I've had a number of requests for rolling resistance tests on tyres, and I've recently done an other batch, so here are results of all the 4 sets I've done. Please note that with the exception of the tests done on a concrete velodrome, these are 'lab' tests done by loading a wheel with a 30kg weight on a 4.5 inch drum, which gives higher figures than obtained on the on the road. As they say, Your Milage May Vary! GREENSPEED TYRE TESTING TABLE 1993 Speed 30kph, Load 30 kg. Tyre Pressure, P.S.I. 30 50 80 100 115 Make, type, size, & pressure rating. Power absorption in watts IRC Road Lite 20" x 1 1/8" R 100 xxx 40.8 xxx 27.0 24.5 IRC Triathlon Duro 700c x 25 R 115 xxx 51.5 xxx 30.8 28.1 LHR 20" x 1.75" Semi Slick (F2) R 50 62.7 41.6 28.9 25.2 xxx Tiogo Comp Ramp 20 x 1.75 R 90 51.3 36.7 26.5 23.2 xxx Road Lite retest xxx xxx xxx 27.6 xxx IRC BMX RACER Z II 20 x 1 1/8 R 85 xxx 53.7 39.8 33.6 xxx Specialized Fat Boy 26 x 1.25" R 100 xxx 50.1 37.4 32.7 30.8 Ritchey Tom Slick K 26 x 1.4 R 50-85 xxx 50.1 36.6 32.0 29.3 IRC Freestyle Pro 20 x 1.75 R 45 -80 xxx 41.1 29.7 25.8 xxx Cheng Shin Semi-slick 20 x 1.75 R 35 50.6 37.4 27.1 23.6 xxx LHR Comp III copy 20 x 1.75 R 45 59.6 45.4 38.0 36.0 xxx LHR Mountain Tread 20 x1.75 R 50-70 58.0 42.5 33.1 30.1 xxx Tiogo Comp III 20 x 1 1/8 R 75 xxx 50.1 39.8 37.4 xxx Tiogo Comp III 20 x 1 3/8 R 40-45 xxx 42.5 35.8 33.3 xxx LHR Road Tread 20 x 1 3/8 R 65 xxx 51.7 40.6 O.O.R. xxx LHR Comp III copy 20 x 1 3/8 R 65 xxx 46.9 O.O.R. xxx xxx Kenda Road Tread 20 x 1 3/8 R 40 xxx 50.4 39.0 xxx xxx Tioga Comp Pool 20 x 1.75 R 30-90 50.1 33.3 23.5 20.0 xxx IRC Freestyle 20 x 1.75 R 45 - 80 xxx 46.9 37.4 33.5 xxx Continental Goliath 26 x 1.6 R 35 - 65 xxx 46.9 35.8 32.7 xxx Cheng Shin Semi Slick 26 x 1.5 R 40 -65 xxx 37.4 29.5 26.3 xxx Kenda Semi Slick 26 x 1.95 R 40 - 65psi xxx 46.9 37.4 34.3 xxx Continental Super Cross 26 x 1.95 R 35-65 xxx 51.7 43.9 xxx xxx LHR Mountain Tread 26 x 1.5/1.75 R 50-70 xxx 45.4 37.4 35.8 xxx Vee Rubber 26 x 1.75 R 40 xxx 45.4 38.2 xxx xxx IRC Racer XI 26 x 1.75 R 45 - 55 xxx 53.3 43.0 xxx xxx Continental Grand Canyon 26 x2.125 R35-65 xxx 49.0 42.2 40.6 xxx Moulton - Wolber 17 x 1 1/4 R 70 xxx 48.9 33.4 30.3 xxx IRC Kik Super MX8 16 x 1.75 R 45 -55 51.6 36.3 29.8 29.0 xxx IRC Kik Super MX8 16 x 1.75 R 45 -55 36.2 26.5 19.0 16.7 xxx (with tread ground off) LHR Road Tread 16 x 1.75 R 50 61.8 44.6 35.9 xxx xxx LHR Golden Dragon 16 x 1.75 R 50 61.8 44.5 35.3 31.4 xxx IRC Kik Super MX8 16 x 2.125 R 40 -50 56.5 39.9 32.2 xxx xxx OOR = out of round (casing failure) xxx = not tested at this pressure GREENSPEED TYRE TESTING AT BURWOOD VELODROME 14/2/1997 Machine:- Mt Eliza S/C Quicksilver - Greenspeed Sports Tourer frame & carbon fibre/Nomex fully faired body. Average speed for number of laps at 160bpm heart rate. IRC Road Lite 20" x 1 1/8" @ 120psi 43.55kph Tioga Comp Pool 20" x 1.75" @ 100 psi 44.56kph GREENSPEED TYRE ROLLING RESISTANCE TESTING April '97 Rolling resitance in watts at 30 kph on 4.5" roller, 30kg load