Measuring Outside Tire to Outside Tire
A 64-inch UTV can look almost identical to a 60-inch model, but that small difference may decide which Black Hills trails it can use. Measuring outside tire to outside tire gives you a practical starting point for checking width-restricted routes. This guide explains how to measure accurately, avoid common mistakes, and match your machine to trail information before you unload.
Why outside tire width matters on South Dakota trails
What the width limit tells you
Some motorized routes in the Black Hills are restricted by vehicle width, while others allow wider machines. A route marked for machines 62 inches or narrower, for example, may not be suitable for a UTV that measures wider than that threshold. The restriction can affect whether you can ride a particular trail, even if the machine can physically fit between the trees or rocks.
That is why a brochure’s description of a machine as “compact” or “trail-sized” is not enough. Two side-by-sides can have similar seating, engine size, and body shape but different tire spacing. If you are choosing trails near Rapid City, Hill City, Spearfish, or Deadwood, the width of your machine can shape which routes are practical. Start with [South Dakota Trail Width Limits] and check route-specific information rather than assuming one measurement applies everywhere.
Width is only one part of trail access. A machine that meets a width limit still needs to follow other applicable rules, including route restrictions, closures, and permit requirements. A permit does not make a restricted trail open to a wider machine, and a plated machine does not automatically have access to every motorized trail. For a broader overview of the system, see [South Dakota Trail Maps and MVUMs].
Which part of the ATV or UTV should you measure
For an outside-tire-to-outside-tire measurement, the basic idea is to measure across the outermost sidewalls of the tires on the same axle. The tires are the reference points—not the distance between the wheels’ centers, and not the vehicle’s overall length. On most four-wheel machines, measure the axle that produces the greater outside-to-outside width.
This gives you a useful, repeatable measurement for comparing your machine with trail-width information. But do not confuse a tire measurement with a guarantee that every part of the vehicle will clear a narrow passage. A mirror, fender flare, cargo attachment, or other accessory may stick out beyond the tires. Those parts can matter when judging real-world clearance, even when the tire measurement is the figure you are using for a width category.
If the trail authority’s wording or measurement method is unclear, do not guess. Check the details for the route and the machine-width rule that applies to it. [How South Dakota Measures Trail Width] is a useful companion when you need to understand how width labels relate to actual vehicle measurements.
How to measure outside tire to outside tire
Get the machine ready before measuring
Park on firm, level ground, such as a flat driveway or an even staging area. A sloped surface can make it harder to hold the measuring tape straight, while uneven ground may tilt the tires and distort the result. Set the steering straight ahead so the front tires are not angled outward or inward. If the front axle is the wider one, even a small steering angle can make the measurement misleading.
Use the tires as you normally ride them. Check that they are inflated to the pressure you use for the type of riding you plan to do, and make sure the machine is carrying any equipment that could affect tire position or vehicle shape. You do not need to simulate every possible trail load, but measuring a bare machine and then adding unusual wheel spacers or tire changes can leave you relying on an old number.
It helps to have another person hold one end of the tape while you read the other. A long straightedge, level, or two plumb lines can also make it easier to identify the outer edges if the tape is difficult to keep level. If you are measuring alone, take your time and repeat the reading rather than trusting a tape that has slipped around a tire bulge.
Follow a simple measuring process
- Park on level ground and point the steering straight ahead.
- Identify the axle that appears widest. If you are unsure, measure both axles.
- Find the outermost sidewall point on the first tire.
- Stretch the tape in a straight line across to the outermost sidewall point on the tire opposite it.
- Read the measurement at the same height on both tires, keeping the tape level and taut without pressing into the rubber.
- Repeat the measurement. If the readings differ, reposition the tape and check again.
- Write down the axle measured, the tire setup, and the result.
Measure from the outside edge of one tire to the outside edge of the tire across from it. Do not measure hub to hub or from the inside edges of the tires. Those methods produce a smaller number and can lead to a false sense that a machine fits a restricted category.
For example, imagine the distance between the inner edges of a UTV’s tires is 48 inches, but the outside edges are 64 inches apart. The relevant outside-to-outside result is 64 inches, not 48. That distinction becomes important when a route has a maximum-width category. If you are comparing your result with a 62-inch restriction, do not round a measurement down or treat a borderline result as safely under the limit.
Record more than one number when the machine has been modified
Tire size, wheel offset, spacers, and suspension changes can alter the width of an ATV or UTV. If you have changed any of these, measure the machine as it sits now rather than relying on the manufacturer’s original specification. A machine that once fit a narrower category may no longer do so after a wheel or tire change.
It can be useful to record two measurements: the outside-to-outside tire width and the widest point across the whole machine. The first helps you compare against trail-width information that uses tire measurement. The second helps you think about physical clearance around rocks, trees, gates, and other obstacles. Label the figures clearly so you do not accidentally treat them as interchangeable.
