52cc Predator Auger Powered X-Games FS20 BMX

[16v4nrbrgr]

They still sell a Mongoose with those alloy split five star mags. I really don't like those wheels on the Torrid bike, I'm not a fan of swirly spokes and on BMX mags I think its asking for failure.

Those Apse solid 5 stars look like some solid wheels, I also have some Apse scooter wheels on my Motard and I like them a lot.

I have some disc brake spoked wheels I might use on this bike if I don't save them for another build, which I probably will do because the cantilever brakes have proven sufficient.

 

[d_gizzle]

I got to ask,where did you get 20" disc wheels? I know where to get a rear wheel(cyclesus) but the only front wheel I've found is $115 from Calhouncycles. That's kinda steep.

 

[16v4nrbrgr]

I have them left over from my X-Games Motobike which has Teny magnesium mags now. The Motobike wheels use extra thick Chinese pattern (lil bigger than ISO 6 hole) scooter rotors good for motorbikes. I have a special bike in mind for the disc wheels so I'm gonna save them, instead of working too hard to improve a bike that stops well enough with regular rim brakes. Once you start going over 25 mph drums and discs become more of a necessity, as well as if you or your bike are really heavy.

Since your bike is chrome, some lowrider bike disc wheels shouldn't be hard to find with Google. They're out there.

 

[d_gizzle]

Ok,I rember those. The front wheel is a rear wheel with an adaptor.

 

[16v4nrbrgr]

That's all I've found other than wheels from specialty bmx/mountain bike things like the Motobike. You could certainly build a set but that would take some work.

 

[d_gizzle]

Guess I'm gonna have to spend some money with Calhoun.

 

[d_gizzle]

So I went to Walmart today to buy the bike,and of course it was gone. Got to looking on eBay and found these-

http://item.mobileweb.ebay.com/viewitem?itemId=281044597366

Gonna get a set in the morning I do believe.

I took a picture of the Genesis Torrid and didn't realize until today that on the same rack was the new FS20. Now its a Thruster model I guess?

 

[16v4nrbrgr]

For some reason there are a bunch of different BMX bikes named FS20, I'm not sure why.

I'd be careful running those swirly mag wheels, they don't look very strong to me.

 

[16v4nrbrgr]

The frame is very similar underneath, the unique feature allowing this type of drivetrain.

This silver bike looks interesting for motorizing for sure. The one that came before it, if you find one, doesn't have the bottom tube so you could fit a lot of suicidal engine down there, lol. This one looks like it would be easy enough to do the same thing with the auger engine. The bike is made from steel and sells for $112, if anyone wants a motorized one let me know, I could buy a frame and weld a mount to it for an additional $200 or so, it would take a days work.

 

[16v4nrbrgr]

It's been raining for almost a week but I finally got to ride today and it was great. I played with richening up the top end screw setting but that really didn't help much, it was set well stock. I ended up a little richer than stock since much more than that was cutting my redline down.

The skid plate that I made is much better than the cast one on there previously, turns out the old one was the source of the horrible harmonic buzzing. Now the bike actually sounds pretty good through all rpms, really wicked when it gets on the pipe, it makes a burly big bore noise for such a lil high revving bugger.

 

[d_gizzle]

I bought the wheelset,my wife bought me the Torrid.

As for the strength of the torrid wheels-they are die-cut and unless I'm mistaken they are like a car rim,one piece,no welds. Unlike the apse wheels we both like. Both 20" apse wheelsets and the 12" set as well look like crap next to these,no joke. Still waiting on the 18 spoke set to come in the mail.

 

[16v4nrbrgr]

UM well, no, the 12" APSE scooter wheels I have are one piece cast. Just be careful with those wheels because the spoke design is one of the weakest I've ever seen in a BMX mag, plus they're metal, so if one fails its all jagged and stuff, not like a Tuffmag plastic wheel which will just moosh. I was skeptical abot the Teny mags for my other build until I saw a video with a mountain biker jumping off a staircase on a MTB with them.

Just be careful, and start a thread for your bike.

 

[16v4nrbrgr]

I checked out a Mongoose Rebel which has the split five star spoke "magnesium" alloy wheels at target a while back, and I'm not sure if they were forged or not but I certainly hope so, because for that material they certainly didn't make the spokes very thick, or the surface finish on the un-machined faces very nice. I thought it was a rad BMX but dismissed it at the time since I don't quite trust those wheels, look full of stress risers and low density casting. If the spoke design looks to thumb its nose at the design principles derived from statics and strengths of materials, then it might flex and get into the dynamic fatigue properties of the aluminum/magnesium, which are extremely poor.

 

[d_gizzle]

I'm not sure if I'm gonna motorize these bikes but where to start a thread? The tavern?

