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Nov 19, 2014, 01:40 PM
Fly, crash, rebuild, repeat
Thread OP
New Product

HobbyKing BSR BZ-222 1/10 Racing Buggy Thread


I wanted to get an official thread going for this buggy, as I think quite a few people are curious about it. Anytime someone claims to build a racing buggy for less than $100 shipped, it's worth checking out. Which is exactly why I bought one!



I'm going to be posting a series of videos and write ups documenting this buggy; how it is built, pros/cons, what breaks, etc. So, lets get started with a video!

Hobby King BSR BZ-222 Review: Part 1 (10 min 35 sec)


Initial impressions

Pros:
CHEAP!
very "tight", and slop free
Tires actually feel usable
Flexible plastic=durability (usually)
ROAR legal dimensions
nice shocks (for the price)

Cons:
Front tires are 4x4 buggy sized. Why?
Front axles are very small, thin, bolts
Shock towers very flexible
Battery compartment is restrictive of battery size, even though there is lots of adjustment
32p pinion and spur gear....why!?!


Much more to follow! I'll be editing this post and those to follow as I learn more about the buggy.
Last edited by Chubbs; Nov 19, 2014 at 02:02 PM.
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Nov 19, 2014, 01:40 PM
Fly, crash, rebuild, repeat
Thread OP
First off, let me apologize for my camera. I don't know what happened, I think the lighting was just bad enough that the pictures were bad without a flash, and just good enough that the flash overdid it. Regardless, here's some pics

Some pictures of the gearbox/diff disassembly:

The complete gearbox assembly is attached to the car with about 8 screws under the chassis. Here's the removed unit, along with the comically large 32p spur gear



Inside the gearbox. The belt is surprisingly thick, probably around 10mm wide. I was expecting something small, like the tail rotor belt on a 450 helicopter. The BZ-222 belt is much larger. Biggest selling point for me...NO GREASE!!! It was great opening up a gearbox, and not getting nasty gear grease all over the place. The belt and sealed diff means everything should be clean inside.




The differential arrives with grease in it. I said I was going to run the buggy bone stock, but this is the one thing I changed since I was in it anyways. I cleaned the diff out and filled with 20,000 cSt silicone diff oil.



Another gearbox pic



The shocks, I'm happy to say, are filled with real silicone oil. This was a little unexpected, since my Turnigy Trooper came with some weird brown motor oil stuff in the shocks. The oil feels thin and doesn't offer a whole lot of damping, but we'll see how it handles. (I know, the picture is terrible...sorry)

Also notice, there is no rubber bladder in the shock cap.


Here is the front "axle". That plastic piece fits inside the wheel bearing. An M3x22 bolt is inserted from the inside, through the plastic "axle", and protrudes through the wheel, where it's secured by a 5.5mm nut. A very odd design, in my opinion.





A few tech specs they never tell you about in the product listing:

Shocks: 12mm inside bore diameter. Rears are 95mm long eye-to-eye, fronts are 81mm long eye-to-eye. Stock shock pistons have 6 holes which is a lot.
I'm now running 1000cSt oil in front and 1200cSt in rear and it feels about right.

Rear wheel axles are 5mm diameter. Threads are approximately 4mm dia

Rear wheel sizes:
width: 38.27mm
Max overall Diameter: 61.25mm
Bead diameter: 56.84mm
offset: +8.4mm

Transmission: 1 complete turn of the input shaft (spur gear) moves the buggy forward 13.9cm with proline Proton rear tires fitted. this surprised me a bit, as that's a longer rollout than I'm used to (not real "rollout", but that's what I call it). Not a big deal, just surprising.
Last edited by Chubbs; Nov 30, 2014 at 05:06 PM.
Nov 19, 2014, 01:41 PM
Fly, crash, rebuild, repeat
Thread OP
I got the electronics put in, and of course that means I must drive it immediately, even if I don't have a good place for it. So here's the maiden run.

Hobby King BSR BZ-222 Review Part 2: First Run (2 min 48 sec)


I can already tell rear traction will be an issue. This thing basically spun tires most of the way down the driveway. The stock motor is 3300kv, my motor is 3500kv....so the speed of mine should be indicative of what the RTR will do. Gearing is stock.


EDIT 11-24-14

I got the BZ-222 to the track this weekend, and learned several valuable things.

First thought that came to mind at the first corner...."Holy Oversteer!!!!". Wow, this was one tail happy car, and not in a good way. This was on an indoor clay surface, decently prepped as it was the day after race day. The BZ-222 was virtually un-drivable as set up out of the box. It entered the corner nicely and pivoted well on the drag brake (which was minimal), but the moment any power was applied, she swapped ends. It took a very, very careful trigger finger to keep it pointed in the right direction.

The suspension was also very soft, which I suspected from the beginning. It didn't take off from jumps well due to the chassis bottoming out, nor did it land well for the same reason.

So, too the bench it went. First order of business was to firm up the front end. I swapped out the stock shock oil for some 600cSt oil, and it felt exactly the same. I suspect the stock oil is either 500 or 600 cSt. I went up to 1000cSt oil and it started feeling like a real race buggy. Still tail happy, but it took off from jumps much better.

