Topline Mountain Cranks

Topline cranks were designed and manufactured by John and Phil Trenerry of Precision Tooling. If they look familiar, it will be because they were originally sold as Grafton Speed Sticks – at this time the brand name Topline did not exist.

The problem was that Precision Tooling didn’t have sufficient knowledge of the bike industry and were unsure how best to market their product. Their only previous experience with bike components was being briefly contracted to produce CQP cranks – which is probably where they got the idea to produce a dog bone style crank.

This led to Phil Trenerry calling on an old acquaintance, John Grafton, who was currently at the pinnacle of the mountain bike brake market with his legendary Grafton Speed Controller cantilever brakes. Shorlty after, a verbal deal was struck which would see John Grafton market the cranks as a Grafton product in 1991.

However, their partnership didn’t last long and both parties went their separate ways. So in 1992 Precision Tooling started to market the cranks under their own new brand, Topline. John Grafton then went on to design his own iconic cranks, Grafton Joystix and released them the same year.

Topline made some minor alterations to the Grafton Speed Sticks before re-releasing them as Topline Mountain cranks. The first change was to flatten the profile of the balls at the back of the pedal threads so the cranks wouldn’t require such a long bottom bracket axle. The second change was to replace the 5mm allen head bolt which held the spider in place with a titanium bolt which the had the head ground down.

Otherwise, the cranks were still the same beautifully machined 7075-T6 aluminium units in a subtle dog bone style with arms tapering from the bottom bracket to the pedals. The arms retained the grooves machined on either side to keep the weight down. The pedal hole not being drilled all the way through the arms is a feature which makes these cranks instantly identifiable as a Precision Tooling product.

The cranks were initially released with a 110mm BCD triple spider and in colours Black, Polished (non-anodised) and Purple. The bonus was that the cranks were now supplied with titanium inner chainring bolts.

With the extra titanium goodies and a lower RRP than when sold under the Grafton banner, this made the product even better value than before.

As popularity and demand grew, numerous different spider configurations became available: 110mm BCD and 94mm/58mm BCD triple, 94mm/56mm Suntour MicroDrive, 110mm BCD BMX single, 130mm BCD road double and 135mm C-Record road double. And the range of colours increased to cover all popular colours, including various mixed crank arm and spider colour combinations.

There is no doubt that Precision Tooling were onto a winner with their cranks. They were exceptionally popular in an era of weight-weenies, when cutting weight was almost a religion for cross country riders – think <a href=”http://velocipede.co.uk/dictionary/#HairsineRatio”>Hairsine Ratio</a>.

The only flaw these cranks have is that the non-drive side crank arms are prone to cracking at the bottom bracket axle end. If using them today,
it is worth checking them regularly.

This design could probably be credited for influencing Tune Big Foot cranks some years later – the similarity is striking.

Length: 160, 162.5, 165, 167.5, 170, 172.5, 175, 177.5, 180mm
Axle: Square taper
Colour: Black, Blue, Gold, Green, Pewter, Polished (non-anodised), Purple, Red, Silver
Weight: 444g (177.5mm)
RRP: $179.99
Made: USA