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JagerDanger
08-02-2020, 02:14 AM
A few weeks ago, I purchased the plans for the ST2 Next Gen buggy from Badland. Plans looked good and straight forward. However they do not give suggestions on what to use for ujoints, with the exception of discontinued parts they use to have I guess. So they call for 1" ujoints for 1" shaft with 1/4" key stock. Theres only a handful of ujoints I'm finding that would fit the criteria however there's a few issues. Surplus Center has ujoints that would work, but they are only rated for 10-28hp, my engine is rated for like 50hp or so. For reference these plans call for a 400cc to 1000cc engine. The others being Spicer 1000 series ujoints. However these do not have a power rating or a maximum angle rating. The other option that I could do is Spicer 1310 ujoints. However these require 1 1/4" with 1/4" keyways, but they have a decent power rating and have a 27⁰ to 33⁰ max angle.

Another question I have is, sprockets. Instead of using the plans layshaft/jackshaft, I'm going to use a Polaris gearbox. It has a 3.5:1 high and a 6:1 low range. I'm going to gear it 13 on the gearbox to a 52 tooth on the axle spool. What do people use for sprocket hubs? How long do aluminum sprockets hold up to abuse? Are their steel sprockets that I could use around the 52 tooth count? I've already done the math, with the 3.5:1, the .76 over drive and the 4:1 final ratio, I'm at 10.64:1 final ratio in high range and at 18.24:1 in low range.

Edit*

Another question is, the plans call for using 5x4.5 trailer spindles and hubs in the front and using cut CV axle stubs from a Geo Metro and attach them to the rear axle. 15" steel wheels are common for this bolt pattern, but the pictures of the buggy seem to insinuate something around a 10" or 12" wheel with like a 20 or 22" diameter tire. Would it be better to try to find a 4on4 or 4x110 hub to fit on that would open up for more common ATV and UTV wheel sizes? If so any recommendations for that?

darwinpayne2000
08-03-2020, 01:19 AM
I don't have all the answers to your questions, but here are a couple of thoughts

In my (limited) experience, everyone uses aluminum sprockets once you start getting above 35+ teeth, probably due to the weight. I'm using #50/530 aluminum sprockets that I purchased from azusaparts.com. I liked the price and I could pick basically any tooth count that I wanted. They come with a simple 1" bore or a 1" bore and a 4x4 inch bolt pattern. They sell a 1" sprocket hub that fits the 4x4 bolt pattern, so that is the route I went, but I also welded an additional piece of keyed hub material to the existing hub to provide support for a longer key. I haven't had the aluminum sprockets for a long time, but I figured that a 530 aluminum final drive sprocket would hold up longer than the thinner 520 sprockets, plus they're compatible with the ubiquitous #50 industrial sprockets that fit 1" keyed shafts. Win-win.

My brother-in-law took a set of steel ATV rims, cut out most of the center, then welded in a new mounting plate with a 5x4.5 bolt pattern. I asked him why he didn't just buy a set of trailer rims with the right pattern and he said that he needed beadlock rims. I'm sure there are other ways to get the same result, but that was his solution.

JagerDanger
08-03-2020, 04:22 PM
I had forgotten about Azusa, I'm use to the older Auzsa company Azusa Engineering. But glad to know that the aluminum sprockets seem to hold up. I had found a 4on4 bolt pattern for trailer hubs with the same bearing size recommended through Northern Tool. If worse comes to worse, I'll look into cutting out the middle hub and weld in the bolt pattern needed. I had thought even doing wheel spacer adapters, but I'm not sure how it would affect the geometry with steering and how they would hold up overall. I've only found maybe 1 set of wheels around 10" diameter for trailers with the 5x4.5 bolt pattern, but they come with tires as well, I just want the wheel.

I'm looking to use Kenda Bearclaw K299. But the largest wheel those are listed for is 12".

darwinpayne2000
08-03-2020, 09:36 PM
If you're working on your front hubs, then you can try the approach used on the Shredder II buggy. It's the same approach I used and I haven't had any problems. Take a 4x4 or 5x4.5 trailer hub and weld on tabs to create a bolt pattern that fits your rims. My front rims are off a Kawasaki or Yamaha, I don't remember which. Polaris front rims have an even wider bolt pattern, so take your pick. Polaris has both 10" and 12" front rims with two different bolt patterns (10" Trailblazer vs 12" Sportsman), just to keep it confusing for Polaris owners. The Kenda Bearclaw 25x8-12 tires would fit the 12" Polaris rims, no problem.

