Dynamo Hub SP (Shutter Precision) for Brompton Titanium Skewer (MiniMODs)

World's lightest and smallest dynamo hubyet with ultra high performance. (Review by road.cc)Details (for Brompton)6V 1.5W Ultra compact dynamo hub for wheel size 400mm to 658mmUnique aerodynamic shape, low resistance and super light weight, make for and increadably efficient hub.The unique aerodynamic shape of the hub has been optimized to a golf ball size, while attaining an unprecedented weight only 299g.Output Notes from Shutter PrecisionThe SP-9 Series real output is 6V 3W for 20”, however for 26”/700C its output is very close to 6V3W but still a little bit less at low speed & therefore, it cannot pass German StVZO regulation. For the German market SP must get StVZO approval so the 9 series was used to apply the new regulation i.e. 6V 1.5W LED. And 9 series got 6V 1.5W LED StVZO approval.Its output is definitely not 1.5W. Shimano 1.5W hub output is real 1.5W. We don’t like it & also we checked 1.5W with other dynamo lights. It is not enough. Although 9 series is marked with 1.5W, its real output is much higher than 1.5W.- 7.9mm QR to suit Brompton (74mm OLD)- Weight 299g- Axle Type : QR (Titanium Skewer Included / MiniMODs )- Non-disk- 28 Holes- Black or SilverFrom wheel size 400mm(16”) to 535mm(20“):The 9 series output perfectly matches German StVZO 6V3W/20” regulation. As can be seen from the table, from wheel size 400mm(16”) to 535mm(20”), the 9 series output is designed to meet StVZO regulation.From wheel size 646mm(26”) to 716mm(28”):According to German StVZO, it requires 3V output at a low speed of 5km/h. If the 9 series is set on wheel sizes of 646mm(26”) and 716mm(28”), it offers 3V output speed at 5.8km/h and 6.4km/h respectively. To have 3V output, it only needs to slightly increase speed up to 1.4km/h. Furthermore, according to German StVZO 6V3W regulation, it requires 5.7V output at 15km/h. If we set the 9 series on wheel sizes of 646mm(26”) and 716mm(28”), this 9 series offers 5.7V output when speed at 15.7km/h and 17.7 km/h respectively. To have 5.7V output, it only needs to increase speed up to 2.7km/h. As for 6V3W, the German StVZO approved hubs in the current market normally offer 6V3W output when speed around 17km/h. The SP 9 series offers 6V3W output for 646mm(26”) and 716mm(28”) wheels when speed at 16.7km/h and 18.6km/h respectively.