Disc Brake dilemma (Please Help)

Im 21 years old and working up the USAC racing categories, losing body weight is not an option (60kg @5’9) Im currently on the market for a new race bike. I’ve decided to go with the Giant TCR (carbon wheelset, dual sided power *on both models discussed here) I simply cannot pass up the value for money and Giant will replace frames for free if damaged while racing (pretty sweet deal!) The Rim variant is 15.5lbs and the disc is 16.7 lbs! :flushed: As someone who lives in the mountains i’m very confident with rim brakes but the sound of great braking in the wet sound very nice considering it rains here 30% of the time. I plan on doing crits where weight doesn’t matter as much, however I plan on doing several climbing road races and uphill time trail series. My goal is solely on racing and being fast will the 1.2lbs of extra weight on the bike REALLY be that detrimental and or is it worth it? This is a VERY big decision and one that will last me for the foreseeable future, so making the right choice is paramount. Any help is greatly appreciated.

Thanks, Caleb

Bikes:
TCR Advanced Pro 0 Disc (16.7lbs)
TCR Advanced Pro 1 (15.5lbs) - would upgrade this to Di2

The weight doesn’t matter. 1.2 lbs is nothing.

I prefer my rim brake bike because it’s easier to maintain and the brakes don’t rub. I used to have a disc brake bike. I had to re-center the calipers and true the rotor often. It gets to be a pain if you travel a lot. The braking is nice, but you don’t brake in a race.

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I say go with the disc brakes. It’s very doubtful that 1.2lb will make or break you, but going downhill in the rain on carbon rim brakes just might.

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Since you’re buying something to last, don’t buy old tech.

Get the discs.

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I have alloy tubeless wheels i would use for training if I went Rim Brakes

If you do go with rim brakes I suggest keeping a separate set of brake pads for your carbon and aluminum wheelsets. The pads used on aluminum rims will pick up little bits of aluminum and damage your carbon rims.

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Well versed in this i have raced on carbon Tubs and currently train with alloy wheels (Swiss Stop make the best carbon pads i’ve used so far)

I’d go disc brakes. It’s great to have the additional stopping power when you need it.

In addition, if you end up wanting to change or add wheelsets in the future, many of the new ones are disc only. Enve’s new Foundation series is an example of this.

You might also be able to shave some weight on the Giant in the future as you tweak things.

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Im just worried as someone who will travel A LOT to race with this bike, Ive heard so many disc brake horror stories with rubbing ect…

Mild rub is usually really easy to fix. I carry a truing fork with me when I travel.

This video from Park Tools is quite good and walks you through different scenarios for truing.

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Thank you!

This is interesting… I’ve found disc brake MTB and Road bikes a revelation, being so much easier to maintain than rim brakes. I don’t think I’ve ever had a rotor that didn’t run true, and even if a calliper needs re-aligning it’s a question of loosening two bolts, squeezing the brake on, and tightening the bolts again. Replacing the pads is also simple - drop the wheel out, remove pads, insert new ones.

Whereas on rim brakes I would have callipers that didn’t retract/open properly, pads that would wear unevenly, need frequent adjustment, etc. To a degree I guess it’s a case of what you’re familiar with - but for me, but the benefits of discs are as much the ease of maintenance as actually being able to stop better.

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I might be lucky, but I never had a prob with my disc brakes. It’s almost maintenance free. As in everything at first there are few new things to learn, past that it’s amazing.

I don’t travel with my bike so no experience in that… but can’t see the prob. Even if you are worried with the disc damage, set up centrelock it takes 30 sec to remove and install.

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Half a kilo difference is nothing really, especially for consistent braking. I don’t know about where you lives weather, but I went out yesterday in glorious sun and got rained on. It changes so quickly which is why I’ve not got carbon rims, it’s just too variable but that really depends on where you ride. Also think about if your racing, you could end up in somewhere hilly and wet.

Mtbs have had discs for 2 decades now and bar some brands being a bit crap generally they’re reliable, and my mtb gets worse treatment than my road bikes for sure. The biggest issue I have with my mtb discs was my slightly lackadaisical cleaning routine contaminating the pads - this isn’t a disc error but a end user issue.

I’d also want to look to the future, all my bikes are ridden for years before being replaced, some companies don’t have top end bikes with rim options anymore and I think this will include more companies as time goes on. This means that you’ll start to see less and less options for new wheels. This year that’s fine but 5 years time who knows.

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disc, that’s where everything is going. disc is more aero!

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I don’t know about the disc is more Aero - feel like I saw a test that it was pretty neutral. However, don’t buy a bike that is Rim if you’re spending more than $1500. All the wheel technology is now focused on disc with tubeless tires. Every brand is dropping rim from their new models (e.g the very popular tarmac sl7 thread). That giant seems like a pretty good deal price wise. You mentioned converting to Di2 on the rim Giant - how much of a weight penalty comes from that at the ultegra level - specifically what does the battery weigh? If you want to obsess on groupset weight - you can dive into this: https://ccache.cc/blogs/newsroom/2019-road-groupset-weight-comparison

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The majority of rubbing disc brakes can be sorted by loosening the bolts that hold the callipers into the frame, then squeezing the brake lever hard whilst tightening the bolts back up. Takes a few minutes to do at most! Also if you’re travelling, I’d advise taking the rotors off the wheels and putting them somewhere they won’t get damaged.

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I’d 100% go with discs too.
Rim brakes also limit your tire choice to 25/28mm max. So they don’t go well with the current trend of wider tires for more comfort.

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Its only around 100 grams heavier so nothing really

Go for the rim brakes. Who needs more effective, reliable and low maintenance braking anyway? That weight saving might lose you 4 seconds up your favourite climb and it’ll be worth it even if it means you’re unable to avoid that major pile up on the downhill. I always insist on drum brakes on my cars. Good enough for Fangio!

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