Trek gear up for the disc brake revolution with new Domane Disc

We chat to Trek's Michael Mayer and Ben Coates about the new Domane Disc

by David Arthur   May 9, 2014  

Domane_Disk_Angle

Disc brakes on race bikes it's a hot topic and the trend du jour. Last week Trek showed it wasn't a trend they would be ignoring wit the release last week of the Domane Disc. Their first foray into t he world of disc-equipped performance road bikes will initially be available in two versions, the £1,600 Domane 4.0 and the £6,000 Domane 6.9. 

The bike created a few talking points. So we had a chat with Trek's Road Brand Manager Michael Mayer and Senior Road Product Manager Ben Coates about the Domane Disc, asking them for their view on the future of road bikes with disc brakes and to explain some of the new technology in the Domane Disc. 

Do you think disc brakes the future of road bikes?

That is a complicated question, while the easy answer is yes, the reality is that is not that simple or cut and dry. For some applications, disc brakes are not only the future but they are the here and now.  There are plenty of riders that see the value of versatility and braking performance that disc brakes offer.

The bigger question that I believe you are asking is, if they will be common place for the future on all or most road bikes? That is where it gets complicated. Taking into account UCI regulations (which might change), weight, aerodynamics, cost, rotor size, chain line, brake rub etc, there are a lot of hurdles to jump over. That said, as an industry, we are in a similar position that mountain bikes were in not too long ago. Only time will tell if we can jump over all of the hurdles to make disc brakes common place.

Why did you choose the Domane to launch your first road bike with discs, and not the Madone?

Domane platforms makes sense for how the bike is ridden, where the bike can be ridden and the growth of the endurance crowd. Just like the Boone is spec'd with Disc brakes, the Domane is the next obvious choice.

Yes, disc brakes offer superior braking performance over calipers; but the brakes, rotors, and wheels are a bit heavier than their rim brake counterparts. Plus, there are simply more rim brake wheel choices available, particularly on the high end, and riders are more likely to have a few pairs of those already in their stable. But for that adventure-seeking customer looking for supreme braking performance in all conditions, disc brakes are the way to go. Domane Disc fits this crowd.

Have you had to make many changes to the frame and forks to account for the disc brake forces?

No changes to the frame and fork geometry. New completely designed fork top to bottom designed for post mount Disc brakes. New carbon layup to handle the stress of disc brakes. New designed chain stay for the same purpose.

Is there any weight penalty in the frame and fork compared to the standard Domane?

Yes,  there is an overall weight addition when adding Disc brakes. Slight increase to frame and fork itself and more to the addition of the brakes themselves.

What sort of tyre clearance can we expect on the frame?

With the removal of the caliper and brake bridge you have an increase in tyre clearance.
25c is the max tire we can spec legally. We have some selling restriction because of CPSC and CE clearance models.  We feel tire size is definitely a preference and 25c a great all around size.  We cannot say we recommend a bigger size.

Why bolt-thru axles? Most new disc road bikes are appearing with regular quick releases.

Thru axles significantly stiffen the frame-wheel interface for more steering precision and better cornering, thanks to less flex in the system. They also ensure that the wheel is precisely placed in the dropout each time it is installed. This helps eliminate disc rotor rub from the wheel being crooked in the dropouts because of improper installation. Domane Disc is also compatible with quick-release wheels.

All Domane Disc models come set up with thru axles, but are convertible to QR if you're looking to run an existing wheelset. The rear converts to the 135mm QR disc standard.

Do you see bolt-thru as essential to the future of road disc bikes?

We feel the bolt-thru is a benefit to the road category. Just like mountain bikes evolved to this technology and acceptance, we feel road will also follow this path or develop an even more improved method over both.
UCI racing discs will most likely develop new technology.

Many disc skeptics talk about slow wheel changes. Is that the case with bolt-thru?

