Building a road bike: Still worth it to go rim over disc?
 

Turns out I'm more mechanically-inclined towards road cycling than I realized when I first got into it, so I've decided that for my next bike I want to try picking the parts and making it truly mine, better deals on pre-made bikes not withstanding.

It's intimidating to know what will work best for you given the range of options out there. One of the big questions I'm facing is whether it is worth it to go with a rim brake frame or to pony up and go disc brake.

Personally, I don't really have a great preference, as they both have some good arguments to be had. For rim brakes, I've only used rim brakes up until now and never had a problem with them. They are generally lighter than disc brakes, generally have better aero properties, there's a wide range of affordable frames out there that still take rim brakes (although this will attenuate in the future), and relatedly (and crucially for those of us who are not pros or hedge fund managers) they are more affordable. You can find Shimano Dura Ace Di2 rim brake groupsets on eBay for ~$1200 or less.

On the other hand, disc brakes are obviously higher performance in terms of stopping power w/ better modulation. Crucially however they are more sustainable going into the future as disc brakes become (if not are already) the industry standard, particularly in the higher end range of components and builds. On the flip side, they are substantially more expensive than rim brakes.

So my thinking right now is that the sustainability argument for disc brakes is a bit overblown, as I'm thinking I can stock up on rim brake pads and pilfer eBay for components as needed, and if I build a high end rim brake road bike this year I could get a solid 10 years or so out of that bike. In fact, I would speculate that a carbon frame would wear out before the brake system would, as I see Shimano Ultegra rim brakes still kicking it 10, 15 years later.

What do you all think? As an admitted noob at this, I'd be happy to hear your thoughts on whether it's worth it to build a high end rim brake bike today (and spend that extra money on, say, a wheelset), or whether it would best to "get with the times" and go disc?

Some details about me as a rider just building an identity if it helps inform your thoughts:

• I'm pretty new to road cycling, but I love it so far.
• My favorite parts about cycling right now is sprints on the flat, but I kinda like climbing in a weird, twisted way. I suck at it, but still.
• I tried a carbon handlebars and hated them. Something about my FSA Omega Compact alloy handlebar just felt "right" by comparison.
• All the folks I ride with use SRAM, I'm the weird one with Shimano.

Lower cost is the only reason I can see at this point to go with rim brakes. Advantages like "better aero" are pretty spurious given that pretty much all high end cutting edge aero bikes are disc only. As a "noob" it isn't going to matter anyway. So don't overthink stuff like this. Same goes for weight. The difference won't matter.

Another factor you might want to consider is tyre width. Personally, I wouldn't buy a new frame with less than 32 mm tyre clearance and that rules out most rim braked frames.

But overthinking things is what i do professionally! (I'm a professor). But in all seriousness, good points.

Me too. I did in fact worry about this a lot, but went with discs (when it was a new thing on road bikes, in 2014), and have zero regrets. I would never buy another bike without hydraulic disc brakes (or a frame without mounts).

You also got outstanding advice on getting a frame that will enable you to run wide tires. Personally, I wouldn't get anything that prohibited mounting 38mm tires.

If you're interested in running your tires tubeless, there's a very limited selection of tubeless rim brake rims.

Well, I'm a retired accounting professor and used to be good at making the simple complex . . .

In this case, pretty straightforward, though.

I spent most of the last year riding a bike with Shimano di2 with disk brakes. They work fine. Recently got my custom ride with Campy Chorus rim brakes.

My experience is that the Campy brakes are functionally equivalent to the disks. Or maybe I should say, they work just as well.

Good luck with your quest!

Yeah, showing my noob-skin there, because now that it was mentioned and I'm thinking about it, the roads where I am are not great. I've had two flats in the last three weeks by hitting gravel in our bike lanes. That, combined with the potholes and other road goodies really motivate wider tires.

Interesting you went from disk -> rim while most other riders are going the other direction. Any reason? From what I can tell, folks who run Campognolo swear by it.

Here is a nice and balanced article on the subject from Rodriguez Bicyclez in Seattle (they know a thing or two about brakes):

https://www.rodbikes.com/articles/di...sco-fever.html

Tubeless is the way to avoid regular flats. Combined with wider, higher volume tyres at lower pressure.

"Building A road bike"

I believe I've found your problem. Building bikes is like potato chips - you can't do just one!

A comment about not buying a frame that can handle less than 32mm tires was made earlier because rim brakes can't fit wider than that.

...but they can. Easily.
There are multiple brake calipers that are high quality and can handle a 35 or even 38mm tire. TRP and VeloOrange both have really well reviewed options. Mt main road bike has trp957 calipers with 32mm tires right now, and a 35 easily fits. The calipers are stiff and react consistently, just like short reach calipers.

I think the killer reason for going disc is carbon rims. My carbon rims have been through shocking potholes without issue and they're so darn lightweight.

I really like my rim brake bikes, but I find braking is superior with disc and especially in the wet.

It was more a question of checking if the frame has enough tyre clearance. A lot of modern rim brake road frames have limited clearance, while new disc brake frames are nearly always designed to accommodate wider tyres.

How new to road riding? No matter how carefully you pick your first bike, it will not be optimum for you, and you'll be taking this experience to move on to bike #2 and then bike #3. Based on extensive experience with folks needing service, bike #3 is about right or getting close. So I recommend you try a lot of bikes and don't spend a lot right away.


More:

• Really good mechanical discs have about the same stopping power as good rim brakes. I'm riding R8000 rim brakes over some long long descents, and they are really good. Direct-mount rim brakes are even better.
  
