Yamaha Big Bear 400 4x4 IRS Tire Size
GarageDex's powersports data shows the Yamaha Big Bear 400 4x4 IRS runs a 25/8-12 front tire and a 25/10-12 rear tire. Tire sizes vary by year - see the table for each range.
Tire fitment by year
| Years | Front tire | Rear tire |
|---|---|---|
| 2012 | 25/8-12 | 25/10-12 |
| 2010 | 25/8-AT12 | 25/10-AT12 |
| 2009 | 25/7-AT12 | 25/10-AT12 |
386cc. Tire sizes read as width / aspect ratio - rim diameter. Match all three numbers to the rim.
Tires for your Yamaha Big Bear 400 4x4 IRS
This bike runs a 25/8-12 up front and a 25/10-12 at the rear. Match the size stamped on the sidewall (or shown in the table) - powersports tires are size-specific, so the numbers matter more than the brand.
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Frequently asked
What tire size does a Yamaha Big Bear 400 4x4 IRS use?
GarageDex's powersports data shows the Yamaha Big Bear 400 4x4 IRS runs a 25/8-12 front tire and a 25/10-12 rear tire. Tire sizes vary by year - see the table for each range.
What do the tire numbers mean?
A size like 25/8-12 reads as tread width (mm) / aspect ratio (% of width) - rim diameter (in). Match all three so the tire fits the rim and clears the swingarm and fender.
Do the Yamaha Big Bear 400 4x4 IRS tire sizes change by year?
Yes - fitment differs across the years we cover: 2012 runs 25/8-12 front / 25/10-12 rear; 2010 runs 25/8-AT12 front / 25/10-AT12 rear; 2009 runs 25/7-AT12 front / 25/10-AT12 rear. Match your exact year in the table.
Can I fit a different tire size?
Stick to the stock size - it's matched to the rim width, speedometer, and handling. A wider tire can rub the swingarm or fender and throws off the speedo, so only deviate on a shop's advice.