"rider on the bike in the normal ride position" -- Isn't this like saying "missionary style" -- Like anybody ever does that either??? I guess I'll have to adjust my toe-in while I'm hanging off one side with my butt almost touching a foot peg.....

I've never adjusted older bombs, so I don't understand this pain, although its a extremely valid point on quads with poor geometry.

Seriously, if your caster/camber changes that radically on a bike with 12" of travel, you should be fixing the bad geometry and not adjusting the toe-in with a rider on board.

jbt

 

toe should be checked with rider on board on any bike. no matter how good the geometry, toe does change with suspension travel, some worse than others yes, but they all still do, and nothing can be done about that. its not a fault of caster or camber, its the angle of the tie rods, and we can't change it. but if got an idea of how Slowride, I'm all ears.

the DS geometry isn't that bad, not even the old ones, it just needs set up right since the factory refused to set it up right before shipping.

too many bikes came from the factory with the toe set way off - mine, like many others, was over 1/2" toe out, very stupid, and this gave the early models a bad rap. but this is easily corrected, and most people that ride my bike with the factory suspension set up correctly wearing good tires can attest that it handles very well, and even better than a lot of bikes wearing aftermarket a-arms, simply because lots of people don't set-up the new ones right either.

 

[img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-smile.gif[/img]

 

check my pictures when they become available. Yes I know my bars got a little tweak to them.

Right front is fully extended with shock on, Left front is full compressed with shock off. I would have done pictures with both shocks off, but I lost interest after jacking up the Left with no appreciable change in Geometry.

Bottom line is the bomb geometry and design is dang good. Hightower, I'm thinking you fall into what I categorize as a purist.


jbt

"I'm not bored, I just put a fresh keg in the kegerator today, sssOOO, I needed to be close to it anyway.....[img]i/expressions/face-icon-small-smile.gif[/img]"

 

Slowride, have you ever checked the bumpsteer on your Bomb? I have never had the time to check it yet. Looks like it would be close but I have never checked it with a dial indicator. Just wondered if you or anybody else has?

 

Doc,

I haven't seen *any* negative steering input from the bomb. What is measurable when on cement becomes obscured by a lot variables well beyond casual conversation.

Take the -10 degree rake in the bombs frame. Its in line with the best machines, and a lot of the $75k buggies aren't even wise to needing this, yet.

Imagine a flat botton quad "nosing in" onto level ground at approxiamately +30 degree angle. The a-arms induce an appreciable amount of stiction and have a tendancy to want to rip off the frame. Ouch.

During the same scenerio, the bomb has a -10 engineered into the frame added to the +30 impact angle allowing a net impact angle of 20 degrees. Much safer and easier on hardware. Not to mention the -10 degrees causes a feeling of safety in the way the bike tracks at high speeds.

If the bomb weighed 350lbs with an electric start, reverse and punched like a methed out drunk'n banshee, I could don the rose colored glasses and say I'm in nirvana.

jbt

 

Thanks for the info S.R. When I get time I will bump my Bomb and see what I come up with. I have all the tools, but not the time. [img]i/expressions/face-icon-small-disgusted.gif[/img] It looks like it will be close like you have found out. Thanks again.

 

purist indeed...and I should clarify that when I use the word drastic I'm talking about less than 1/2" of toe change when measured from center of front of tire at hub height and center of rear of tire at hub height, which would probably be no more than 1/8" showing from straight edge to rim on either wheel. but to me that's drastic.

Slowride thanks for being a fellow geometry defender, I've been preaching up Bomb's geometry from the getgo, riding the original stock a-arms for over 3 years with never a complaint.

Now I'm not sure here, and if you know the answer I'd like to know, but I read in 2 different sources when the "new" style a-arms came out that the geometry was identical to the "old" ones, that they only appear different due to more economical means of manufacture, and that the greatly improved factory handling of the first year Baja over old yeller was due to better tires and toe setup. one magazine in particular actually swapped the baja rims and tires with old yellers, and had the handling characteristics migrate as well. But I've never actually heard anybody measure caster of both and publish or post the facts. I'd just like to know for curiosity sake, but I don't have access to a newer model to do any measures.

 

My opinion of the front suspension difference between the original ds and the baja bikes was lower a-arm. Mine are slightly bent below the shock mount and the older ones aren't.

I've never compared them side by side.

From what I've read, the new vipers have an aluminum upper to save weight, but it didn't change the geometry.

Again, I haven't compared it side by side either.

I also read the new radial tires made a dramatic difference over the older bikes as well. But the desert shredded my rears so fast, I went to an old school bias ply, and love them. The fronts have worn real nice, so they are still around.

jbt