Tag: 4 wheel drive

Posted on by Sophia Tung

Acton Blink Qu4tro (production version 02/03/18) – Huh?

This review was originally published on February 5th, 2018 and reflects my honest opinions at the time of publication. No part of this review has been redacted in any way. It has only been corrected for grammar and spelling.

Follow the discussion on Reddit here

If you want the TL;DR, see end of review

Today (02/03/18) was a rare, sunny, California “winter” day. At around noon, I answered my apartment door to welcome a friend, Marvin of Bay Area Eskate, who had graciously agreed to let me ride and test his brand new Acton Blink Qu4tro. I’d previously had experience riding this board. Acton themselves had previously invited me down to their Santa Clara headquarters to test the prototype version of the Qu4tro. I had many thoughts about the prototype board at the time, but I also believed that my concerns were related to the fact that the product was in prototype phase and not at all ready for public consumption. Now that the board is in production, I will be reviewing the board as is, assuming that Acton has put in the required QC and intended for this to be the final product.

Hardware

Let’s start with the deck. The deck itself hasn’t changed much from the prototype, and I still harbor the same concerns as I did when I tried the prototype. It’s made up of three distinct pieces. The front and rear scaffolding, to which the suspension is attached, and the middle electronics housing, which… houses electronics. The deck is as durable and stiff as it was in the prototype. It is also as heavy and flat as it was in the prototype.

Because the deck is so incredibly heavy, it has more inertia than other boards. This translates into a whole host of problems, chief amongst them excessive inertia. This means that braking is a lot weaker due to forward inertia (though I suspect hub motors and the braking curve are also major contributors in this area) and carving is a lot harder due to difficulties experienced when trying to throw the deck around while fighting forward inertia (carving is also very hard because of the suspension and four wheel drivetrain; I’ll get to that later). The problem is further exacerbated by the fact that the deck is also completely flat, with no curve at all. This makes it very hard for your foot to get a good grip on the surface for control. So, in addition to wrangling a heavy deck, you’re also constantly trying not to slide off. All this does not make for a very good deck, which generally is supposed to enable you to enjoy the ride, not inhibit you and be something you have to explicitly wrangle around. Plus this also makes the entire board heavy and is a bitch to carry.

Besides the rather unfortunate deck, the rest of the hardware is less grim. There are white front and red back lights as well as white side lights, all of which are controllable via the app. Though, as of the time of writing, there seems to be some bug that prevents the Android app from controlling the lights properly. It is worth mentioning that these are visibility lights, as they do not get bright enough to illuminate any meaningful distance of the road ahead of you. The trucks (not suspension!) and hub motors seem to be the same ones as the Blink S2. They work, though I do worry about some of the reports of hub motors falling off on the S2 and wonder if they could happen on the Qu4tro. I’ve included pictures of the hardware and innards for those interested below.





Suspension

I suspect the suspension system will polarize a lot of people. The main problem here is physics.

Here’s the thing. Currently, the way a regular TKP (traditional kingpin) or RKP (reverse kingpin) truck is set up, there’s a pivot cup and a kingpin that forces the truck to only rotate in a sort of semi-circular fashion in one plane around the pivot point. In other words, the truck rotates around the axis determined by the pivot point and the kingpin keeps it in place. However, with Acton’s suspension trucks, in addition to the regular RKP single plane rotation, the suspension is further allowed to deform in infinite directions due to the nature of the design. See my beautifully drawn graphic for an example of what I mean:

Keep in mind that in a traditional suspension, you only want yourself to be suspended along one axis. If you need to be suspended along more than one axis, you add more *distinct* axis along which to be suspended. You almost never want yourself to be suspended in all possible axis, because then you’re really just jiggling around. That’s what’s happened with the suspension on the Qu4tro: You’re really just… jiggling, which prevents you from properly turning or carving with confidence at any reasonable speed. The suspension will deform and neutralize the majority of your turn. It’s honestly not great, and the default hard bushing Acton includes doesn’t make it any better.

Edit: Avenue, the makers of the original suspension trucks, have informed me that they have in no way licensed their suspension trucks for Acton, nor are they working with Acton on suspension trucks. Here is their statement:

[Statement Removed Due To Ongoing Legal Dispute]

I’d originally written a how-to and review on Avenue TKP suspension trucks modded onto my Carbon GT and quite enjoyed it, so please do not let this review scare you away from suspension trucks!

Remote

The biggest thing here is the lag on the remote. It’s just inconsistent enough during low end acceleration to get annoying. Sometimes, I would try to accelerate to a slow speed but end up just sitting there for a bit before the motors kicked in. I have no idea what the issue here is.

As far as I can tell, the outer shell design of the remote is left over from Acton’s original remote-as-carrying-handle idea. They’ve simply taken off the bits that make the idea work. This is unfortunate due to several reasons:

  1. The original tradeoff of the ungainly remote design would have been fine had the remote been able to act as a carrying handle. This is no longer the case. Since you can no longer clip the remote to the board, you would obviously try to put it in your pocket. The remote does not fit in your pocket.
  2. The design itself is not very ergonomic. The angled bits make the remote very weird to hold for people with larger hands. My hands are considered small and even I felt that holding it was a bit… strange.
  3. There’s no deadman switch. Even Evolve has seen the value of a remote with a deadman switch. This would have maybe been ok if the throttle was in a less easily triggered place, but nope, it’s very exposed.

