I think that thing doesn't really exist
But for us that use hub motor at high speed and nearly never use the large gear of the freewheel, this could be appreciable.
So until someone else find a source for them.. ( i know that it exist some 14T or 15T single speed freewheel... but...)
Due to the strange and rare X5 axle lengh i have on my 5302, i must shorten my 7 speed 11t freewheel to get enough threaded lenght on the axel.
I thought that for those who would like to save weight and have a 11T gear without the rest of the gear or just to remove some gear when using with hub motor, this could be some good solution.
So here is the pics of my little upgrade
The goal is to save my old gen 5302 that have an Axel lenght problem. Yes i could buy one of those HT motor for 260$.. but it is still cheap to modify that casette by removing the undesirable gear and also to add a disk brake adaptor and weld it with 3M epoxy!
Next step.. : cutting the extra lengh of the clutch that i dont need.. on that diameter... the only lenght i need is to just enough hold in place the 11T gear.. no more... ( Yes.. i'll epoxy it to hold in place with metal aerospace grade epoxy DP-420)
By doing that i'll save around 10mm on the AXEL.. and save the weight of 6 larger gears