PSI 40 60 80 100 120 140 160 Tyre HFR Duro 16 47.0 37.8 31.9 xxxx xxxx xxxx xxxx Schwalbe 16 xxxx 30.0 26.6 23.8 xxxx xxxx xxxx Primo 16 xxxx 30.0 25.4 23.8 22.7 xxxx xxxx MW Slick 17L xxxx xxxx 28.6 25.8 23.7 22.3 20.9 MW Slick 17B xxxx xxxx 29.3 26.1 24.4 23.0 xxxx Conti GP 20 xxxx xxxx xxxx 28.6 25.5 23.7 xxxx Schwalbe 20 xxxx xxxx 37.8 34.3 31.7 30.0 xxxx Conti TT 20 xxxx 34.3 29.8 27.9 25.4 xxxx xxxx Comp Pool 20 xxxx 27.8 25.2 23.0 20.9 xxxx xxxx Haro 20 42.7 32.9 27.2 xxxx xxxx xxxx xxxx LHR 20 47.9 35.5 30.2 xxxx xxxx xxxx xxxx Road Lite 20 xxxx xxxx 32.4 31.3 29.2 27.6 xxxx Primo 20 xxxx 31.4 26.8 24.7 23.4 xxxx xxxx Kenda 20 xxxx 39.5 34.4 30.7 29.3 xxxx xxxx Tyre details. HFR Duro 16 x 1.75" 47 - 305 R 40 psi Schwalbe City Jet 16 x 1.95" 54 - 305 R 80psi Primo 16 x 1 3/8" 37 - 349 R 85psi Moulton - Wolber Slick 17 x 1 1/8"? Latex tube R 120psi ? Moulton - Wolber Slick 17 x 1 1/8"? Butyl tube R 120 psi? Continental Grand Prix 20 x 1 1/8" 28 - 406 R 120 psi Schwalbe City Marathon 20 x 1.25" 32 - 406 R 110psi Continental Top Touring 20 x 1 3/8" 37 - 406 R 70psi Tioga Comp Pool 20 x 1.75" 47 - 406 R 30 - 90 psi Haro 20 x 1.75" 47 - 406 R 40-50psi LHR semi slick 20 x 1.75" 47 - 406 R 50psi Road Lite 20 x 1 1/8" 28 - 451 R 100psi Primo 20 x 1 3/8" 37 - 451 R 85psi Kenda 20 x 1 3/8" 37 - 451 R 90psi xxxx = not tested at this pressure GREENSPEED TYRE ROLLING RESISTANCE TESTING 20/09/97 Rolling resitance in watts at 30 kph on 4.5" roller, 30kg load PSI 40 60 80 100 120 140 160 TYRE Nokian 40.3 31.7 26.8 22.8 21.2 xxx xxx Hundyn 52.0 39.2 33.1 29.6 27.4 xxx xxx San Marino 45.8 35.7 30.9 xxx xxx xxx xxx ACS 48.6 36.1 29.6 27.8 25.8 xxx xxx Tioga ST 39.1 31.0 27.1 24.4 24.0 xxx xxx Monte DD 62.7 47.1 38.5 35.3 32.3 30.9 xxx Primo 40.6 31.9 27.4 24.4 21.6 20.6 xxx Cheng 52.6 32.9 27.6 xxx xxx xxx xxx Monte C 52.6 40.2 34.8 30.5 xxx xxx xxx Comp Pool 37.6 28.9 24.8 22.0 20.2 xxx xxx AC Liner 61.1 49.8 39.9 32.9 28.6 xxx xxx Spin Skins 42.7 34.3 29.6 26.8 24.3 xxx xxx Thorn Proof 63.9 47.0 38.8 32.9 29.6 xxx xxx Greentyre 68.9 1. Nokian City Runner 40-406 (20" x 1.5") 75psi 2. Hudyn HPV 20" X 1 1/4" (32-451) 90psi 3. Vredestein San Marino 47 - 406 (20 x 1.75") 40 psi 4. ACS 20" x 2.0" 100psi 5. Tioga Comp ST 20 x 2.125" 90psi 6. Vredestein Monte Carlo Double Density 37 - 406 55 psi max 6.0 bar 7. Primo Comet 20" x 1.37" (37-406) 100 psi 8. Cheng Shin 649 20" x 2.0" 35psi 9. Vredestein Monte Carlo (single density) 35 - 559 (26 x 1.35) 55 psi 10. Tioga Comp Pool 20 x 1.75 90psi 11. Comp Pool + Mr Tuffy type liner (AC Flat Spot) 12. Comp Pool + Spin Skins Kevlar tyre liner 13. Comp Pool + IRC Thorn Proof tube 14. Greentyre Blizzard 20 x 1.75 Micocellular Polyurethane Tyre Regards, Ian. Ian Sims, GREENSPEED, Recumbent Bikes, Trikes & HPVs Australian Distributor for Open Road, UK, & RCN, USA. 69 Mountain Gate Drive, Ferntree Gully, VIC 3156, AUSTRALIA, Phone +61 3 9758 5541 Fax +61 3 9752 4115 E-mail greenshp@ozemail.com.au web page http://www.ihpva.org/com/Greenspeed/