Next order of business was to lay the rear shocks down a bit. I moved the upper shock mounts to the inner-most position on the tower. Again, she still oversteered, but it was improved.

Next, Camber. I dialed in about 2 degrees (eyeballing it) of negative camber in the rear, and that started to improve things a lot. It was STILL tailhappy, but usable. I could at least get it around a track if I was careful. Instead of being un-drivable, it was just "lively". But still, it didn't hook up well.

This was all in rear motor. I pity anyone who tries to set this up mid-motor.

At this point, I retract everything I said about the tires in the first video I made...the tires are NOT usable in my opinion. They feel soft and somewhat sticky when they are clean, but as soon as they hit the dirt they stop working. In comparison, my MC compound Proline Suburbs feel about the same dirty or clean. Furthermore, the stock BZ-222 tires wear out at an astonishing rate. I'd say after 2 battery packs on the track, and the brief time I spent on the driveway shooting video (less than 1/4 pack), the rear tires are half gone. It's amazing they are wearing so quickly.

Bottom line, throw away the rear tires. The fronts could still be usable since they are 4wd tires, and therefore fat...they have a tendency to overpower the rears anyways. But really, they all need to go I think. A new set of M4 Proline Proton rears are on the way. Fronts will probably follow.

Now, for gearing. The stock gearing is tall for my 3500kv motor. It got pretty warm, but would be fine for an 8 minute main. If I were going to be using this in my yard as a basher, the stock gearing would have to go. I suspect the stock 3300kv motor would be about the same, but I can't say for sure.

Finally, durability. This was a high point really. I took some pretty good tumbles, and smacked into a stationary car on the back stretch, and I broke one piece: the rear motor guard. It attaches to the top of the gearbox with screws, and that part was fine. The issue was at the bottom, where it attaches to the chassis, or should I say where it doesn't attach. It is held in place by 2 plastic nubs that poke through screw holes in the chassis (denoted by arrows).


These plastic studs sheared right off, and left the rear motor guard flapping around in the dirt. It will need to have some holes drilled and be screwed in place. Below is the fix...hopefully it isn't a problem anymore

Last edited by Chubbs; Nov 25, 2014 at 09:36 AM.
Nov 19, 2014, 01:42 PM
Fly, crash, rebuild, repeat
Thread OP
Final review video:
Hobby King BSR BZ-222 Review Part 3: Full Review (12 min 46 sec)



A few of the highlights:

Most of what I said above remains true. The buggy has proven pretty durable so far, with the rear motor guard being the only broken piece after many tumbles. There is one other thing (which I didn't mention, because I don't think it counts), the front shock tower broke during transit from the track. I don't know what my Rustler did to it in the duffle bag, but the shock tower was fine going in, and broken coming out. For durability purposes though, I'm only considering things that break on track, not one-off flukes that happen due to careless packing.

Another thing to be replaced: Get some better rear wheel nuts. The stock ones had a habit of working themselves loose. I replaced them with some traxxas nuts (which have little ridges in them to bite into the wheels) and have not had the problem since.

I took out the 3500kv system, which I was really disappointed with, and replaced it with a 17.5T turnigy trackstar motor. I'm very pleased with it so far, it seems to be at least as fast as the Thunder Power 17.5 I use in my other buggy. Final gearing is an 87T spur (team associated, 48p), and a 28t pinion. I could get more aggressive with gearing for a quick 5 or 8 minute main race, but it would likely get too hot for any extended 15minute practice session. The 87/28 combo is a good all around ratio, and is only mildly warm after 20 minutes of track running.

I am still having a bit of trouble with power on oversteer. I have decided to use a thinner oil in the diff, to see if that helps. I knew 20k was pretty high from the start, but I have used it with success in other cars (a DEX210 buggy, and my Traxxas Rustler). This BZ222 though, just doesn't seem to like it.

After it's all said an done, i'm satisfied with the buggy for what I paid. I don't think it will ever be a serious competitor to a Losi 22, or a B5, or any of the top tier buggies. But for $100, it's a good value for the money I think. It will get you into racing at a decent price, and you can be competitive at the club level with it. If you want to take racing seriously and race with the big boys, then you probably won't be shopping at hobbyking anyways.

Edit:1-23-15
I replaced the 20k rear diff oil with 1200cSt shock oil, and the power-on over steer is gone. I also put stiffer springs on the front (red, from hobbyking), though I think I may go back to stock. The buggy now has a slight tendency to run wide on corner exit, but it isn't bad. It's very easy to drive this way, as you can be very aggressive with the throttle, and it never bites you.

Still no further breakages of any parts.
Last edited by Chubbs; Jan 23, 2015 at 02:25 PM.
Nov 19, 2014, 02:36 PM
Fan of just about anything RC
SoloProFan's Avatar
Some interesting details already. The 32dp gears are probably because these are more bulky, though it limits gearing options, and tend to be more noisy than 48dp. For a basher use this might be a good thing, but for racing 48dp would be better. Maybe these are going to be released as upgrade/option?

Thin front axles, you mean those are not 5 mm and 4 mm nut?

