ThunderTiger 1/10 SparrowHawk XB (EP Buggy) mini review

[littlegiant]

This is my first buggy which I got it from someone who ran it brand new for only like 30 min or less. Well it looks almost brand new and from the looks of it, it has probably been through at most 2 battery packs. My initial impression of the buggy was that it seemed to be very well built and tough. The plastic parts are well moulded and they feel nice and solid. The buggy is definitely designed with durability in mind with an almost all metal drive train. Metal diffs, metal output diff cups, metal center shaft and metal cvds. Like most other 1/10 buggies, the Sparrowhawk XB comes with full bearings.

The buggy is pretty light at 1360g (I actually weighed it) without battery. It is just slightly rear heavy though. The weight distribution may be difficult to adjust because of the limited chassis space. I have tried fitting in a HW80A brushless esc but the esc is simply too big. HW big EZRUN escs are definitely a no-no in this buggy unless you don't mind running the buggy without is body shell.


Diff gears -
The diffs are made of hardened steel. I did open up the diffs to have a look at the interior. Well these are planetary diffs with 2 spider gears in each diff. The internal (spider and bevel) gears are made of hardened steel. The diffs are sealed meaning that they can be tuned using differential oils. However the stock "oil" used has a very high viscosity, kinda like sticky grease. The diff action with the stock "oil" is however very smooth and light as the wheels spin very freely. The diff cases are made of thick tough plastics and they feel really hard. Well I will put a brushless system in the buggy someday to see how well the diffs will hold up. And oh, do check the shims on the diffs. My buggy has the shims on the wrong side of the diffs (both front and rear). I don't know if the previous owner made the mistake of putting the shims on the wrong side of the diffs but I doubt so. Just check the diff shims to be sure.


Spur gear -
The 48p slipper (with a beautifully machined slipper hub) spur gear is actually exposed to the underside of the chassis via this slot hole located beneath the spur gear. The purpose of the slot hole is so that bigger spur gears can be used. Frankly speaking, I find this a real stupid design. It is like asking for tiny stones or sand particles to go in between the spur and motor pinion to screw them both up. I covered the slot with tape. The buggy needs a real gear cover for protection from sand and stones.


Main Drive shaft assembly -
The main (center) drive shaft is made of aluminium and is hollowed out for weight reduction. This is a beautiful piece we are talking about here. It is very well polished. The job of this main drive shaft is to transmit power from the main shaft to the front diff pinion. The main drive shaft is coupled to the front diff pinion with a piece of plastic. This may be a cause for concern as I don't know if the plastic coupling is going to hold up under brushless power. Let's just hope that Thunder tiger will release a metal upgrade if the plastic coupling proves to be a problem.


Battery brace -
The battery brace is held on using 2 body clips that clip onto 2 screws that are screwed onto the chassis. So that means that the brace's height level is adjustable by simply turning the screws clockwise or counter clockwise depending on the thickness of the battery that it is going to brace. But do take note that not alot of adjustment can be done due to the limited length of the screw.


Steering assembly -
The steering is extremely sloppy. I have 4 rc trucks, namely the mini-lst (well known for its aweful steering assembly), the e-savage, the micro-t and the sparrowhawk XB. The sparrowhawk XB has the most slope in its steering assembly. The wheels can move a good 5 degrees in either direction due to the slope. The slope is mostly due to the ball joints in the steering assembly. The ball studs are smaller than the ball link cups and this is what's causing all that slope. Someone should really let ThungerTiger know that their XB buggies need bigger balls to run well. The stock ball studs have 4.9mm diameter. 5mm diameter ball studs will probably be slighly better. Anyway this is a small issue that can be easily fixed. Either get ball studs with a slightly bigger diameter or wrap the ball studs with teflon tape. I got rid say 80% of the slope using teflon tape. And oh, I simply have to mention that the steering links (59mm from center of ball to ball) aren't adjustable. If you are looking for adjustable turnbuckles, the most suitable ones will be the Traxxas Jato/ Rustler turnbuckles (58mm). It seems that the steering turnbuckles of the DF-03 are suitable as well. The buggy is unable to make sharp turns. Its turning radius is really huge for a 1/10 buggy. My modded e-savage can do tighter turns. I probably need to tune or mod this buggy for it to turn tighter.


