The one that's in mine was 38'' and i just ordered a 1'' end to end axle from BMI Karts that's 36'' so I'll find out if its to short , I don't think it will be because it had the right side tire pretty far away from the frame with a lot of spacers , BMI had the best price $25 and i didn't want one that stepped down to 3/4'' on the ends , I wanted it like the one in the Carter Brothers kart i have. Also BMI was quite a bit cheaper on everything i got , rims , hubs , bearings , It was $145 vs. $210 where i almost ordered it this morning. Definitely worth looking around.