Posts
58
Joined
3/27/2007
Location
Forney, TX
US
Edited Date/Time
8/24/2015 3:25pm
On my bike the front end is pushing in corners and not staying planted well... Suspension has been done twice and still no luck... Anyone else had similar issues and what did you do to help it? I am considering trying the DR D Engine relocation kit to adjust weight distribution. Would triple clamps help?
Any help would be greatly appreciated. ~ Roger
Any help would be greatly appreciated. ~ Roger
The Shop
I've got a 14yz450. After getting my suspension finally dialed right for me, getting forward on the bike is the biggest help in turning it. With the bike's weight being further back you really have to get forward on it to give the tire some bite. I'm 6'1" at 175 lb. So a bit taller bar mount to get forward more helped a lot.
As stated above, tire selection and good suspension setup made the most difference to me. Also, not paying attention to non-Yamaha riders/magazines saying it pushes in corners was a good first step.
Eventually I found flatter standard height bars, these suited me better, they pulled me further forward, the bike turned easier for me, with less pushing in the corners.
Remember I am old school and I don't ride over the front like modern riders.
First, I'll say that I'm a 160 lbs Intermediate. This is my first four stroke motorcycle of any kind. I spend most of my time racing a YZ125 in the 30+ and 25+ classes.
I moved the forks up in the clamps as others have mentioned. I tested with 5mm fork height to start with. The groove in the fork tube aligned with the top edge of the upper clamp is the 5mm setting. I felt like that was a bit too much for this chassis, so I ended up with the groove just below the upper clamp. My dial caliper says 4.1mm.
Next I played around with the clickers. The high speed damping on the shock works well at 2 turns out. That was the MXA recommendation in their test, and it works well.
This week I installed a 143.5mm linkage (the stock linkage is 142mm). That worked out really well with around 105mm of sag, but I felt the bike wandering a bit mid corner. The solution for that wandering front end was a little counter-intuitive. I actually raised the rear end by reducing sag (more shock spring preload). I am right around 103mm to 104mm of sag at this point and the bike works really well. Raising the rear allowed me to sit a little farther back (more central on the bike) to initiate a turn. Once in the turn, I was central and the forks weren't under as much of my weight, so the front end rebounds a bit more at apex and the bike goes pretty smooth through the corners.
The valving is a bit slow for me, so the bike still feels like it has about 2% less traction than my buddy's '13 Kawi (with Showa A-Kit suspension), but I rode them back to back today and felt really confident on the YZ450F for the first time.
The engine is really gnarly, it makes that stock '13 Kawi 450 feel like a 250F. If you don't have good throttle control, the YZ450F will unsettle a bit in corners. I have a GYTR tuner coming in this week, so I'll play with some smoother maps. I hear the Travis Preston map is a great all-around setting.
Here are a few laps from today, riding the YZ450F and the KX450F I mentioned above:
Also, don't be afraid to mess around with the sag on this bike. Start at 105mm and try adjusting about 1/2 of a turn on the preload nut at a time, then go ride it. Try more pre-load, then try less. Find your sweet spot. Each full turn of the preload nut on most modern bikes works out to around 3mm of change in your race-sag.
Don't get caught up in the actual sag numbers, just use the 103 - 107 range as a starting point and adjust it by how it feels. When you get it where you like it, take several measurements, average them and write it down.
In my opinion, this YZ450F chassis is fairly sensitive to chassis setup.
Pit Row
Thank you very much for the input and advice. I will give these things a try this weekend when I am able to get back on the bike.
If you are at Thunder Valley this weekend, stop by and say hello. Kiana will be racing the adaptive race on Sunday.
~ Roger
The biggest thing I have noticed is getting the balance or the front and rear suspension to work together. It seems even when I do slight adjustments, I have to try and keep both the front and rear working in unison if that makes sense.
Forks 4mm up
108mm of sag
Bars in the rear holes with the mounts facing forward.
Clickers in the ballpark of MXA settings
Cycra powerflow kit
'15 motor mounts
MX32 tires
I am a long time Yamaha rider, so the following is just what I have felt.
The bike had really good turn in, mid corner would push and over-steer on exit. Went from 105mm of sag late spring to 108-109mm of sag. I raised the forks up to try and balance out the chassis and get more weight on the front end. It helped slightly along with ditching the stock MX51 tire.
This past weekend, installed the PC lowering link and set the sag at 104mm. Bike felt solid through both flat corners and off camber. Didn't sense the front end searching or wandering. If you get up on the front of the bike and lay it over with the gas on, it will track now. With the snappiness of the motor, if you chop the throttle mid corner you will upset the balance and it will go all over the place. I am really happy with the progress, it feels like a completely different bike with the lowering link. Going to do some more testing this weekend on suspension settings to see if we can improve upon where its at now.
Front brakes need work, so plan on upgrading to a larger front rotor too. All that power needs to get stopped somehow and the 240mm rotor ain't cutting it.
I'm not a fan of the 90 on the front of any bike if there are any ruts. I spend a lot of time at Washougal and a few other tracks here in Washington and Oregon that form ruts in the corners due to high moisture and some clay in the soil. I feel like it's harder to put the 90 front tire into a rut and keep it there. I find myself using the front brake a whole lot more to keep the 90 down in the rut. That isn't specifically on the YZ450F, just my observation about the 90 tires in general.
I'm not trying to talk anyone out of running an 80 or a 90 front... Just some things to consider if / when you try out the 90.
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