| Many of us have zero money, but this mega thirst for | | | | The third thing to understand is that pulleys are |
| a go kart. The belt drive can be the most cost effect | | | | sensitive to heat build up and can if not selected |
| drive system that you could implement, on your low | | | | properly fly apart or melt. The zinc die cast pullies, |
| cost cheap go kart. | | | | especially the small ones, are designed for fractional |
| There are, however, issues with a belt drive that need | | | | horsepower motors such as electric fans and so forth. |
| to be understood prior to just diving in and making this | | | | The sudden engagement will heat up the pulley to |
| belt drive system. | | | | 300+ degrees F and cause the zinc or aluminum to |
| First thing to understand is the final drive ratio. Is the | | | | melt and fly apart. Be sure to invest in a good quality |
| engine actually going to be able to turn this system or | | | | steel pulley, especially if the pulley is being used as a |
| will it stall. Keep in mind that the rpm for engagement is | | | | clutch driver. |
| typically not very high, like 1200 rpms. So your | | | | The fourth thing is that there is much debate over |
| calculation needs to reflect that. The HP curve for an | | | | making belts go around corners, do twists or all sorts |
| engine is approximately linear, so if the rpms are | | | | of design gymnastics, but the truth of the matter is that |
| decreased, then the HP needs to decrease | | | | belts are designed to flex and carry loads. |
| accordingly. | | | | The fifth thing is "What kills a belt?" Four things kill belts: |
| For example a 5 hp motor will put out 87.5 in-lbs of | | | | 1. Sudden engagement (shock loads) |
| torque at 3600 rpms. But the same engine will put out | | | | 2. Prolonged Slipping |
| only approximately 1/3 of that at 1200 rpms (29.1 in-lbs | | | | 3. Poor Tracking |
| of torque.) | | | | 4. Improper load tension sizing |
| Keep that in mind or you will be sorely disappointed | | | | If you keep these four issues in check you will have a |
| when the go kart repeatedly stalls or burns up belts. | | | | long lasting go kart drive system that will last years |
| The second thing to understand is that a belt clutch is | | | | instead of weeks. And finally, belt drives, especially |
| very hard on belts. Especially when neutral drops or | | | | clutch belt drives, are very driver dependant. Like a |
| high rev engagement are done repeatedly. The ideal is | | | | clutch on a car, one poor engagement can wreck a |
| to have the belt engage at the lower rpm and then | | | | clutch, the same goes with belt drives. |
| have the engine lug up to the desire cruising speed. | | | | |