Shimano Tiagra 10-speed transmission review
The latest incarnation of Shimano’s ‘serious entry-level’ Tiagra road groupset brings 10-speed transmissions to lower price levels for 2012 despite the general creeping up of bike prices over the past couple of years.
And the new Tiagra isn’t a poor relation to Shimano’s spendier components. It provides a clean, light shifting feel and wider gears than previous road offerings from Osaka.
If you’re in the market for the kind of sub-£1,000 bike which will likely come with Tiagra, you might wonder why you need an extra gear. Shimano’s answer is their new 12-30t cassette which adds a bit of gear range without whopping gaps between sprockets – down to a 1:1 ratio with a triple.
Unlike other 10-speed systems, Shimano haven’t hidden Tiagra’s gear cables under the bar tape. That’s a good thing – we’ve seen a lot of 105 and Ultegra systems shift poorly because the cable routing was tight, but this avoids the problem. It may not look as tidy, but on bikes that are likely to see hard commuting and sportive use it should improve reliability and certainly makes cable replacement easier.
The external cable routing means Tiagra also offers a slightly thinner lever hood shape than Shimano’s other 10-speed systems, and a collection of shims provides reach adjustment for smaller hands. Our Tiagra set came with a 50/39/30t triple chainset and shifts front and rear were quick, accurate and practically effortless.
Shimano’s triples are a puzzle though. They provide a 30×30 low gear, which is only a fraction lower than SRAM Apex’s 34×32. For the extra complication, it’d be nice to get a really low bottom gear for very steep hills, carrying loads or when you’re simply knackered at the end of a ride.
Shimano could provide that with, say, a 24-tooth inner ring and balance the range with a 38-tooth middle. Our only other criticism is that the secondary lever action has a plasticky feel compared with Shimano’s more expensive shifters.
This article was originally published in Cycling Plus magazine.