2019 Trek Madone SLR 6 review

A few months back Trek revealed the sixth iteration of its race-proven Madone road bike. In recent years the Madone has transformed into an all-out aero road machine promising uncompromising performance while still delivering a comfortable ride.


The latest version is said to further refine the Madone platform with the addition of a disc brake option and a revamped IsoSpeed dampening system among a raft of other improvements.

Trek Madone SLR 6 Disc-16.jpg


The Madone SLR frame sits at the top of the range and makes use of Trek’s lightest 700 series OCLV Carbon. Aside from the all-important disc brake option, only available on the SLR variant, the stand out feature on the Madone SLR is the adjustable IsoSpeed decoupler.


Trek’s marketing tells us that the new adjustable version of the IsoSpeed decoupler, now fitted to the top tube, is 17% more compliant on the softest setting while 21% stiffer on the firmest setting when compared to the previous Madone. Dosed with some heavy scepticism, I was pleasantly surprised by this feature, but more on that later.


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No. 6 - As a side note, the naming in the Madone family had me a little confused initially. Although now in its sixth iteration, within the Madone SLR lineup there is an SLR 6 and SLR 8 where the “6” and “8” refer to the specification level rather than the platform version.


We tested the Trek Madone SLR 6 Disc, equipped with a Shimano Ultegra 2x11 groupset and Bontrager Aeolus Comp wheels. The new SLR frameset is impeccably clean in its looks, with an integrated, cable-free cockpit and internal cable routing throughout. In the silvery-grey colour-way supplied, the bike reminded me of a stealthy navy frigate or fighter jet, filling my inner eight year old with glee. The bulky tubing on the SLR may not be to everyone’s taste, especially on the louder colour options, but in this navy inspired livery it feels well balanced.


The Madone SLR comes with an integrated aero seat post and on the 56cm frame, the 160mm post supplied as standard was just short of my required extension. Thankfully Trek also offer a 205mm post and had one delivered to us within two days. Given my abnormally long legs for my height, this shouldn’t be an issue for most, but still worth checking.


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The two-piece bar and stem houses all cables to create a beautifully simple cockpit. The attachment point allows for +5 or -5 degrees in angle adjustment via a four bolt system neatly tucked away on the underside.


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The Bontrager Aeolus Comp wheels piqued my interest as upon closer inspection you may note that these are aluminium rims with a carbon aero fairing. This somewhat unconventional approach provides the aero advantages you’d want on a bike like the SLR (and let’s be honest, the “aero look”) while keeping the price in check. While they’re not the full carbon deep sections you might be inclined to expect at this end of the market, this choice likely helps to squeeze the price under the R100 000 mark.


On a related note, although out of the box the wheels are fitted with 25C Bontrager tyres, the frame supports up to 28C tyres according to Trek, but it looks like there's enough room to go even wider if you wish.


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Below is a full component breakdown for the 2019 Trek Madone SLR 6 Disc as tested.



  • Frame700 Series OCLV Carbon, KVF (Kammtail Virtual Foil) tube shape, Adjustable Top Tube IsoSpeed, Micro-adjust seatmast, tapered head tube, BB90, flat mount disc brakes, 12 mm thru-axle, invisible cable routing, control centre, precision water bottle placement, Aero 3S chain keeper, DuoTrap S-compatible
  • ForkMadone KVF full carbon disc, carbon tapered steerer, carbon dropouts, hidden cable routing, flat-mount disc brake, 12 mm thru-axle
  • HeadsetMadone integrated, stainless cartridge bearings, sealed, 1-3/8˝ top, 1.5˝ bottom
  • Bottom bracketBB90
  • CranksetShimano Ultegra, 50/34 (compact)
  • StemMadone-specific internal cable routing
  • SeatpostMadone carbon seatpost, 25 mm offset w/integrated light mount
  • GripsBontrager tape
  • HandlebarMadone-specific adjustable aero VR-CF, internal cable routing
  • Front derailleurShimano Ultegra, braze-on
  • Rear derailleurShimano Ultegra
  • BrakesShimano Ultegra flat-mount hydraulic disc
  • ShiftersShimano Ultegra, 11-speed
  • SaddleBontrager Montrose Elite, titanium rails
  • WheelsBontrager Aeolus Comp 5 Disc Tubeless Ready, 12 mm thru-axle
  • ChainShimano Ultegra
  • CassetteShimano Ultegra, 11-28, 11-speed
  • TyresBontrager R3 Hard-Case Lite, 120 tpi, aramid bead, 700x25c
  • Weight8.4kg (56cm)
  • PriceR 98,999.00


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On the road

Typically a race-oriented aero bike has to make some compromises in terms of handling and ride quality in the pursuit of speed. The Madone SLR, however, offers a degree of comfort and handling not usually associated with this category of bicycle.


