Title 40
SECTION 86.529-98
86.529-98 Road load force and inertia weight determination.
§ 86.529-98 Road load force and inertia weight determination.(a)(1) Road load as a function of speed is given by the following equation:
F = A + CV 2(2) The values for coefficients A and C and the test inertia are given in Figure F98-9 of this section. Velocity V is in km/h and force (F) is in newtons. The forces given by the equation in paragraph (a)(1) of this section shall be simulated to the best ability of the equipment being used.
(b) The inertia given in Figure F98-9 shall be used. Motorcycles with loaded vehicle mass outside these limits shall be tested at an equivalent inertial mass and road load force specified by the Administrator. Figure F98-9 follows:
Figure F98-9
| Loaded vehicle mass (kg) | Equivalent inertial mass (kg) | Force coefficients | Force at 65 km/h (nt) | 70 to 60 km/h coastdown calibration times | |||
|---|---|---|---|---|---|---|---|
| A (nt) | C (nt/(km/h) 2) | Target time (sec) | Allowable tolerance | ||||
| Longest time (sec) | Shortest time (sec) | ||||||
| 95-105 | 100 | 0.0 | .0224 | 94.8 | 2.95 | 3.1 | 2.8 |
| 106-115 | 110 | 0.82 | .0227 | 96.8 | 3.18 | 3.3 | 3.0 |
| 116-125 | 120 | 1.70 | .0230 | 98.8 | 3.39 | 3.6 | 3.2 |
| 126-135 | 130 | 2.57 | .0233 | 100.9 | 3.60 | 3.8 | 3.4 |
| 136-145 | 140 | 3.44 | .0235 | 102.9 | 3.80 | 4.0 | 3.6 |
| 146-155 | 150 | 4.32 | .0238 | 104.9 | 3.99 | 4.2 | 3.8 |
| 156-165 | 160 | 5.19 | .0241 | 107.0 | 4.10 | 4.4 | 4.0 |
| 166-175 | 170 | 6.06 | .0244 | 109.0 | 4.36 | 4.6 | 4.2 |
| 176-185 | 180 | 6.94 | .0246 | 111.0 | 4.53 | 4.7 | 4.3 |
| 186-195 | 190 | 7.81 | .0249 | 113.1 | 4.69 | 4.9 | 4.5 |
| 196-205 | 200 | 8.69 | .0252 | 115.1 | 4.85 | 5.1 | 4.6 |
| 206-215 | 210 | 9.56 | .0255 | 117.1 | 5.00 | 5.2 | 4.8 |
| 216-225 | 220 | 10.43 | .0257 | 119.2 | 5.15 | 5.4 | 4.9 |
| 226-235 | 230 | 11.31 | .0260 | 121.2 | 5.30 | 5.5 | 5.1 |
| 236-245 | 240 | 12.18 | .0263 | 123.2 | 5.43 | 5.7 | 5.2 |
| 246-255 | 250 | 13.06 | .0266 | 125.3 | 5.57 | 5.8 | 5.4 |
| 256-265 | 260 | 13.93 | .0268 | 127.3 | 5.70 | 5.9 | 5.5 |
| 266-275 | 270 | 14.80 | .0271 | 129.3 | 5.82 | 6.1 | 5.6 |
| 276-285 | 280 | 15.68 | .0274 | 131.4 | 5.95 | 6.2 | 5.7 |
| 286-295 | 290 | 16.55 | .0277 | 133.4 | 6.06 | 6.3 | 5.8 |
| 296-305 | 300 | 17.43 | .0279 | 135.4 | 6.18 | 6.4 | 6.0 |
| 306-315 | 310 | 18.30 | .0282 | 137.5 | 6.29 | 6.5 | 6.1 |
| 316-325 | 320 | 19.17 | .0285 | 139.5 | 6.40 | 6.6 | 6.2 |
| 326-335 | 330 | 20.05 | .0288 | 141.6 | 6.50 | 6.7 | 6.3 |
| 336-345 | 340 | 20.92 | .0290 | 143.6 | 6.60 | 6.8 | 6.4 |
| 346-355 | 350 | 21.80 | .0293 | 145.6 | 6.70 | 6.9 | 6.5 |
| 356-365 | 360 | 22.67 | .0296 | 147.7 | 6.80 | 7.0 | 6.6 |
| 366-375 | 370 | 23.54 | .0299 | 149.7 | 6.89 | 7.1 | 6.7 |
| 376-385 | 380 | 24.42 | .0301 | 151.7 | 6.98 | 7.2 | 6.8 |
| 386-395 | 390 | 25.29 | .0304 | 153.8 | 7.07 | 7.3 | 6.9 |
| 396-405 | 400 | 26.17 | .0307 | 155.8 | 7.16 | 7.4 | 6.9 |
| 406-415 | 410 | 27.04 | .0310 | 157.8 | 7.24 | 7.5 | 7.0 |
| 416-425 | 420 | 27.91 | .0312 | 159.9 | 7.33 | 7.6 | 7.1 |
| 426-435 | 430 | 28.79 | .0315 | 161.9 | 7.41 | 7.6 | 7.2 |
| 436-445 | 440 | 29.66 | .0317 | 163.7 | 7.49 | 7.7 | 7.3 |
| 446-455 | 450 | 30.54 | .0318 | 164.9 | 7.61 | 7.8 | 7.4 |
| 456-465 | 460 | 31.41 | .0319 | 166.0 | 7.73 | 8.0 | 7.5 |
