ENDUOTM EVOLVE COMPETITIVE CYCLING 2O21 03 INTRODUCTION 05 THE ISSUE WITH CURRENT DRIVETRAIN SOLUTIONS 10 INTRODUCING THE ENDUO™ EVOLVE 16 WORK WITH US 17 METHODOLOGY & APPENDIX 18 GLOSSARY OF TERMS CONTENTS 02 01 OUTLINE IMPORTANCE OF FOCUS ON SHIFT TO NEW THE SAME MARGINAL GAINS AERODYNAMICS DRIVETRAINS MATERIALS FUNDAMENTAL TECHNOLOGIES In competitive cycling, Traditionally, cycling teams Recently, there has Despite aluminium Competitive cycling is still where a place on the (especially track cycling been a shift in focus components being flooded with bikes using podium is decided by teams) have primarily from aero to drivetrains, commonplace and effective the same fundamental milliseconds, it is never focused on aerodynamics where manufacturers are in cycling applications, roller chain and sprocket been so apparent that – increasing efficiency increasingly expanding carbon fibre is considered design that was invented marginal gains play a through minimising losses the size of chainrings superior for the stiffness, in 1880 by Hans Renold, considerable role in the caused by wind drag. and sprockets in order weight-saving and aesthetic and has remained largely creation of champions. to increase power benefits that it brings. unchanged ever since. With transparent data, transmission efficiency This is evidenced clearly wind tunnels and high-end from the rider to the bike. It is no longer rare for This limits the efficiency, by Team GB and Team testing facilities, we are cyclists to use carbon fibre lifetime, and material Sky (now Ineos) dominating now learning more than But there’s a limit to how chainrings, although the potential of current cycling under Dave Brailsford ever about aerodynamic much you can increase proposed performance drivetrains on the market. following an increased performance. the size of a component benefits these bring are focus on marginal gains. before it starts to have a controversial within the detrimental impact on the cycling community. aerodynamics and overall weight of the bike. INTRODUCTION 03 “ INNOVATION HAS BEEN SWIFT AND DRAMATIC OVER THE YEARS, BUT THE ONE THING THAT NEVER SEEMED TO CHANGE WAS THE CHAIN AND DRIVETRAIN COMPONENTS. Marc O’Brien Spellman Dublin Port INTRODUCTION 04 ENERGY LOSSES Take away: there are three primary 02 frictional loss interfaces. In a chain-drive bicycle drivetrain, there THE ISSUE WITH are multiple sources of energy loss, including damping and striking energy. But the most significant source of loss is that of friction, which occurs at five CURRENT DRIVETRAIN key contact interfaces in the drivetrain. SOLUTIONS Bush–roller HOW DRIVETRAINS WORK “ Roller–tooth Link plate–sprocket Every single watt of Every competitive track and road bicycle power is transmitted drivetrain uses a fundamentally identical through the drivetrain, so even a small method to transfer power from the pedals percentage to the wheel: a roller chain wrapped of improvement can around a sprocket and chainring. In result in significant almost every case, the tooth design reductions of loss and therefore increases in of different sprockets and chainrings performance.” are indistinguishable, and yet there are – significant drivetrain losses associated Dan Bigham Pin–bush with existing tooth designs. Wattshop / HUUB Wattbike Link plate–link plate THE ISSUE WITH CURRENT DRIVETRAIN SOLUTIONS 05 In well-aligned, single-speed drivetrains, “ LIMITATION I: RELATIVE MOVEMENT the frictional losses associated with the Aside from performance, those lost watts are To enable engagement and link plates can be neglected, meaning actually wearing disengagement from the sprocket, that the primary loss mechanisms of away your drivetrain the roller is made smaller than the interest are pin-bush, bush-roller and components, decreasing product life and gulley in which it sits, allowing the roller-tooth losses. therefore increasing the roller to rotate, push and pull on cost of your drivetrain the side of the sprocket tooth. The pie chart below shows the system.” contribution of each of these interfaces – Dan Bigham (Wattshop / Unfortunately, this difference in diameter to the total frictional losses in the HUUB Wattbike causes additional movement between drivetrain. the roller and the tooth through the sprocket rotation, the net effect of which is to incur unnecessary losses at this interface, decreasing the lifetime and Contribution of interfaces to total frictional losses performance of the drivetrain. Pin-bush Bush-roller 72% 21% Roller- sprocket 7% THE ISSUE WITH CURRENT DRIVETRAIN SOLUTIONS 06 LIMITATION II: HIGHLY LOADED The load on the bush-roller interface ” ARTICULATIONS depends on the contact force applied In a sport where one second is a lifetime and on the roller by the tooth, while that on Frictional losses originate wherever 10 watts is 1st or last, the pin-bush interface arises from the any improvements are surfaces slide against one another under combination of the chain tension applied welcomed with open a contact load. In the standard roller arms.” and the roller-tooth contact force. The chain setup, these losses occur