Do you even know what OEM stands for?
Apparently most don't but most know what it is. Stock parts. Manufacturer's Original Equipment. Or Original Manufacturer's Equipment. But they, whoever they is, went with Original Equipment Manufacturer. OEM.
Whateves.
A few simply say stock parts, i.e. the parts on the bike from the factory. Several of these stock parts (or OEM) get replaced right away with aftermarket parts by some riders. Did you know certain aftermarket parts actually represent OEM for various bike brands?
OK then. Well. Do you stick with stock, I mean OEM, or upgrade to aftermarket?
Depends on your goals. Finances too. A handful of parts don't have an aftermarket counterpart, so really you only have one choice in that situation. First let's do a brief rundown on the differences between the two. Totally brief. You already know. Gotta fill air time. You feel?
OEM Dirt Bike Parts
The stock parts that come on the bike from the factory made typically by the company that built the dirt bike. These parts ensure fit and compatibility and meet the specifications for normal operation and that comply with the manufacturer's warranty.
Aftermarket Dirt Bike Parts
Parts made by third-party companies generally for the purpose of upgrading the performance of your dirt bike.
Now you might think bike manufacturers don't put a lot of effort into stock parts (i.e. it's good enough!) like the exhaust, thus the range of aftermarket exhaust companies offering lighter weight exhaust systems that help with torque and speed. In fact, the aftermarket trade extends to almost every part on your dirt bike but most focus on performance and comfort. Depending on brand, aftermarket parts sometimes come with an upgrade in price too. You pay more.
But you might be surprised to learn OEM often rival aftermarket. Not in every aspect, of course, but you can get away with riding and racing a fully stock bike. And I quote:
"OEM stuff is really good. There may be some cheap stuff like chains and sprockets, rims and a few other bits and pieces. A stock exhaust actually performs really well, but it is heavier and doesn't look as cool. Personally, I would purchase OEM parts the majority of the time over aftermarket for reliability purposes. The OEM's put in way more R&D then most of the aftermarket companies."
Straight from the keyboard of MotoSport's resident former pro. Look around the blogs if you want to know who. He's not famous to you but he is to us.
By the way, rather than the factory pros getting decked out in all the best aftermarket upgrades, don't you think putting everyone on a stock bike, regardless of brand, would establish a real test of riding and racing skill, and the better bike manufacturer?
Pros and Cons: OEM vs. Aftermarket Dirt Bike Parts
Feature
OEM Parts
Aftermarket Parts
Fit & Compatibility
Perfect fit for your dirt bike's MMY
Reputable brands make to spec
Quality Control
Consistent quality
Top brands may exceed OEMwatch for knockoffs
Warranty
Manufacturer-backed
Varies by brand
Price
Could be more, could be less
Could be more, could be less
Availability
Often easy to find for new bikes
More options, especially for older models
Performance
Matches OEM performance
Offers performance upgrades
Customization
Limited to original specs
Unlimited options
When to Choose OEM Parts
| Feature | OEM Parts | Aftermarket Parts |
|---|---|---|
| Fit & Compatibility | Perfect fit for your dirt bike's MMY | Reputable brands make to spec |
| Quality Control | Consistent quality | Top brands may exceed OEMwatch for knockoffs |
| Warranty | Manufacturer-backed | Varies by brand |
| Price | Could be more, could be less | Could be more, could be less |
| Availability | Often easy to find for new bikes | More options, especially for older models |
| Performance | Matches OEM performance | Offers performance upgrades |
| Customization | Limited to original specs | Unlimited options |
When to Choose OEM Parts
The parts you can't get in the aftermarket market like engine and transmission parts and suspension bolts. Only OEM. Therefore, choose OEM parts for
- Critical Components: For engine internals, transmission, crankcase, frame, and suspension bolts, choose OEM as the only safe and reliable choice.
- Warranty Concerns: Use OEM parts to maintain warranty coverage.
- Guaranteed Fit: The manufacturer built the spec so when you want easy installation and 100% compatibility choose OEM.
- Long-Term Reliability: Manufacturers design and construct OEM parts for longevity and consistent performance.
When to Choose Aftermarket Parts
- Performance Upgrades: Aftermarket exhausts, clutch, footpegs, handlebars, air filters, and wheels often outperform OEM and weigh less.
- Cost Savings: Aftermarket dirt bike plastics, levers and brake components often cost much less than OEM and perform as good if not better. Example: A 2025 CRF250 a stock slip-on costs ~ $600, you can get a stainless steel FMF slip-on for about $350 or aluminum for less than $700.
- Customization: Manufacturers don't spend a lot of time making several options for the same part, so go aftermarket for different colors, styles, or features.
- Availability: Older bikes and discontinued models lose their rights to OEM. Aftermarket parts may be your only option.
The casual rider, trail rider or beginner unlikely needs high performance aftermarket upgrades and can get by sticking with OEM. However, the serious racer looking for enhanced power and an edge on the track should look at aftermarket exhaust, clutch, brakes and wheels, to start.
It doesn't hurt, regardless of your experience or type of riding, to check aftermarket parts - once OEM parts need replacing - to see if a cost savings benefit exists or for preferred customization and enhanced performance. MotoSport partners with industry trusted aftermarket brands so whether you choose OEM (we got schematics!) or hit the open market know we have researched the brands to ensure you get the best parts for your needs.
