2005 ROBERTS 12+ pound "BACKPACK" ULT COMPACT RACER

The following text was provided by he owner of the bike, Neil Carlson, cyclist, London, England:

Perhaps the ultimate demonstration of what can be done to make a superlight steel racing bike. This state-of-the-art machine is one of the lightest truly "rideable" bicycles and, perhaps more notably, it is almost certainly the lightest folding bike in the world. However, this is certainly not a commuter’s dream, but an out-and-out racer.

In its debut at the London Cycle Show in September 2004, the bike weighed just over 12lbs (5500g). When fitted out for riding on the road (changing tubulars, chainrings and cassette), it weighs just under 13lbs. For 2005 I’ll try to get the bike down to 12.5lbs riding weight.

So far, the bike has been ridden for three days on a trip to the foothills of the Pyrenees, based in Carcassonne in the South of France. This means that I think it would be unfair to base a comprehensive review on first impressions. Moreover, my current fitness levels leave a lot to be desired! However, I can’t fault the BTCs, the bike’s portability made travelling light work, and the riding was unforgettable (can’t wait for my next cycling trip!)

As something of a light bike enthusiast, for some years I had been looking at building the lightest racing bike that a professional rider would consider suitable (for mountain stages in a multi-day race). Even the UCI minimum weight regulations did not deter me from searching out the best lightweight parts.

Then, about three years ago, my objective changed. I had been riding my S&S BTC-equipped Roberts Custom Compact Audax for a few years at home and on trips to France and Italy. Since touring hasn’t really been an option since the arrival of my son, and my racing days are probably past, my greatest cycling pleasure is to be able to go and ride somewhere special – counting down the switchbacks on a col, negotiating the bends on a scenic coastal route, flying along on smooth tarmac with the wind behind me.

Living in a big city, this means travelling – usually by train or plane, as we don’t have a car (with the money I spend on bikes, who can afford a car?). Any cyclists based in the UK knows how difficult getting bikes onto trains can be, especially over long distances. And the no-frills airlines’ baggage limits seem to be shrinking all the time. By the time my Roberts Audax bike was broken down into the S&S backpack with the essentials (helmet, shoes, toolkit and spares, pump, cycling clothes) it was already beyond these weight limits, as well as being awkward to carry.

Thus the new objective was born – create an ultralight racing bike that could be transported in a compact, lightweight, easy to dis/assemble package, to make the most of whatever time I could snatch to spend riding. Something reliable, guaranteed to heighten my riding experience and help make up for any shortcomings in my fitness.

After a visit to Chas Roberts’ workshop in Croydon, South London to discuss the idea, he agreed to go ahead. Sourcing the tubing took time, as various brands and tubesets were obtained and weighed to find the right combination. In addition, against all tradition, this was the first (and only?) frame produced at Roberts that was TIG-welded, rather than brazed, to keep the weight down. To compliment the carbon forks, a carbon rear triangle was joined to the steel main triangle.

As with anything so ambitious, there are snags and caveats. Some parts proved difficult to obtain, others did not match up to the advertised claims (Special mention must be made of THM, CAT Carbon, Extralite, Zero Gravity and Schmolke Carbon for their excellent service and outstanding components). It’s worth bearing in mind too that some of the selected parts have weight limits, though anyone under about 170lbs (77kgs) should be fine.

It would be easy (and much cheaper) to have Chas build up a machine that hits the 6.8kg UCI limit precisely for racers who want to travel light (but who may not be lightweights). Not only would you be getting a light bike, but the superb road feel, durability and repairability of steel, in a frame built by hand to your exact specifications.

So what’s the bike like to ride? Unless you’ve ridden a sub-14lb bike, you simply won’t have experienced just how fast a bike can accelerate when you stomp on the pedals. Stiffness at the BB is only half the story. Even seated climbing is vastly improved by the reduction in mass. It’s almost like it’s just you, with no bike underneath. The carbon forks and rear triangle soak up road shocks so effectively that I kept dismounting to check for slow punctures. Descending was surefooted – the bike corners as if it’s on rails – and the lateral stiffness of the forks seemed to help prevent front brake rub when climbing hard out of the saddle. As for the BTCs and the ride, there’s nothing to say. When one is riding, it’s as if the couplings didn’t exist. They do only what they are there for – and flawlessly.

This bike has been a labour of love, with a gestation period (5+ years) and a monetary cost (around 7,000) that just doesn’t bear thinking about. Still, if you have a family, lots of spare cash and a need for speed, this might just do the trick… If anyone wants to see the ULT Compact, the bike should be on display at Roberts Cycles in Croydon, South London from March 2005.

A full parts list is given below, with all weights taken using a digital (1g) scale

Part

Make + Model

Weight(g)

Frame (front)

Roberts Columbus Foco, S&S BTCs

575

Frame (rear)

Roberts Columbus Foco, Dedacciai Blacktail S&S BTCs

1013

Fork

THM Scapula SP Tuned 1.125" (182mm)

222

Headset

Extralite The Head 1.125"

62

Spacer

5mm carbon 1.125"

2

Ahead cap/Plug

AX Lightness (5g) + Extralite UltraStar (9g)

14

Seatpost collar

Spicer Cycles Ti

16

Stem

Extralite Roadstem UL 1.125" 110mm

97

Handlebar

Schmolke Carbon TLO (42cm ctr-ctr)

142

Seatpost

AX Lightness 350mm

144

Saddle

AX Lightness Sprint Superlight

54

Crankarms

Cat Carbon (L arm 113g / R arm 186g)

299

BB

TNT SL Ti 107mm

116

Chainrings

Carbon 38/48 (37/26g)

63

Chainring bolts/Washers

Miscellaneous aluminium

11

Crank bolts

Middleburn self-extracting Ti (tuned)

20

Brake/Shift levers (2)

2004 Campy Ergo 10 Carbon (BTP clamps)

310

Brakes (2)

Zero Gravity (135g w/Deda bolt) (Zipp pads 46g)

181

Brake cables

CLB Alloy

55

Rear derailleur

Precision Billet Proshift (custom short cage)

163

Front derailleur

2004 Campagnolo Record 10 Carbon

65

Derailleur cables

Gore Ultralight

54

Cable splitters (3)

Unknown Aluminium

18

Pedals (2)

Speedplay X/1 Ti (BTP alloy plates)

130

Chain

Wippermann Connex 9X1 Ti (102 links) - lubed

232

Cassette lockring

EFFE aluminium

5

Cassette

EFFE aluminium one-piece 11-21 9-spd

89

Front hub

Tune Mig 66 (front wheel 461g)

85

Rear hub

Tune Mag 160 (rear wheel 543g)

176

Rims (2)

LEW Custom

560

Spokes (30)

DT Revolution/DB

173

Nipples (30)

DT Al

10

Tubs (2)

Tufo Elite

220

QR (2)

Heylight Al/Ti

48

Bar tape

Storck (black) + plugs

59

Tub tape

Jantex

22

Bottle cages (2)

BTP Kevlar

12

Total (Show Build)

5517

(12lbs2oz)

To Make "Useable" Need To Change To:

Tubs (2)

Conti/Veloflex/Tufo road tubs (225g ea)

230

Chainrings (2)

Stronglight 48 & TA 38 aluminium (77/32g)

46

Cassette

Cycle Dynamics Ti 11-23 9-spd (142g)

53

Total (On The Road)

5846

(12lb14oz)

 


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