Steering servo -
The steering aseembly is powered by a standard size plastic gears servo from Ace RC. The servo is really crappy. It moves slow, has long lag time (slow response to input) and there are plenty of play in the output gear. To make things worse, the output gear can even slide in and out of the servo case. This will definitely affect steerng. I swapped in a HXT digital high speed servo with metal gears and the steering is almost instantaneous. I say change the servo if you want to race with this buggy.

Servo saver -
Nothing bad here. I really like the servo saver. Simple design and works really well with zero slope. 3 different plastic splines are given and you can use the servo saver on any of your futaba/JR/hitec standard sized servo.


Shocks -
No complain about the shocks. Smooth and plush with no bouncing with the stock setup. The shocks feel tough to me. You have to use stiffer springs if you want to jump the buggy.


Alu Rear Toe plate
I will recommend any Sparrowhawk XB owner to protect the exposed alu rear toe plate with a piece of plastic strip to absorb impact just in case the buggy goes rear on into something hard. Just cut out a piece of plastic with the same shape and stick it over the alu rear toe plate with double sided tape.


Motor/ESC
The 17T motor uses brass bushings (no ball bearing here...). It is pretty ok considering that it can move the buggy to around 40-45 kmph with a 2S lipo.
Acceleration with this motor is fairly good too. The esc seems to be pretty well made. It only runs at 6 cells nimh or 2S lipo max and is easy to program. Although the esc and motor are somewhat ok in their application, they run hot. After a 5 min run (mostly hard acceleration, full speed then hard braking), the motor tipped at 73 degree celsius. The esc performs better considering that it has been operating under the buggy's body shell with zero airflow. It was around 55 degree celsius. Ambient temp was 32 degree celsius. The stock motor is definitely not going to last under this kind of temperature. Due to the chassis's design, there is almost zero airflow under the body shell. However there is this cooling port (basically a big rectangular hole in the chassis) positioned right under the motor. I've tested a feigao 5407L 3511kv HW80A on 3S with this buggy using the stock pinion. Top speed more than doubled with crazy accleration but the motor temp was only slightly over 50 degree celsius even after a 15 min run. The HW80A was cool to the touch. The buggy was very nimble with brushless power. My SparrowHawk XB is defintely staying with a brushless setup.


Wheels
Race-ready pre-glued tires? Bullshit. The wheels on my buggy were badly glued. Alignments were so off that the wheels wobble so badly. The wheels were also badly balanced. The buggy simply shaked like it was on fit when I apply full throttle to it. These wheels degraded the handling of the buggy so much that I thought the buggy was really dififcult to drive. That was until I realised that the wheels were having major problems. I had to boil the wheels to unglue the tires before regluing them properly. I had the wheels balanced too. Having balanced wheels improved the handling the buggy several notches up. So please balance the wheels if you want good driving characteristics from your RC vehicles.


Tx/Rx
Cheap 40Mhz AM/TX set. Pretty standard features on the TX: Trim, sensitivity and Throttle ATV. The AM radio works fine but AM has its limitations. A brushless setup on the Sparrowhawk XB but the buggy could only go about 50m away from me at the carpark when it started glitching. It will probably do better in a wide open space with no power lines around.
From what I know. FM and 2.4Ghz radios works better with brushless system
compared to AM radios.


Having sorted out what that have to be sorted out with this buggy (other than the turning radius), the buggy performs surprisingly well for a $200 USD 1/10 EP buggy. With a good brushless setup, the buggy is very fast, nimble and handles really well. The driving characteristic is really good. The buggy is very predictable and very easy to control. Its stabilty comes from its relatively low CG. Well I did made a few high speed turns (the feigao on 3s lipo) with this buggy on asphalt and was surprised that it didn't traction roll. Spare parts are cheap and the drive train is definitely designed for brushless power. Other than its big turning radius and the cheap radio set, I have no complaint about the SparrowHawk XB. However I can't say anything about how this buggy performs at a race track or how well it can jump because there is no proper dirt track near to where I stay. I mostly run my trucks at the neighbouhood park or carpark. However I do believe that this buggy can be made race worthy with better parts (better steering servo, carbon chassis, better oil shocks, a more powerful setup and etc...).

Baseline: Right out of the box - Ready to run? Yes. Ready to race? Hell no!