February 21, 2011

IRD Rotary brake

The history of mountainbiking is filled with small companies that tried to make their mark by refining existing component designs, there are only a few companies that had the engineering know-how to design and fabricate their own unique parts. One of these companies was IRD or Interloc Racing Design.

IRD was founded by Rod Moses who partnered with Ray Baldwin to produce some of the most well engineered components to be found! Although they are probably most famous for the invention of the two-bolt seatpost, which until today is copied by a lot of companies, their brake designs is what i'm most interested in.

In the eighties and the beginning of the nineties the u-brake was used as an alternative over standard cantilever designs. The problem with cantilevers is that they pivot at the bottom end of the brake-arms and that they are mounted on the seatstays. Because the seatstays are longer and often thinner than the chainstays they will flex outwards resulting in lost perfomance. U-brakes are best mounted under the chainstays and that combined with a pivoting point in the middle of the brake-arms gives a lot less flex.

IRD came up with an ever better design. Although the pivot point and the brake pads are held in the same position as a standard u-brake, the way the power is delivered is just brilliant and powerful!

The photo above shows the mechanics of this brake. The cable that sticks out at the top of the brake wraps around the big wheel which is mounted to the right arm at top center. The other end of the cable is fixed on the big wheel on the other side of it's mounting point. The mounting point allows the big wheel to rotate. What happens is that when you pull the cable the big wheel will swing out to the left, pushing the top of both arms outwards and both brake pads together crushing the rim!

February 15, 2011

Specialized S-Works

When i think of mountainbikes i think back to the first half of the nineties, the booming years of colorful cnc-machined parts and experimental bike designs. The years when mountainbiking still meant to be self supporting and Tomac thundered down the mountain with his Tioga Diskdrive.
I also rembered an issue of the magazine Mountainbike Action which had a test of the most gorgeous mountainbike ever, the Specialized S-Works Steel! To me this was the bike to dream about, expensive, rare and precision made by the Japanese. Being only 17 it was unobtainable for me so i settled for a Koga Miyata Trailrunner carbolite. But trough all those years this was the frame for me to have!

Than the incredible thing happened, my dream frame appeared on a retrobike forum. It was still in a very good condition and for some reason didn't sell. So i got in and bought it for little money including the gorgeous Nitto S-Works seatpost.

This also gave me the opportunity to choose and buy the components that i could never afford and really make it my dreambike! Finding the components actually took quite a long time but for some reason the right components just appeared on auction sites like they where meant for me to buy them at a very reasonable price.

The bike than was powder coated in a very understated grey finish and was carefully build up by me resulting in a very light and beautifully riding bike, the best i have ever had!

After it's maiden ride during a retrobike meeting it was refitted with road slicks. This because my riding is mostly on the road.

Frame: Specialized S-Works Steel
Fork: Tange
Headset: Specialized Steel
Stem: Nitto Dirt-drop
Handlebar: On-One Midge (finish stripped)
Levers: Shimano
Tape: Cinelli cork
Seatpost: Nitto S-Works
Seat: SDG Bell-Air titanium
Seatbolt: Odyssey titanium
Brakes: IRD Widget
Bracket: Specialized titanium
Cranks: Shimano Deore XT 170mm
Chainwheel: Surly 40 teeth
Pedals: Cranks Bros Egg-Beater SL
Chain: Shimano
Cassette: Shimano 8 speed
Hubset: White Industries
Quick releases: Salsa titanium
Spokes: Stainless
Rims: Araya RM-14
Rear derailleur: Shimano Deore XT
Tires: Schwalbe Marathon Racer 26"x1,5"