julio 25, 2026
Free expedited shipping worldwide! (Normally 1-2 weeks days anywhere in the world) ** Check out the Intelligent Design Cycles blog for tips on how to wire hub dynamo lighting systems ** Buy With Confidence! Intelligent Design Cycles is earliest and ONLY company officially authorised by Shutter Precision to sell their products with a VALID worldwide warranty on Ebay. * Please note this is the higher power "P" series 3 watt version.* Quick release is not included. SP 8 Series hub dynamos SP hub dynamos are unrivalled in every sense of the word. They are more efficient, technologically advanced, simpler and lighter in weight than any competing hub dynamo by class. When lights are on, the P-8 (3W) and S-8 (3W for 20" and 2.4W for 700c) hub dynamos achieve an incomparable efficiency of 72 percent (i.e. watts of mechanical energy converted directly in watts of electrical energy - minus wasted muscular effort that would otherwise be propelling rider and bicycle forward). Before the introduction of the PD-8X in 2013, SP's 8 series hub dynamos were the most efficient available on the global market. To our knowledge, they remain the most efficient in the world - except for the PD-8X. SP's P-8 and S-8 series hub dynamos are respectively 7 and 17 percent more efficient than top German and Japanese rivals when measured at 15 km/h (9.3 mph), the "gold standard" specification set under the rigorous German StVZO standard for hub dynamos. (See P-8 and S-8 Efficiency graphs in pictures.) Perhaps more significant is the fact that the 8 Series hub dynamos have dramatically less drag when lights are off in comparison to the same top-of-the-line Japanese and even German hub dynamos. At 30 km/h (18.6 mph), the P and S series hub dynamos generate well over 50 percent less drag than the nearest Japanese rival and nearly 25 percent less drag than the most efficient German counterpart. Notably, they produce less total drag in comparison to competing hub dynamos at all speeds tested while also producing more power! Moreover, this efficiency gap widens considerably at speeds above 20 km/h.In terms of weight, the rim brake versions of the P-8 and S-8 series hub dynamos are a full 63 and 10 grams lighter than their nearest contenders, thus making the SV-8 not only the most efficient, but also the lightest hub dynamo on the planet. The disc brake versions are similarly at the top of their class in terms of lightness of weight. About Shutter Precision Shutter Precision (SP) was founded in the classic spirit of a "garage-based" Silicon Valley-style start-up. Its founders are young engineers with substantial expertise designing and producing the sophisticated micro motors that articulate fragile shutters in high-end cameras. Their adventure into the bicycle field began in 2007 with a vision to bringing their expertise to crafting the most efficient and technologically advanced hub dynamos for powering lighting systems and electronic devices on bicycles. When they initially gathered their collective personal savings together with loans from family, friends and friends of friends, they had not anticipated that their journey of financial uncertainty, toil and sweat would also include (sporadic) ulcers. By 2011, however, their painstaking efforts had culminated in a diverse line of state of the art hub dynamos incorporating the latest advances in the field of micro-motors - i.e. technologies resulting from large industrial scale R&D programmes that would have been cost prohibitive for the bicycle field. It is the stuff of legend that when the design concept incorporated by SP engineers in their generator mechanism was originally reviewed by their world-renowned German competitor in patent format it was then considered (with a sigh of relief) technically infeasible for manufacture. Since then, SP hub dynamos have passed from CAD-based "proof of concept" exercises through extensive lab testing of numerous prototypes and finally rigorous real-world field-testing of final products. Testing is on-going even today via sponsorships of top endurance cyclists in Australia and the UK. This regimen has not only proven the feasibility of the SP hub dynamos for manufacture, but confirmed their superiority in efficiency and mechanical rock-solidness. At EuroBike 2011, even the previously incredulous greeted the founders of SP with (gregarious) approbation. The axiom that more complexity is not always better is nowhere more true than in the case of the 8 series hub dynamos. In fact, the design of the generator in these hub dynamos incorporates fewer parts, is mechanically far simpler and is more easily manufactured than existing world-class hub dynamos. Excruciating efforts directed towards product and manufacturing process engineering has made 8 series hub dynamos cost viable for production entirely in Taiwan despite strong price competition vis-à-vis hub dynamos from large international brands produced in China. The heart of the SP generator mechanism is a solid high-specification magnetic ring that rotates alongside copper coils as the wheel turns to produce electricity. This novel mechanical design is crucial as most modern hub dynamos rely on a number of magnets bonded onto the inside of the hub's shell. When hub dynamos breakdown, it is often due to failure of the bonding adhesive holding the individual magnets in place - such breakdowns are more common in colder climates that accelerate deterioration of bonding adhesives. The design of SP hub dynamos makes this type of catastrophic failure virtually impossible. Who says you can't have it both ways. Whether you pride yourself on having the best of everything, or on selecting purely based on value versus performance, SP hub dynamos "have your back". This is true even if you are a crusty old curmudgeon wedded (if not welded) to the ideal that durability is the only factor worth considering. The "less is more" philosophy held dear by the creators of SP hub dynamos is clear in their mechanical design, beautifully understated silhouette and undeniable proof that price is not always prerequisite performance - much less quality and durability. To the best of our knowledge here at Intelligent Design Cycles, SP hub dynamos are today peerless in the world bar none.* Please note that for the PD-8 disc-brake version of SP hub dynamos (and not the PV-8) version, the flange diameters are asymmetric (see spec sheet in pictures). The spoke PCDs are 52mm & 58mm (disc side) and the flange diameters are 60mm and 66mm (disc side).* Owners of bicycles with 20" wheels. We recommend the P series hub dynamos even for 20" wheels as they will produce more power/light at lower speeds. The risk of burning out lamps is unlikely as modern dynamo LED lights have in-built voltage limiters. I run a PD-8 on my Bike Friday without problems and can hardly notice the additional drag. If you plan to recharge electronic devices, the extra power is a key benefit available only to 20" wheel bicycle owners.* Please feel free to write if you are interested in additional specifications.* FREE SHIPPING by first class post anywhere in North America, Western Europe (customers in Italy and Spain are requested to provide daytime phone numbers to ensure delivery) and East Asia. For other countries please inquire.* Please note the seller is not responsible for any costs associated with import or domestic taxation in the destination country. Our experience is that US customers have not been assessed import charges for private purchases such as these. If you are assessed, please let us know so we can advise future customers. The Shutter Precision Two Year WarrantyAll SP hub dynamos come with a full two-year limited warranty against manufacturer defect beginning from the date of purchase. SP stands behind their products and will repair or replace free of charge products found to be defective. High-mileage users are particularly valued customers and hubs that have not suffered a defect, but simply have worn bearings due to extensive use, can be sent back to the manufacturer for new bearings free of charge within the two year warranty period (customer pays for two way postage). Similar service after the warranty period is available for a reasonable USD 30.00 (the amount includes the return postage). This is the best service policy we are aware of in the industry. Please note that SP hub dynamos are not user serviceable.Intelligent Design Cycles proud to be an agent for SP hub dynamos. With the exception of EU member countries, Intelligent Design Cycles is an authorised agent for SP products worldwide and is the exclusive distributor for SP products in Australia. In short, dealer inquiries are warmly invited.