primarily – shape of the tooth is very important in the tense side of the chain where Marc O’Brien in governing the force at the sliding Spellman Dublin Port the chain is wrapping or unwrapping interfaces, and therefore the frictional around the sprocket or chainring, losses in the system. known as chain articulation. The chain articulation causes significant sliding between the pins, bushes and rollers as the bodies are forced to rotate relative to one another through the articulation. The input power from the rider simultaneously applies a very high tension to the chain, which causes the sliding to occur under very high contact loads. Articulation link THE ISSUE WITH CURRENT DRIVETRAIN SOLUTIONS 07 ROLLER CHAIN Energy loss ARTICULATION TYPE Inner link Comparing these two types of When considering the source of articulation, it can be found that more the articulation losses, in particular energy is lost in a bush articulation the pin-bush and bush-roller losses than in a pin articulation because of previously shown, a distinction must the larger number of interfaces that be made between the different types slide during the bush articulation. of articulation: pin articulations and bush articulations. These different These articulation types alternate with articulation types are a result of the every articulation of the chain because two types of link – the inner (narrower) of the alternating inner and outer links link and outer (wider) link. in the chain’s construction. This means that it is almost impossible to completely Pin articulation eliminate either articulation type. The outer links articulate via what are known as pin articulations. In this case, Outer link the inner link remains stationary relative to the sprocket, while the outer link rotates about. This rotation of the outer link, and corresponding pin, causes sliding between the pin and the static bush, inducing a loss at this interface. LOST WATTS Well-documented physical Bush articulation testing research shows that roller The inner links articulate via bush chain drive efficiency reaches articulations, where it is the outer link values of up to 98%, dependent that does not move relative to the on the conditions applied to the sprocket, while the inner link rotates. drivetrain. This equates to 20 The effect of this is that there is sliding watts loss at an input power on the inner surface of the bush between of 1000W. the bush and static pin, as well as on the outer surface of the bush between the bush and static roller. THE ISSUE WITH CURRENT DRIVETRAIN SOLUTIONS 08 WHY SPROCKETS MATTER For this reason, the best approach to THE ONLY CURRENT SOLUTION: reduce drivetrain losses is undoubtedly LUBRICATION AND SURFACE Within track cycling, a common trend to focus on reducing losses at the TREATMENT is to focus on reducing the losses rear sprocket in combination with associated with the chainring, with Outside of a design change, the only the chainring to offer the greatest less of a focus on the sprocket. thing cyclists can currently do to combat possible increase in efficiency the implications of relative movement, over the entire drivetrain. However, only 20% of drivetrain losses high loads and unnecessary friction, is to actually occur at the chainring, compared mitigate the sliding friction by applying to the 80% lost at the sprocket. This lubrication and other treatments to is because the articulation angles of component surfaces. the chain when wrapping around the sprocket are so much larger than those Despite there being a wide range of at the chainring. lubricants on the market, the differences in relative performance are unclear and they have a very limited capacity to improve a drivetrain’s efficiency before other factors play a more significant role. Comparison of sprocket and chainring energy losses Sprocket Pin-bush Bush-roller Chainring Roller-tooth 0 10 20 30 40 50 60 70 80 Articulation loss (%) THE ISSUE WITH CURRENT DRIVETRAIN SOLUTIONS 09 INTRODUCING THE The Enduo™ Evolve is a revolutionary conventional drivetrains, increasing Up to new sprocket design developed overall efficiency and lifetime of the Watch the exclusively by New Motion Labs. chain, chainrings and sprockets. explainer video 30% increase in drive lifetime By enabling the roller chain to securely The Evolve benefits competitive cyclists engage on both sides of the sprocket across all events. By minimising the tooth – otherwise known as Dual amount of energy lost through the Up to Engagement – the Enduo™ Evolve offers drivetrain, athletes are able to transfer many advantages over conventional more power and race even faster. 1% technologies, including increased higher efficiency drivetrain efficiency, longer lifetime and less friction. LESS This design drastically reduces the frictional losses witnessed on WEIGHT ENDUO EVOLVE 10 BENEFIT I However, unlike conventional roller chain BENEFIT II PREVENTING RELATIVE MOVEMENT chainrings/sprockets, the roller on the REDUCING ARTICULATION LOSSES other side of the tooth is a supporting In the roller pairs which engage each Standard roller-chain sprockets are roller.