experimental front suspension

[YZ Otis]

I like this kinda stuff. Wonderin where all this travel is going to be. Will the bike sit real high? Will a lot of the travel be in sag? 14" is a bunch. The compression side is easy, can't go past the frame hitting the ground. I'm interested in how you will use the rest of the travel & what kinda application this is intended for. I'm not messin with you, I've been working on a suspension for about a year and have come across a few things to ponder. Once you get the long travel other little problems appear. One of my problems is down hill braking or even braking into a corner. Controlling weight transfer with long soft shocks gets weird. I'm working with a sway bar that solves some problems but steals some of the gains. Any ways, I've run into lotsa compromises & I'm really interested in what you discover. My goal is a bit different, to have long travel, much less bump steer and a near stock track . Lookin forward to your progress.

 

[Blaner]

intersting, I agree Otiz, downhill braking can be a problem with alot of travel, you can fix this by stiffening the shocks, but then what is the point of the long shocks?

im tuned in! nothing like suspensions to get the mind running

 

[sicivicdude]

I like this kinda stuff. Wonderin where all this travel is going to be. Will the bike sit real high? Will a lot of the travel be in sag? 14" is a bunch. The compression side is easy, can't go past the frame hitting the ground. I'm interested in how you will use the rest of the travel & what kinda application this is intended for. I'm not messin with you, I've been working on a suspension for about a year and have come across a few things to ponder. Once you get the long travel other little problems appear. One of my problems is down hill braking or even braking into a corner. Controlling weight transfer with long soft shocks gets weird. I'm working with a sway bar that solves some problems but steals some of the gains. Any ways, I've run into lotsa compromises & I'm really interested in what you discover. My goal is a bit different, to have long travel, much less bump steer and a near stock track . Lookin forward to your progress.

All the same problems I'm going to run into and I have NO more solutions than you do for any of it....

The bike is going to sit higher than stock (or it currently does) and you're right, the compression side is easy

The intended application is, like most of my projects, to satisfy my own curiousity. I'm going to be riding this bohemoth down at busco beach and around my yard.... I'm doing it because I enjoy tinkering, and I really have no goals past that point.

Compromises are a way of life.... The main compromise for me is going to be track width. I ride occasionally through the woods and adding 4"-6" in width may prove to be a detriment..... we'll have to see when it's all done!

 

[best]

You guys are getting me all excited!
Stock front suspension is currently the worst thing about my Blaster, worse than the drum brakes actually.
I am used to 11" of front and rear suspension travel on the dirt bikes and I really miss it.
I measure 7" maximum travel with possibly 8" to ball joint bind on present Blaster front suspension.
You say 6" maximum, but are you taking the cushioning into account?

My snowmobile and Raptor 660 only have 9" of travel but handle bumps much better than the Blaster.
11" front travel works exceptionally well on my dirtbikes, and would be fine for the Blaster.
Since we are working with arms, we can leverage our shocks and get any travel with any length shock.
The trick is: we have to start with a good balance of spring and control, a good shock.
So a good quality shock even in the stock 14" length would work, or any length will do, but for
various reasons, longer is still better because it will be closer to direct acting.
Now, what to do with the extra travel? Higher ride heights destroy handling. The extra travel should
go into "droop" for when your machine unloads or comes off of the ground. It is the jumps that
really use up every inch of travel. 9" of compression and a good shock will handle most obstacles.

Front suspension will be my next Blaster project, probably next Fall, so I am listening to you guys
carefully. I liked some of the ideas presented here. I really like the idea of bringing the A arm pivots
closer together in the center, but it conflicts with my desire to leave the frame alone and have this
a bolt on exercise. I too, do not want an overly wide machine. I trail ride, and while my son's 4" wider
machine seems to go anywhere I do, I want to keep it narrow.

