My WR450F tight woods "racer" build.



168 replies to this topic
  • MidlifeCrisisGuy

Posted September 08, 2014 - 11:10 AM


have you tried a taller rear sprocket? i know you said your bikes idles at 6mph with current 12/51 gearing, i've always setup my bikes for 3mph at idle to go fast in tight gnarly single track, i think a 12/55T or 12/56T will get you there.

 

Laugh all you want, it works.  2nd and 3rd gear really usable on tough climbs.  The bike has 5 gears, why not use them ?   Its not like the MX bikes are out running me on top end.



  • DRS

Posted September 08, 2014 - 11:35 AM


Laugh all you want, it works.  2nd and 3rd gear really usable on tough climbs.  The bike has 5 gears, why not use them ?   Its not like the MX bikes are out running me on top end.

 

i believe u when you say it works for you,  it's quite common for a less experienced rider to require a bike be nerfed to their particular skill level before they can feel comfortable riding in certain terrain.



  • MidlifeCrisisGuy

Posted September 08, 2014 - 11:35 AM


Rear suspension tidbit.

 

I read about a lot of big guys riding WR450s.  I also read about people setting their race sag to numbers higher than 100mm, like 105mm, etc.

 

Here is a little secret.  The WR450F steers terrible when the back end is low.   They feel like ponderous pigs.  The rider generally feels "behind" the bike in terms of control.  When the suspension is set like this, you don't pick a line, you wish for a line and deal with whatever you get.  Its awful.  

 

The 2012+ WR450Fs only have 11.6 inches of rear travel.  The recommended race sag on page 4-4 in the service manual is 90 to 100mm.  That is the amount of sag that the Yamaha engineers had in mind when they set up the geometry of the bike.  If you run more sag than this, expect it to be operating with geometry outside its design. 

 

Furthermore, big, tall, lanky riders end up sitting further back on the bike.  When they do that, they compress the rear suspension more and the bike turns like crap when you are seated.  Especially when you are wearing a heavy pack, which moves the rider COG even further back.  Sliding up to the tank helps, but the rider is constantly doing it and its a compensating move.

 

There are several possible solutions to the front/back balance problem.  1) Heavier rear spring.  2) Proper sag setup. 3) Raise the fork tubes in the triple clamps. 4) Move the bars ahead further.  (Ever compare the arm reach of a 6'1" guy to a 5'10" guy ?  That is how much further back the tall guy is on the bike, given the same arm position.  Its like 2 inches and the tall guy is heavier too.)

 

My bike turns well with 92mm of sag, measured with me standing.  I'm running a 6.0 spring even though race tech says I need a 5.8, max.  I'm also running my bars further forward thanks to an extra set of holes in the YZ triple clamps.  It all helps.  My comparison bike is a 2010 YZ250F.

 

I've run less sag than that in testing.  It turns better yet, but shock absorption is off because there is too much preload on the shock and not enough "free" travel.  

 

My sag numbers also aren't right.  When my race sag is in range,  my static sag is like 12.5mm.  I'm going to try a 6.4 spring.  I expect it to improve the suspension as well as the handling.   I'll report back when I do.      


Edited by MidlifeCrisisGuy, September 08, 2014 - 11:41 AM.


  • MidlifeCrisisGuy

Posted September 08, 2014 - 11:38 AM


i believe u when you say it works for you,  it's quite common for a less experienced rider to require a bike be nerfed to their particular skill level before they can feel comfortable riding in certain terrain.

 

I'll be sure to tell my vet expert friend that a guy on the Internet called him "less experienced".  LOL.  He'll get a kick out of that.  He's helping me with these decisions.  



  • DRS

Posted September 08, 2014 - 11:47 AM


I'll be sure to tell my vet expert friend that a guy on the Internet called him "less experienced".  LOL.  He'll get a kick out of that.  He's helping me with these decisions.  

 

oh wow i had no idea you had a vet expert friend...    :worthy:     vet experts don't get winded and red faced following a noob on a wr450's in the tight woods dude.  what does it say about your buddies so-called skills that you (a noob) can leave him in the dust when the terrain gets at all technical? it says a LOT!    FYI anyone can sign up and run expert class, even you... means nothing, and less than nothing when you say it on the internet to get respect.    :facepalm:


Edited by DRS, September 08, 2014 - 12:07 PM.


  • MidlifeCrisisGuy

Posted September 08, 2014 - 12:24 PM


My vet expert friend wasn't riding the 200xc.  Different friend.

 

The vet expert class is usually faster than the young guys.  Depends on the conditions.  Its all about skill.  My vet expert friend won the class several times when he was riding competitively.   He isn't a pro, but he knows what he is doing.

 

I'm sick of arguing with you guys.


Edited by MidlifeCrisisGuy, September 08, 2014 - 12:26 PM.


