Friday, September 3, 2010

Project Super Scope: Foundations

by: Terry Best
terry@twohubs.com

Without a doubt the four heaviest components (if you don't count the drivetrain as a single entity) of a mountain bike build are the frame, wheels, fork, and the hydraulic disc brakes.

WHEELSET:

Having sorted out what I wanted for the frame I started to ponder the possibilities for a wheelset that would allow the bike to remain lean but also remain true to the theme. First and foremost I had to have something lightweight, however the durability and appearance were a close 2nd and 3rd.

Stan's Notubes ZTR Crest rims came to mind due to their 340g weight, excellent ability to run tubeless with the widest range of tires, and their solid strength to weight ratio. Looking back at all the nice wheels I've ridden on and owned, the one common denominator has always been DT Swiss hubs. There might be a couple of hubs out there that weigh in slightly less than the DT Swiss 190 Ceramics, but I know they will not hold a candle to the 190s in terms of performance, reliability, and long term serviceability.


Rims and hubs having been covered all I had to do was pick spokes. The lightest option? Titanium. Critics might argue that titanium spokes stretch and flex too much resulting in a loss of stiffness (for pedaling performance) and durability as the rim experiences more stress. Such could be the case, but it really depends on a number of factors; the build, the rider's riding style, and of course the rider's weight. I wouldn't recommend such a build to a very aggressive 180 + lb rider that has a background in breaking wheels / spokes (and collar bones). After all, it's a cross-country bike....To finish first, first you must finish! In conclusion I can assure you that the fact that Titanium spokes being available in gold had no influence in my decision. Our 'DT 190 Ceramic Ti' wheelset weighed in at 1240g (including Olympic Valve Stems and Stan's rim tape).

TIRES:

This German bike would get German tires - Continental has long been a trusty 'go-to' tire manufacture for me as they always offer something for the job at hand. The orange graphics on the sidewalls which fit well against the Scope's paint scheme had very little to do with my decision.. I wanted something light, fast, but also somewhat versatile. A tire that I could run tubeless with the Stan's Notubes rims, roll fast, and provide predictable cornering in dry/hard conditions. At the top of the menu - the Twister Supersonic (26 x 1.9) at a claimed 370g. Pleasantly surprised to find each tire weighing in at just around 350g!

BRAKES:

Finally an easy decision here. The lightest, most powerful, and consistent hydraulic disc brake available on the market is the R1 produced by Formula Brake in Italy. The only issue with going with the R1s is the red anodized highlights. Fortunately, after quite a lot of research, a handful of emails and telephone calls, luck would steer me toward a one-off OEM (out of Europe) set of R1s with gold anodized hardware. To further conform to the black and gold theme of the bike I replaced the R1 hydraulic hoses with the straight black counterpart of from the heavier duty 'The One' brake system from Formula. An additional 15 grams of weight (and a few extra points for style I might add!) was saved by replacing the Aluminum lever blades with Formula's carbon replacements. For those who find themselves riding in very cold climates - the carbon fiber lever brades are an essential upgrade as the carbon does not have the tendency to get very cold as temperature drops.


Steven's implementation of an integrated post mount for the rear brake caliper not only simplifies the rear-end by making it look cleaner, but also provides for better brake feel and a reduction in weight (by well over an ounce). Up to 15 grams in weight are saved by replacing the four steel caliper bolts with Aluminum (not to mention that the latter can be obtained with a gold finish!). It is important to note that the post mount configuration is more suitable for the use of lightweight hardware to the lack of sheering force that the bolts see. For an IS (International Standard) mount the bolts are configured perpendicular to the travel of the rotor and see much higher loads. Most important to note is that Formula Brake only recommends using the factory provided (stainless steel) hardware to avoid serious injury. Weights: front brake 179g / rear brake 198g (rotors not included).

Furthermore, Formula Brake only recommends using their steel rotors with their brake systems. However, with the right brake pad compound and strict cross-country use, I have had great experiences with lightweight altneratives. A brief phonecall to Chris LaCasce of Scrub Components left me salivating over a set of Scrub 'Race Day' 160mm rotors with black magnesium centers and gold (colored) retaining rings. A few days later the box arrived and I immediately. Weighing in at only 48g / rotor I knew this was an area of great weight savings as nearly two Scrub Race Day discs weigh the same as one 160mm Formula disc.

FORK:

With an extensive background consisting of more mainstream brands here in the US such as Fox Racing and Rockshox, the allure of the Swiss - based brand and its mainly carbon lightweight forks was difficult to resist. Deciding to go with DT Swiss was a bit of a gamble considering the lack of experience and exposure I've had with the company's suspension line.

All of the XRC forks consist of a carbon fiber crown, steerer tube, and lowers. However, the most appealing fork for his project without a doubt the XRC 100 Race. At 1170 grams and without the added complexity of a remote cable-actuated and handlebar-based lockout, I felt the XRC 100 Race would be the best option. After a handful of delays the project was left on hold as this fork proved to be the the most difficult item to acquire.
Stay tuned for the third installment of the Stevens Super Scope blog.

Wednesday, September 1, 2010

Project Super Scope

by: Terry Best
terry@twohubs.com

PURPOSE:

Lightweight hardtails always drift in and out of the minds of nostalgic mountain bikers who have time to fantasize and are guilty of being weight weenies. Every couple of years I find myself being lured back into the world of hardtails as manufacturers release new frames and components and the possibilities become greater. 2010 has proven to be just that and I recently decided to embark down a no-expenses-spared path to create a very light (yet ridable for everyday use) hardtail mountain bike.

CHOOSING A FRAME MANUFACTURER:

In this day and age manufacturers are vectoring towards maximizing margins and minimizing manufacturing costs - all while offering a full range of product to satisfy every type of cyclist.

Stevens Bikes in Germany does not completely conform to this new approach and continues to focus its energy on producing performance bikes for the hardcore enthusiasts. Stevens Bikes has always aimed to deliver uncompromised performance via the latest composite technologies, a borderline excessive attention to detail, and in the lightest of packages.

Upon viewing their 2010 Performance mountain bike line I immediately became curious as to what the true potential was of Stevens' Scope Team hardtail frame:

SIZING:

My preference leaning towards a 90mm to 100mm maximum length stem for a cross country bike, the 610mm top tube measurement for the 20" frame would be a perfect fit. The 18" frame's 590mm top tube would be acceptable, but unfortunately my 79cm saddle height (center of bottom bracket to the top of the saddle) would require just too much seatpost and steerer tube. After removing my newly acquired 20" Scope from its well packaged box I weighed the frame (with derailleur hanger) at 1140 grams. Not bad!

GOING GOLD:

The Stevens Scope proudly presents the German national colors of black, red, and yellow on the dark raw carbon and white canvas. My past projects have always incorporated common colors in cycling such as red and white, etc. A few short moments later while viewing the frame from afar I noticed that the thin red pinstripes next to their yellow counterparts did something very special for the yellow - I had an idea. After holding up a pair of gold Tune DC16/17 mountain bike QR skewers against the top tube I authenticated my theory that gold would stand out superbly against the Scope's unique colors.

While trying to accumulate premium lightweight components I realized obtaining parts that incorporated gold would be difficult. Fortunately I'm a stubborn person with quite a lot of patience. So the journey begins..