As for instability of long travel and soft springs and shocks, I already ride that.
It is called an enduro bike. How you manage it is by managing your weight positioning, mainly by
standing up on the pegs and shifting the weight through your feet and arms.
On the Blaster this is hard to do. The low seat and bars don't lend to a standing stance.
Have a look at the newest snowmobiles. SkiDoo has lead the pack with a new riding stance
that allows standing. Higher seat and bars, lower foot position. How can we do this on the Blaster?
I have raised my steering stem 3", how about lowering my foot pegs 2". Anyone done this?


sicivicdude, have you seen these joints? Not exactly what you were asking for but not a bad price for joints AND pins:
4 Blaster C-Moly 28,000 lb PRO X Ball Joints By American Star | eBay

 

[sicivicdude]

You guys are getting me all excited!
Stock front suspension is currently the worst thing about my Blaster, worse than the drum brakes actually.
I am used to 11" of front and rear suspension travel on the dirt bikes and I really miss it.
I measure 7" maximum travel with possibly 8" to ball joint bind on present Blaster front suspension.
You say 6" maximum, but are you taking the cushioning into account?

My snowmobile and Raptor 660 only have 9" of travel but handle bumps much better than the Blaster.
11" front travel works exceptionally well on my dirtbikes, and would be fine for the Blaster.
Since we are working with arms, we can leverage our shocks and get any travel with any length shock.
The trick is: we have to start with a good balance of spring and control, a good shock.
So a good quality shock even in the stock 14" length would work, or any length will do, but for
various reasons, longer is still better because it will be closer to direct acting.
Now, what to do with the extra travel? Higher ride heights destroy handling. The extra travel should
go into "droop" for when your machine unloads or comes off of the ground. It is the jumps that
really use up every inch of travel. 9" of compression and a good shock will handle most obstacles.

Front suspension will be my next Blaster project, probably next Fall, so I am listening to you guys
carefully. I liked some of the ideas presented here. I really like the idea of bringing the A arm pivots
closer together in the center, but it conflicts with my desire to leave the frame alone and have this
a bolt on exercise. I too, do not want an overly wide machine. I trail ride, and while my son's 4" wider
machine seems to go anywhere I do, I want to keep it narrow.

As for instability of long travel and soft springs and shocks, I already ride that.
It is called an enduro bike. How you manage it is by managing your weight positioning, mainly by
standing up on the pegs and shifting the weight through your feet and arms.
On the Blaster this is hard to do. The low seat and bars don't lend to a standing stance.
Have a look at the newest snowmobiles. SkiDoo has lead the pack with a new riding stance
that allows standing. Higher seat and bars, lower foot position. How can we do this on the Blaster?
I have raised my steering stem 3", how about lowering my foot pegs 2". Anyone done this?


sicivicdude, have you seen these joints? Not exactly what you were asking for but not a bad price for joints AND pins:
4 Blaster C-Moly 28,000 lb PRO X Ball Joints By American Star | eBay

I pulled springs off of stock shocks and ran it through it's travel. At perfectly perpendicular to the frame, the spindle has ~6.5" of travel. I measured a "safe" amount of 6" with no binding and no hampering of the turning radius including a small amount of cushioning.

You could theoretically build any length unequal length a-arm system around any length shock absorber and get the same control and spring rate. The trouble is finding a shock manufacturer that makes "stock length" shocks that are designed around a 650 lb rider weight LOL! With the increased leverage that the longer arms have on the same length shock, the spring and valving become "weaker". Using longer shocks with longer arms keeps the spring rate happy as well as valving happy as well as acting more directly on the ball joint AND taking out any flexing that the a-arms might do relative to the load and pivot points.


I'm going to start designing the lower control arms the same way that I started with the +3 +1's I'm currently building. I started by making the pivot tubes and welding tubes that go down to the ball joint in place. I then set the frame about 2" off the concrete and put a tire, hub, spindle, and ball joint combo on the ground beside it. I then put the ball joint at bind at that ride height and welded it into the tubes at that angle. From there, I fabbed up the upper ball joint mount by doing basically the same thing, I dropped off the tire (for weight purposes) and held the spindle nearly horizontal to the ground (due to unequal length a-arms "pulling" the spindle in as they travel upwards) and put the upper ball joint in a bind and welded the mount. It ended up I had a fully workable suspension that could go no lower than the frame 2" off the ground (with 21" tires) at total bind. Both ball joints tracked each other (degree for degree) through the entire travel until they both bind nearly together (the upper binds a little sooner on both ends due to it being a shorter arm). After I had done that, I went back and compared what I had gotten physically to the numbers I had calculated during the planning stages. Once I had the angles I was happy with (after a tiny bit of adjusting) I welded them all up solid and began building all of the other parts....

