Back in 2013, just after I found MMM, we owned 3 vehicles which I think added up to about 3% of our net worth.
In 2016-2017 we got rid of all our stuff and moved across the country. We didn't own a car for a year so we were sitting at 0% for a car with 2 cheap bikes. With just our bikes, 0.03% of our worth was in transportation at that point.
These days we are back to owning a (cheap) car and it's about 0.09% of our worth. The bike collection has grown and is probably worth more than the car now (2 fat bikes, 2 city bikes, 2 touring bikes, 2 tandems plus a plethora of other junk bikes I've gotten for free) so probably around 0.2%-0.3% of our worth is in transportation these days.
I hope to start welding some wacky bikes together from all my salvaged bike parts but I doubt that will really change our worth. They might be worth something to me but probably not much to anyone else.