250-500cc Gearing for single track on WR300

These are the type of trails I spend most of my time on...

View: https://youtu.be/Z2d9WjF0nVk



View: https://youtu.be/g4MrNC2hrSU



With that in mind, the stock gearing is too tall on the WR300. Thinking about swapping the stock 13/48 gearing for 12/50 to get 1st gear more user friendly on tight trails. Will I need to swap the new stock chain to run this gearing? How large can I go in the rear before needing an extra link or two?

Also, I have a PWK (used off ebay, was on a SM WR300) waiting to go on the bike and likely will add an FMF Gnarly pipe and silencer to help move the power a bit lower in the RPM range.

What are your thoughts and experiences?

Thanks,

Heath

The fastest easiest way is just put a 12 on the front I would start there I have done that it was really low King of the moto low As for the rear you can go to a 52 but you need to trim the bolt that holds the chain guide on
I run a 52 in my 125 and some times put that wheel on my 250 or 300 and it works but is really close The 12/48 is really low If you need the 50 let me know as I believe I have a few new 50 tooth sprockets will sell you cheap

I found 13:50 to be the best for my WR250, it had good slow trials no stall ability and could still top out at a reasonable speed. 13:48 required much more clutch work to do slow speed techniques without stalling. I would think 12:50 would make 1st gear useless. I buy a 120 link high quality "O"ring chain and cut it to fit (usually 3-4 links) so that the axle adjuster is middle to rear of the slot. This allows clearance for a MT43 trials tire to grow at high speed if you are inclined to use one and having it toward the rear helps in high speed stability.

Thanks for the advice.

I like for 1st gear to be my "OH CRAP!!!" gear. At 13/48 it'll cause more "Oh Crap" moments than it'll save me from. I'll likely grab a 12 and a 50 and try one change at a time and see how each effect the speed in first gear. I'd like to be able to crawl through a rough section (or get my butt out of trouble when I blow it) without stalling or needing enough throttle to get the WR on the pipe. Just want it to keep moving forward.

I hope the change in the carb will help keep the lower throttle openings more consistent than the TMX. Have read the FMF exhaust will move the power a bit lower in the RPM as well. She'll be a goat by the time all is said and done.

Heath

I struggled with my gearing in the beginning and found out it wasn't my gearing I was actually struggling with, but the jetting. Once I kicked the TMX to the curb for a Lectron, 13/50 worked great. I didn't try, but I think the stock gearing would work fine with it.

13/50 my vote. 12/50 would have a top speed of about 18MPH @ 9000rpm!

My 300 came with a Rekluse and now that I'm used to it, it is the shitz in the tight and slow and OMG! stuff. Even with just the EXP 2.0 it has saved my arse many times, no matter how bad I crash or get tangled up the bike just idles and waits patiently. Freakin' brilliant! Def a compromise in riding tactics, doesn't slow me down at all. In fact I can gear taller, 13/46 currently, and still have plenty of 1st gear grunt. I know, not quite what you're asking, but just my 2 cents worth.

I have a 2006 WR250 with 13/50 and Rekluse Z- start pro, it's awesome in tight single track.
I have tried 13/52 with the stock chain it works fine.

I can't imagine 12:50 on the 300,you would be shifting constantly and top out at 40mph,not to mention it would want to rip out of your hands. I run 14:49 and it works great in everything. But I do not have the crappy tmx like stated before, carb makes a huge difference.

13/50 on single track for the 300 seems perfect for me 99% of the time. Also a pwk carb and a pro circuit pipe and high comp head. Similar type of trails. BTW...those trails look fabulous!! Go Kentucky...I had no idea

2007 WR 250 with Dynaring 13/49 works great in the tight stuff.

Thanks again for all the tips and advice.

Looks like I'm gonna try the 50 first and see how it does. I'll move up or down on the gearing depending on how it likes or hates the single track. May not need much of a change once the PWK is on the bike in combination with the FMF exhaust.

Got a trip to Burning Rock next month, and the mountainous single track trails will be the litmus test on the set up.

Heath

My (used) WR250 came with a 12 front and stock 48. I never thought it was too tall, until I rode my buddies KDX220. That thing is geared really low compared to mine, and is a total tractor. Tractor is okay for me, because like you, I ride lots of single track. The WR250 is my dedicated trail bike that never even sees a double track. I have a 49 rear sitting in the garage to see what is like at 12/49. I just can't get myself to do it. But I'm very curious. If I had a 300, I probably wouldn't go much lower than 13/49 or 13/50.
Here's a gear ratio chart to help with your decision:

I've been running 12/51 on my CRF450 for several years, and its just about perfect.

Will try and order the sprockets in the next week or so and see what it feels like. I'll definitely report back on the differences.

Heath

Your wr300 has a lot of flywheel weight compared to a CRF450, it also has flywheel effect from a larger capacity ignition stator + the advantage that 2 strokes don't flame out like a 4 stroke will. If your carb is jetted right you should be able to do about any slow speed trials skills with 13:50 and not have stalling issues.

umm im probably so far in the minority but i use 15/48 on my 360 no issue lowdoen complete chuggalong on idle no throttle or blistering top end that doesnt worry me on the road but fire tracks damm its fast.

With 13:50 gearing and a MT43 tire that would grow at high speed my WR250 would do 80mph wide open and with 13:48 it would only do 82mph, probably because it couldn't pull the 48 gear in stock form. With the Lectron and the FMF pipe I'm betting it is much faster but since then my speedometer was slightly modified by a tree and has found a new home at the landfill. I'm thinking 75mph with a knobby and maybe 85 with a MT43 but I can't prove it.

Makes sense to me. The effective diameter of the tire slightly changes the final-final gearing.

Yes it does and thats how i rubbed through my mudflap and scuffed my swing arm didnt realise they deformed so much, i run a cst surge on the back not sure of exact speed flat out but its in the 80's sat nav on in a rally over long open fire roads
Seems to keep pulling thats gnarly and lectron with silly high gearing suppose i should put a trial tyre on it an hit 90 but thats silly fast and rarly do i have the track open enough to use it, in tight woods the gearing is also spot on so 15-48 is 360's gearing.
Probably should stick the 12t front on and practice balancing on the rear for a week or so.

For PNW woods riding on my '11 wr300, which is what I ride 90% of the time, I've been using 13:50 for years but rarely ever use 1st as it's too jumpy. Most single track is somewhere in 2nd, 3rd, and even 4th if it open up. For desert riding I go w/14:50 for a little wider spread. However, I kept the 14:50 gearing for yesterday's Sparkplug Enduro at Tahuya, which is lots of tight single track in the woods (I did the Desert 100 the weekend before and didn't have time to switch back to 13:50) and think I'm going to keep it there for more woods riding as it felt smoother and less jumpy in the tighter stuff and I didn't need to change gears as often with the wider spread. 1st still had plenty of pull, but a little less jerky than w/the 13:50.