 

[Rich]

I think your on to great ideals and possibly a new quad sport.Moab ATV rock crawling.I have always liked the ideal of these little quads with a spider like stance.Ive out grown this quad but always liked the thought of a concept look and finding ways to get a little more out of it.

 

[sicivicdude]

I think your on to great ideals and possibly a new quad sport.Moab ATV rock crawling.I have always liked the ideal of these little quads with a spider like stance.Ive out grown this quad but always liked the thought of a concept look and finding ways to get a little more out of it.

LOL We'll see how "spider like" it is when it's all done. Right now it's all in planning stages (and in my head) on paper only

 

[YZ Otis]

Didn't really grasp how you're steering links will work. Something like Polaris pro steer but with idler arms attached somewhere between the top & bottom pivot tubes? Maybe you could find a cheap box & rob the parts but replacement parts for these are pretty expensive.
Polaris Predator 500 Steering Box | eBay

I understand this experiment is for your entertainment so you can't lose no mater what you try. I'm sure you can achieve zero bump steer but wether it's worth complicating the steering system is something to discover. Little trade offs Not moving mounts is a major handicap.
Happy fabing I:I

As for instability of long travel and soft springs and shocks, I already ride that.
It is called an enduro bike. How you manage it is by managing your weight positioning, mainly by
standing up on the pegs and shifting the weight through your feet and arms.
On the Blaster this is hard to do. The low seat and bars don't lend to a standing stance.
Have a look at the newest snowmobiles. SkiDoo has lead the pack with a new riding stance
that allows standing. Higher seat and bars, lower foot position. How can we do this on the Blaster?
I have raised my steering stem 3", how about lowering my foot pegs 2". Anyone done this?

Unlike a bike, my problem was corner to corner, weight transfers to compress the outside front lifting the inside rear wheel. Tuck & roll baby ... ... Adjusting ride style is necessary for sure. When the kid tested one of my first setups he came right back & said, goes over bumps great but this thing wants to roll over. I was so disappointed ... LOL ... little problems

 

[sicivicdude]

Didn't really grasp how you're steering links will work. Something like Polaris pro steer but with idler arms attached somewhere between the top & bottom pivot tubes? Maybe you could find a cheap box & rob the parts but replacement parts for these are pretty

I understand this experiment is for your entertainment so you can't lose no mater what you try. I'm sure you can achieve zero bump steer but wether it's worth complicating the steering system is something to discover. Little trade offs Not moving mounts is a major handicap.
Happy fabing I:I

Not moving mounts is a large handicap. Not adding any additional mounts is a monumental handicap. I'm going to do neither and achieve both if my plans work out.

The basis of the zero bumpsteer setup is the rather unusual condition the blaster has that almost no other quad does. The upper a-arms have a single mounting tube. I'm going to make maybe something similar to what you pictured BUT I'm going to mount it so that it uses the middle of the upper a-arm pivot tubes to work.

Think of it like this. I'm going to put another pivoting member in between the two 3/4" tubes that make up the upper a-arm and mounts. The middle tube on each side will move seperately from the upper a-arm but both sides will be tied together so they will "swing" at the same angle. The steering stem will push these third tubes and assembly side to side. The tie rods will come off those third tubes and down to the spindle.

If you look at the picture I drew in paint (Paint FTW!), these are the unaccounted for black lines that "drop down" off the upper ball joint mount and have two green lines coming into them (instead of the single green line tie rod on the left).

Then on the outboard side, I'm going to correct the bumpsteer issue on the spindle end by making a bracket that bolts under the lower ball joint nut and goes upward to above the stock upper ball joint "pinch mount" and just above the stock upper ball joint pinch mount, there will be a horizontally mounted heim joint with his misalignment spacers to allow full turning radius.

The end result of this SHOULD be a suspension that's super soft (with lotsa bitching travel) and has no bumpsteer without any permanent frame or spindle modifications (an absolute must in my opinion). if I don't like this setup, I could simply remove it and go back to what I currently have without any detriment.

 

[sicivicdude]

Looking at the way that my Woodward Fab bender works, I'm trying to figure out how to do MGC a-arms. I would probably need to do each side separate to that I could start at one end and band until the entire tube is done and then take that tube out and start over with another tube to do the other tube. I don't see anyway to make a single tube with the correct shape and then cut it apart to go around the ball joint mount....

