Derby 27.5 x 40mm HD Wheels

Width (internal): 33mm
Weight (pair): 1,730g

Available: 29in x 35mm, 27.5in x 40mm and 26in x 40mm

Derby 27.5 rims come in three flavours, depending on your riding style and the terrain of choice: light, heavy duty (HD) or downhill. They’ve all got the same external design, but they vary in wall thickness. Our test HDs are built with strength in mind; they’re not for those looking for a lightweight cross-country race rim. They came in a top-end build, with Chris King hubs, from Derby itself, although Just Riding Along is the current UK rim stockist.

These ones have an internal width of 33mm, an external width of 40mm and 32 straight drilled spoke eyes (angled holes will be available soon). One feature that I was a little unsure about was the 6mm-tall hookless rim sidewall: it just didn’t look high enough and I was worried about burping them. I ran the front wheel with less than 10psi on a couple of descents just to see if I could burp it, but I’m pleased to say not even a sneeze of sealant came out.

I’m less than kind to wheels, running as low a pressure as I can on the front and only a couple of psi more on the back, so I was keen to see what sort of punishment these rims would take. I set them up tubeless with a Specialized Butcher up front and a Slaughter out back. They were ominously tight to fit, but they inflated perfectly, and stayed up with no trouble.

During climbing and accelerating I was overwhelmed by the traction on offer, even with a fast-rolling tyre in winter. On an iced-over moorland climb, the voluminous rear tyre gripped on all but the thickest ice patches. And the low weight for the girth gave fast acceleration and a nimble feeling bike.

But it was on the descents that I really felt the improved performance of carbon rims and the extra width. In my usual style I picked some of the worst lines through rock gardens without even flinching. When I spotted a hook or tight line, I could execute the move with ease. Tyres with more volume and grip, with less tyre roll and chance of burping. What more do you need? I’m a believer!

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