ReX
TY 4 Stroke God
I just received the 05 Yamaha CDROM. In all of the shots of the RX-1 taking corners at high speeds it is clearly understeering.
Is the understeer as severe as it looks?
It also looks like there really isn't any adjustment to put a little more weight on the skis without sacrificing weight transfer. It's too bad they don't have something similar to the FRA adjustment at the shock connection to the front suspension arm. It could be used to dial in the ratio of downward pressure from the front to rear suspension arms.
My personal preference after setting up Polaris sleds for many years is to extend the limiter straps to the point where they just help minimize the shocks from topping out too hard, reduce the preload on the front track suspension shock to put more weight on the skis and use the weight transfer control to just keep the skis on the ground in a straight line race (when sitting normally - just off the ground when sitting at the back or standing). I can dial in the best of all worlds...
How have you fellows lucky enough to try out the 05 RX-1's found the handling when pushing it to the limit around corners?
Steve
Is the understeer as severe as it looks?
It also looks like there really isn't any adjustment to put a little more weight on the skis without sacrificing weight transfer. It's too bad they don't have something similar to the FRA adjustment at the shock connection to the front suspension arm. It could be used to dial in the ratio of downward pressure from the front to rear suspension arms.
My personal preference after setting up Polaris sleds for many years is to extend the limiter straps to the point where they just help minimize the shocks from topping out too hard, reduce the preload on the front track suspension shock to put more weight on the skis and use the weight transfer control to just keep the skis on the ground in a straight line race (when sitting normally - just off the ground when sitting at the back or standing). I can dial in the best of all worlds...
How have you fellows lucky enough to try out the 05 RX-1's found the handling when pushing it to the limit around corners?
Steve
LazyBastard
TY 4 Stroke God
You've got to realize that those test shots were taken in slush - anything would understeer there.
As far as the weight transfer... you are asking to have the skis up and down at the same time. MAKE UP YOUR MIND! You want more ski pressure, decrease the weight transfer. You want less ski pressure, INcrease the weight transfer. Its a one-nut adjustment on 05. In addition to that, you still have LIMITER straps. Preload is totally unrelated.
As far as the weight transfer... you are asking to have the skis up and down at the same time. MAKE UP YOUR MIND! You want more ski pressure, decrease the weight transfer. You want less ski pressure, INcrease the weight transfer. Its a one-nut adjustment on 05. In addition to that, you still have LIMITER straps. Preload is totally unrelated.
1xr
Expert
Maybe they kept the ski pressure down to keep the apearance of both ski's staying on the ground, where the 03 and 04 don't.
ReX
TY 4 Stroke God
LazyBastard said:
Have you watched the CD? No slush - just ideal trail conditions.
You can easily set up a Polaris Xtra-10 suspension to provide a very good compromize, including very little ski pressure when straight line racing (sitting back a little) and to keep the skis well on the ground (and not understeering) when coming out of corners (sitting forward a little).
Watching the 05 RX-1 videos, the sled seems to have at best moderate weight transfer for straight line acceleration, yet severe power on understeer coming out of the corners.
Here's a piece off the CDROM (doesn't show the worst power on understeer though):
http://www.yamaha-motor.com/products/sno/media/video/05/RX-1_pt7.mpg
On the CDROM the videos of the Vector, Rage, and Warrior don't show the same amount of power on understeer.
LazyBastard
TY 4 Stroke God
I have watched the CD. That was definitely wet slimy snow.
If you have good weight transfer, that MEANS that the skis come UP.
If you want a compromise, which is what you talk about, it means that you have NEITHER perfect weight transfer, NOR perfect handling. Put the transfer rods HALF WAY for this. I guarantee that your *made in america* could be adjusted for better transfer or better cornering. The neat thing about the Yamaha's is that YOU can adjust the transfer ON THE FLY - it takes 2 seconds. You can set it for compromise in the middle if you want, or SET IT PERFECT FOR THE CONDITIONS.
If you have good weight transfer, that MEANS that the skis come UP.
If you want a compromise, which is what you talk about, it means that you have NEITHER perfect weight transfer, NOR perfect handling. Put the transfer rods HALF WAY for this. I guarantee that your *made in america* could be adjusted for better transfer or better cornering. The neat thing about the Yamaha's is that YOU can adjust the transfer ON THE FLY - it takes 2 seconds. You can set it for compromise in the middle if you want, or SET IT PERFECT FOR THE CONDITIONS.