Keep the numbers with your trip notes or a photo of the measuring tape in place. If you are traveling with a group, share the measurement with the person planning the route. A quick check before the trip is much easier than discovering at a trail junction that one machine in the group cannot continue.
Avoid measurement mistakes and match your machine to a route
Common mistakes that produce an unreliable result
The most common error is measuring from the wheel centers, hubs, or inside sidewalls instead of from the outside tire edges. Those measurements answer different questions. If you are checking an outside-to-outside width, the tape needs to span the full distance between the two outer tire surfaces.
Another mistake is measuring with the steering turned. The front tires may sit at an angle, making the distance appear larger or smaller than it is when the machine is pointed straight. A tape that sags, runs diagonally, or is held at different heights can also change the result. Repeat the measurement from a straight line and check both axles if the machine’s shape makes the widest point hard to identify.
Finally, do not rely solely on a catalog specification, a seller’s description, or a number from a friend with a similar model. Trims can differ, and modifications are easy to overlook. Even machines with the same model name may have different tire sizes or wheel setups. A direct measurement of your own vehicle is the safer baseline.
Compare your measurement with route information
Once you have a reliable number, check the specific route or trail system you plan to ride. Some areas include narrower routes alongside routes that accommodate wider machines. A general description of the Black Hills trail network is not a substitute for checking the individual route category and any current closures or restrictions.
A trail-planning app such as onX Offroad can help you review routes and organize a trip, especially when you are comparing options across a large riding area. Treat digital maps as a planning aid, not as permission to ride. Check the applicable official map or land-manager information for the route, and confirm that its width category matches your machine. For more help choosing a route category, see [South Dakota Trails Under 62 Inches] and [South Dakota Trails for a Wide Machine].
If your measurement is close to a limit, leave yourself a margin rather than assuming a borderline result will be accepted. Recheck the measurement, confirm how the specific route defines vehicle width, and consider choosing a route with a wider allowance. A few extra minutes with a map can save a long backtrack once you are out on the trail.
Plan for the whole group, not just the widest machine
When several ATVs or UTVs are traveling together, plan around the widest machine that needs to use the route. A route that works for a narrow ATV may not work for a wider side-by-side in the same group. Share measurements before leaving and agree on a route that everyone can legally and practically ride.
This matters in the Black Hills, where a group might stage near a town and then spend hours moving between trailheads or route choices. If one machine cannot use a section, the group may need to split up or change plans. Checking widths ahead of time helps avoid putting a less experienced rider in the uncomfortable position of deciding whether to turn around at a narrow junction.
Use onX Offroad or another mapping tool to compare possible routes and mark alternatives, then cross-check the chosen plan with official information. Before departure, also review [South Dakota Trail Conditions Before You Ride] and [South Dakota Trail Closures to Check First]. Width alone does not tell you whether a trail is open or suitable for the day’s conditions.
| What to check | How to check it | Why it matters |
|---|---|---|
| Outside tire width | Measure across the outermost tire sidewalls on the widest axle | Helps compare your machine with width-restricted routes |
| Overall vehicle width | Check mirrors, fenders, and accessories beyond the tires | Helps assess physical clearance through tight spots |
| Modifications | Measure after changing tires, wheels, spacers, or suspension | Changes can make an old measurement unreliable |
| Route category | Check the specific route information and official map | A trail system may include routes with different width limits |
| Group measurements | Plan around the widest vehicle in the group | Prevents a machine from being turned back mid-ride |
A practical pre-ride width checklist
Before loading the trailer
Measure your ATV or UTV on level ground with the steering straight. If the machine has been modified, measure it in its current setup. Write down the outside tire width and, separately, the widest overall point. If the number is close to a posted limit, measure again with another person helping and avoid rounding down.
Then match that measurement to the routes you intend to ride. Check the specific width category, applicable land-manager information, permits, and any route closures. You can use onX Offroad to help organize possible routes, but confirm important restrictions with official trail information. For a machine that has recently changed tires or wheels, repeat the measurement before each trip rather than assuming the old note still applies.
At the trailhead and on the route
Before unloading, take a moment to confirm that the route you are about to use is the one you planned and that no signs indicate a restriction or closure. If you encounter a sign that conflicts with your plan, follow the posted direction and choose another route. Do not assume that a nearby wide trail means every connecting route is open to the same machine size.
A careful measurement will not make a narrow trail wider, but it can prevent a frustrating mismatch between your machine and your route. Measure from the outside of one tire to the outside of the opposite tire, verify the route’s specific rules, and plan with the widest vehicle in your group in mind.
Disclaimer
This article is for general informational purposes only and does not constitute professional advice. Laws, prices and regulations vary by location and change over time. Consult a qualified professional for guidance on your specific situation.
