Middleburn RO1 cranks are compatible with square taper type bottom brackets. The RO1-SQ-175 crankset weight is approximately 437g including lock ring. Middleburn RO1 cranks are available in lengths of 160, 165, 170, 172.5 and 175mm and come in either a silver or black finish. These cranks work on the standard 44mm chain line for road bikes. All Middleburn cranks are machined with a JIS taper.
Middleburn cranks were first developed in 1991 and since then the cranks have undergone many refinements. The design is the result of advanced 3D and stress modelling technique that ensures they are amongst the stiffest cranks on the market but also light too.
The cranks are hot forged from high quality 7075 T6 aluminium. They then go through a CNC machined process and are then hand polished followed by being anodised before being re-machined with the Middleburn logo. All cranks go through the same procedure so whichever crank arm you choose will be to the best quality. The Middleburn cranks do not come with self-extracting bolts, these can be purchased separately from the website.
Using a 107mm square taper bottom bracket the Q factor is approximately 148mm.