10/07/2009Enter the Dragon

The first fully-functional samples of DMM's single stem, dual axle, hot forged cams have been assembled this week - enter the dragon. Born out of fire and made in a country that proudly has a red dragon at the centre of its national flag, the name fits. Simon Marsh at DMM commented: "I've never seen so much excitement in the office over a new product. Everyone has been stopping-by at the Cam Assembly Unit to see the Dragons being put together."

Six colour-coded sizes are used to cover a range from 20mm to 114mm, based on a constant cam angle of 13.75°. Not all manufacturers use the same angle for spring-loaded camming devices (SLCDs). DMM believes that this angle offers the best combination of holding power and expansion range. The logarithmic spiral is the mathematical theory behind ensuring that the line between the axle and point of contact is always at a constant angle to the rock surface, irrespective of the unit's orientation.

To prevent corrosion the cam lobes are anodised. A Duplex cable system is used, 5mm cable on the stem and 3.2mm on the loop, so that the unit has the same flexibility through 360°. Whether the placement is vertical or horizontal you'll reap the benefits.

The cable assembly is overmoulded using Zytel, offering good flexibility and durability with proven reliability in a variety of climatic conditions. The trigger bar is made from the same material with a 'relief' designed grip to help you get that crucial placement first-time, even with sweaty fingers. As with our 4CU and 3CU range, Dragons have an extendable Dyneema sling, allowing you to carry fewer quick draws, saving on bulk and weight on your harness.  

You'll find Dragons in the shops this coming Spring. The samples will be unveiled on the DMM stand at the European Outdoor Trade Fair at Friedrichshafen in Germany from 16th July - 19th July, so be sure to drop-by and have a look at them if you're there (Hall B2 - Stand 102).

Note:
If you are interested in the physics behind SLCDs and want to know more about constant cam angles have a look at this technical review by John Middendorf at bigwalls.net. Quite who invented the spring-loaded cam using the angle of 13.75° is controversial. In the States it was between Greg Lowe and Ray Jardine but you can read more about it at supertopo.com and needlesports.com.

Photos: Fred Hall assembling one of the first fully-functioning Dragon samples.