Lift to Tire Size

Nov. 01, 2005 By ORC STAFF
There has been a great deal of discussion on the Suzuki mailing list on about what is the best way to lift a Samurai and which kit gives the best ride and axle articulation. The the most frequently asked question has to be “What size tire will fit?” The largest tire that will fit on a stock Samurai is a P215, or a 27 inch. The information presented here has been provided by Suzuki after market parts suppliers, subscribers to the mailing list and my own experience with the Samurai. It is not intended to prove that one lift type is better than the other. It has been collected to help you match lifts available to tire size for your application and off-road needs. There are benefits and concerns that can be associated to both types of lifts.  If you have input for this article please email me direct. I would like to incorporate your ideas into this series. The internet provides all of us a unique opportunity to express our opinion in real time! Don’t waste your chance to make this a live series on Samurai lifts.
“How To” Spring Over Axle “How To” Shackle Reversal
I have been a Samurai owner for a number of years and have had many styles of lifts and tire combinations installed on a 87 Samurai. The first being add-a-leaf, now that was a ride.  The short wheel-base Samurai is not known for a good ride even stock, install an   add-a-leaf set and you have made an excellent paint mixer. That had to be the worst ride ever experienced. They were removed very shortly after being installed. The next attempt at a taller truck was a set of three inch springs. The ride was much better and they allowed room for larger tires, but…I needed more. Three inches was not tall enough. The Spring Over Axle idea was borrowed from other solid-axle truck owners. At the time of installation it was the only lift available larger than three inches. It made available a 4½ inch lift for the already very off-road capable Samurai. This lift was on the truck for a number of years. Problems: One problem personally experienced with type of lift was axle wrap. It turned a well made set of National springs into an “S” shape. Samurai owners have also reported occurrences of early spring failure on stock springs. They attribute the broken springs to the extreme upward spring travel and excessive axle wrap.    My SPOA lift was just recently removed in favor of the latest innovation for the Samurai, a Shackle Reversal Kit (SR) and OME springs. The SR lift can be installed in stages. You can start with the two inch lift; running your 29 inch or smaller tires. After the tread life has been utilized three inch springs can be added for a five inch lift which will allog for 31x10.5 tires. Calmini’s kit is fully bolt-on. No drilling, welding, driveshaft or steering modifications are required. The Shackle Reversal can be installed in about 6 hours. Impressions so far, the reversal kit will provide very stable ride characteristics and give you two inches of lift. Problems: the tires have made contact at the back of the front wheel well under extreme compression with 33 x 12.5 tires. If you run tire sizes that are recommend by Calmini for their kit you will not have contact problems. Extended bump stops will compensate for clearance problems if you are running larger tires.

RTI Challenge

Spring Over Axle  Shackle Reversal
ORC hopes to pull off a ramp travel index, off-road and road test comparison on the Samurai. Steve Kramer has offered the use of Calmini’s RTI ramp for a challenge between a Shackle Reversal equipped Samurai and a Spring Over Axle lifted Samurai. Calmini will provide the SR truck and Petroworks has offered a SPOA equipped truck. The only requirement imposed by ORC is that the trucks have to be daily drivers. This event will be open to all Suzuki products. ORC could use your help to make this event happen. Do you know of an event scheduled near Bakersfield or Fallbrook California around the middle of November where the RTI Challenge can be held? Can your club host the RTI Challenge? Please contact ORC if you would like to help coordinate this event.

Ramp Travel Index (RTI)

RTI is a good indicator of articulation, however, on- and off-road characteristics are the most important factor in choosing a suspension system.
Glenn Wakefield- “I’ll just go off of my experiences with Four Wheeler magazine… We did ours in a paved parking lot with even tire pressures and no funky weight shifting. We crept up the ramp until immediately when a tire left the ground (or ramp if you were over 1000). The distance is also measured from the center of your hub down… not from the front edge of a tire. This is to say… if you can get your left rear tire to touch the edge of the ramp, but it lifts before you get the center of your hub over the front part of the ramp, you did not score 1000. Shocks should be on… though this is a good test of if your shocks are inhibiting travel. 20 degrees has always been the standard ramp. Scores of 1000 (perfect) were very rare when this universal measuring system was created. However… so many vehicles are sporting so many trick suspensions, Four Wheeler said they may go to a 25 degree ramp next year. BTW, 1000 may sound like a very easy and attainable score… but it ain’t so.”

