16 August 2010

bikefix Exclusive Review: Park Tool TW-5 torque wrench

Despite relying on them extensively in my professional life, I for a long time put off the purchase of my own torque wrench. Its not that I didn't think them valuable- I knew that they were- but the prices were always a bit high for a non-essential (or, more accurately, non-fun) purchase. The decision to take the plunge was made for me one day when a carbon fiber handlebar's response to a new brake lever install was the chilling of fibers breaking. It was time.

As cycling components get lighter and more precisely engineered, the importance of proper installation increases exponentially. No one really wants to return to the days of customers breaking thin-walled aluminum handlebars or seatposts on the road or trail. Component manufacturers are doing ever better jobs at putting material where it's needed and removing it where it isn't. Because components are built to have just enough material to meet their intended use, the way in which they mate has become increasingly critical. Going apeshit on fasteners in order to prevent loosening is a good way to damage components and ensure that parts will fail sooner than intended.

Of course, all of this presumes that manufacturers are basing all of those installation torques neatly laser marked our parts on something, be it theory, experiments, or experience. We have noted in the past when identical parts (sold under different brand names) have different installation torques, which does make us wonder...

In any case, the destruction of a $150 handlebar made me reconsider the value of a $124 investment in a torque wrench, and that's what Park's TW-5 costs. A Taiwanese-made ratcheting breakover (or "clicker") style torque wrench, the TW-5 can be set to apply 3-15Nm of torque through its 1/4in drive. I ordered mine through a local shop given its competitive price and Park's reputation for high quality tools. At the same time, I also ordered the company's SBS-1 metric socket set to ensure that it could communicate with the various Allen and Torx fasteners on my bikes.

The TW-5's adjustment is made through a reasonably easy to read modified micrometer-style knob (major increments are viewed through a small window). There is a metric-to-imperial conversion chart on the body and the whole thing comes in a nice hard case with a 1/4-to-3/8in drive adapter. A note about tool cases (and Park is hardly alone here): Why on Earth can't they make a pocket or slot for the folded up instruction sheet in the case itself? Just sitting the manual on top of the tool virtually ensures that it will be discarded, especially in a working shop environment. In any case...

In use, my biggest complaint about the TW-5 (aside from having to remove and keep track of the manual every time I pull it out of its case) has more to do with the SBS-1 socket set than the wrench itself. Because the low-range wrench uses a 1/4in drive and the socket set 3/8in drive, it means the the provided adapter is needed with every use. Of course, the wrench doesn't fit in the case with the adapter mounted, so that's one more step towards making its use less instinctive. In addition, a couple of the SBS-1's Allen bits have already begun to round off- disappointing from a company like Park (and for the $38 asking price). I'd recommend looking at other companies for a (1/4in drive) socket set that will meet your needs.

Though the modified micrometer style adjuster may be easier for lay mechanics to read, the TW-5 seems no better made or worse than similarly-priced micrometer style torque wrenches I've purchased from McMaster Carr. That doesn't make it a bad deal- the TW-5 seems like a well-made tool and my complaints really center around the case and sockets. Add in Park's reputation for standing behind their product and it's a pretty safe bet even if something were to go wrong. Neither complaint (except the rounded hex tools) impact the tool's primary function, which is helping to ensure that lightweight and torque-critical parts are installed properly and in doing so preventing costly and dangerous failures- something the TW-5 does well.

marc

www.parktool.com

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