If you don't want to weld on tabs, then cut a circular adapter 1/4" thick with the correct bolt pattern and mount/weld it to the hubs. A quarter-inch won't change the front geometry much.

I'm using the Azusa 4x4 front hubs with a 3/4 inch spindle, but there's no reason you can't use trailer hubs.

Here's a picture from the Shredder plans, plus a picture of my (ugly looking) hubs.

JagerDanger
08-04-2020, 12:59 AM
Looks doable and something I might look into. One of my thoughts was to use the Azusa live axle hubs for the rear, I'm just not sure if those will hold up well or not. I'm fine with not using ATV wheels, long as I can find the trailer wheels that will fit the tires and bolt pattern without any issue.

So another thing speaking of the front hubs, the plans for the buggy and will I think all the other buggies with the exception of the Megalodon and MS2, they only call for a single rear brake. It looks like with yours and maybe you can explain it better, but it appears that you extended the bearing section a bit more and then put a hub to mount a brake rotor on to, is this correct? My original thought was if I had enough room in the rear end, I would do dual inboard brakes with Wilwood SC2 twin piston calipers instead of the single piston.

JagerDanger
08-06-2020, 01:00 AM
Are split sprockets worth it or is it just better to leave the sprocket solid?

darwinpayne2000
08-07-2020, 12:09 AM
I'll snap some pictures of my brake setup either tomorrow or Saturday so you can see how I did it. Four-wheel disc brakes will make it stop on a dime.

As far as split sprockets . . .

I ordered a custom rear sprocket for my (never completed) two-seater buggy. It didn't cost much to have them make it a split sprocket. Changing out the sprocket on the setup I planned to use would have been a big hassle, so I went with the split. On my single seater, the sprockets are easy to replace, so they're solid.

JagerDanger
08-08-2020, 06:15 AM
Yeah I noticed it's only a $0.50 charge for them to make it a split sprocket. I'm just curious if it shortens the life of the sprocket more or not.

darwinpayne2000
08-08-2020, 08:25 PM
Pictures!!! Every likes pictures!!

So, in response to your question about how I designed the front brakes . . .

I'm using Azusa front hubs with the tapered bearings. This buggy is scaled-up from a go kart, so it originally had 8" rims. That dictated a 6" brake rotor and small-ish brake calipers.

The Azusa hub is 2" in diameter. On one of the racing go kart websites, they sold a 6" x 1/8" brake rotor with a 2 inch center hole. It slides on really nice. From there, it was a matter of cutting a mounting ring with a 2 inch center hole. (I used bi-metal hole saws and a lot of patience to cut the rings.) Slide everything on, mark the holes on the ring for mounting the brakes and weld everything up. Perfectly. I'm a big believer in spacers, so I designed it to use small washers between the mounting ring and the brake caliper, in case I didn't weld the mounting ring perfectly perpendicular to the hub. As it turned out, I got it right and the spacers are just spacers and not shims.

The spindle is a 3/4" grade 5 bolt and the brake caliper mounting bracket is fashioned from a piece of plate steel. Drill the center hole for mounting the bracket over the spindle and calculate how far out the caliper needs to mount to fit over the rotor.

I was a little worried that the small rotors and brake calipers wouldn't provide enough stopping power, but I could drive the buggy at full speed down the trails and still stop on a dime!!

Also, that's not rust on the hub, that's patina. :)

darwinpayne2000
08-08-2020, 08:43 PM
Some more details on the brake setup.

Originally, I used a master cylinder off a Chinese buggy parts website. It's a dual master setup (shown sitting on my buggy headlight). The cylinder bores were teeny tiny, but boy, did it work great. I had to adjust the rods pressing the master cylinders in to balance the front/rear brake setup, but, like I said, it would stop on a dime with those tiny rotors and calipers. After a couple of years, the master cylinder started to leak and I figured that a replacement would also start leaking eventually, so I went a different route.