I think the one place this can effect is if the bike is raced in a road race. But otherwise changing a wheel is not that much hassle. The time on the bike and ride performance outweighs the wheel change time. Disc brakes rubbing on a MTB sucks. Disc brakes rubbing on a road bike is unacceptable.

Plus, one of the beauties of our interchangeable dropout system is that you can swap the front dropouts from left to right. That means you can put the lever on the traditional side (left)—or you can keep the lever out of the way of the rotor by putting it on the non-disc side (right).

Can we expect to see this new technology feature on future road models in the Trek range?

I am not exactly sure which technologies [we meant disc brakes] you are referring to but in all, the answer is that we are already cross-pollinating technologies where it makes sense and developing new technologies where it doesn’t. We have borrowed knowledge from our MTB friends in the building on thru-axles, balanced post mount and carbon armour. We have put IsoSpeed and disc brakes on the Boone platform. OCLV is a company-wide technology that we continue to leverage. We will continue to utilise the right technology for the right products in the future.

After working on this new Domane, what do you see as the next development of this sort of bike?

The Domane is an amazingly versatile platform with an incredible ride that is focused squarely at going fast by being smooth and efficient. The opportunities to increase speed by targeting those two focal points are tremendous. A little imagination and reflection on the current bike will help us drive to the next one. What will that be? Good question…


Thanks to Michael and Ben for their time. Some interesting answers there, especially his views on bolt-thru axles and the UCI's stance (and whether that will change) on disc brakes in the professional peloton, and how this might push the development of frame and fork designs and bolt-thru axles. Are we about to see a lot more new road disc bikes with bolt-thru axles in preparation for a change of the rules by the UCI?

Most new disc road bikes coming out are sticking with conventional quick release axles that have been used since Tullio Campagnolo invented the concept in 1927. It hasn't changed much since. We saw a lot of disc road bikes at Eurobike last September and the majority had conventional axles, but a few brands like Giant and most notably Storck bucked the trend with bolt-thru axles. Some think this is the way forward for disc road bikes.

When we chatted to Markus Storck about his use of similar bolt-thru axles on his new road bike, he explained to us that it's is the extra stiffness they provide, but also allowing the fork and rear stays to be designed with fewer layers of carbon fibre, because the axles provide a lot of the necessary stiffness. So there's less carbon in the sides of the fork legs and in the seatstays and chainstays.

There are a lot of people in the industry who reckon the disc brake revolution is coming, as we found out when we interviewed the likes of Keith Bontrager, Ben Coates, Dan Jones, Mark Reilly and others last year.

10 user comments

Oldest firstNewest firstBest rated

Pourquoi pas 'le Disque?

joemmo's picture

posted by joemmo [914 posts]
9th May 2014 - 8:21

18 Likes

I think this is a debate which will soon pass and disks will be everywhere you look on road bikes, just like they are on mountain bikes.

When I moved to hydraulic disks on my mtb (ten years ago...) the performance benefit was absolutely massive, and I've never looked back.

You get: much more power, nicer lever feel, consistency in all conditions, lower maintenance, no compromised rim design for needing a brake surface, no wearing out your expensive rims, I could list more.

The market is led by performance improvements - for me the improvements are stark!

My only question is, what is taking so long?

posted by Streamliner [6 posts]
9th May 2014 - 14:54

27 Likes

Because there is a pretty big marketing problem selling disk wheel bikes to racers if they are substantially less aerodynamic (apparently a disk brake increases drag about the same amount an expensive aero rim reduces it).
Also, since aero wheels are such big sellers, manufactures won't be happy if disk brakes kill the aero wheel market.
You could still sell "aero" disk wheels, but once people realise they are a croc, what might happen to sales?
From the noises the UCI has made about disk brake bikes and rim brakes being supposedly "incompatible" there is perhaps some thought of an agenda to "fix" the problem by outlawing rim brakes.
There is obviously a big risk of consumer backlash against this, so maybe there is pressure to hold off until aero disadvantage of disk brakes can be eliminated or at least mitigated by technical advances.
This looks to be a big ask from a technical point of view since the consensus seems to be that road bikes need better cooling for disk brakes than mountain bikes, (better cooling=more drag). For an example of this check out shimano road disk brakes with frilly (drag inducing) coolers on inside edge of the disk.
http://brimages.bikeboardmedia.netdna-cdn.com/wp-content/uploads/2013/06...

