars? This seems more like a valid anti-carbon clincher argument than a pro-disc one.




*See, they're even influencing me!

[Clean39T]

People keep going on about disc brakes strictly in terms of the braking experience but for me there are other real benefits. The main one is the freedom the frame designer has to give good clearance. That allows wider tyres with concomitant benefits of better comfort from lower pressure, ability to cope with crap roads, while still maintaining excellent speed.

Compass 32s on 25s under R8000s w room to spare. Though I much prefer the ride with 26s on 25s...for all the reasons imaking20 lists...and find that adequate for gravel roads that cars also use...though not for fire-roads...

[mpulsiv]

Yeah, the extra clearance afforded by direct mount brakes is pretty awesome. I keep wanting to have a bike that comfortably clears 27-28mm tires* - even though I never end up actually riding them, including gravel. I've done gravel on 28c clinchers (~18mm ID) twice at different pressures and never ran such a large tire again as I just found the ride so bouncy. My best times on several gravel segments have come on 25mm tires. For sure, that's a little less fun on really chunky stuff and if I was spending 50+ miles on gravel in one shot - I may sing a different tune.

By no means am I trying to challenge you specifically with this anecdote - I just think it's worthwhile to actually type out somewhere on the internet that 28mm+ tires aren't actually required to ride gravel. Forums and product sites everywhere seem to make this some sort of rule - I think it's really only driven by the desire to sell more product* (need specialized tires, rims, and frames, and brakes for every type of ride!)

What tire were you using and pressure that you found bouncy? Are you chasing PR’s on gravel? It defeats the purpose of riding gravel vs. tarmac. Sure, wider tires is not required but vastly preferred to enjoy the ride. I find 32mm GravelKing at 50 psi quite harsh for my taste. Give me at least 38mm to put a smile on my face.

[Miller]

The trouble with the word 'gravel' is that it doesn't just describe one type of thing in the way 'tarmac' more or less does. Gravel can mean the thousands of miles of unpaved roads in the US which to me, from photos, look flat and well graded other than not being sealed. Those roads don't look too demanding on tyres (I could be wrong).

Gravel in the UK can mean anything from a farm track with ruts where vehicle wheels go, to muddy, rocky and overgrown bridleways that really would be better ridden on a hardtail MTB if it weren't for the easier stretches in between where a drop bar bike scores. In this environment you're looking for a wide, grippy tyre that will deal with mud while retaining decent ride characteristics for tarmac. That means compromise, of course.

[ryanw]

My 2p...

Discs are 100% the future unless the big companies can produce carbon wheels that stop in the wet.

I've had Zipp 404 Firecrests and currently on Enve 4.5 NBTs. They both perform well in the dry (Enves still not great on big descents like Madone / Braus), but in the wet (we get a lot of that in the UK), they are quite frankly dangerous.

My next bike shall be the new S5D when it's released or the new Venge. I love the Madone SLR Disc but it's a heavy old brute.

[Imaking20]

What tire were you using and pressure that you found bouncy? Are you chasing PR’s on gravel? It defeats the purpose of riding gravel vs. tarmac. Sure, wider tires is not required but vastly preferred to enjoy the ride. I find 32mm GravelKing at 50 psi quite harsh for my taste. Give me at least 38mm to put a smile on my face.

Wait, you're not allowed to chase PRs on gravel?

I'm just saying that level of enjoyment is subjective and I think it comes down a lot to how much feedback you want. Not to mention I've got no interest in riding MTB tires on the asphalt on the way TO the gravel.

I was riding Specialized Roubaix Pro tires - which are great - in 25mm.

[Beaver]

I've had Zipp 404 Firecrests and currently on Enve 4.5 NBTs. They both perform well in the dry (Enves still not great on big descents like Madone / Braus), but in the wet (we get a lot of that in the UK), they are quite frankly dangerous.

Are the Enve really not any better? Other users and some reviewers state differently.