I grabbed the master cylinder out of a Geo Metro and redesigned the brake setup. It worked okay, but not as well as the original setup. The master cylinder bore is too big for the size of the rotors and the brakes. Last year, I had to replace the rear brake rotors, so I went with a 7" rotor on each side and that works better. It's back to (mostly) stopping on a dime again. I really should upgrade the front rotors to 7", but since it works "good enough" and I have a hundred other things to work on, . . . .

The big advantage of the current master cylinder is that it's easy to replace. Last year, it suddenly failed on me, so I just went down to O'Reilly Auto and picked up a replacement. I was back up and running in about an hour.

JagerDanger
08-13-2020, 12:27 AM
Thanks for the explanation on how you did the brakes, definitely gives me a lot of insight of how to do it. Sorry took me a few days to get back on here and respond.

JagerDanger
08-20-2020, 10:46 PM
My plans for this have not changed, but will be pushed to the back burner for a while even after I get a house. Will be picking up a VW aircooled buggy that someone had built either late 80s or early 90s. It had been licensed in Minnesota for street driving. 4 speed manual transmission, mostly square tube frame. It's been in a barn since 1994, maybe 1993 per the license plate tags. I have some things I want to do to it once I get it in my possession. It will be staying with my dad until next Summer while my wife and I find a house. I should be going up to Minnesota before then a couple times and maybe work on it a bit.

JagerDanger
11-20-2020, 12:31 AM
I guess for a bit of an update. Went up to Minnesota in the first week of October and went to the farm in Wisconsin to pick up the VW buggy. It's a very scratch build, 2" square tube all over including the cage. Has a short Chevy/GM bench seat with lap belts. Master cylinder is shot. The clutch cable is janky. The front I beam axle is welded to the frame and not clamped in place like normal ones are.

Ended up getting an extra engine, front I beam axle, another transaxle, many carburetors, original steering wheel, several fan shrouds, original gas tank and many other random type 1 VW parts.

Very few parts will be salvageable from the buggy. Frame has too many terrible welds, it would take at least a day of cutting, grinding, and another day worth of welding. Overall wheel base is too short to be safe. So I'm going to have to get a different buggy frame and transfer everything to that, scrapping the square tube or keeping it all for other stuff. Looking at a knock down (weld your own frame) kit Acme Warrior.

Considering the buggy was street legal up through 1994, I may build that one up first and do the ST2 later. I'll need a new welder for either project anyway, current one will not be up to the task.

darwinpayne2000
11-24-2020, 03:10 PM
One advantage of living in the upper Midwest. You have lo-o-o-n-n-g, cold winters where there's nothing else to do except work on your buggy. ;)

Good luck on your project. Moving the VIN from the old frame to a new, (totally tubular, man!) frame sounds like a sound plan.

JagerDanger
11-25-2020, 11:07 PM
One advantage of living in the upper Midwest. You have lo-o-o-n-n-g, cold winters where there's nothing else to do except work on your buggy. ;)

Good luck on your project. Moving the VIN from the old frame to a new, (totally tubular, man!) frame sounds like a sound plan.

Back when I was in Minnesota, that was the case lol. But being in Nebraska, winter is more tamed, at least in Lincoln. Further west or north, it's similar to Minnesota. My wife and I are hopefully getting a house this summer, so I'll have a place to build both projects.

JagerDanger
11-27-2020, 01:27 AM
Plans on the Badland calls for 11 3/4" shocks for the front and 16 3/4" for the rear. They call for dual shocks front and rear on each a-arm. I'm hoping to modify and just one shock per A-arm. Any suggestions on shocks that will work the long run?

K-fab
11-27-2020, 03:37 PM
Any Fox or King would/should be good. FOA, uh... Pretty much any of the more popular brands.

Easy to tune, pretty universal, lots of springs that fit.

Fox Air shocks are probably the best, bang for the buck if your not racing - they do require a little bit of setup equipment (nitrogen bottle, regulator and attachment to charge the shock) but they're usually the least expensive and one of the easiest to tune. Very user friendly and would work well on a car your size.