This is largely thanks to the IsoSpeed Decoupler system, which as the name suggests, decouples the frame at the junction of the top tube and seat tube. The two frame components are connected by a series of bolts and elastomer dampers with a sliding adjuster to change the feel of the frame.


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The separate sections of frame which make up the IsoSpeed Decoupler system are visible below the top tube.


With the damper on its most compliant setting, the ride is incredibly smooth while the frame still feels responsive. Sliding the adjuster to the firmest setting created a remarkable difference in the ride feel. Bumps in the road that had been almost entirely softened were now jarring and ever-present. To the point where on the bumpier road surfaces I had just sailed through unphased, I was now easing out of the saddle to find relief from the shocks. On a smooth surface, this harshness would be welcome and the obvious distinction in ride quality is a testament to just how effective the decoupler is.


As an aero race bike, the SLR feels great. Without a wind tunnel and a PhD I can’t say how much faster it is or isn’t, but suffice to say that in the drops it gives the impression of speed. The stiff frame lends itself to quick accelerations and the bike holds speed with ease on flats and rolling hills.


Given the class of bike, you can’t expect it to be an outwardly nimble climber, but aside from carrying a little extra weight, I was impressed with the feel on the climbs. Particularly out of the saddle where aero bikes tend to get increasingly awkward as the gradient ticks up, the SLR felt quite composed and comfortable. It’s by no means my first pick for a Hors catégorie ascent, but for any local road race it’s a perfectly capable climber.


Overall the bike handles well with a very stable, confident feel on the downhills. Although stable, the bike still responds well to sharp directional changes without the twitchiness that can accompany the aero label.



The Trek Madone SLR 6 delivers an unmatched ride quality among a crop of ever improving aero road bikes. Add to that great handling and good climbing manners, this aero road bike is quite simply a great road bike. The top end frame construction and dampening features do add to the price, but it seems Trek has indeed solved the aero plus comfort equation.



Trek Madone SLR 6 Disc-1.jpg


MDJ, Dec 03 2018 02:06

Ahhh my dream bike at the moment - 100k before the Di2 upgrade ;). How do you get one of these for a test ride ... quite a bit of cash to drop and find out you don't like the ride feel!

CASSIE1975, Dec 03 2018 02:36

Stunning bike, WOW...even WITH a set of ALU wheels and Ultegra groupset, sadly still outside of my Price Bracket.


That frame sounds VERY interesting...depending on your settings and road conditions, it can be 2 or 3 bikes in one...that is some engineering!


Will be keeping an eye out on the Classifieds for a secondhand beauty :-)

mon-goose, Dec 03 2018 02:58

i don't really know my stuff so I might be completely wrong but R100k for a 8.5kg.. seems a bit much

PeterF, Dec 03 2018 03:08

You should add to the cons that should you require a longer seatpost it will set you back an additional R4k.

lechatnoir, Dec 03 2018 03:15

Ahhh my dream bike at the moment - 100k before the Di2 upgrade ;). How do you get one of these for a test ride ... quite a bit of cash to drop and find out you don't like the ride feel!


Yes! and that's just for the test ride...  ;)

Furbz, Dec 03 2018 03:20

i don't really know my stuff so I might be completely wrong but R100k for a 8.5kg.. seems a bit much

yep. i also cannot get over the weight 

Pure Savage, Dec 03 2018 05:49

I reckon with carbon rims this will be 7,7kg, not too bad for a aero bike.

Brother Brett, Dec 03 2018 08:12

Aero frame with compact crank, controversial much?

MDJ, Dec 03 2018 09:01

Aero frame with compact crank, controversial much?


Yeah, clearly targeting the mamil market ;). She is beautiful though ... 

PeterF, Dec 04 2018 07:18

Aero frame with compact crank, controversial much?

Not really sure it is an issue :-


53x11 at 100rpm = 60.7km/h

50x11 at 100rpm = 57.3km/h


So a difference of 3.4km/h!

Jaco-fiets, Dec 04 2018 01:38

My fav bike at the moment!!!

buchanan, Dec 04 2018 04:46

That's a very heavy bike. Almost 2kg heavier than my Felt F2.

PeterF, Dec 04 2018 06:29

That's a very heavy bike. Almost 2kg heavier than my Felt F2.

But your Felt F2 is not an aero bike, and does it have disc brakes?

Headshot, Dec 05 2018 01:00

What does a similar Giant aero road bike cost? Or one of those famous TT breaking Canyon's?