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My Simplon Razorblade: World Marathon Championships

A couple of months ago I profiled my Simplon Cirex full suspension bike. Now we take a look at my lightweight climbers bike, the Simplon Razorblade 29 hardtail which I raced at World Marathon Championships last weekend. For me the course over 102km with 4200m ascent best suits a lightweight bike. I also rode this bike at European Championships in April and the choice on the start line was split pretty evenly between hardtail and full suspension but the 2 elite winners were both on hardtails. Whilst the course demanded a quick climbing machine there were some super rough technical trails which required strong wheels and tyres.

Rather than going into detail about the specification I'll talk about the differences from the Cirex. The bike began life as a Razorblade 29 X01 Eagle which anyone can buy from Simplon. The Razorblade is my choice of bike where possible, its super fun to ride, the geometry gives a short wheelbase and agile steering but the bike bike still manages to still feel stable on bigger mountain descents. Whilst the Cirex is like a mountain goat the Razorblade is like a rocket, each time I ride this bike I think wow this is quick!

One of the major upgrades you can do to any bike is the wheelset, rotational weight is said to have 6 times the effect of weight elsewhere. I'm rolling on a set of Mountain Trax 27mm Carbon Rims. These are built onto an American Classic front hub, chosen for its light weight. On the rear I'm running a DT Swiss 240 hub which offers reliability, the hub is upgraded with DT's 64 point ratchet and both hubs now spin on ceramic bearings. The wheelset is built with DT Swiss Revolution spokes. Whilst there are lighter wheel builds around this combination comes in at just under 1400 grams and offers reliability and easy tubeless compatibility. If I was building again I'd consider the new carbon ultralight rims.

Tyres have been swapped from Schwalbe LiteSkin tyres to a SnakeSkin Rocket Ron front and Racing Ralph rear for this event. Fast rolling and good puncture resistance are essential. I ride 2.25” tyres as they provide a bit more grip and allow me to run a slightly lower pressure, normally around 20 psi or 1.3 bar. Whilst I’ve taken the risk using LiteSkin tyres at cross country races and on marathon courses I know like Grand Raid it’s not worth the risk here. The Snake Skin tyres are incredibly easy to inflate on the wheels I use with just a track pump and are tubeless ready so don’t use up the sealant to seal the sidewalls like a lighter tyre would do. The Rocket Ron front tyre will give me a bit more predictability if the weather in unfavourable on race day.

The suspension fork has been swapped out from a Rockshox to a Fox Float Stepcast 100mm fork. On the Cirex I run a Magura TS8 Elect fork with wireless remote lockout switch. Whilst I’ve found the Fox forks to require more maintenance than others they work well with controlled compression and good small bump sensitivity. The Fox forks flex under braking a lot more than the Magura fork but this is only noticeable on the road.

Brakes have been swapped to Magura's Carbon brakes, possibly the lightest brake on the market. It’s been about 5 years since I last rode Magura brakes and the new ones feel powerful and controlled. On this bike I run 160mm rotors front and rear with titanium mounting bolts.

I train with power every day and find it useful for pacing on climbs during a race. Also the data afterwards gives you information you can use in training. On this bike here in Italy I’m running the Rotor Rex INpower with a 32t oval chainring. The small size necessary for the steep dolomite climbs, usually I’d run a 36 or 34 tooth chainring.

The Sram Eagle groupset is fantastic, the wide spread of gears with the 10 – 50t cassette is ideal for racing in the mountains. The standard jockey wheels on Sram Eagle have caused me problems in the past though. Excess play causing the chain to drop so I'm running a set of C-Bear Eagle jockey wheels to solve this problem. Another gripe with Eagle is the rear derailleur can be quite fiddly to setup and if you don’t have a fresh cable fitted it often struggles to drop into the bottom gear. A set of Time XC8 Carbons pedals complete the drivetrain, these pedals have proved reliable year after year with minimal maintenance.

My choice of saddle is the Fizik Tundra 00 which offers a lightweight comfort perch for long multi day events. The wings of the 00 Carbon saddle flex which is what I find provides the comfort, I’ve tried the cheaper version of the Tundra and many other saddles but never found anything comfortable.

I run a USE Ultimate RIP flat bar cut down to 680mm, the bar has 9 degree sweep which is both comfortable and good for handling. A USE Evo 27.2 post offers comfort with a little flex from the carbon fibre and weighs just 108 grams. Bike Ribbon SIO2 Silicone grips provide a comfortable hold with good grip in all conditions. A MT Zoom stem cap, seat clamp and bolt through axles save further weight. I have a short upper body so prefer a low stem on my bikes to help me get the weight over the front and improve agility through tight trails, I therefore run a short 80mm -17 degree stem.

Two USE carbon bottle cages carried OTE Sprorts nutrition during World Championships, without a dedicated support team I relied on volunteers to help me in a couple of feed zones and took 2 bottles each time. Not ideal when trying to keep things lightweight but essential. I carry most of my gels in my back pocket, you need quite a few in a 5 hour race.

I carried 2 Lezyne CO2 gas cans and the inflator head, a Weldtite tubeless repair kit, a spare set of Sram Eagle chain links and a carbon multitool with chain tool all in a small saddle bag. A spare inner tube was attached to the frame using a MT Zoom Handy Strap.

The bike in this build weighs 20.2 lbs / 9kgs, a respectable weight for a reliable bike build.

FRAME – Simplon Razorblade Size Medium

FORK – Fox 32 Stepcast 100mm.

HEADSET - Acros AZX 219 Blocklock

REAR DERAILLEUR – Sram X01 Eagle 12 Speed

SHIFTER - Sram X01 Eagle 12 Speed

BRAKES – Magura MT8 Carbon with 160mm rotors front and rear

CRANKSET – Rotor Rex INpower with QX1 chainring

BB-SET – C-Bear MTB Pressfit Ceramic 41mm for 30mm

HANDLEBAR – USE RIP Carbon cut to 680mm

GRIPS – Bike Ribbon SIO2 Silicone

STEM – Simplon Simplon Zero 80mm -17

SEATPOST – USE Evo Carbon 27.2mm inline

SEAT – Fizik Tundra 00

HUB (FRONT) – American Classic with ceramic bearings

HUB (REAR) – DT Swiss 240 with XD freehub, 64 point ratchet and ceramic bearings

CHAIN – Sram X01 Eagle 12 Speed

CASSETTE - Sram X01 Eagle 12 Speed

SPOKES – DT Swiss Revolution

RIMS – Mountain Trax Carbon 27mm.

TIRES – Schwalbe Rocket Ron 29x25 Snake Skin front. Schwalbe Racing Ralph 29x2.25 Snake Skin rear.

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