JagerDanger
11-27-2020, 05:04 PM
I may have to go that route. I was hoping to go a bit more economical at first. 15 years ago, it should have been relatively easy to find the shocks the plans call for. Closest I can find for the front if I go by the plans are 12" eye to eye from Azusaeng.com. They are cheap oil filled hydraulic shocks with springs to help, but I bet a time or two on the trails will wear them out. Seems like shocks are the single most expensive parts (even with the engine in my case). I'll probably look more at Fox, since those air shocks seem to be more reasonably priced.

JagerDanger
11-27-2020, 08:42 PM
So looking at FOA and Fox, both more or less need to wheel travel. Is there any easy way to figure this out by just going off the blueprints or should I build it and then buy the shocks later?

aschn
11-27-2020, 10:27 PM
you can build the buggy without shocks, but be careful when you weld in the shock tabs and other components around the A arms.

If you are building off plans, you could make a few sets of tubes that take the place of the shock. One set could be full-out and the other set could be full-in.

Also, look into AFCO shocks. They're used primarily for dirt track and drag racing, but SAE Baja buggies use them as well. They use the nitrogen filled coilovers shocks with adjustable rebound or compression.

You should be able to find some used on eBay or marketplace or just buy new.

Good luck!

JagerDanger
11-27-2020, 11:15 PM
you can build the buggy without shocks, but be careful when you weld in the shock tabs and other components around the A arms.

If you are building off plans, you could make a few sets of tubes that take the place of the shock. One set could be full-out and the other set could be full-in.

Also, look into AFCO shocks. They're used primarily for dirt track and drag racing, but SAE Baja buggies use them as well. They use the nitrogen filled coilovers shocks with adjustable rebound or compression.

You should be able to find some used on eBay or marketplace or just buy new.

Good luck!

With AFCO shocks, do you know what category one should look under or do you know what model Baja SAE use?

aschn
11-27-2020, 11:18 PM
They are the 63 series Afco shocks. I personally wouldn't go with the adjustable ones since it's easily to re-shim them and honestly the adjustment clickers don't make a world of difference.

JagerDanger
11-28-2020, 02:51 AM
Does AFCO ever run a sale or sell them in pairs or sets? $380 each is a bit steep. I'll browse Ebay and other places incase the 63 series can be had cheaper.

K-fab
11-28-2020, 02:38 PM
Fox Airs generally run 200-225 a piece.
Bang for the buck... I sound like a broken record.

JagerDanger
11-28-2020, 04:30 PM
Yeah $225 or so isn't bad. I've only recently heard of FOA, Fox, I've known about for many years, so they have name recognition with myself and family.

JagerDanger
11-28-2020, 11:56 PM
Looks like I'm going have to do one of a couple things, modify the buggy in a way where I can run a more common length shock front and rear, by using the plans as a guideline but modify. The problem I see with the current design is that the front set of shocks are tucked inside the frame, rather than the shock towers being exposed like the ST2 Long Travel is.

Top of that, going to swap out the Arctic Cat Hex drive driver and driven for a Polaris P85 or 90 driver/driven so I can more easily use the Trailboss 350 gearbox I got this past summer. Hopefully it'll hold up to the 500cc 2 stroke, if not, going with a layshaft/jackshaft setup the plans come up with.

So comparing the ST2-LT and the NG plans, the LT front A-arm shock towers are welded on to the top of the body, does not appear to be reinforced. Rear shocks are bolted to the rear of the cage next to the seat head a bit on the outside. So at least with the fronts, it'll be easier to get a more common shock length if I do the mounts externally, rather than internally like how the plans show. Both appear to have very similar a-arms in size, so it could end up as a combination of the two. Maybe keep the rear shock mounts similar as the NG, but with a different mounting position to accommodate a longer shock that is easier to get a hold of.

JagerDanger
12-01-2020, 11:05 AM
Trying to find clutch sets sucks these days for older sleds. I can find the Comet 102c uncaliberated easily, the driven 100D however is a pain to locate. The Polaris P85 and P90 drivers and driven are also a pain to locate even though they were quite common. Replacement clutches for the Arctic Cat Hex are just as difficult. I can find majority of the replacement wear parts, just not the whole setup. I do see why some say the 102c/100D setup isn't an upgrade on some vs the P85, the overdrive ratio is like .95 for the 102c/100D whereas the P90 has a .76 overdrive.