Cheers si coe, yeah I thought 6.5t was a bit mental for indoors I got it with the buggy but I am going to replace it with a 13.5t soon, The transmission ratio for the B44 is 2.5.1 I'm not sure what it is for the b-max, I've popped a 24/81 in the B44 I'll see how it feels with that in, when you say left behind on the straights if you don't have a high gearing, is that due to the car just having more acceleration and not much top speed with low gearing? and is it just trying to find a blance between good acceleration and good overall top speed? sorry for the noob questions I'm pretty new to this cheers.