The front wheels puzzled me as well. Though for a basher it's not that odd. Are those hex 12mm btw?
Latest blog entry: For the love of the hobby!
Nov 19, 2014, 03:30 PM
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SporadicIdiocy's Avatar
Does look pretty decent for the price. Is it another rebrand which I can get parts from other vendors? If so, it might be worth picking up just to bash around the yard.
Nov 19, 2014, 03:35 PM
Fly, crash, rebuild, repeat
Thread OP
I imagine the 32p gear was for durability, as it's certainly beefy....but I don't think it's necessary. Every other 2wd vehicle i've had, has always been a 48p spur gear, and i've never had a problem with stripping them unless I botched something. Furthermore, when they DO strip, I think it's likely they are saving another gear by sacrificing the spur. I have a whole collection of 48p pinion gears...but not a single 32p. It's just a pain, really. an unnecessary pain, in my opinion.

The hexes are 12mm, yes. The wheels/tires should make good practice wheels for other vehicles.

The front axles are simply an M3 bolt, with a 5.5mm nut securing them. For comparison, my V2MR uses a an axle with M3 threads tapped into it...so the axles are substantially larger, as they fit an entire m3 bolt within them. My DEX210 was the same way.
Nov 19, 2014, 03:37 PM
Fly, crash, rebuild, repeat
Thread OP
Quote:
Originally Posted by SporadicIdiocy
Does look pretty decent for the price. Is it another rebrand which I can get parts from other vendors? If so, it might be worth picking up just to bash around the yard.
I don't believe so. This appears to be a completely new design by hobbyking.

That's not to say other parts won't fit. I've already seen talk about the front axles on the RCtech forums, and people are speculating that Losi front axles will fit. Some parts will inevitably interchange with existing vehicles, even though the BZ-222 isn't based off of any existing cars.
Nov 19, 2014, 08:10 PM
Registered User
Jimmy the Heater's Avatar
Be sure you take the slipper apart and take pics of the tiny pins that the discs key into...That looks like the biggest weak spot to me from looking at the RC Tech thread. Lots of stress on a very small part. Pure speculation on my part, and I hope I am wrong, but it's something to keep an eye on.
Nov 20, 2014, 11:11 AM
Fly, crash, rebuild, repeat
Thread OP
Quote:
Originally Posted by Jimmy the Heater
Be sure you take the slipper apart and take pics of the tiny pins that the discs key into...That looks like the biggest weak spot to me from looking at the RC Tech thread. Lots of stress on a very small part. Pure speculation on my part, and I hope I am wrong, but it's something to keep an eye on.
I wish I would have seen your post yesterday...I just had the diff/gearbox apart last night. I have a couple of pictures of those little pins, but they are incidental. The pins weren't my focus.

They are very small, and easily lost. And if you lose one, you're dead in the water...so DON'T LOSE ONE!!!

We'll see if it is a weak point or not. I actually don't see a huge problem with them. Those pins are pretty tough since they're in a shear configuration. There is one for each slipper clutch plate, so they share the load there. There is a third pin on the end of the input shaft within the gearbox, but it's protected by the slipper clutch so it shouldn't see many shock loads.
Nov 20, 2014, 12:50 PM
Fan of just about anything RC
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I haven't seen pins like these break before. These are also used to fit a wheel hex over, and other cars also use these for the slipper, like for instance the Team C 1/10 scale 4WD cars. I think the spur or the slipper pads will fail before the pins can. But you do need to be careful not to loose these, indeed.
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Nov 20, 2014, 01:33 PM
Fly, crash, rebuild, repeat
Thread OP
Quote:
Originally Posted by SoloProFan
I haven't seen pins like these break before. These are also used to fit a wheel hex over, and other cars also use these for the slipper, like for instance the Team C 1/10 scale 4WD cars. I think the spur or the slipper pads will fail before the pins can. But you do need to be careful not to loose these, indeed.
Agreed, pins in these arrangement are commonplace on RC cars, but not pins so tiny. They are really, really small. Too small to handle with a normal man's fingers. I had to use tweezers to reinstall them. I would guess they are probably 1mm dia, 4mm long.

Still, I doubt it will be a problem. Tiny as they are, I suspect they'll probably hold up just fine.
Nov 20, 2014, 01:56 PM
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1mm is pretty thin. The ones I encountered are 2 mm mostly, so a lot bigger then.
Latest blog entry: For the love of the hobby!
Nov 20, 2014, 09:39 PM
Registered User
Jimmy the Heater's Avatar
There was a picture of those tiny tiny pins over on the URC thread on this car....Sadly URC is down with no ETA of it coming back or else I would link the pic over here. And yes they are much much smaller than a wheel hex pin.

I hope I am wrong...this buggy was designed for 2s use so it might very well be ok. But I'm still skeptical.
Nov 21, 2014, 12:12 AM
Registered User
Jimmy the Heater's Avatar
I was wrong...It was the 222 thread on RC Tech, not URC. Petrock's post...full of measurements on the car as well as the pins, about 3/4 of the way down.

http://www.rctech.net/forum/13664537-post92.html


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