Lift Comparison

Spring Over Axle


Shackle Reversal


  • Stock Springs
  • Room to fit 32x11.5 tires
  • Great articulation
  • Improved on and off-road handling
  • Cost: $599.00
  • 22 inches of axle articulation
  • Provides 4-5 inches of lift
  • Combo Kit 3"" Springs
  • Room to fit 31x10.5 tires
  • Great articulation
  • Improved on and off-road handling
  • Cost: $695.00
  • 25 inches of axle articulation
  • Provides 5 inches of lift
  • Fully bolt on
Cons Cons
  • It is definitely more work to do a SPOA with welding etc., but if you are serious about going wheeling it’s worth it.
  • If not done properly it could make your rig unstable and potentially dangerous to drive on the street.
  • If the welds are not done properly you could damage an axle tube.
  • Spring  wrap has been experienced on some trucks.
  • Cost depends on whether you gather all the parts and do the work yourself, or if you get a shop to gather them and complete the project.
  • Axles should be disassembled for the welding process.
  • Drag link, if not modified, can hit the right spring on hard turns.
  • Body roll if the sway bar is removed.
  • On the Samurai, some feel the vehicle may be too light for the shackle reversal to work as effectively as it does on a Jeep or a Scout.
  • Tires sizes over 31 inches may require longer bump stops, or the axle moved   forward to prevent tire to fender contact when the spring is in full compression.
  • Brake dive can increase dramatically if improperly valved shocks are used.

SPOA Comments

Gary Munck (Petroworks) “I have done at least 20 SPOAs with the same results that are in the Pro column. Better handling, better ride and much better articulation. It is definitely more work to do a SPOA what with welding etc. but if you are serious about going wheeling it’s worth it. I recently bought a Samurai with 3"" springs, 2""shackles and 32"" tires (got it cheap, dead motor) It now has a new motor, so I have had a chance to drive it to see how the 3"" springs compare. The ride is the same as stock, the articulation is also about the same as stock, the handling with longer shackles is very unstable. It looks good just sitting there.  I have given some thought as to why the articulation and ride are much improved after a SPOA. Certainly some of the gains in ride and handling are due to changing worn parts like bushings and shocks. Adding larger wheels and tires means a wider track and obviously better articulation. (wider track = more leverage against the springs). Using springs that were designed for the truck means that they will work well in most conditions. We have sold and installed many SPOAs and have had only rave reviews from the people who have them. To be honest I have not spent enough time studying the suspension geometry of the Suzuki to post a definitive answer as to why the SPOA works so well with the Samurai. If you are in the Southern California area come by and drive a Samurai with SPOA, then you can judge for yourself.”

SR Comments

Steve Kramer (Calmini) “By installing the Shackle Reversal Kit you are changing the position of the front spring shackle from the leading end of the spring to the trailing end of the spring, thus duplicating the same setup that the rear springs have from the factory. If you install a longer shackle to the front of the stock or aftermarket lift spring (stock front-shackle configuration), you reduce the positive caster angle of the front axle, which is not in the least bit desirable. There are several benefits with Shackle Reversal that apply to handling and ride quality as well as articulation. In the area of handling, when using the stock ‘flat’ spring or any aftermarket positive arch lift spring (like Calmini, Trailmaster, Rancho and others), the springs will deflect (bend) under load. Shackle Reversal can maintain or even increase the needed positive caster through the entire compression movement of the suspension. This configuration also lifts both ends of the front spring, and this is important. Due to the fixed relationship of the steering knuckle to the axle tube, the Shackle Reversal Kit maintains correct pinion angularity. This prevents the decrease in positive caster that causes a ‘wander’ condition. Shackle reversal improves ride quality because the vector forces (bump in the road) required to deflect or move the suspension are absorbed in the same direction that they are applied. Under these conditions, it also takes less force to make the suspension work. Axle articulation, using the stock spring with the CALMINI Shackle Reversal Kit, increases from 11 (or less) inches to 18 inches! One way to apply the Shackle Reverse conversion and lift the vehicle 5"" over stock is by using the custom Calmini spring designed for the shackle reversal kit. This system is fully bolt-on. There is no need for welding or grinding, and the steering linkage and driveline require no modifications. Customers can install the kit in their driveway--no need to sublet to a commercial fab shop--using common hand tools. This shackle reverse with lift spring approach provides clearance for 31x10.5 tires plus 25 inches of axle articulation. Our customers describe much improved on and off-road driving characteristics.”

What size tire fits?

Tire Size 29x9.5 30x9.5 31x10.5 32x11.5 33x12.5
Lift Required 1.5 2 3 - 4 4 - 5 5+
Body Mods None None Minor Minor Required

Lifts available

Springs OME 1.5"" National 3"" Calmini 3"" TrailMaster 3""
Shackle Reversal Calmini 2""&
5"" Combo
Warrior ¾""& 2""
Spring Over Petroworks Summit Off-Road
Lift Kit TrailMaster
A three inch body lift is also available. Using larger tires will have an effect on your power. Ring and pinion or reduced  transfer case gearing  modifications are highly recommended. For the greatest performance do both.
--Larry Harris Newsletter
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