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Ultimate upgrades: Silca Hiro Chuck v.2

Stu Bowers
20 Jan 2017

The Silca Hiro side-lever locking chuck v.2 is the pump connector of a mechanic's dreams

Tools, to an aficionado of the bicycle workshop, are more than simply functional items. Yes, they are created to do a particular job, but that’s a bit like saying a Breitling will tell the time. 

Some tools perform the task with exceptional proficiency and are objects of beauty in their own right, such as this Silca Hiro Side-Lever locking chuck v.2, which to a professional mechanic is tantamount to tool pornography. It’s certainly no ordinary track pump connector, and with a pricetag of £105 neither should it be.

Primarily it was designed for disc wheel operation, compact enough to fit in the fiddly cut-out where the valve sits, and capable of maintaining an airtight seal beyond 250psi, but its appeal need not be limited to just track and time-trial enthusiasts. 

‘The Hiro came about from my time working at Zipp, when I was handling the Pro Tour teams in Europe,’ says Josh Poertner, now president of premium bicycle pump manufacturer Silca. ‘Most of the mechanics had the Japanese Hirame chucks, which were rare, very expensive and highly coveted. But we found the Hirames had issues, broke with some frequency and had absolutely no spare part availability. 

‘Silca’s vision was to make something much more robust that was also completely rebuildable. We worked really closely with Pro Tour team mechanics to perfect the design of the Hiro. Remember, at the pro level crazy things happen, so if the team bus rolls over the thing it’s nice to be able to rebuild or replace parts quickly and efficiently. Now around 80% of pro team mechanics have purchased one. I feel honoured that folks at this level pay for parts like this.’

Poertner accepts that the pricetag is on the high side for a pump connector (a basic one will cost £5-£10), but believes that the workmanship involved justifies the expense.

‘We make the entire assembly from 17-4 stainless steel,’ he says. ‘It was developed originally for aircraft landing gear for naval aviation where you needed the strongest, lightest thing possible with incredible corrosion resistance. The downside is of course it’s really expensive and then also really time consuming and expensive to machine too. 

‘All of the parts are machined in the USA on Citizen Swiss lathes to keep to incredibly tight tolerances, and also to do some of the very complicated cross-drilling and milling. Each one is then hand assembled and tested. We hand test to 160psi using two different valve stems – representing the high/low ISO tolerance limits for valves – to ensure the chuck doesn’t leak. The metal parts in the Hiro have a 25-year warranty. We are that serious about this chuck. You’re buying it for life, and we’ll stand by it. But I totally get that it’s expensive for home mechanics.’

If you’re still not convinced you need a valve connector that costs the equivalent of three decent track pumps, will outlive you and eventually be worthy of becoming an heirloom to be passed down through generations to come, just get one in your hands. The refinement and feel alone will be enough to convince you. If you’re a true connoisseur, that is.

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