Adjustible Caster

[Honda 250r 001]

http://www.walshrc.com/index.cfm?cfid=1580238&cftoken=22349635&fuseaction=product.details&ProductID=121223
This seems like a good idea to me. It adjusts the caster as your suspension goes through its travel. Seems like it would help out quite a bit, what are the downfalls of this? It looks to me like it would add positive caster for more stability when you were at high speeds and lower caster for more responsive steering while cornering!

[Honda 250r 001]

No one? really? ha

[D Bergstrom]

Houser came out with the Trictrac system years ago, pretty much the same thing, as the suspension compresses, there is less castor. Not something I would want for my type of riding. Years ago when I first bought castor adjustable a-arms I did some experimenting. Ran the quad with the most castor I could put in it, then with the least. The least amount was just plain scary. As soon as I took off, there was a big speed whoop section, after going through there with less castor and the quad darting around like crazy, figured I had enough of the less castor idea.

About a year later I was talking to desert racer Wayne Matlock. He said he tried a 700XX with the trictrac system once, said the same thing, it was just scary at speed hitting whoops.

I think this Houser sytem was mostly designed for TT racing or lower speed stuff. You have to figure, anything at high speed that makes the front suspension bottom hard is going to get a little sketchy. Maybe Walsh has a little different range of castor that it goes through, but still not something I would have any interest in.

Doug

[D Bergstrom]

Actually, after looking at the link, looks like the system Walsh has is only for the Yamaha 450. I have read that they have some issues from the factory with castor. I know Houser also makes a fix for those (Cecco bracket), so this is more appears to be more like the Cecco bracket then the trictrac system.

Doug

[hontrx265r]

yes this is easily illustrated in a simple drawing, but essentially the upper and lower arms are not parallel by changing the angle of their relation your changing the way the caster moves through compression and extension. ie.. the caster "gain" they are speaking of. I haven't ridden a yfzR but in theory it would work how the trac-trac does for bikes that do not have that relation. It seems most change it on the yfz for xc, but I did notice Wienen uses the walsh version on his mx bike so I'm sure its personal preference. my thinking is that maybe on the yfzR they exaggerated it too much, and it makes the bike twichy but thats just a theory...

[89trx250r]

I dont wanna hijack here but hontrx265 do you know what it would be like to run the LTR setup on the yfzr cause I read a tweet from Mike Walsh that said Chad's yfzr will be running that setup...Will that in combination with this bracket(s) make it that much better or what?

[hontrx265r]

I'm not sure and was wondering the same about the ltr. I put a post up in the open forum. I have a hard time believing that using ltr spindles/flag stem on all other manufacturer bike is going to be an improvement, when the geometry in the rest of the suspension is different for each of those bikes....

[wilkin250r]

Originally posted by hontrx265r
I'm not sure and was wondering the same about the ltr. I put a post up in the open forum. I have a hard time believing that using ltr spindles/flag stem on all other manufacturer bike is going to be an improvement, when the geometry in the rest of the suspension is different for each of those bikes....

I saw the post, but I don't know enough about the specifics to really answer the question. But I do know enough general information to add my 2 cents.

A couple degrees of caster, bump steer, and other things like that can indeed vary significantly between manufacturers. Wasn't it Cannondale that was described as having a "twitchy" front end? An otherwise fantastic machine doomed to failure because of a caster problem. It's the kind of issue that the casual rider can't pinpoint, but a professional racer will definitely notice, and it could be as simple as one or two degrees. Like I said, I don't know the specifics, but it is the kind of issue I can see as a very real possibility. Sometimes manufacturers just stumble on a superior design. Take tie-rods for example, I've seen kits to convert Yamaha over to the Honda style of tie-rods because they are a superior and more robust design. I've never heard about the LTR having significantly better spindle geometry, but I wouldn't be terribly surprised if they did.

The Walsh product described above doesn't look quite the same as the Houser Tritrac. The Walsh product looks like it's correcting what they believe to be a flaw in the YFZ design, changing the A-arm mounting points to change the characteristics as the suspension travels. This explains why it's only available for the YFZ, if none of the other brands exhibit this flaw, or not to such a severe degree.

[D Bergstrom]

Originally posted by wilkin250r
The Walsh product described above doesn't look quite the same as the Houser Tritrac. The Walsh product looks like it's correcting what they believe to be a flaw in the YFZ design, changing the A-arm mounting points to change the characteristics as the suspension travels. This explains why it's only available for the YFZ, if none of the other brands exhibit this flaw, or not to such a severe degree.

Yeah, my first post was from just reading Honda 250R 001 post and not actually looking at the link. After I saw the link, it is not the same as Houser's Trictrac, but like their Cecco bracket. Like others have said, correcting an issue with the YFZ.

I also agree with Hontrx265r, I don't think that just bolting on a set of LTR spindles to any quad is a cure all. The entire front suspension has to work together. The entire front end geometry has to be looked at, not just the spindles.

Doug

[hontrx265r]

Not to beat this up but I want to be clear, I wasn't trying to say the bracket looks like tric/trac, but basically by adding that bracket they are removing that "tric/trac" type movement from the spindle. The geometry of the original yfzr chassis is what creates the "caster gain" the bracket removes some of that. Again my guess is it was too twichy to begin with.
On the Ltr I'm not knocking the handling of the bike, they are a great bike, I have one. I'm simply implying that there is more to the package then what is being retro'd to other bikes.. so the results cannot be equal. Things like the spacing between the upper and lower a arm, kick up, flag height not just width. these things all need to work with the spindle to achieve certain results and it is impossible for the setup to have the same impact on 3 mfg's bikes when the chassis are not the same.. and again I'm not saying it doesn't work on one or the other... but all, I find far fetched.