I have used a coil spring compressor to spread the chain stays on a couple of bikes to fit a 3" tire. I have done it on these two bikes
here is a picture of the set up on the coke bike, I bolted a hub in the rear and the coil spring compressor on the chian stays
this picture shows the room when you are done
now click this picture to see a video of how to set up the coil spring compressor to spread instead of squeeze
here is a picture of the set up on the coke bike, I bolted a hub in the rear and the coil spring compressor on the chian stays
this picture shows the room when you are done
now click this picture to see a video of how to set up the coil spring compressor to spread instead of squeeze