We were blown away by the premium 6-Series Domane, which introduced us to the pavé-pancaking IsoSpeed fork at the front and decoupler technology at the rear. You get these on the 4.3 as well, and the bike finished in the top five of our 40 Cycling Plus Bike of the Year contenders:
Tech ed Warren Rossiter talks through the Domane 4.3
Ride & handling: Comfort without compromise
Any worries that a lower grade of carbon or spec would dilute the effectiveness and performance of the 4.3 are unfounded – it’s 1.8kg (4lb) heavier but also £5,200/US$4,430 less than the 6.9, and for £1,800/US$2,499 you get a simply astonishing frame and an addictive ride quality.
First ride impressions are fairly conventional, until you realise that the usual road chatter and vibration is muted to the point of being barely noticeable, although the road feel, so crucial to precise handling, is unaffected.
Arguably, the road feel was accentuated because the Domane seems to be in contact with the surface more of the time. Turning into corners on roughly patched tarmac was refreshingly undramatic, the wheels seeming to tuck in and bite instead of skipping across the surface.
With such impressive stability and poise, exploring the Domane’s limits becomes de rigueur on almost every ride. Go looking for rough stuff expecting to lose fillings and instead you’re cosseted by a sublimely floaty feeling.
Of course, on the most extreme roads there’s still an element of vertical movement, but sudden kicks and general vibration are removed. Not beating about the bush – the Domane’s ride is little short of astonishing.
Frame & equipment: IsoSpeed tech with functional kit
The IsoSpeed system doesn’t have a threshold below which it feels inert. There is no intrusive movement that could affect your pedalling action, as the active component of the Domane is the whole seat tube, not just the seatpost.
The decoupler is basically a rotational pivot attaching a lug on the front of the seat tube to the top tube, allowing the tube to bow and flex along its length in isolation from the frame, with no more effect on seating position than a slim carbon seatpost. The increased active length results in several times more shock absorption without the need for excessive movement in a restricted space.
Complementing the rear end is the IsoSpeed fork. This has a 1 1/8in to 1 1/2in tapered steerer tube for huge rigidity, and a constant radius curve that continues slightly ahead of the dropout to maximise its bump-smoothing ability.
Despite sounding like a full suspension bike, the Domane sports an oversized down tube and muscular asymmetric chainstays, which envelop a simply massive BB90 bottom bracket shell, and combined with the fork’s lateral stiffness make it as responsive as any fast road bike out there.
As ever, at this price there are some parts we’d quickly upgrade, and with so much technology in the Domane’s frame the wheels are the obvious place to start. The Bontrager Approved hoops roll well and resisted the worst we could fling them at with no problems, but they aren’t on the same level as the frame and are a little sluggish.
Shimano’s 105 was faultless as ever, though Trek still include an integrated chain catcher to prevent it dropping between chainset and bottom bracket. The exclusively Bontrager finishing kit is all competent stuff, but could benefit from judicious upgrading when budget allows.
That said, we’d gladly choose to take the Domane out more often than more exotic machinery because the frame offers so much comfort with no performance penalty. A stunningly simple but superbly accomplished design.