Good news is, I'm getting pretty handy with benders so I think I can "hit the marks" to make the two tubes the same

 

[best]

Unlike a bike, my problem was corner to corner, weight transfers to compress the outside front lifting the inside rear wheel. Tuck & roll baby ... ... Adjusting ride style is necessary for sure. When the kid tested one of my first setups he came right back & said, goes over bumps great but this thing wants to roll over. I was so disappointed ... LOL ... little problems

Ahhh, that makes sense.
The back has total roll stiffness already, sounds like the front needs some too if we are going to run soft long travel shocks.
Some sort of sway bar on front?

Steve

 

[sicivicdude]

Anything that fights sway is also going to fight travel unless it's designed in from the get go. It's very difficult to add anything that won't limit.

 

[YZ Otis]

For me, I try to take big stuff as straight on as possible. In that case the sway bar just follows the travel. I've played with the idea of an easy disconnect bar but haven't come across many situations where I thought it would be better disconnected. For my needs the sway bar is a must. It just complicates dialing in the suspension a bit. Ya need to have enough travel and find a bar diameter/length with a happy torsion that you can fine tune with leverage. I didn't get much response to my plea for pics & info on aftermarket sway bars so I looked at what I could find, guessed at dimensions and stumbled on from there. I'm working with 1/2" Chromalloy rod ... looks like it will work for me ... always little compromises but the word difficult is just an inspiration

 

[best]

A lot of the new automotive swaybars are actually hollow.
Lighter for the same torsion.
Longer arms off the bar would allow plenty of travel.
We are not faced with the same issues as the 4x4 crowd who are all disconnecting their swaybars.

Steve



Steves Four Wheel Drive 4WD 4x4 Van Nova Scotia Canada

 

[sicivicdude]

For me, I try to take big stuff as straight on as possible. In that case the sway bar just follows the travel. I've played with the idea of an easy disconnect bar but haven't come across many situations where I thought it would be better disconnected. For my needs the sway bar is a must. It just complicates dialing in the suspension a bit. Ya need to have enough travel and find a bar diameter/length with a happy torsion that you can fine tune with leverage. I didn't get much response to my plea for pics & info on aftermarket sway bars so I looked at what I could find, guessed at dimensions and stumbled on from there. I'm working with 1/2" Chromalloy rod ... looks like it will work for me ... always little compromises but the word difficult is just an inspiration

Well, post up some info! If I find that I need anti-roll capacity, I'll have that information handy.

 

[YZ Otis]

Well, post up some info! If I find that I need anti-roll capacity, I'll have that information handy.

LOL ... Still collecting info ... If you find you need anti-roll capacity I'm sure you'll find a way that suits your modifications ... wuz just pluggin some things into your thought process so you can think on it from the get go ...

 

[ddq]

I've got a couple questions. If you plan to use the full amount of travel those shocks offer, how are you going to do it so that the shock bottoms out before the frame hits the ground?

Also, I like the idea of a zero bump steer bike, but I also have my doubts about building one while using a stock blaster chassis.
Third, is this going to be a setup for a straight line desert bike?

 

[Chuckie25]

Why not do a cante lever long travel design? Like the front end of F1's or even the Weapon-X Quadzilla chassis? Insane clearance and travel with shorter shocks.

 

[sicivicdude]

Why not do a cante lever long travel design? Like the front end of F1's or even the Weapon-X Quadzilla chassis? Insane clearance and travel with shorter shocks.

I got a crazy awesome deal on a set of Works triple rate 19.125" long shocks.

Plus, with a large pipe in the way, there's nowhere to lay the shocks down behind the a-arms to drive the cantilevers....

Draw up what you have in mind and show me the error of my ways. I'm always open to new ideas!

 

[Rich]

I dont see how people think its going to bottom out ect.Thinking about it the bike is going to gain about 3 inches of lift and 3 inches of droop.The thing is going to float over hard turrain and depending on how good the shocks are like fully adjustable springs and valving both compressing and decompressing I think its going to be pretty darn stable.10 inches 12 inches wider in front over stock is perfect with plus 1 inch front rim 4 inch backspacing to keep rotors safeAs is with plus 3 arms I still have my front wheels fliped thats about 5 inches on each side and perfect.Blaster is way to small and compact on the stock set up imo.Still plenty of room for trail riding and still smaller or narrower than a yzf 450?