Tire travel

[DoctahDeane]

Hey folks - I was building a TD, then found one done that was very much like what I was planning. In my garage, now :-) Starting to go through things and tweak as necessary. It's good but needs to be made road-ready. Does anyone have an opinion about how much clearance to leave in the wheel well for vertical travel of tires? There are wimpy 12s on there now. I'd really like to go to 14s or at least 13s. There are two bolts through the top dead center of the metal fender (now surrounded by wood) and the clearance with the 12 inch tires is 2 1/4". Photos might help - here are two. I appreciate any feedback.

[Sparksalot]

You didn't mention what your axle/springs/suspension is. Leaf slipper springs or something more robust.

Rose has slipper springs. About 4 years ago, I flipped the axle to the top of the spring, and notched the spring carrier to give clearance. You can see how generous the clearance is in the photo. In 10,000 miles since, I've yet to see it bottom out. I'm currently running 13" 80 series trailer tires. I have a set of 14" wheels, and will soon put on 70 series tires, for the same diameter, but use car not trailer tires.

[DoctahDeane]

You didn't mention what your axle/springs/suspension is. Leaf slipper springs or something more robust.

Rose has slipper springs. About 4 years ago, I flipped the axle to the top of the spring, and notched the spring carrier to give clearance. You can see how generous the clearance is in the photo. In 10,000 miles since, I've yet to see it bottom out. I'm currently running 13" 80 series trailer tires. I have a set of 14" wheels, and will soon put on 70 series tires, for the same diameter, but use car not trailer tires.

Thanks for this reply. Mine is simple - leaf springs. This is a great idea. I just looked underneath and the leaf springs sit in top of the axle now in a U shape, so maybe if I kept them on top but flipped them, over which would make the point of the curve at 12 o'clock, not 6 o'clock where it is now? Is that what you mean? I think I'm probably exposing my lack of education about this topic. I'd really love to get 13s or 14s on here as I intend to use it a LOT. Thanks again.

[Sparksalot]

My axle was originally underneath the springs. I flipped it to be on top. Doing that dropped the overall height by 4 inches.

If yours is already on top, then you can measure the clearance to the underside of the frame. That will be the max deflection. Hopefully it’s less than what you measured between the tire and fender. The difference between these two will give you an idea of how much more tire you might be able to fit.

Btw, this link gives a handy comparison of tire sizes and diameters.
https://tiresize.com/chart/

This is what I used to confirm my 13 to 14 comparison without a change in overall diameter.

[DoctahDeane]

Btw, this link gives a handy comparison of tire sizes and diameters.
https://tiresize.com/chart/

This is what I used to confirm my 13 to 14 comparison without a change in overall diameter.

This looks like it'll be really helpful. Thanks a lot!