  • DRS

Posted September 08, 2014 - 02:33 PM


My vet expert friend wasn't riding the 200xc.  Different friend.

 

The vet expert class is usually faster than the young guys.  Depends on the conditions.  Its all about skill.  My vet expert friend won the class several times when he was riding competitively.   He isn't a pro, but he knows what he is doing.

 

I'm sick of arguing with you guys.

 

thanks for the regurgitated info but i'm well aware of a vet expert pace, i seriously question that you are...

 

if you don't want to be called out then don't compare your unchecked skills to your friends unchecked skills and expect us all to fall over with excitement and jealously like you just discovered the magic bullet to going fast. if you like your bike then fine, but don't expect others to follow your advice for having to spend more time working on your bike than you do riding it, in order to enjoy it.  most riders with half a brain are aware that the bike is not the limiting factor in going fast, you on the other hand are having a hard time grasping that concept. enjoy your bike.


Edited by DRS, September 08, 2014 - 03:14 PM.


  • stevethe

Posted September 08, 2014 - 05:37 PM


Geez getting schooled by a one year vet rider. Not. Must have a new cam and a plate of light weight skillets. :smashpc:  Does the bike have a 1/2 Hp more or less. The Dyno will never know. Something about subjective yip yap. :goofy:



  • MidlifeCrisisGuy

Posted September 10, 2014 - 12:25 PM


I'm pretty happy with how my bike is coming together.  Its getting where I want it to be.  Better in some ways than I ever thought it would be.  Its a blast to ride.

 

The weight has come off nicely.   I've got a few more ideas on making it lighter.  I'll tackle some of them over winter.

 

It steers quite well now.  A better front tire, adjusting the front/rear balance and changing the triple clamps have really helped.  I'm delighted how I can pick lines and control the bike in and around ruts and going through corners.

 

The engine is fabulous. Fantastic.  Outstanding.  I'll leave it alone for a while.  Though I am probably not done with it.

 

The front suspension is working better.  I upped the fork oil to 350cc and the forks are staying up better.  They seem to absorb stuff pretty well.  I'm not saying that they are perfect, but they are not the weak link right now. 

 

My next focus is the rear suspension.  Its presently the weak link on my bike. 

 

I'm presently running a 6.0 spring and have the high speed damping turned way out.   The issue is harshness running over roots at high speed.  I'm standing a lot when I'm riding and it would be nice to have a bit more seat time to save my legs.  However its rough when I'm seated and running over roots, which happens a lot.  I'd like a better ride over small stuff at higher speeds. 

 

I think I'm at the end of the tuning spectrum with the stock shock.  I purchased a 2007 YZ shock and linkage on ebay for $70 and $80 respectively.  I'll rebuild it and revalve it and see where I get.   I bought the second shock because it was inexpensive, I want to do A/B testing and I want to have a shock on the bike while I work on the other shock so I am never waiting on a shock to ride the bike.

 

I also purchased a 6.4 spring.  The Racetech calculator says I need a 5.8, but my sags are off with the 6.0.  Can't hurt to try the 6.4 and then I won't have to swap springs when I swap shocks, unless I want to compare the shocks with the same spring.

 

Lots of fun ahead.



  • Monk

Posted September 10, 2014 - 12:51 PM


Do the YZF SWINGARM mod, close to 2lb savings between swingarm and hub and excellent handling results...

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  • MidlifeCrisisGuy

Posted September 10, 2014 - 01:03 PM


Do the YZF SWINGARM mod, close to 2lb savings between swingarm and hub and excellent handling results...

 

I looked at it.  Was going to be part of the 25 pound weight removal.   Weighed the 2 swing arms and linkage and the difference was like 8 ounces.   The back hub is lighter too, but not by a whole lot.   The magazine article that published the 2 pounds weigh saving had their numbers wrong.  They also spent like $300 on brand new TCs so that the number plate had a hole to bolt to.  It wasn't well researched.

 

BTW, its not really all the YZF swingarms.  Its the 2010+ YZ450F and the 2011(?) + YZ250F swingarms.   Its the ones where the linkage mounts under the swingarm instead of using a bolt through the arms themselves.   And the axle diameter is different too, 25mm versus 22mm IIRC.

 

I'm not sure its worth it.  Its not tops on my list at this time, though some of the YZ250 boys have done it and swear by it.  I think that is due to better linkage ratios, but I'm guessing when I say that.

 

Gotta love all the parts interchangeability and the inexpensive parts available for these Yamahas.



  • Monk

Posted September 10, 2014 - 01:18 PM


I looked at it. Was going to be part of the 25 pound weight removal. Weighed the 2 swing arms and linkage and the difference was like 8 ounces. The back hub is lighter too, but not by a whole lot. The magazine article that published the 2 pounds weigh saving had their numbers wrong. They also spent like $300 on brand new TCs so that the number plate had a hole to bolt to. It wasn't well researched.

