electrik

So.. can either of you explain why disc brakes aren't popular with the touring crowd?

sstorkel

Bicycle tourists are, by and large, Luddites and curmudgeons. Give 'em another 15-20 years and they'll be all over disc brakes. Maybe 10-speed drivetrains, too

jabberwocky

I posted my thoughts earlier in the thread:
I'd also add that discs can interfere with racks and fenders (which has largely been solved by moving the caliper mount to the chainstay, but can still sometimes cause issues).

electrik

Maybe we're in for a trend like this one... better not hold our breath

electrik

Ah, sorry.. yeah i think that is mostly ironed out in the rear. The front rack/fender can take some thinking to figure out though but is typically solvable..

jabberwocky

Whats sort of amusing is that you can go back ten years and find pretty much the exact same discussion regarding discs happening in the MTB realm. The same arguments, the same reasons discs were bad/pointless, etc. Even into the 2000s, there were some shops that actually refused to stock disc-equipped bikes because "they were just a fad". At some point, discs went from being a bit of a luxury item to the market norm, and eventually even lightweight race bikes (the last big holdout for rim brakes) transitioned to discs. Nowadays, go into a bike shop and you'll have trouble finding a MTB for sale with anything but discs, and rim brakes are basically limited to vintage bikes and retro-grouches.

Now, I don't know if that will happen in the touring realm. I will say that I wouldn't be surprised to see some of the more popular touring bikes coming equipped with at least disc tabs on the frame and fork, to give people the option.

KonAaron Snake 

Sorry...I don't mean to derail things...but my understanding of aluminum and carbon fiber and fatigue is a bit different. It doesn't matter how much thicker the tubing is, EVENTUALLY aluminum and CF will both fatigue into uselessness. We learned about fatigue factors with aluminum from airplanes...after so many flights, they'd always tear apart. Making it thicker, stronger, etc (which adds weight to the point where it has no advantage over steel) just means it fatigues later...it still eventually fatigues. Maybe that time period with aluminum and CF is now so long as to be irrelevant, but crashes, every impact...etc...are all just a little less life it has left. Also...when steel fails, you usually see it bending before it goes. Aluminum is more likely to just fail without warning.

Steel either breaks with a stress or it doesn't. There's no combined wear issue. To me that means light weight CF isn't really a long term tubing material. For folks who change bikes every three seasons, it probably doesn't matter...but I tend to want mine to last.

I'm NOT an engineer and could definitely have this totally wrong.

electrik

Basically CF has a higher yield strength, which makes it have a longer lifespan... if you inelastically deform steel by forcing it past the yield point then you are fatiguing it... CF is harder to push past the yield point.

Boeing is even using CF in it's new 787 planes for wings and fuselage.

https://www.calfeedesign.com/whitepaper4.htm I quickly came across this, which seems to support the notion.

KonAaron Snake 

I'm not sure, but I think you might be confusing flex and fatigue. I am almost 100% positive that steel has virtually no fatigue and I know that CF has a fatigue factor...which is why the CF makers all say the fork and frame need to be replaced after a major crash. You can't always see the damage or wear. With steel, it either bends or it doesn't.

electrik

It is true that CF yields suddenly(same with Al) and steel has a more progressive yield... so i guess steel is more user friendly if heavy.

KonAaron Snake 

I'm not trying to say that CF and Aluminum (well, CF anyway) don't have advantages...the weight advantage and feel of CF is fantastic. I think CF is GREAT for people with more cash than me who can change out their bike every 5 years or so. I also think steel still has a place in the bike world (at least until titanium becomes more affordable) and that many times a steel bike is the right bike.

bobframe

"But rims are consumables for bicycles with rim brakes anyway."

I suspect this is correct. So, if braking characteristics were identical between all forms of rim brakes and disc brakes, this would seem to me to be the deciding factor in choosing between them.

No?

jabberwocky

One of the best articles on bike frame metallurgy is here:
https://www.63xc.com/scotn/metal.htm

Its somewhat old (from the 90s) but very in depth, and dispels many of the common myths around various frame materials.

KonAaron Snake 

Awesome article!

Leebo

I've got disc brakes on two steel frames, one dirt, one commuter, the best of both worlds.

sstorkel

FWIW, my first carbon fiber road bike lasted 15 years and was still going strong when I sold it last year. The current one is much better constructed; I expect it will last a lot longer than the first one... as long as it isn't involved in a major crash.

KonAaron Snake 

I think it's really hard to properly judge CF and aluminum on endurance and shelf life since they really haven't been along that long (especially for CF). I'm sure a lot of how long the bike lasts depends on weight, how it was ridden...etc. It might be that the aluminum and CF bikes are so over engineered that the fatigue factor issue is a more a theoretical issue than a real one. I'd like to get a CF bike at some point, but I really like my ti and steel...I also think if I'm worried about weight I need to look at my belly and calorie count before frame materials.

CCrew

Oh, just the components.... and a minor thing like the frame Haven't really looked have you?

rossiny

Wow read through a bunch of these comments . I guess it boils down to how fast your going down a hill and for how long . I'm in the midwest so I doubt there would be that problem.. my cantilever brakes on my vintage Schwinn Passage work fine, however I guess if I lived in a very hilly area ,,, disc brakes would probably be much safer because of the heating on the rims. Now I feel I need to get a disc brake touring bike for my fantasy fast downhill tour

Trevtassie

Brains, this thread neeeeeds Brains...... growlllllllllllllllllllllllllll arrrgh!

indyfabz

Pro tip: Before you start descending through the posts, pay attention to the date of the OP.

P.S. Plenty of touring bikes now have disc brakes. In fact, Surely now sells only a disc version of its popular LHT.

djb

2022 thread title, "why are there no touring bikes sold with rim brakes?"

2025 thread title " why are there no touring bikes sold with triples?"

2035 thread title " why are there no touring bikes sold without the magnatronflux e-motor and integrated handlebar/ human interface ?"

cyccommute 

If you have something to say, start a new thread rather than drag out an 11 year old thread to comment on.

That said, I still hold the same opinion towards disc that I did 11 years ago. They aren’t “superior” to rim brakes. They are the same as rim brakes. I have ridden in mountains on road bikes, mountain bikes, and loaded touring bikes for 40+ years. I’ve even ridden tandems in those same mountains. Not once have I ever overheated a rim even when riding down those same mountains at 50+mph. How well a brake performs has more to do with how they are used than what the actual mechanism is.

The way that you avoid heating the rims...or rotors, for that matter... is to use the brakes quickly and sparingly. Hit them hard, slow down, and get off them. That’s for any kind of brake. You don’t squeeze on the brakes at the top of a hill and keep them on to the bottom. That’s how you overheat brakes.

Tourist in MSN

Some of us are slow to adopt, my 2017 build has disc on back and rim brake on front. Since this thread started in 2010, I was half way there seven years later in 2017, that suggests in 2024 I might get around to building up a bike with disc front AND rear.

tyrion

Please don't call them Surely.