What is the difference between a solid rear axle (SRA) and an independent rear suspension (IRS)? Pros and cons? Which one is right for me? Let's dig into the long debated topic of which one is best, SRA vs. IRS.
Before we get too far into the weeds, Valor Offroad offers wheels for both SRA and IRS fitments. The general rule of thumb is any wheel will fit an IRS application however because a SRA requires an aggressive negative offset, only certain wheel styles will fit the rear axle. Check out our Solid Rear Axle collection to check out all of our options if after reading below you think SRA is the best fit for you.
Solid Rear Axle
The original and oldest option of ATV axle design, the solid rear axle (SRA) is a standard for most work, farm and ranch style operations. Because the axle is one solid piece, there are less moving parts involved which means in theory there are less parts to go bad or need replacement over time. On SRA style ATVs, the rear axle is a solid pipe connecting both rear wheels for unmatched strength while offering very limited flexibility.
- SRAs were designed to have a lower rolling center, decreasing that uneasy feeling like your machine is going to tip on uneven terrain.
- Solid Rear Axle machines maintain relative ground clearance (depending on tire plus sizing compared to OEM sizes), allowing the driver to know the exact amount of clearance while driving, crawling or traversing an obstacle.
- As you add weight/accessories to the rear of the machine, clearance remains constant.
- If the terrain ever gets super technical, a solid rear axle can make for a very rough ride. Because of the rigidity of the solid axle, overall flexibility take a huge hit.
- As one tire crawls over an obstacle, the other wheel/tire is adversely affected. This lack of flexibility can quickly suck the fun out of a long ride when your body is absorbing the terrain instead of the machine/suspension.
- Compared to IRS options, the overall clearance on SRA can be significantly less.
Independent Rear Suspension
An independent rear suspension (IRS) drastically changes the comfort level of the rider, absorbing all of those bumps and obstacles with ease. Because the axle is split, as each wheel is tackling an obstacle the other is able to respond to the terrain independently, improving rider comfort and offroad capabilities.
- Smoother ride. When one tire crawls over a rock, the other tire maintains contact on the trail, creating a smoother ride over rough terrain.
- Are you older or have some troublesome joints from age or past surgeries? This style axle/machine is a better option for you to help alleviate some of the bumps and jostling ATVs are known for.
- Folks who want the better crawling/offroad capable option between the two typically go for IRS because of the constant contact to the terrain no matter the obstacle.
- IRS can provide nearly double the clearance compared to SRA.
- As you add more weight to the machine, the rear IRS will sag and actually decrease overall clearance. If you load the rear of your machine with accessories (or additional seat), you will drastically decrease the vehicle's offroad abilities.
- Because the IRS has additional moving parts compared to the SRA, the IRS is more prone to mechanical failures and will need maintenance.
- You'll need to be mindful of stability with an IRS machine especially in off-camber terrain or cornering as your chances of a rollover are increased.
It's important to take under consideration what kind of riding you plan to do first before you go test ride a new ATV.
- Are you a dirt road kind of guy and don't plan to offroad? Either option is a great solution as neither will offer better/worse tire wear or handle flat roads better than the other.
- Looking for a work horse to tackle heavy duty work around the job site or farm? The SRA will get the job done with little hassle.
- Looking for the ultimate comfort and enjoyable ride no matter the terrain? The IRS will keep your teeth from rattling out of your head.