I have spent a lot of time testing on the 2026 MX machines you see below. I (as well as a couple other members of our team) have went back and forth on several bikes to see which gearing would be good for the average rider. I did the evaluations on tight clay based tracks to flowing sandier based type desert courses as well as some east coast deep loam. Since the word “gearing” is still in the subject line in a lot of my emails, I thought I would condense some of the best gearing specs I have come up with for the 2026 MX test machines I have tested so far.
A couple of these gearing specs have evolved since 2025 so don’t expect some of these to be the same from last year. This page over the years is ever evolving (edited) so as we put more time on these bikes we may try something that works better, so if you’re thinking about changing your gearing, bookmark this page and check back from time to time to see if your bike has evolved. I DO NOT however just change the gearing for the sake of changing the gearing, like some other media testing outlets. However, if a certain bike does need an engine character change or maybe the transmission spacing needs help, we will try different gearing. These gearing specs are for stock engines or with aftermarket mufflers. If you have engine work done to your bike, chances are your gearing spec could be different. As usual, if you have any questions I am here to help you. Email kris@keeferinctesting.com and I will be happy to assist you
Yamaha:
YZ250F: Stock 13/50 | Recommended: 13/49
Going to a 49 helps stretch 2nd gear on the 24-26 YZ250F engine configuration has lost some pulling power in second gear. Going down a tooth will allow you to pull 2nd gear longer which you will need. The YZ250F spools up quick (quick revving) and requires a lot of shifting from the rider. This will help alleviate a little of the shifting work from your left foot.
Recommended YZ250F ECU Setting: https://www.keeferinctesting.com/2024-yamaha-yz250f-optional-ecu-maps/
YZ450F: Stock 13/51 | Recommended 13/50
East coast/deep dirt conditions we have been running 13/50 gearing as it helps lengthen second gear on the 2026 YZ450F. Second gear seems very short as the new 2026 YZ450F (with the new intake, muffler, port shape) doesn’t pull second gear very long and can’t pull third gear in corners so dropping a tooth helps make second gear more usable.
Recommended YZ450F ECU Setting: https://www.keeferinctesting.com/2026-yamaha-yz450f-east-and-west-coast-baseline-suspension-ecu-settings/
Kawasaki:
KX250: Stock 13/50 | Recommended: 13/51
Going to a 13/51 helps with third gear roll on power out of corners. The added tooth doesn’t negatively affect the second gear stretch as much as we would think so sticking to this 13/51 gearing has been better for this new airbox layout Kawasaki has. With the new 2025-2026 KX250 airbox being a little small, the low end recovery isn’t quite as good as the older 2024 so going up a tooth will also help the rider get into the meat of the power quicker.
KX450: Stock 13/50 | Recommended 13/50
If you’re riding anything tight or rutty, I prefer a 13/51 but for flowy/Southern California tracks the 13/50 is the way to go. We tried a 13/51 on the 26’ KX450 and didn’t initially care for it but as we rode with the 51 tooth more back east we liked the chassis character more for the small bump absorption (length of swingarm pivot to center of axle) and helping us get into third gear quicker. The KX450 is tough to ride in third gear as second gear is so usable with the stock gearing. We even found ourselves using first gear in some areas which is unheard of in the world of 450s. The 51 helped recovery of the softer engine that the KX450 has as well as gave us a little tighter feeling on acceleration out of corners (“tighter” means more response and a less free feeling). An aftermarket muffler and some mapping really does help wake the KX450 up more than other 450s in its class.
Suzuki:
This gearing spec can roll bike a few years. Hopefully Suzuki has some updates soon!
RM-Z250: Stock/Recommended 13/50 White coupler (Stock)
RM-Z450: Stock 13/50 Recommended 13/51 White coupler (Helps pulling power down low on deep tracks).
Honda:
CRF250R: Stock | 13/50 Recommended: 13/51
(Helps rider get into third gear earlier and gives more pulling power without sacrificing too much second gear roll on). The stock 13/50 is decent for sweeping/faster tracks but third gear is still too short and even when we tried going down a tooth, third gear still seemed to short. With the 13/51 this can help second gear pick up/recovery out of corners and get you into 4th gear quicker which actually feels like third gear. Honda needs to work on their 2nd-4th transmission spacing for 2027. If you have a 2026 Honda CRF250R Works Edition, the 13/51 gearing is also good. The RWE has more mid range power so the extra tooth is not needed but it does help the RWE’s recovery in soft soil.
CRF450R: Stock | 13/49 Recommended: 13/50
I would rather go to a 14/52 on the CRF450R but the slave cylinder is too close with a 14T installed. Going up a tooth can help you with lugabiity because the Honda isn’t that great as the Yamaha or KTM when riding a gear high, but the 26 CRF450R is better with that than the 24 was. However, I still prefer the connectivity the 50T brings to the Honda so give this a try and see if it helps make cornering a little easier.
KTM:
250 SX-F: Stock: 14/51 | Recommended: 14/52
This will help third gear roll on response through corner exits in soft dirt conditions without sacrificing much 2nd gear pulling power. If riding hard pack dirt, leave gearing stock.
350 SX-F: Stock 14/52 | Recommended 14/52
450 SX-F: Stock 13/51 | Recommended 13/51
I have tried going to a 13/52 but it didn’t help my third gear roll response on as much as I would like so I settled on a 13/51 in order to be able to use send gear more/longer. as the KTM has a long second gear. If you want to use 13/52 it will help with recovery in third gear if you’re riding softer dirt (east coast).
Gas Gas:
This set up on both bikes will help settle the rear end out of corners and help with 2nd-3rd gear transition exiting corners.
MC 250: Stock 14/51 Recommended 14/52
MC 350: Stock 14/51 Recommended 14/52
MC 450: Stock 13/49 Recommended 14/52
Triumph:
The 2026 Triumph TF250/450 have an excellent engine character, but both bikes could use a little more recovery in third gear so going up a tooth can help with shifting into third gear sooner or possibly carrying third gear more depending on your roll speed through corners. Either way this gearing will give more response to the smoother roll on character of the UK engine package.
TF250-X: Stock 13/48 Recommended 13/49
TF450-X Stock 13/48 Recommended 13/49