"On wet roads, the 202 NSW brake better than all other wheelsets in this review save for the ENVE which takes wet braking on carbon brake tracks to another level." https://intheknowcycling.com/2017/08/30 ... ng-wheels/

"I also have about 2,500 miles on the new track on my 2.2s. The noise takes a minute to get used. There's a winding down sound when you stop. I suspect the pads will wear faster. They stop nicely dry or wet. I've done technical descents wet and they were fine."
https://forums.thepaceline.net/showthread.php?t=189769

"Turns out braking in the wet is not only possible but highly impressive with the new SES 3.4s. I'm not a huge fan of carbon for wet weather riding because the braking performance is often lacking, but the SES 3.4s delivered reassuringly consistent and reliable retardation even when the rain was bouncing off the road and riding through massive puddles deep enough to almost engulf the rims.
With carbon rim brakes there's usually a delay after pulling the brake lever before anything happens. Not so with the 3.4s. There's no delay from pulling the brake lever to the brake blocks applying pressure on the moulded brake track. It’s very reassuring. We climbed and descended some really good fun roads and I was able to approach the corners with a confidence I rarely experience with carbon clincher rims.
Granted there’s some decline in braking performance compared to dry weather braking, but it isn’t anywhere near as bad as most other carbon rims I've yet tried. I found them a revelation." https://road.cc/content/news/218781-fir ... her-wheels

[spdntrxi]

Enve's NBT is very good in the wet.... the OBT is scary.. I have 3 sets of NBT enve's.. would not hesitate with them in the wet.

[ryanw]

On my Grandads grave, the NBTs in the wet are horrendous.

I’ve tried Enve black pads and SwissStop Black Princes, both great in the dry, but awful in the wet.

I’m 85kg and bike is a Cervelo S5.

[RyanH]

What brakes are you using? Braking performance with Enve NBT and ee was pretty abysmal. 9100 was night and day better.

[mpulsiv]

What tire were you using and pressure that you found bouncy? Are you chasing PR’s on gravel? It defeats the purpose of riding gravel vs. tarmac. Sure, wider tires is not required but vastly preferred to enjoy the ride. I find 32mm GravelKing at 50 psi quite harsh for my taste. Give me at least 38mm to put a smile on my face.

Wait, you're not allowed to chase PRs on gravel?

I'm just saying that level of enjoyment is subjective and I think it comes down a lot to how much feedback you want. Not to mention I've got no interest in riding MTB tires on the asphalt on the way TO the gravel.

I was riding Specialized Roubaix Pro tires - which are great - in 25mm.

Frankly, I haven’t heard anyone chasing PR’s on gravel. This discipline is really not into it. I’m not saying that we don’t race on gravel but majority of gravel rides is soft pedaling.

25mm on gravel is doable if you love massive vibration from head to toes or if you are insensitive and totally dig minor sensation. For me, rolling on narrow tires is an unpleasant experience.

[ryanw]

What brakes are you using? Braking performance with Enve NBT and ee was pretty abysmal. 9100 was night and day better.

I went from DA 9000 to the new EEs.

Didn't notice any difference between the two reeally.

As I said, in the dry they are spot on (until they really heat up on mountain descents), but there is zero modulation or stopping power in the wet.

[Beaver]

What brakes are you using? Braking performance with Enve NBT and ee was pretty abysmal. 9100 was night and day better.

This seems to be a very subjective matter.

I use EE with Zipp 404 and Red 22. They are excellent wet and dry.

https://weightweenies.starbike.com/foru ... 4#p1420883

In general my experience is that brake pads have far more influence than the calipers, unless you use very flexy ones as e.g. AX Orions.

What brakes are you using? Braking performance with Enve NBT and ee was pretty abysmal. 9100 was night and day better.

I went from DA 9000 to the new EEs.

Didn't notice any difference between the two reeally.

As I said, in the dry they are spot on (until they really heat up on mountain descents), but there is zero modulation or stopping power in the wet.

You went with the stock black Enve brake pads? Do you align the pads parallel to the brake track or a litte V-shape?

[ryanw]

I've used both Enve Black and SSBP on both sets of wheels.

I would say the Zipps were actually better in the wet than the Enves, which has made me contemplate swapping the Enves for some NSWs.

Pads aligned perfectly, I've even played around with the pad height against the rim, to no avail.

[Beaver]

Really strange. Maybe we get some more opinions, I was thinking about getting some Enve, now I am in doubt.