• Discs are going to add roughly 2 pounds to your bike between the rotors, heavier calipers, bulked-up frame and fork, and bulked-up rims/spokes/hubs. Plus $500+ to your tab. Are you doing warp speed descents in the rain? Do you have arthritic hands or carry camping gear on your bike?
  
• Bike weight is the biggest factor in road performance - particularly wheel weight. Riding with a group - the last thing you want is to get dropped off the back on a climb or a hard acceleration out of a corner.
  
• Fat tires (>25mm).. Just how heavy are you? If you are appropriately cyclist svelte, then fatter tires are heavy, less aero, and have higher rolling resistance. The heavy fatter rims required for these tires double-down on this disadvantage. Tires and wheels suitable for gravel riding are too slow for fast road riding.
  
• Tubeless: if you live in goathead country or do not know how to field change a flat, then I guess tubeless is good. Otherwise, this is a PITA solution inappropriately borrowed from the MTB world. Like the other items in the list above.
  
• Finally, the bike industry and associated bike shops: listen carefully what they say, but remember that they are always trying to sell you something. Something new.
  

Rim brakes are very good, and as addressed earlier, there are some ways to run bigger tires with them. I have a bike with carbon rims and old Weinmann rim brakes, but I would never recommend it. Cable actuated discs are very good, also. In my opinion hydraulic disc is the only way to go on anything remotely new and nice, worth every penny.
Aero disadvantage and weight of a disc set-up (I'm dubious of the 2 pound claim) will not get you dropped on a local ride or race, you will get dropped because you burned too many matches or are simply out-gunned and out-motored.
If you really like sprinting, after you get your road bike get a track bike with front brake and an 85 inch gear or so, for fun and road sprint training (assuming you have flat to gently rolling places to ride)

Big reason, I'm a hardcore traditionalist when it comes cycling!

I ride for enjoyment and health. I ordered a David Kirk custom steel frame about a year ago and decided to go with Campy for the cachet factor and--after reading many good reviews of Campy hardware--the reputation for excellent performance.

The Kirk would take over 10 months for delivery so I bought a Ribble titanium road bike to tide me over. Ribble equipped with Shimano 105 di2 (electric and disk).

The Ribble satisfied my curiosity about electric shifting and disk brakes and I have only good things to say about them here.

Nonetheless, having had the Kirk for about a month (and 300+ miles) now, I'm completely sold on Campy mechanical group sets for the kind of riding I do.

My serious thoughts are that setting up the cables and all for rim brakes is a lot easier than setting up hydro disc brakes. BUT, IME as good as the latest generations of rim brakes are, hydro disc brakes are better. My question would be, what kind of riding are you doing? Because of road closures from all of the rain we got this winter, have mostly been riding more rolling terrain without any big descents, so it's not a big deal. If I were doing big descents, I prefer the discs, but the rim brakes work fine, too.

I live in flatland Delaware, I do ride when it is wet. The biggest issue with both rim and disc brakes is getting them set up properly, that is usually easier with rim brakes. Once you learn how to get the disc brakes set up, and do it a couple of times, really not an issue. MY experience is only with mechanical disc, never had hydraulic. With rim brakes, the pads, and rims being used have a big affect on performance. Kool Stop Salmon pads, or other brands of that type, and machined rims, IME, are go to for me. For overall braking performance, for where and how I ride most of the time, I give a very slight edge to disc, more about the modulation than the actual stopping.
Looking at the future of availability does not concern me, but, if I was younger and looking at long term, pretty sure hydraulic disc is the way I would go. If I was looking to get new mechanical disc brakes, I would be looking at the TRP Spyres, or another brand that has dual piston braking. I like to think I would still have a rim brake bike.

Asking this forum regarding cycling advice becomes like writing a letter to the editor in 1977 Bicycling Magazine as the advice received is about as relevant on many occasions. Modern rim brakes are great but not superior to Disc, but that does not negate your desire for a rim brake bike. Just like a VW Bug was a good vehicle but in no way is comparable to a modern VW Golf.

But rest assured you will love your bespoke to you bike regardless of braking system selection.

You should definitely spend a lot of time pondering this decision because, if you make the wrong choice, you will never recover from it.

Rim brakes have always worked just fine for me over the last 20 years or so that I've been biking seriously. That said, disc brakes instill more confidence on steep descents. For me, this psychological benefit of discs outweighs their objectively better stopping performance difference.

Beyond braking, however, disc configurations provide other benefits like not worrying about your carbon rims delaminating (if using rim-brake carbon wheels), and having wider tire clearance (this is incidental to how frame designs have evolved and not due to disc brakes per se).

My biggest apprehension towards discs is that they tend to be heavier (as a system: rotors, calipers, fluid, wheels, etc.) but I must admit that modern disc setups of today don't suffer as much of a weight penalty as they did just a few years ago. As such weight would not be a deciding factor for me now.

Thinking about this the other way, what advantages do rim brake bike provide over discs? Cost, weight, and simplicity/purism come to mind.

Both are viable. If you ride in the wet or long descents you probably would lean towards disc brakes.

If you are a retrogrouch like me, lean towards rim brakes.

Realize that medium to high end Shimano (ie 105/Ultegra/DA) will not support rim brakes going forward.

I've built up many bikes and built up four disc frames. Disc doesn't add over a pound of weight. Support for new rim brake groupsets is fading quickly. Disc frames can accept wider rims and tires. I have 23-25mm IW hookless rims that allow tire pressure in the 50's with 28-30mm tires for a greatly improved ride. I use carbon rims and don't have to worry about brake pads wearing out a rim. Even finding new rim brake frames is difficult.

There's some great deals on SRAM force axs parts right now.

Heads up for the OP. This guy has an unhealthy dislike of most new bike tech and thinks it is only suitable for fat dentists.