Review: Trek Domane SL 5 Disc Road Bike

So you WANT a Trek Domane SL5 Disc? Of course you do...

(but utter it quietly, do you really need one?)

The ultimate example of WANT vs. Need.

From the moment you see this bike’s stealthy pro-looks close up your eyes light up and you can't help but think “oh yesss!”.  

From the moment you sit on this bike you can’t help but smile and think “I want one”.

But do you really need one?

Well here is a summary of my time with one and my thoughts around answering this question for you. Opinions expressed here are completely my own following taking up an offer from Trek Store Milton Keynes for a demo bike for a spin in return for a deposit.

I had the bike for a week and rode c165 miles on a range of roads, cycle paths, elevation profiles, in wet, dry, windy and debris-strewn conditions during that time. I road a 54cm frame.

To see the full nerdy spec of the bike jump to the end.

The Frame

It's 500 Series OCLV Carbon – so it’s pretty light but also tough.

Front & Rear IsoSpeed –  in layman's terms this is “suspension” for road bikes e.g. it absorbs the lumps and bumps of the road and minimises the jarring to you the rider. This is a total joy to experience!

(Understatement) this is an extremely comfortable bike to ride and I would definitely put a Domane frame on my possible list for future n+1 consideration for UK road riding.

It’s light enough but feels sturdy exactly because it is; it’s strong and stable – sure it’s what you may expect but the return you get is a joy to ride with just enough of a sporty edge to make you want to go thrash it.

If you haven’t ridden a bike with IsoSpeed before, at first the rear IsoSpeed has you thinking you have a semi flat tyre but after a few rides you are soon taking for granted the comfort return from the flex offered. The rear is more noticeable, imo, in normal riding to the front, as obviously more weight is on your saddle than your bars. It treats the Great British bumpy road as a playground and noticeably reduces your cursing of the lumps and bumps by those around you. Not to mention minimise those post -ride achey shoulders.

The front IsoSpeed comes more to the fore on descents, especially bumpy ones. The extreme sensation I would compare it to is thinking you have a loose headset! The reality is that that is the IsoSpeed flex at work and once you become familiar with the return you get it is a joy on uneven descents. Obviously it is doing its thing on the flat too but it was downhill that it’s pushed to the extremes and I really felt it at work.

One of the main things I observed following a 5 hr ride on some single track country lanes covered in debris and littered with pot holes etc. was in my shoulders. Having done this route many times I knew that normally I ended up with tight/sore shoulders from the tensing of handling the brutal surface, especially on some descents.

However, with this Domane there was none of that and it wasn’t until the end that you realise this and credit has to go to this astonishing frame.

The Wheelset

Two words; zoom, zoom. Visually they add a touch of pro bling to this bike and from a ride perspective they also add a touch of fun and a bit of edginess.

There is no doubt that the wheels in this package are the offset by the groupset but they just add to the feeling that this bike just wants to do anything, including go fast.

Having never had deep rims before there was clearly a large dose of enjoyment, for me, to be had from that ‘woomf, woomf’ noise they generate when you're roasting along on the flat.

They are however a handful to handle in the British winter (which is when I rode it) and sturdy frame or not there were several occasions I had to catch myself from flying sideways. It certainly added to the excitement factor, although to be fair the gusts were quite extreme, c30mph+ and in cross winds it doesn’t take you long to figure out you can counter balance the wind with your body to keep in a straight(ish) line.

This bike is sold as a do-anything bike but would you want to take this pimp carbon rims off-roading? Hmmm, I'm not so sure you would. While the rims aren't needed for braking you'd still be gutted seeing them with off-road scars, so if you are thinking of making this an all rounder, you just added a second set of wheels to your NEED list.

The Tyres

The SL5 comes with beast-like 32mm slicks which on paper sound ridiculous and you’d think the preserve of your commuter ride – I for one was fully expecting to find myself swapping them straight off for regular 25mm rubber.

BUT when you see the whole bike - optically it all kind of works, the tough frame with a pro look, the carbon rims and these out-of-norm road 32s and somehow it appears to visually all work.

With the fatter tyre this obviously allows you to run lower pressures than you would normally in your 23 or 25mm road slicks, which you come to realise is all part of the package here.

Less pressure, wider rubber = way more comfort, which compliments the IsoSpeed perfectly. Especially for UK roads.

They are tough too, Bontrager’s Hard-Case Lite (a name which doesn’t quite make sense) outer casing proved to be a real toughie, much more than I certainly expected for February conditions in the UK, 165 miles on crappy roads, in crappy weather, no punctures.

Sure there is a resultant increase in your drag factor when descending but running these up at 85 psi you still get a good enough roll to keep your speed going on the flat .