| 466-475 | 470 | 32.28 | .0319 | 167.1 | 7.84 | 8.1 | 7.6 |
| 476-485 | 480 | 33.16 | .0320 | 168.3 | 7.95 | 8.2 | 7.7 |
| 486-495 | 490 | 34.03 | .0320 | 169.4 | 8.06 | 8.3 | 7.8 |
| 496-505 | 500 | 34.90 | .0321 | 170.5 | 8.17 | 8.4 | 7.9 |
| 506-515 | 510 | 35.78 | .0322 | 171.7 | 8.28 | 8.5 | 8.0 |
| 516-525 | 520 | 36.65 | .0322 | 172.8 | 8.39 | 8.6 | 8.2 |
| 526-535 | 530 | 37.53 | .0323 | 173.9 | 8.49 | 8.7 | 8.3 |
| 536-545 | 540 | 38.40 | .0323 | 175.1 | 8.60 | 8.8 | 8.4 |
| 546-555 | 550 | 39.27 | .0324 | 176.2 | 8.70 | 9.0 | 8.5 |
| 556-565 | 560 | 40.15 | .0325 | 177.3 | 8.80 | 9.1 | 8.6 |
| 566-575 | 570 | 41.02 | .0325 | 178.5 | 8.90 | 9.2 | 8.7 |
| 576-585 | 580 | 41.90 | .0326 | 179.6 | 9.00 | 9.3 | 8.8 |
| 586-595 | 590 | 42.77 | .0327 | 180.8 | 9.10 | 9.4 | 8.9 |
| 596-605 | 600 | 43.64 | .0327 | 181.9 | 9.19 | 9.5 | 8.9 |
| 606-615 | 610 | 44.52 | .0328 | 183.0 | 9.29 | 9.5 | 9.0 |
| 616-625 | 620 | 45.39 | .0328 | 184.2 | 9.38 | 9.6 | 9.1 |
| 626-635 | 630 | 46.27 | .0329 | 185.3 | 9.47 | 9.7 | 9.2 |
| 636-645 | 640 | 47.14 | .0330 | 186.4 | 9.56 | 9.8 | 9.3 |
| 646-655 | 650 | 48.01 | .0330 | 187.6 | 9.65 | 9.9 | 9.4 |
| 656-665 | 660 | 48.89 | .0331 | 188.7 | 9.74 | 10.0 | 9.5 |
| 666-675 | 670 | 49.76 | .0332 | 189.8 | 9.83 | 10.1 | 9.6 |
| 676-685 | 680 | 50.64 | .0332 | 191.0 | 9.92 | 10.2 | 9.7 |
| 686-695 | 690 | 51.51 | .0333 | 192.1 | 10.01 | 10.3 | 9.8 |
| 696-705 | 700 | 52.38 | .0333 | 193.2 | 10.09 | 10.4 | 9.8 |
| 706-715 | 710 | 53.26 | .0334 | 194.4 | 10.17 | 10.4 | 9.9 |
| 716-725 | 720 | 54.13 | .0335 | 195.5 | 10.26 | 10.5 | 10.0 |
| 726-735 | 730 | 55.01 | .0335 | 196.6 | 10.34 | 10.6 | 10.1 |
| 736-745 | 740 | 55.88 | .0336 | 197.8 | 10.42 | 10.7 | 10.2 |
| 746-755 | 750 | 56.75 | .0336 | 198.9 | 10.50 | 10.8 | 10.2 |
| 756-765 | 760 | 57.63 | .0337 | 200.1 | 10.58 | 10.9 | 10.3 |
| 766-775 | 770 | 58.50 | .0338 | 201.2 | 10.66 | 10.9 | 10.3 |
| 776-785 | 780 | 59.38 | .0338 | 203.3 | 10.74 | 11.0 | 10.4 |
| 786-795 | 790 | 60.25 | .0339 | 204.5 | 10.82 | 11.1 | 10.5 |
| 796-805 | 800 | 61.12 | .0339 | 205.6 | 10.91 | 11.2 | 10.6 |
| 806-815 | 810 | 62.00 | .0340 | 206.7 | 10.99 | 11.3 | 10.7 |
| 816-825 | 820 | 62.87 | .0341 | 207.9 | 11.07 | 11.4 | 10.8 |
| 826-835 | 830 | 63.75 | .0341 | 209.0 | 11.15 | 11.5 | 10.8 |
| 836-845 | 840 | 64.62 | .0342 | 210.1 | 11.24 | 11.5 | 10.9 |
| 846-855 | 850 | 65.49 | .0343 | 211.3 | 11.32 | 11.6 | 11.0 |
| 856-865 | 860 | 66.37 | .0343 | 212.4 | 11.40 | 11.7 | 11.1 |
| 866-873 | 870 | 67.24 | .0344 | 213.5 | 11.48 | 11.8 | 11.2 |
(c) The dynamometer shall be adjusted to reproduce the specified road load as determined by the most recent calibration. Alternatively, the actual vehicle road load can be measured and duplicated:
(1) Make at least 5 replicate coastdowns in each direction from 70 to 60 km/h on a smooth, level track under balanced wind conditions. The driver must have a mass of 80 ±10 kg and be in the normal driving position. Record the coastdown time.
(2) Average the coastdown times. Adjust the dynamometer load so that the coastdown time is duplicated with the vehicle and driver on the dynamometer.
(3) Alternate procedures may be used if approved in advance by the Administrator.
[63 FR 11849, Mar. 11, 1998, as amended at 80 FR 9104, Feb. 19, 2015]