BTW, its not really all the YZF swingarms. Its the 2010+ YZ450F and the 2011(?) + YZ250F swingarms. Its the ones where the linkage mounts under the swingarm instead of using a bolt through the arms themselves. And the axle diameter is different too, 25mm versus 22mm IIRC.

I'm not sure its worth it. Its not tops on my list at this time, though some of the YZ250 boys have done it and swear by it. I think that is due to better linkage ratios, but I'm guessing when I say that.

Gotta love all the parts interchangeability and the inexpensive parts available for these Yamahas.


The 8oz is wrong.... Over a pound on the swingarm alone...

  • Monk

Posted September 10, 2014 - 01:22 PM


I made the spacers for the 25mm-22mm axel...


20140819_153109_zpsqgzq5xf2.jpg
20140819_165918_zpsxkr2hqbj.jpg

Edited by Monk, September 10, 2014 - 01:23 PM.


  • MidlifeCrisisGuy

Posted September 10, 2014 - 01:23 PM


The 8oz is wrong.... Over a pound on the swingarm alone...

 

I was at a bike wrecker and we weighed the parts on his shipping scale.   I was all ready to buy them.  It might have been 12 oz, but it wasn't a pound.   The magazine said it was 2 pounds.   Wasn't any where near that.  If I'm wrong I'll look into it again.

 

Its an expensive way to lighten a bike.  I'm frugal.

 

The rear sub frame has me thinking though...


I made the spacers for the 25mm-22mm axel...

20140819_170044_zpsnhiwhu21.jpg[/quote]

 

Wrong picture, Monk ?

 

I was going to machine the axle spacers too.


Edited by MidlifeCrisisGuy, September 10, 2014 - 01:24 PM.


  • Monk

Posted September 10, 2014 - 01:26 PM


The stock swingarm came in @ 13.0lbs

20140814_155208_zpsdrnkhvh6.jpg

The YZF swingarm came in @ 12.0lbs

20140814_155326_zpsew4p7taz.jpg

So a 1lb weight savings ain't too bad...

I did the conversion @ for about $300...

Edited by Monk, September 10, 2014 - 01:27 PM.


  • MidlifeCrisisGuy

Posted September 10, 2014 - 02:27 PM


All exactly the same parts on each ?  I see the top one has no bushings in the linkage piece, though that would increase the weight savings.

 

Which bike did each swing arm come from ?  Our comparison was a 2012 WR450F and a 2011(?) YZ450F.  Or so I was told.

 

Its still not 2 pounds for the swing arm alone.  Good research anyway.   You aren't afraid to get your hands dirty working on a bike !  Funny both you and I have scales on our work benches ! LOL.


Edited by MidlifeCrisisGuy, September 10, 2014 - 02:30 PM.


  • Monk

Posted September 10, 2014 - 02:30 PM


All exactly the same parts on each ? I see the top one has no bushings in the linkage piece, though that would increase the weight savings.

Which bike did each swing arm come from ? Our comparison was a 2012 WR450F and a 2011(?) YZ450F. Or so I was told.

Its still not 2 pounds for the swing arm alone. Good research anyway. You aren't afraid to get your hands dirty working on a bike !


All the same parts... 2lbs between the swingarm and rear hub. Swingarm is off a 2011 YZ250f

  • MidlifeCrisisGuy

Posted September 10, 2014 - 02:31 PM


The stock WR seat is 2.91 pounds.   And its as hard as a rock.   I think I can do better.    And that weight is really high on the bike, where it makes the most difference.

 

I dare you to try the 22mm TCs. 

 

My friend thought I'd get unstable "KTM steering" as he called it, but my bike is good.   Sure makes it handle in the tight stuff. 

 

The only machining you need to do is bore out the fork holes from 54mm to 56mm.  I did it with a boring head and did a nice job, but it would be easy to do on a CNC machine as well.  2010+ YZ450Fs and 2012(?)+ YZ250Fs have them.  These bikes have 54mm upper fork tube diameters.


Edited by MidlifeCrisisGuy, September 10, 2014 - 02:34 PM.


  • MidlifeCrisisGuy

Posted September 10, 2014 - 02:35 PM


All the same parts... 2lbs between the swingarm and rear hub. Swingarm is off a 2011 YZ250f

 

I wonder if the 450F arm was 4 ounces heavier.  The first arm is from a 2012+ WR450F ?



  • Monk

Posted September 10, 2014 - 02:45 PM


I wonder if the 450F arm was 4 ounces heavier. The first arm is from a 2012+ WR450F ?


My YZ 250. From what I've understood, your WR and my YZ share the same arm...




 
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