The groupset

Let's get straight to it - most off-the-shelf bikes have a make-weight component in there somewhere and in the case of the SL5 it is the groupset. Shimano 105 on what is a £3,300 (rrp) bike is frankly always going to raise an eyebrow among the bike snob. Especially one with £3.3k to drop on a bike.

Don’t get me wrong though, 105 is of course fully reliable and today’s 105 is definitely improved from 5 years ago and I found nothing to complain about its operation at all and let's be honest it probably didn't make me slower either. But if you know your groupsets then instantly you can't think you should get more for this money, regardless of whether it makes a different or not.
I run 105 on my own winter bike and have never had a problem with it. My issue is perception, 3 grand is a significant price threshold that you expect rewarded with all round good components however Trek could maybe have done better here, imo.

Don’t believe me, well the reaction from 4 fellow bike enthusiasts when they saw the bike was pretty much as follows:

-        "Wow, looks like a pro bike.... what’s it sell for?"
         "£3,300"
    "£3.3k?? and it’s only got 105….?"

Like I said, it’s perception and that matters in today’s arm’s race of bike sales.

The cockpit

Most things in this bike are about ride comfort (the frame, IsoSpeed, the tyres) and the same is true here too.

The hoods look deliberately extended at first glance and once out on the road you again realise why. For anyone who likes to ride on the hoods whilst putting the power down, they are perfectly set for this. I let a mate have a spin on the bike and he was straight to this position and commented it was perfect and very comfortable.

The bars too often a fine balance between road-thrasher and ultra comfort. On the drops and the bar is skinny like your summer roadie, sit up top and you have a wider bar made for cruising at comfort and climbing with ease.

The stoppers

For me the world of disc brakes is not an alien one, as I ride cross and mtb as well as on the road, so I know what it is like to have brakes that stop in all conditions.

Discs on a roadie? That was one of the main curiosity factors that I was keenest to explore with this demo ride.

So do they make a difference? Without a doubt.
Response time is so much quicker – I swapped mid-ride with a mate and I immediately thought his brakes were not working, they were, it was just such a gap in response time.

For some the instant response might be problem in the short term but I think over a number of rides your confidence would increase and it would translate to better descending very quickly.

My test rides were in winter on dirty and debris-ridden and often wet roads but there was no difference in braking from the first to the last mile.

The killer question though, is that better braking worth the extra weight?

I can see arguments either way on this one, if you are an out-and-out weight-watcher then you’d never consider then out of principal. On the flip side if you want confidence in stopping, are carrying “free” weight you could lose off your gut or butt before worrying about every gram on your bike, then I can see you opening the door to a disc-based road bike.

Yes, they add more weight but I really believe if you have weight to lose on your body, focus on that over the weight of your bike first.

I also can see a world where disc brakes are on the majority of road bikes, definitely in the “winter bike” section of your bike stable. Why wouldn’t you? A bit more weight for winter-long solid and assured braking – I can see it happening, a lot. Not least because the whole idea of a winter bike is that is one that can take the conditions and if it is heavier than your summer bike, well so what? Come summer you’ll feel the benefit for sure of having ridden a ‘heavier’ frame all winter.

As for the arguement about disc brake safety, well it's BS about the rotors themselves but what is a risk is braking distances, these vary hugely and in a group that could make a differnce - albeit maybe not a lot more in us average roadies where technique and confidence also factor but at a pro level there would be a big difference I'm sure.

The gearing

I've made this distinct from goupset as it is notable feature of the SL5.

Running a compact 50/34 chainring with an 11 speed cassette that has the range 11-32.

32 is a key detail of this spec. Consider the factor that we have a good but not top-top end carbon frame, carbon rims but disc brakes we know this isn’t going to challenge the UCI weight limit. The SL5’s additional mitigation to its weight is that get-you-up-anywhere 32 tooth on the cassette.

I rode this on a hilly route with c5.5k feet climbing and while early on I was resistant out of my own stubbornness not to drop all the way to the 32 on climbs I did turn to it on climbs at the back end of our route. I could have battled on without it but drop all your gears and you are spinner-winner right there and could take out almost any climb.

So for sure this extra gearing is a nice offset to the reality of riding a disc road bike.

A further benefit, for me personally although some bike geeks may disagree, was the additional range you also get on the big ring. I like to spin the big ring a lot, to the point of occasionally entering extreme gearing territory. With the 32 tooth, you can sit in the big ring and spin an easy gear without having to go all way to the 32. It’s a real minor point but if you’re into marginal gains this would be one that allows a lower big ring gear without having to go quite so extreme.

The looks

They speak for themselves. The SL5 looks like a stealth weapon and you can easily picture it on top of a pro-team car.

The off-road factor

Officially this is marketed as being on and off-road capable, now while I have no issue that the frame is made for both I have 2 concerns about the off-the-shelf SL5 going off-road:

1.    The wheelset. As mentioned above, these are wheels for thrashing it on long, undulating or flat roads. At around £1.25k on their own to buy, I don’t see anyone wanting to hit any off-road trails and risk trashing them. Unless money is no object.

