Full-on front end

[tfaith08]

So I'm about to be done with the Banshee and I'm gonna build my wife's Blaster up like I should have in the first palce. I know or can easily figure out everything I need to know to get it how I want it, but I'm held up on suspension for the moment.

Plans so far:

Ported and stroked 240 on pump gas
VF4
33pwk
Undecided on pipe
Swingarm (roundhouse) length will be decided after riding with the built engine
Banshee axle
Hydro conversion (YFZ calipers fo sho)
Pro-peg nerfs
Whatever controls the wife wants
Probably pink plastics
Probably pink frame
Probably pink chain
Probably pink seat
Probably a Starbucks logo on the hood


I understand suspension very well, but I don't know the aftermarket for Blasters. I want to get as close as possible to 50" wide. I definitely want a long-travel setup for the easier tuning of longer shocks and because I'll be taking it for a spin on the track from time to time when she doesn't ride. I'll figure out shocks at a later date...

My real question is the arms. What options do I have? Would I be better off with a long-travel Blaster setup or a YFZ or TRX450R geometry conversion? I have a YFZ frame and a TRX450R parts bike, so making that happen wouldn't be too much of a concern. I'd like to be able to use 18.5" shocks so I can just use my Elkas from the banshee and effectively have a reason to upgrade mine to Evols.

Thoughts on the ultimate (achievable) front end. Ready, set, go.

 

[jus_me]

If you can find a set of SMS (Snyder motor sports) +5 5/8 +1' long travel a arms then a set of 4+1 offset rims you should be just under 50" (49 1/4"). You can also run the Trx front brakes,spindles,hubs, lines etc.. If you have them.. They use 16" front shocks so if you have the front shocks from the parts bike you could use those also.

 

[Awk08]

my rearend is about 49-1/2" wide with tusk +6 axle and yfz rims.

my front end isn't but an inch or so skinnier with +3+1 ASR arms and factory 4+1 YFZ rims
in the stock 1" out - 4" in position.
flipped with the wider lip out it's well over 50"

 

[tfaith08]

Dang, I was hoping to get close to some 20" shocks. They're so much easier to tune...

I may do a YFZ conversion. I'm gonna tear it down to the frame when I have time after my trip to Durhamtown. I'll take measurements and see what has to happen for the YFZ front half to be merged onto the blaster mid and rear section.

I'm gonna call around to a few shock manufacturers and see who has the most rear shock travel. Most are 5.5" or less. If I can get a rear with that or more, I'll try to have a swinger made with the shock mounting tab on bottom for a better rising rate although the leverage ratio will be altered severely. I know King shocks have a ton of travel, but they also ask for a ton of money.

 

[jus_me]

There are couple threads on yfz a arm swaps onto the Blaster.

 

[tfaith08]

I think that mating the front half of the YFZ chassis to the Blaster chassis would be a better solution though. It would probably be just as much welding, but I'd get the rake, upper shock mount location, lower stem mounting location, and arm mounting locations all to YFZ specs and could order anything from a YFZ to bolt up to it.

This would allow me to run YFZ arms and shocks without having to worry as much about a custom setup since the geometry is different. The more I think about it, the more I want to do it this way. The aftermarket support for a YFZ far exceeds that of the Blaster.

Luckily, I have 80% of a YFZ front end at my disposal.

I think that a long travel YFZ front end with an LSR Outlaw style +2 or +4 swingarm would be pretty damn quick through the whoops. If nothing else, no one has quite done this before and I'll be pioneering something.

 

[Larry's Shee]

Well, least this is now going the direction the title suggested.
Do you plan on stretching the wheelbase forward any? How much?

 

[Awk08]

I think that just putting a blaster engine into a full YFZ would be a better and easier solution though.

fixed that for ya

 

[tfaith08]

Well, least this is now going the direction the title suggested.
Do you plan on stretching the wheelbase forward any? How much?

Maybe. I'll have to do some math and figure out what needs to go where. I have a guy that I work with that's gonna do some work on my Banshee frame. If I like how it turns out, I'm gonna have him do the work on the Blaster frame. It'll be more in-depth, but I'll want to see where I'm at on the geomtery and weight distribution first. There will definitely be lots of chromoly and every single unnecessary component removed.

My ultimate goal is to make a super-light, very capable toy that can be taken to an MX track and be as fast as the 450s. I don't see any Blaster keeping up with the 450s on the track unless it's kept super light.

fixed that for ya

Well, I'd considered that, but I have a few holdups.

1. Notably that I have the means to acquire a front end and not the entire bike. I have a frame and a front end, that's it lol. I have an entire Blaster already.

2. I've always wanted to tinker with a mega travel no-link setup and this is my chance to do it on a bike that isn't expensive. I think I can get 15" of rear travel without any problems as long as my math is good (super simple on a no-link setup). Can you imaging pegging that thing out through the whoops on only the back tires? Hehehe... I'm going to have the shock mount on the bottom of the swingarm and the upper shock mount moved to facilitate a bigger shock. I may have to break down and buy a King shock as I can't think of any manufacturers that produce a rear shock that exceeds 5.5" of actual shock travel.

3. Weight

4. If I did get my hands on a full YFZ, I'd build it to compete in AMA sanctioned races because this one surely won't be making it into any.

5. The total work required to get a Blaster to my goal will be less than what it will take to get a YFZ there.




PART 2 OF THIS MEGA POST

Overall goals with the frame:

-Ease of repair and maintenence

The subframe will be removable and made of chromoly and the seat and rear fenders will be attached. That way, 4 bolts grants me access to everything I need on the back half of the bike. The subframe will also act as the grab-bar to keep cost, weight, fabrication, and clutter to a minimum.