Musky Hunter
Pro
And so it begins............. 
ReX
TY 4 Stroke God
LazyBastard said:
Different opinions...
Snow looked good enough to me that I'm sure my '97 Storm with the current setup would go into a nice both ends sliding drift (if I was leaning far enough out to keep it track side down).
Ideal weight transfer to me is when the sled is setup so that the skis are just touching the snow on a WOT launch in good traction snow conditions when I'm keeping my weight rearwards. More transfer is ideal for looser snow, but I like my skis on the snow in all conditions. I also don't loose many races on the lake with "my ideal" setup (sled isn't exactly stock though).
Ideal cornering to me is when the sled is setup so at any throttle position with me tucked up closer to the tank the front and rear will start to slide at just about the same time when pushed to the limit around a corner. Rolling the throttle in and out while cornering to the limit the sled doesn't start to under nor oversteer.
It took me a couple of years and lots of effort (lowered 4", custom shock valving, springs, pre-load, etc.) to truely dial the sled in after installing a Camoplast 9860 track (1.25" lug). It's an awesome handling and accelerating package now (if only I could keep the motor together - hence the 05 RX-1).
I'm trying to think ahead and figure out what needs to be done with the RX-1...
LazyBastard
TY 4 Stroke God
All you have to do is adjust the transfer rod to where you like it. Thats what its there for.
ReX
TY 4 Stroke God
LazyBastard said:
LB,
It's not as simple as simply adjusting the transfer rod and everything is perfect for all acceleration rates.
Consider this:
With a mono-shock system, depending on where the shock couples with the suspension arm there is a relatively fixed ratio of "twisting" moments(for normal cruising suspension height) applied to each arm (pushing the slide rails downwards) and therefore a relatively fixed ratio of downwards force on the rails by each suspension arm.
To take an extreme case, lets assume I've designed a mono-shock suspension to produce a ratio of 10:1 downwards force on the rails at the front:rear suspension arms. With this setup there is little ski pressure all the time, and every small amount of throttle lifts the skis up in the air - unless I adjust the transfer rod to keep the skis on the ground. With this suspension, with the slightest amount of throttle the transfer rod is controlling the weight on the skis. It is impossible to set the system up so that at the limit of spinning the track, the skis have the minimum weight on them as they will have almost the same weight on them at light throttle.
Going to the other extreme, where the rear of the skid sees the most downwards force, a transfer rod may be useless as there is always lots of weight on the skis.
With most traditional suspensions the front shock spring preload can be tweaked to balance the weight transfer and ski pressure and the transfer rod can be used to keep things in line when your accelerating very hard. The system works well and allows for a nicely dialed in neutral handling machine.
Anyway, the point is - with the monoshock this front rear force balance can't be tuned. What bothers me is seeing the 05 RX-1 understeer significantly in the promotional videos and knowing that the only bandaid available is the transfer rod. In the video it seemed to understeer at constant speeds, and got worse when on the throttle - hopefully the scenes with the major understeer are accelerating at WOT and the limiter can regain control of that. If it's at light throttle there's no way to adjust the front/rear ratio.
Of course there are othe options like deeper keel skis, taller/larger OD wear bars, etc. - not to mention using the limiter strap to help dial it in (which might work well with the mono-shock).
LazyBastard
TY 4 Stroke God
Keep your polaris. Its obviously way better. :ORC
QCRider
TY 4 Stroke Master
LazyBastard said:
Every once in a while LB you just kill me.
I see no issue with adjustability in the Monoshock skid at all. If you read through the information on the Yamaha site, there is a separate adjustment for everything you want from that suspension.
QCRider
TY 4 Stroke Master
Check this out and you will see a method to adjust for Preload, Dampening, Weight Transfer, and as always Ski Pressure is adjusted by the Limiter Straps.
http://www.yamaha-motor.com/products/sn ... ch5002.htm
I see absolutely no problem in getting this suspension to ride exactly the way we want.
http://www.yamaha-motor.com/products/sn ... ch5002.htm
I see absolutely no problem in getting this suspension to ride exactly the way we want.
kmer
Expert
LazyBastard said:
Oh that's a good one.
Swiss Sledder
TY 4 Stroke God
QCRider said:
Did you notice in the link that the hyfax is now wider to improve durability? I hadn't noticed or heard that Yamaha was addressing hyfax wear on the 2005 model, but this was certainly a point discussed on this site last season. I am not sure if making it wider will fix the problem based on Dukesters analysis. Any thoughts?
