By Jim Langley
- Comes to the rescue when nothing else work
- Airtight seal every time
- Side-lever means it fits where other chucks/adapters won’t
- A joy to hold and use
Source: SILCA and available at Amazon https://amzn.to/2P66e0c.
Use: In my home shop and at events and races – dozens of tough tires inflated
RBR sponsor: No
How obtained: Purchased
Size/Weight: 76 x 25mm / 79 grams
Beautifully engineered and machined chuck ensures airtight connection every time.
If you’re the type of roadie who likes to help friends (and strangers) with their bikes at rides and events – or if you have hard-to-inflate tires yourself, allow me to introduce you to Silca’s Hiro chuck. The name Hiro comes from the Japanese chuck that inspired Silca to invent theirs. But it’s pronounced hero, because this little gem will save the day when dealing with tough tires.
What makes Silca’s Hiro chuck special is its side-mount design. This lets it fits into tight spaces. I first learned of it because I needed a chuck that would allow inflating tires on carbon disc wheels (not disc as in disc brake but as in aero disc wheels).
Aero disc wheels are challenging to inflate because they have solid sides to minimize wind resistance. This means there’s only a small hole for the pump at the valve, which makes it hard to fit the pump head on to inflate tires. Sometimes you can get the head on the valve but you can’t move the chuck’s locking lever to get it to seal.
Many riders choose these wheels for time trialing and at every time trial I would run into riders struggling to inflate their disc wheels. And, even I sometimes had trouble inflating my own wheels. My little box of valve extenders, adapters and unique pump heads didn’t always do the trick.
With the Hiro chuck in my toolkit I finally had a surefire way to help riders at races and myself, too. Plus, it can come in super handy when you’re dealing with too short valves, too.
The valve shown barely pokes through the rim. If you try to put a pump head on it, if it even holds, it will hold until you start inflating at which point the pressure blows the head off the valve. You can hold the head on the valve and pump that way, however, air will leak out making it hard to fully inflate the tire.
The Hiro’s ingenious design makes easy work of both locking onto valves like this and providing an airtight seal. And, once locked on there’s no need to hold the chuck in place.
It works so well because of a few clever features. Like most pump heads there’s a rubber grommet inside the Hiro to grip Presta valves. But the Hiro has a proprietary elastomer gasket for the best grip. And, on top of the chuck is a knurled, threaded cap that you can turn easily by hand to fine tune the elastomer’s grip as necessary for the situation you’re dealing with and the type of valve.
The other key feature, is the Hiro’s long locking lever, which uses a cam on the side to compress the chuck elastomer and firmly lock onto valves. Also, unlike many chuck locking levers that you have to lift, which can be hard to do and tends to pull the chuck off the valve, the Hiro’s is pressed down. This is easy to do and doesn’t move the chuck’s position on the valve one bit.
Silca says the Hiro can handle up to 300 psi (some smooth-surface-only racing tires are inflated insanely hard). I didn’t test this but I have inflated to 130 psi to check its grip on different valves and it held fast every time. One of the things I like the most about the Hiro is that, thanks to its airtight seal, you always get a nice pressure reading on your pump gauge from beginning inflation right up to when the tire is ready to ride. It’s also one of the easiest to remove chucks and never gets stuck on Presta valves thanks to a built-in spring that releases the grip when you open the lever.
In conclusion, I can understand how $65 may seem like a lot for what is essentially a spectacular valve adapter, but if you appreciate using and owning extraordinary bicycle tools, and especially if you like to be the go-to mechanic in your riding group – I am confident you’ll love this beautiful tool.
From SILCA, here are the Hiro’s specifications:
- Full metal construction, guaranteed for 25 years and covered by SILCAShield warranty
- Effectively seals on valve stems as short as 10mm!
- Uses SILCA 254 High-Tech Elastomer gasket
- Adjustable gasket pre-load allows for custom fit on any valve and also compensates for gasket wear
- Spring-loaded lever for better force management and positive on/off feel
- Male Schrader thread fits into any Schrader pump chuck, or use SILCA Thread-On Schrader Adapter to fit to bare hose or Presta chuck
- Bulletproof high-pressure, disc compatible chuck for high pressure situations
Ride total: 8,940
Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s streak of consecutive cycling days has reached more than 8,000. Click to read Jim’s full bio.