Shimano Tiagra FC-4700 48/34 chainset

Shimano's Tiagra FC-4700 chainset isn't going to set the world alight, but in this 48/34-tooth guise does make for higher cadence in your top gear and, depending on the terrain, less need for changing to the small chainring. If you live/ride in a fairly flat part of the country and you're in need of a new chainset it's one to consider; personally, I'd prefer a lower climbing gear too.

When we first looked at the newly designed Tiagra back in 2016, David was generally very impressed. His review was about the groupset as a whole, but he had this to say about the chainset: "This is the biggest component in terms of visual appearance when viewing a bike from the side, and it's here that Shimano has made the biggest stride forward. It has taken the same four-arm design as debuted on Dura-Ace all those years ago.

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"It's available in 52/36 and 50/39/30 configurations but I suspect the 50/34 compact option I tested will be the most popular chosen by bike brands speccing new bikes. The new four-arm design has a 110mm bolt circle diameter (BCD) and allows you to swap the chainrings to any configuration, which saves swapping chainsets if you want to adjust the gear ratios. Different crank lengths are available too."

What's changed since then is that it's now available in this slightly odd 48/34-tooth pairing, which is what I've been testing.

The chainset went on my 2014 Vitus, which – contrary to what your thoughts might be regarding bike journos and all the new kit we get – was still running its original FSA Gossamer Pro compact 50/34-tooth chainset.

The Vitus had a bit of a mish-mash of parts from new – FSA chainset, Shimano 105 shifters and mechs, Tiagra cassette and Tektro brakes.

I'd changed the 10-speed cassette from the original 12-30 to 12-32 (what a difference those two teeth make), and upgraded the brakes to 105. For a while I ran some secondhand shifters, but 'upgraded' to the latest Tiagra along with new mechs at the same time as fitting this chainset.

The difference in performance between old and new chainset is, I'm afraid, hard to detect. I can't tell whether the chain moves any more or less easily from one ring to the other, and I can't say I've noticed the 93g difference in weight – the old FSA chainset it replaced was 757g, compared with the Tiagra's 850g. The latest 105 chainset is 713g.

The only 'noticeable' difference – and I have to remember to concentrate – is that I don't need to change from big ring to small as often. It depends on the terrain you're riding, of course, but it's given me a more usable range in just the big ring, with the mid-sprocket ratios lower than they were previously.

> How to get lower gears if you’re struggling in the hills

I have to say, in all my leisurely riding I haven't noticed the lower top-end ratio. I don't mind spinning along at speed but I'm not a demon racer type, and 48x12 is fine for my liking.

It didn't occur to me until afterwards, but on one stage of last year's Ride Across Britain I found it a struggle to keep up with a group who had seemed to be riding at my kind of pace, despite it being flattish, and I wonder whether that was simply down to me spinning a slightly lower gear than the rest of them. Good excuse anyway...

> How to get ultra-low gearing for your gravel bike adventures

One thing I do really like is that the new chainset has 165mm cranks, whereas the old one had 170mm (170, 172.5 and 175mm are all available too). My custom-built Paulus Quiros has 160mm cranks, as advised by Jonathan Paulus, and short definitely suits me.

Fitting the chainset is really easy – you just need a Liam.

Liam says: "Fitting this chainset is just like fitting any Shimano crankset. It's incredibly straightforward and requires only one special tool. You'll need Shimano's tool for the bearing pre-load cap and a 5mm Allen key.

"Simply slide the driveside part with the attached axle into the bottom bracket, then place the non-driveside crank on the other side. Before you tighten the clamp bolts, you'll need to add some bearing pre-load. That's a fancy way of saying tighten the plastic cap on the non-driveside. Don't go mad, finger tight will do. Then secure the clamp bolts to 12Nm, spin the cranks to check that they're moving freely, and away you go."

Value

Tiagra is possibly the best-value groupset in Shimano's line-up. You're getting great performance for a fraction of the cost of the higher-end ones, with just a little extra weight.

It also compares well with other sub-compact chainsets – the Miche Graff 46/30 chainset that Steve tested is lighter at 789g (though it does have fewer teeth) but costs £130, and the Praxis Works Alba M30 is lighter still at 749g, with 48/32 rings, but costs £150. FSA's 46/30-tooth Energy Modular 386Evo chainset, meanwhile, is £269.95.

Conclusion

Tiagra is good value for what you get, and here that's a nicely made chainset that gives you a few more usable gears in the big ring by sacrificing some top-end speed. It strikes me as quite a niche product, and debatable whether it's worth the effort to change just your big ring without lowering all your gears. That said, if you're happy with your climbing gears and don't find you're using your 50x11 (or 12) combo very often, it could be worth considering next time your chainset needs replacing. I prefer it to my old 50/34 FSA chainset, but ideally I'd like lower climbing gears too.

Verdict

If you don't mind losing some top-end speed this provides a few more usable ratios in the big ring but no extra climbing gears