posted by imaca [46 posts]
10th May 2014 - 4:57

8 Likes

Both Joemmo and Streamliner have probably like me experienced the transition in MTB from rim brake to disc brake to disk brake with thru-axle. These breakthrough technologies have now trickled down to entry level MTBs for all to be enjoyed.

The difference with road cycling? MTB is not ruled by the (still?) totally corrupt UCI, more interested in bakshish than in advancing the sport and/or protecting the athletes. It is truly amazing and a case study how a sport governing body can inflict so much harm on that sport.

The only concern about disk brakes of the reformed(?) UCI that I read about in these columns is "freinage à 2 vitesses". Wow, disk brakes are so more powerful and flexible than rim brakes that the mix of the 2 standards might cause havoc in the peloton. My guess is that once the UCI gives the green light, the whole peloton will convert at once and rim brakes will be relegated to the past. Buyers of rim braked bling bikes, beware!

The entropy of the universe increases constantly. Carpe diem.

posted by noether [89 posts]
10th May 2014 - 5:00

11 Likes

Concentrating the mass around the axle and "liberating" the rim for better aero designs is a godsend for manufacturers. They should at the same time revisit the 700C wheel size. They did in MTB, and found out that mountain bikers immediately embraced the new standards because they were that much superior, without any downside. Consumers will be ruffled at first, but soon appreciate the massive improvement. The bigger picture is that these technologies will then soon trickle down for all of us to enjoy. Therefore, the sooner disk brakes are introduced in road racing, the better.

The entropy of the universe increases constantly. Carpe diem.

posted by noether [89 posts]
10th May 2014 - 5:16

6 Likes

Lol.

You actually think that the aero difference between a (for example) 30mm rim with rim braking surface vs a smooth disc-only rim shape makes a measurable difference? There's WAY too much turbulence coming off the spokes in the same area for that to have any level of practical difference.

And you are suggesting that the change from 26" to 29" was anything other than pure hype and convenience?

No downside?

You live in fairy land dude.

Bigger rims means dramatically increased rotational mass - maybe not noticeable on a scale, but definitely the tire has an effect. That can work for you (on a long flat or rough road) or against you (climbs, start-stop technical trails). However, a 29" rim is going to have a harder time being as rigid and as strong as a 26". Which is why so many went back to 27.5" (which is most of the way back to 26 due to the effects of pi).

The primary reason for the change to 29 was to create a 'sideways step', to stimulate growth in bicycle sales during an economic downturn (where luxuries are the first to go). They already had the molding and the math for the 29" standard, so it was a low-cost switch. The change to 27.5 was half retcon and half "let's do that again, but this time, I want to be 'first', similar to the tapered head tubes standard.

In order to move to a larger standard than 700c, wheel makers would need a ton of new molding costs. Maybe new rim tape, new jigs for rim builders, new jigs for spoke builders. Bigger hoops either means higher tension or floppier wheels. Higher tension spokes might require bigger nipples. Bigger nipples means bigger nipple holes and beefier (heavier) rims.

And all for what benefit? Everything that MTB got from 29" was give/take anyhow (higher rotational mass or floppy wheels and more cracking at the spoke holes, etc). Naw. Road wheels won't be getting a new size anytime soon.

