Precision Tooling is a family owned machine business that has machined parts from metal for different companies over time. For a period they were the sub-contracting firm making CQP cranks. The relationship with CQP faded and John Trenerry and his father Phil worked out an exciting and stylish design for a crank arm set. Phil's knowledge of metals helped make the arms strong though they appeared delicate. There was initial un-certainty about whether the family should be bold enough to enter the bicycle parts market on their own, under their own name. As it turns out Phil Trenerry had known John Grafton for many years and Grafton's first cantilever brake had been successful. Grafton had been prevailed by others make an entrance in the crank market and the Trenerry's crank held promise though they again were reluctant. The Trenerrys agreed to make the crank they had designed and let Grafton market them. The crankset's popularity and the Grafton name identification lead to immediate market interest. After about a years time we started to be sold the cranks directly from Topline, (which is also known as Precision Tooling), because their verbal contract with Grafton had crumbled. The design remained rightly in the Trenerry hands and they have become very successful using their own name in marketing their own cranks. We've found that generally when splits like this occur, there is usually a problem related to sub- contractors being paid for their work. Have you noticed how similar the Sims cranks are to the last version of Grafton cranks? It's not a well kept secret that Sims was the sub-contractor used to make Grafton cranks after Precision Tooling (Topline)/Grafton relationship ended.
A Micro Drive compatible drive arm is an important variation to keep in a crank stable. In 1991, when Suntour cleverly introduced the first Micro crank, immediately the importance of reduced diameter chainrings with the reduced weight and chainstay clearance became obvious. As the concept caught on, more crank makers began to make cranks with spiders drilled for a 56 bolt center diameter inner chainring, and a 94mm BCD middle and outer chainring. Topline was either the second or third maker after Suntour to introduce a crank set with a 56mm/94mm drive arm. The left arm of this set is identical to the two described above. The spider is different from the drive arm used above on just the right arm. Machined from 6.29mm thick aluminum plate, the back side is milled away where possible to reduce the spider weight further. The cranks come anodized in Black, Blue, Pewter Grey, Lavender, Silver, or High Polished un-anodized silver. We stock them in 170mm, 172.5mm, 175mm, 177.5mm, or 180mm lengths. On a special order basis we can order the cranks anodized in Gold, Green or Red, and we can also special order any of the colors mentioned in a 165mm or 167.5mm length if needed. The Topline Micro D arms have a Bike-Pro Q measurement of 151mm. Topline Micro Drive compatible cranks come as right arm, with spider, left arm and a set of five steel inner chainring bolts with aluminum spacers. Chainrings, the double chainring bolt set and crank arm dust caps will be needed separately. The weight of the 175mm long Topline Micro Drive crank arm set with spacer and bolts is 389 grams.