All nuts will be welded to the frame to allow one tool to work on anything.

-Light weight

Nothing that isn't required for safe operation will be used except for fenders. No brackets will remain, nerfs will be pro-peg and the insert welded to the frame to keep the stock BS out of the picture, front bumper will be minimal, etc.

-Perfectly balanced

This is where the swingarm length and front end extension will come into play. I want it to be able to allow whoever gets on it to be able to adapt to whatever they need to without the chassis limiting them. I want as close to 50/50 distribution as possible. Truth be told, this will be a 2-part ordeal, but that'll be fine too.


All in all, it's simpler than I've made it out to be. There's no rush on it. I'll get the front done, then the back, then the subframe, then all the extras. It'll be ridden between each stage. Once that's done, the engine will be upgraded as my wife gets used to it. It's more of something for me to tinker with than anything else - a base for my ideas, if you will.

 

[Awk08]

I want as close to 50/50 distribution as possible

50/50 from the pegs ? which will be the pivot point in whoops
(standing on pegs allowing the bike to pivot to/fro underneath you thru the whoops)

pretty sure I've done those measurements, with +1" forward arms a +3" swinger (what I run) puts the stock peg location almost dead center from axle/spindle centers, which should allow center pivoting in the rough stuff.

BTW, you have seen this ?
http://www.blasterforum.com/threads...complete-front-suspension-to-a-blaster.36120/

 

[tfaith08]

50/50 with the intended rider on it and in aggressive riding position.

I have seen that and I like it! I think I'd do a few things differently though. I'd close the arms in as much as possible and rake it up to about 15°. I'd close the shock mounts in as much as possible to get a longer shock and more preferable leverage ratio spread.

There are many things I'd like to do, namely figure out what I'm actually going to do. Raking it is a mandantory objective in my book. That will alter the wheelbase some though. Not much, but some. I'd lke the arms to be at different angles (when viewed from the side) to have dynamic camber so that there is no camber at ride height and fully extended but more camber as it approaches max travel to help keep the wheels straighter. I know a lot of trophy trucks and buggys do that and for good reason.

I think that the YFZ will act as a good foundation. I'll get it on there, then modify it. Then again and again until it's done to my liking and go from there.

 

[tfaith08]

KOR, I saw you liked my post. You're gonna be involved in this at some point. Go ahead and chime in. You're the professional of the group.

 

[Awk08]

dynamic camber

I'm tuned in

50/50 with the intended rider on it and in aggressive riding position.

not sure I'm following that, sounds like you're talking about 50/50 weight distribution ?
wouldn't that be done with shock adjustments ?


I'm talking 50/50 - pegs dead centered between wheel centers, the pegs being the fulcrum to allow the bike the evenly pivot front to back on the fulcrum (pegs) when blasting whoops.
this would not matter who was riding it, the pegs are centered
best I can do for now is a tape measure on a lappy pic

+3+1 a-arms with +3 swingarm = 7" wheelbase, pegs centered at 3.5"

 

[tfaith08]

Yes, evenly balanced at the halfway point. If your pegs are centered, that would definitely be it. That's the 50/50 I meant!

My goal is 0° camber at fully extended and 10° at full bump. That should keep the wheels straight when landing a big jump and nimble when putting along and under acceleration. The way I'll do it is just to angle the tube that the upper a-arm mounts to up by whatever I need to and then replace the front tube with the correct length piece. It won't be much as I only need it to travel farther back than the bottom a-arm enough to make the spindle rotate 7-10° (5/8" maybe?). If the front end has 11" of travel, the upper arm needs only to travel back by 5/8", so that couldn't be more than 3° difference in angle. I'll just have to double check shock clearence with the upper arm.

I'm planning on about 12° of rake which will also be an easy task since I'll be tilting the entire front end as a whole when I weld the front half of the chasis on. It seems like a lot, but the total work is pretty small, really. Without adding additional material, that's only 8 welds.

 

[Larry's Shee]

Check out "Blastersaurus" he extended the front 10-12", used 250r geo.

 

[tfaith08]

I saw that. There was a bit more tubing than I'd like to run and the stem is at a strange angle. It's a jam-up build nonetheless, but a tad different than what I want. Didn't he run King shocks up front?

 

[Awk08]

Didn't he run King shocks up front?

no, phragle (on here), who originally built and ran the blastersaurus in the baja 1000 and won his class.
it used Motowoz shocks on protraxx arms. there's a thread on here somewhere with the Dirtwheels article on Rob, the original build and his Baja success

some pics in this post: http://www.blasterforum.com/threads/baja-1000-race.44685/#post-557868

wifesblaster and woodrow wilson on here now own both of Robs custom built blasters and have restored/renewed them, rebuild thread:
http://www.blasterforum.com/threads/rebuild-of-the-blastersaurus.56416/


the for sale thread with more suspension pics: http://www.blasterforum.com/threads/blastersaurous-and-a-lot-of-parts.54941/

 

[tfaith08]

I like the Protraxx stuff A LOT. I've decided to buy a Laeger's chassis for the Banshee as the money comes for it, but that'll be a good year or so out.

I'm caught up on this Banshee build for now. I'm ordering some 3/4" .065 wall 4130 tubing on the next paycheck (when I'll have enough to pay Cam at Redline for the engine) and start on my subframe. I'll take a few things from that, I'm sure. Lots of plans, little time.