I looked at my apse scooter wheels just now and I will agree with you,but what is the stuff in the cracks?

As for the strength of the split mags-My brother in law has those and he rides them in the pasture and he weighs about 225. Been riding them about 2 years now with no problems.

As for the Torrid wheels-They 'feel' solid. We'll see how the hold up,I'm about to be putting about 25 miles a day on them.

As for metal wheels breaking-Bitd I jumped off the wall next to the stairs in front of Ada Junior High and broke a steel 5 star front wheel. All 5 stars came off the hub. I didn't even fall off the pedals. But that was a 12 foot drop onto concrete sidewalk.

Also,I've had plenty of 'swirl' style mags as that's my favorite design. Other than a set of gt 3 star fan blades that I treated poorly I've not had an issue with them. I also don't ride in the rain,dirt,grass,pretty much anything other than the road. I know my rights as a bicyclist,and I ride rather fast for single speed bmx.

 

[16v4nrbrgr]

Why not start one here in the MTB/road section if you do motorize it, that's what I thought you intended, sorry for the misunderstanding. I'm glad to hear the new inexpensive mag wheels are so strong, maybe I'm underestimating the alloy and casting porosity of these BMX wheels, they just seemed iffy when I casually looked at them at the department store.

The stuff near the rotors on the Apse wheels is just where their buffing machine didn't polish the castings before they anodized the wheels.

Sorry if I sound like a Debbie Downer, lol, my mech engineering training makes me look at wheels like that with high suspicion because its design kinda looks like it defies radial strength. I feel like we all need to be very cautious because these motorized bikes are really low safety-factor. When I was a kid who only weighed 120 lbs (now I'm 145ish) we all used to avoid mags on our BMX's at least for the rear wheel because we jumped them and they would never hold up, I think a bad pothole or crack at high speed would be kinda similar.

There's nothing beating the personal style of a nice set of BMX mags, they really make a normal single speed bike a coveted creation of beauty.

 

[16v4nrbrgr]

Aw crap, the new aluminum skid plate fatigue cracked off at the mounting tabs to the engine again, no surprise.

Gotta make some steel L bracket legs for the front and I guess rivet them to the skid plate legs, so the tabs held by the bellhousing bolts don't keep doing this. The motor doesn't vibrate much, but at 10k rpm its enough to make the skid plate hit a natural frequency or something.

Another thing about the noise and vibration, it was hot today so I wore a bicycle helmet, and now I'm definitely hearing affected. Gotta add another silencer or something, I know tolerance for this type of thing will wear thin if I don't do something about it.

I'm also going to probably put another clutch in it before the next ride, and lighten it less than I did with this one, so that when it's hot it doesn't engage at 9000 rpm, if I can bring that down a couple grand the noise will be much better, hope the little motor has enough torque to use a lower stall.

 

[16v4nrbrgr]

I was going to try and adapt a O'reilly store Briggs muffler onto the end of my pipe, but looked around on the net to see what others are doing to make their pocket bikes neighborhood friendly.

It seems the best options are a couple mufflers in series, or a big canister.

I'm gonna try out riveting a Happy Time black cat muffler canister in place of the stock (probably unstuffed) canister and see how it does, prolly gonna stuff a stainless brillo in there to keep the cat element from rattling into shards. The racing engine in one of my cars destroys ceramic cats like that, this motor has the same rasp that kills brittle things. Hopefully I can get a combo that doesn't hurt the power too much and makes the bike mellower.

If the repairs to the skid plate to eliminate the fatigue cracking from the oscillations doesn't work, gonna need to look into making a steel one. I found a couple more cracks on the base of the tounge of the skid plate, cause by it cunningly wagging at 10K. Chicks would love this bike, lol.

 

[16v4nrbrgr]

I got sick of the cracking from fatigue, which allowed the skid to make the rudest buzzing noises. Hopefully this landing craft stops breaking, the red arms are steel so it won't fatigue the ears off.

My left leg looks like a microwave pizza (and right one, and wrist, lol), new heat shield. Slipped a black cat muffler over the end with an o-ring and exhaust silicone, and riveted it. It runs just as before but now it sounds bit rounder and a little quieter at idle, hope it stops the bellowing at high rpm. I didn't mess with the clutch because I want to try it like this first, not good to change too many things at once.

 

[16v4nrbrgr]

Today I put some diamond pattern rubber stomp pad material on the underside of the skid, to damp out the ringing aluminum noise it makes since its kinda thin. I also stuck some on the rack so its technically a standing platform (not really, lol). I have a plastic battery box I never used that makes a great stand for it.

 

[5-7HEAVEN]

Curious to know what your gear ratio is.

So the auger transmission is 33:1?