Trek Fuel 90

Price: £1299.99

Frame: US built, custom butted Alpha SLR aluminium

Fork: Manitou SX-R

Stop: Avid SD 3

Go: XT rear mech, LX front and shifters. Bontrager Comp chainset, Shimano M515 SPD’s.

Wheels: Rolf Satellite, BontragerJones AC tyres

Trim: Bontrager stem, Bontrager Race Modified 620mm bar, Bontrager grips, Bontrager FS2000 saddle, Bontrager seatpost

Total weight: 27.5lb complete

From: Trek 01908 282626

Test logbook

Only 2.5 hard and fast hours on this one so far. Mixed rocky, rooty singletrack, rough step and rock sections all swimming in mud. Plus a bit of road work to join it all up.

The Reason

Pretty much every type of suspension system you can think of has now been tried by some builder or another, and the market is now settling round a few proven designs.

Therefore we weren’t expecting Trek to arrive with anything revolutionary, and the fuel is a subtle blend of several existing proven technologies and concepts.
However they have been very attentive with details that most suspension bikes ignore but many hardtail riders hold very dear.

The Rig

Two of the key details Trek wanted to include from the start as unique selling points were twin bottle cage mounts in (rather than underneath) the main frame and room to rest the frame on the shoulder for carrying.

They’ve done this by keeping the lower shock mount as near the bottom bracket as possible and fitting two sets of bottle cage mounts on top of the down tube. It’s a squeeze but you can just about fit two standard sized bottles nose to tail, which gives more capacity than the normal space for one big bottle.

To make shoulder room they’ve kept the triangular rocker linkage mounted as low as possible which also has the desirable effect of lowering centre of gravity slightly.

The rocker itself uses two thin cast triangle sections which are profiled to wrap around the seat tube as closely as possible – so no banged knees there then. The left and right halves are then held together to prevent twisting with a rectangular block bolted between them behind the seat tube and a small cylinder bolted between them in front of the seat tube. Lots of bolts means some extra weight, but it’s the only way to get braces either side of the tube and keep the whole rocker rock steady.

Trek have also configured the rocker to give a very low compression ratio on the shock. This keeps pressures in the Fox float unit around the 100 psi mark, increasing both longevity and sensitivity through the 2.9″ of travel.

In true Trek family tradition (see Fisher Sugar, Klein Adept, Trek STP) the Fuel uses ultra thinwall bonded stays that allow enough flex to eliminate the need for a rear pivot on chain or seatstay. That’s two less bearings to wear and add weight then.

The deep ‘thigh’ section chainstays kicked up to the cast main pivot mount with hollow bracing pipe between them are familiar Trek plumbing pieces as is the externally butted bottom bracket, but then if it works why change it.

Before you ask mud clearance is better than the Klein and Sugar thanks to a more angular seatstay bridge, which doesn’t look a massive improvement but ran perfectly clearly in identical conditions to those that jammed the Fisher.
Trek have ignored everyone else’s move towards cartridge bearing pivots, staying with the small diameter self lubricating bushings they’ve used since their Y bikes, and seeing as we’ve never head any problems with them that’s fine by us. Simple dropout also has bolt holes for carrying an optional interantional standard disc mount.

Joining all these dots is a triple butted aluminium ‘Alpha SLR’ frameset, laser mitred and handmade in the US. The headtube is externally butted, and the downube is one of the largest we’ve seen on a Trek, ovalised vertically at the head and horizontally at the bottom bracket, with a throat gusset to keep everything stiff and tight. The top tube slopes down to the seat cluster for maximum standover height, but there was still enough stretch for speed on the medium size we rode.

The only curious touch is the seat tube extension which is a welded barrel bulged add on that tapers to a narrower diameter than the rest of the broad seat tube.

The Ride

Despite the rocker format the bike comes in at a respectable 27.5lb overall and it manages to ride even lighter than that. The supple but lively initial travel and final rebound stages afforded by the flex stays deliver a ride that’s smooth but responsive enough to feel inspiringly fast rather than flaccid. Even under hard charging power the shock just dips slightly, smoothing traction but never upsetting rythmn. Low shock pressure also keeps the rear very supple through small trail chatter sections and hooks up well through uneven hardpack corners.
The shock stroke is noticeably progressive and free from bottom or top out slam, but it can get caught out by medium / large high speed strikes kicking the rear end up rather than being absorbed. With no rebound adjustment on the shock we were expecting some problems but to it’s credit the response was great in the pressure range we ran it (90 – 100psi), lifting back to full travel fast enough over repeated hits but not kicking out over yumps or steps. How it’ll behave with higher shock pressures we’re unsure but as we’ve said the flex stays go long way to smoothing the first inch or so of travel and rebound.

There’s slight twist and yaw in the back end when shoved hard sideways, but the mainframe is impressively stiff for accurate front end placement and solid power kick out of the saddle.

Handling through the 100mm stem and wide flat bars is spot on. Agile enough to grab sketchy last minute lines but not too skittery to throw you off them again. There’s plenty of room to clamber about in weight sensitive technical sections too thanks to the dropped top tube.

Wind up the speed and it’s still pin-point accurate but the low centre of gravity and decent centre section stretch ensure stability.

In short the handling never gets in the way of attempting even the most rapid response manoeuvres, but it won’t jangle your nerves at the end of a long day ride either. That’ll be pretty much ideal for most people then.

Manitou’s SX-R forks are a similarly affable performer with masses of rebound and compression adjustment. Be sure to whap some extra grease through the Micro lube grease ports before you ride though. We didn’t and despite chunky fork boots they’d locked totally solid after a couple of hours, only resuming service after a full strip down.

Shimano provide XT, LX transmissiom mix which is about par for the price, but shifts are slowed and occasionally chewed over by the Bontrager chainset and SRAM cassette. Bontrager also provide the no nonsense clipless pedals, long seatpost, soft centred saddle, bars, wide flat bars and grips. They’re all as reliable, comfortable and unnoticed as one could wish.

Tyres are also Bontrager’s Jones AC, a small, square knob based tyre that works really well in all conditions with plenty of side tread for banking through corners, knob surface detailing for grabbing rooty traction and close enough spacing to really fly when you hit hardpack. Rolf’s Sattelite wheelset wound up to speed and swallowed rocks happily enough and proper cones allow regular maintenance rather than fit and forget cartridge bearings.

Verdict:

Trek have taken they’re legendarily vice free and neutral hardtail performance and transferred it very succesfully to a suspension format. The Fuel is fast, light and agile enough to keep you free from any feelings of suspension slog or energy sap, but smooth and responsive enough to allow you to ride faster, harder and longer without getting into any control or comfort problems.

However even with a fair amount of sag, the suspension couldn’t be described as deeply plush and it baulks at big hits. On the flipside it never wallows or bobs badly, however tired and lumpy the pedal stroke and the whole bike feels constantly eager, up, down or along which is worth a couple of extra gears worth of psychological speed over mushier wagons. Handling is superbly balanced for every type of riding situation with the hint of flex out back failing to intrude on cornering or technical accuracy.

We wouldn’t reccomend it to riders who like to take the big bad short cut on a regular basis but it offers instantly increased range, control, traction and comfort with no modification of riding style or any other negative side effects.

Performance: 4/5
Value: 4/5

The Fuel 90 is the second bike in the family which starts at the 80 and goes up to the 98 (including disc option and WSD womens option) and the team issue 100. For more information on specs and other bikes in the series Trek over to the Wisconsin based website for the full details.