2.    (Front) Tyre Clearance. With 32mm slicks as standard, front tyre clearance is minimal and if you think that realistically be running at least 32s (with tread) for off-road I see this is a problem. If you have ever ridden off-road with anyone who has a ‘gravel’ bike you will know their pitfall at getting gunked/jammed up with mud then that is what I’d see happening with the SL5. I have a Boone CX and the clearance is vastly different, obviously as this frame is really slanted more to the road.
     For the record, rear clearance is not an issue at all due to the unique IsoSpeed design of the rear stays.

That said, come a dry, summer day with hard trails this would be a whole heap of fun to venture off the tarmac with!

The summary

The Good bits – the frame comfort is a joy, it is tough yet is made to shift when you put the power down and has gearing to get you up any hill, the wheels are amazing and those 32mm tyres are a surprising revelation. Did I mention it also looks awesome?

The Niggly bits – the 105 groupset at the associated price tag (£3,300), front clearance (if considering it an all-roundder).

The main problem – where does this fit in your bike stable???

Want vs Need

Do I want one of these in my bike stable? Absolutely!

Do I need one of these in my bike stable over any other bike I currently have? No.

The SL5 is the embodiment of the cyclist’s continual dilemmas of WANT versus NEED products as I’ll now explain by considering your starting bike stable options.

Here’s my thoughts on whether the SL5 would or could replace some bikes in your bike stable

The new summer roadie?
Q: So you already have a carbon roadie, with light wheels and di2, does this replace it?

A: No. It is fun to ride and gets up even the steepest hills but when it comes to summer fun, weight and all round components win, when you already have a good road bike.

The new winter roadie?
Q: So you already have a winter roadie, it’s reasonable light, rim brakes, with possibly a mish-mash of components flowed down from your summer bike?
A: Possibly from a practicality point of view; frame comfort, tyres, toughness. But £3,300 on your winter roadie? That would be madness which means even if you shopping for a winter roadie you’re not likely going to be thinking about this kind of price range.

Your new all-rounder (bit of road, bit of off road, commuting)?

Q: I don’t own a do-it-all or even any bike right now but I want one that can go anywhere from road miles at the weekend, summer trails and commuting?

A: Now we are talking around the target market. If you have the money and you only want to invest in one good bike that can cover most riding scenarios then the SL5 should be on your list.

If you ride in Britain are not a racer but a real rider, then the Domane should be on your wishlist.

I don’t need it, I just want it!!

That’s really what the SL5 comes down to (ok and many other purchases).

I had a total blast with this bike and it is hard not to not like it or ride without a smile on your face.

I also suspect that this is the same reaction for almost everyone else who gives the SL5 a test run.

You'll love it and want one but in your head you think you don’t really need it.

And with a price tag over 3 grand it even finds itself edging to a home not on the WANT list but on that list you don’t really like to think of which is WANT (but it’s just a wee bit too pricey) list.

The SL5 is simply a pleasure to ride, I was sad to hand it back, I really WANTED it. 

Before I hit publish on this blog I went for 20 mile local loop on my winter bike, felt every bump, had wet roads and was edgy on some corners, do you know what - I think I really NEED a Trek Domane SL 5 Disc.....

The full techy spec from Trek:

Frameset
Frame500 Series OCLV Carbon, Front & Rear IsoSpeed, E2 tapered head tube, BB90, Flat Mount disc brakes, Power Transfer Construction, hidden mudguard mounts, internal cable routing, 3S chain keeper, DuoTrap S compatible, Ride Tuned seatmast
ForkDomane carbon disc, E2 tapered steerer, 12mm thru-axle

Wheels
WheelsVision Metron 40 Disc LTD
TyresBontrager R2 Hard-Case Lite, aramid bead, 700x32c

Drivetrain
ShiftersShimano RS505, 11-speed
Front derailleurShimano 105, braze-on
Rear derailleurShimano 105
CrankShimano 105, 50/34 (compact)
Bottom bracketBB90
CassetteShimano 105, 11-32, 11-speed
ChainShimano 105

Components
SaddleBontrager Affinity Comp, chromoly rails
SeatpostBontrager Ride Tuned carbon seat mast cap, 20mm offset
HandlebarBontrager Race Lite IsoZone, VR-CF, 31.8mm
GripsBontrager Microfibre Tape
StemBontrager Pro, 31.8mm, 7 degree, w/computer and light mounts
Head setIntegrated, cartridge bearing, sealed, 1-1/8" top, 1.5" bottom
Brake setShimano RS505 hydraulic disc, Flat Mount

Weight
Weight56cm - 8.54 kg / 18.83 lbs

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