37's on D30's?
Thread Starter
JK Super Freak
Joined: Aug 2009
Posts: 1,314
Likes: 1
From: Stamford, CT
The weight difference depends on the specific tire, but for MTs the difference is usually between 5-10 lbs for many 12.5" wide tires.
This is not a big difference, but the small changes indicates that most of the mass is in the tread not the sidewall and the tread is being shifted outwards by ~1".
The moment of inertia increases as the square of the tire radius, so the effect is more notable than just a relatively small increase in weight. But is just the load created by the free turning wheels on a smooth surface.
Besides the rotational mass of tire, you now have a longer lever that the shafts and driveline must push. That is how you end up with parts that look like the ones in Suffolk's post.
This is not a big difference, but the small changes indicates that most of the mass is in the tread not the sidewall and the tread is being shifted outwards by ~1".
The moment of inertia increases as the square of the tire radius, so the effect is more notable than just a relatively small increase in weight. But is just the load created by the free turning wheels on a smooth surface.
Besides the rotational mass of tire, you now have a longer lever that the shafts and driveline must push. That is how you end up with parts that look like the ones in Suffolk's post.
JK Junkie
Joined: Jul 2009
Posts: 2,343
Likes: 1
From: The San Andreas Fault
Thanks Spinlock. Nicely put. I imagine it much like a mace (ball & chain). The more mass you have to rotate on the end of the chain, the more difficult it would be to keep the rotational point centered therefore more strength is needed to hold it in position while spinning.
JK Enthusiast
Joined: Aug 2009
Posts: 222
Likes: 0
From: Hoodbridge, Va
It's a Jeep thing dude, you will not be 100% safe 
I guess in the end I could always just go with 35's and save the money to eventually swap axles
JK Enthusiast
Joined: Feb 2009
Posts: 236
Likes: 0
From: Lake Geneva, Wi
Good thread. Most of this has been said but basically if you are going to wheel moderately hard you will break something with a 30 or 44. The nice part of this scenario is that you add quality parts as you go and in the end you don't feel like you unloaded thousands.
As most peole say if you truss, sleeve, gusset add good Ujoints and gears as well as chro-mo shafts you can get by. Eventually the weak link will break.
I got tired of fixing something and got D60's. I wheel pretty hard though. I have friends that wheel a handful of times a year and hardly break anything!
I had a D30 up front and D44 in the rear with ARB lockers and 4.88 gears and here is what I broke in a year... keep in mind I had all the "extra's I listed above!
-4 broken ring and pinions
-4 broken u Joints
-2 broken axles
-1 broken driveshaft
As most peole say if you truss, sleeve, gusset add good Ujoints and gears as well as chro-mo shafts you can get by. Eventually the weak link will break.
I got tired of fixing something and got D60's. I wheel pretty hard though. I have friends that wheel a handful of times a year and hardly break anything!
I had a D30 up front and D44 in the rear with ARB lockers and 4.88 gears and here is what I broke in a year... keep in mind I had all the "extra's I listed above!
-4 broken ring and pinions
-4 broken u Joints
-2 broken axles
-1 broken driveshaft
JK Enthusiast
Joined: Aug 2009
Posts: 222
Likes: 0
From: Hoodbridge, Va
Thanks, I definitely want to get out and do some serious wheeling. Just like everyone else though starting from scratch kind of stinks on the financial end...babysteps. Thanks for the advice though. I love your setup!...nice work!