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Thomson Masterpiece seatpost, seat collar, Elite X4 stem & Dirt Drop bar

CNC’d aluminium has never looked so good

Our rating 
4.0 out of 5 star rating 4.0
GBP £401.00 RRP | USD $435.00
Thomson finishing kit for a road bike

Our review

Brilliantly engineered components that give the perfect finish to your non-carbon bike, but come at a price
Pros: Superb performance; excellent engineering
Cons: High price
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Thomson started producing bike components in the mid 1990s. The parent company, LH Thomson, is a leading aerospace parts manufacturer and it applies the same high-grade CNC (computer numerically controlled) manufacturing techniques to produce high-end parts for bikes.


The brand’s first product was a lightweight (192.1g), one-piece CNC’d seatpost: the post head is machined from the same piece of solid aluminium as the post itself, rather than bonded onto a tube.

The design makes for an incredibly strong structure, which is lighter than a standard post.

Thomson Masterpiece edition seatpost and seat collar

Masterpiece seatpost for a road bike from Thomson
The brand’s first product was a lightweight (192.1g), one-piece CNC’d seatpost.
David Caudery / Immediate Media

This patented design is still in production today and the Masterpiece edition bears the same design as the original.

The post’s machined surface reveals how the material is cut down to a very precise 31.6mm diameter.

The fit into the frame is superb and when combined with Thomson’s similarly precision-machined seat collar (29.7g), it makes for a very secure fit and one that simply won’t budge or loosen.

Seat collar for a road bike from Thomson
The precision-machined seat collar weighs in at 29.7g.
David Caudery / Immediate Media

The clamp has a long 41mm rail seat, which works with both standard and oversized rails. Thomson claims the head can take 440Nm of torque and the tube section can withstand 230ft-lb before either will start to bend.

Fitting a saddle is easy as is adjustment, and with a wide -5-degree to +29-degree tilt adjustment you’ll be able to achieve a precise saddle position. Every element of this (31.6 x 350mm) post screams quality and precision.

  • Masterpiece seatpost: £155 / $160
  • Seat collar: £36 / $40

Thomson Elite X4 stem

Dirt drop bar and Elite X4 stem for a road bike from Thomson
The bar’s subtly shaped profile across the tops makes for a nice handhold
David Caudery / Immediate Media

The same is true of Thomson’s Elite X4 stem, which comes in at 162.1g for 100mm length. Like the post, the stem is machined from one piece of 7000 series aluminium and manufactured to its aerospace parts standards.

Thomson says the stem can be used for anything from road to downhill mountain biking.

The finish is as good as it gets, with both clamp sections smoothed so there are no sharp edges that could damage your bar or steerer.

  • Elite X4 stem: £95 / $115

Thomson Dirt Drop alloy bar

Completing the set is Thomson’s Dirt Drop alloy bar. At 299.8g (46cm) the gravel bar features a short 130mm drop and 90mm reach with a 25-degree flare.

The drop shape and flare is about as wide as I’d go while still keeping the brake levers in a usable position on and off road.

The bar’s subtly shaped profile across the tops makes for a nice handhold and it does a great job of reducing road buzz and jarring from rougher dirt tracks; still, £115 / $120 for an alloy bar is expensive no matter how proficient it is.

  • Dirt drop bar: £115 / $120

Thomson finishing kit overall

Thomson’s suite of components works beautifully. I wouldn’t recommend this all-alloy collection for a lightweight carbon bike, obviously, but if you’re riding titanium, alloy or steel then Thomson’s machined masterpieces will complement your steed perfectly.

Product Specifications


Price GBP £401.00USD $435.00
Brand Thomson


Features Dirt drop bar
Masterpiece seatpost
Elite X4 stem
Seat collar
Material Aluminium