Physics is a thing. Marketing is another. I can see which one you have more time for.
(ps, it's Entropy)

posted by eschelar [41 posts]
10th May 2014 - 6:01

5 Likes

I'd like to see bolt-thru axles become the standard for disc equipped road bikes, this is one area the MTB industry has really stolen a march on the road side. Hopefully now with Cookson at the UCI helm we can start to get some movement on this.

posted by giobox [342 posts]
10th May 2014 - 6:30

7 Likes

"I'd like to see bolt-thru axles"
Why?
2 possible reasons. Keeping the wheel in is shouted about but they don't fall out. Never seen a wheel drop out (road or MTB) that has the QR tightened properly although it must be said that modern alloy QR's are not as good as internal cam steel ones. Those bloody lawyers lips also stop the wheel falling out if you are too stupid to put it in properly.
Another reason touted is stiffness. That may be seen as a more sensible reason and I am sure that if this proves important on the road it will happen.
The through axle could be a good solution in circumstance but its not perfect. Shoving a dirty axle through bearings frequently isn't good. some compromise with a retained axle seems to be the way forward.
I wonder if drop down flaps would work, one each side with a some form of QR. This could easily be self centring which is also a concern amongst some people with regard to discs.

posted by mattsccm [280 posts]
10th May 2014 - 7:11

9 Likes

noether wrote:
Concentrating the mass around the axle and "liberating" the rim for better aero designs is a godsend for manufacturers.

Exactly what part of the brake track is not aerodynamic? What would you put in it's place that's more aerodynamic than it already is?

posted by Nick T [844 posts]
10th May 2014 - 8:44

4 Likes

eschelar wrote:
Lol.

You actually think that the aero difference between a (for example) 30mm rim with rim braking surface vs a smooth disc-only rim shape makes a measurable difference? There's WAY too much turbulence coming off the spokes in the same area for that to have any level of practical difference.

And you are suggesting that the change from 26" to 29" was anything other than pure hype and convenience?

No downside?

You live in fairy land dude.

Bigger rims means dramatically increased rotational mass - maybe not noticeable on a scale, but definitely the tire has an effect. That can work for you (on a long flat or rough road) or against you (climbs, start-stop technical trails). However, a 29" rim is going to have a harder time being as rigid and as strong as a 26". Which is why so many went back to 27.5" (which is most of the way back to 26 due to the effects of pi).

The primary reason for the change to 29 was to create a 'sideways step', to stimulate growth in bicycle sales during an economic downturn (where luxuries are the first to go). They already had the molding and the math for the 29" standard, so it was a low-cost switch. The change to 27.5 was half retcon and half "let's do that again, but this time, I want to be 'first', similar to the tapered head tubes standard.

In order to move to a larger standard than 700c, wheel makers would need a ton of new molding costs. Maybe new rim tape, new jigs for rim builders, new jigs for spoke builders. Bigger hoops either means higher tension or floppier wheels. Higher tension spokes might require bigger nipples. Bigger nipples means bigger nipple holes and beefier (heavier) rims.

And all for what benefit? Everything that MTB got from 29" was give/take anyhow (higher rotational mass or floppy wheels and more cracking at the spoke holes, etc). Naw. Road wheels won't be getting a new size anytime soon.

Physics is a thing. Marketing is another. I can see which one you have more time for.
(ps, it's Entropy)

From your comments, it beccomes obvious that you rely on hear-say rather than own experience. MTBers have now 2 formats to chose from, 27.5 for trail, 29 for XC. I picked-up a 29er because I love long excursions in the rough. Try one and then blush at what you wrote.

Technological advances have made larger radius, light and stiff, tubeless ready MTB wheels possible. Actually the diameter of a 29 inch wheel is the same as that of 700C, MTB tires are much larger, making the whole MTB wheel bigger. The same advances could be applied to larger diameter road wheels. I do not pretend that the benefits are as huge as the switch from 26 to 29, still I would like to hear from a knowledgeable source if 700C still represents the optimal size from a technical point of view. Curiosity is the driver of progress.

Road wheel aerodynamics are in their infancy. The removal of the constraint of having to cope with rim brakes opens up new possibilities for rim shapes and surfaces. The world of physics is richer than you think.

And yes, more wheel sizes increase entropy.

The entropy of the universe increases constantly. Carpe diem.

posted by noether [89 posts]
10th May 2014 - 15:31

4 Likes