There are other design considerations that have been overlooked. The board’s charge information is not glanceable from the remote. You either have to stare at the single blinking LED on the remote to sort of gauge your battery (similar to the battery flashes on the Yuneec E-GO) or fire up the Acton app and wait for it to connect to your board to get a more detailed reading. This is in contrast to every other high end board remote that shows either individual LEDs or a percentage readout on a display. I did not find a place to attach the strap either. These sort of things just feel like UX that could have been easily improved upon but were not.

It is worth mentioning though that even while riding through areas with heavy radio activity, the remote did not lose connection once. It also instantly connected with the board when turning both on, similar to the S and S2. I was pleasantly surprised at how fast I was able to turn both on and get going. It’s just unfortunate that the design is lacking.

Technical Testing

Testride Route: 

Rider specs: 125lb, 5’6″

As part of my reviews, I perform a series of measured, purely technical tests on review units. These tests are meant to push the units to the extreme that their electronics can handle and reveal any problems that may have not been revealed by simple riding tests. Technical tests are done under the most favorable conditions possible.

Acceleration

Acceleration on this thing on flat ground is no joke. On all modes, the Qu4tro accelerated to top speed beautifully and as expected. The curve is smooth and ramps up linearly on all modes. There’s almost no worry of being thrown off the back if you’re prepared. Acton nailed this regard. I will say that it’s not the fastest acceleration out there by hard numbers, but the Qu4tro manages to *feel* fast while accelerating due to even power delivery from the four wheel drivetrain, and that’s really no easy feat.

Acceleration on hills is another matter. On every single significant (+15%) hill I went up, I had power delivery issues even though the app said the board was at close to full battery. Every other small bump or turn I experienced going up hill meant loss of acceleration power. Every loss of power meant ramping back up from 0 again. This only got worse as the battery drained through the course of the day. At around 50%, the board basically refused to go up hills. After charging the board from 50% to 60%, I gave it back to Marvin. After riding for a short time on some relatively calm roads, he completely ran out of power. This should not have happened on the types of road we were on and in such a short time after charging. After we wrapped up our ride, he encouraged me to write about this issue as he was pretty disappointed.

Top Speed

My speedometer said 23MPH at 100% charge and 21MPH at around 70% charge. This is pretty normal behavior and technically satisfies Acton’s top speed claims.

Braking

Good news! Braking at 100% no longer seems to shut down the board! This is a great improvement from the prototype. Braking is also very smooth! This means you will not get thrown off, unlike a certain other “evolved” board we all know…

However, braking in all instances still leaves much to be desired, unfortunately. The curve goes something like this when you apply full brakes:

This is maybe not so problematic at slower speeds. It will ease you to a sort-of-stop in a decent amount of time. Where it does get problematic, however, is at higher speeds going downhill, when you need brakes the most. It takes way too long to get to 100% braking power. I even almost ran into the back of a stopped car once because the brakes took way too long ramping up. That sucks.

Stress Handling

I do acceleration and braking stress testing in a series of eight consecutive acceleration and braking sequences on flat ground. In a system where a lot of power is transferred to and from various parts of the system, this is an important test. Unlike the prototype, Pro mode here revealed no problems. It seems Acton has fixed the braking shutdown issue. Hard acceleration and braking seems to maintain consistency, and I did not get any cutouts.

Turning Radius

Due to the suspension, turning radius was mostly unsatisfactory. I’d borrowed a Boosted Board Dual+ from Last Mile SF to test the turning radius on a standard single kingpin truck, and the radius was better than the Qu4tro’s with both kinds of trucks tuned to the loosest they would go. The suspension on the Qu4tro would also try to bounce you back to neutral with every bump in the turn. This is definitely not desired behavior.

Drag Race

Carbon GT (5.2s) edged out the Qu4tro (5.6s) in the end. We had a couple boosted boards in the race at the beginning but there was no point having them in the end. We would have had a Raptor 2 as well except its FOCbox broke so it’s now in the shop… for the third time. We tried to equalize the external variables as much as possible.

Thanks Joseph from Bay Area Eskate for operating the DJI Spark! Sorry you couldn’t catch up to us in the end with the drone…

 

Ride & User Experience

In addition to my comments on the suspension system, I have some comments about the four wheel drive system. During any sort of harder turn or carve, if all four wheels rotate at the same speed even though their radius throughout the turn is different, the wheels will slip and you will start to slide. This is by nature of the four wheel drive system, but coupled with really slidey wheels, is a huge issue on the Qu4tro. It means you can’t really safely turn or carve at speed. To mitigate this, most modern four wheel drive systems, such as those in cars, have a differential system in place to handle the rotation speed differences necessary to reduce slip. I believe the Qu4tro especially really needs something like an active differential, though I can’t imagine the complexities that go into implementing something like that. It would really solve the slipping issue.

Putting aside wheel slipping, riding in a straight line is a blast. The zero to max power takeoff of the four wheel drive system is really something to experience. The only boards I’ve felt that really parallel the smoothness on takeoff of the Qu4tro is the dual hub drive Raptor 2 and a couple DIYs by /u/Spooky_Ghost.

Conclusion

What Acton has built here, then, is something that could have been much more, but is unfortunately marred by its own nature. I have very mixed feelings about this board, and I’m not the only one. Even the owner of this board told me he had mixed feelings. My personal opinion is that if you live somewhere with smooth, straight roads and lots of hills, this is probably an excellent board. On the other hand, this board seems to struggle climbing up hills at battery levels under 70%, which is supposed to be its claim to fame. The jiggly, ineffective suspension and heavy deck doesn’t help its case either.

My, what a dilemma.

TL;DR

Wanna be fast and torquey in a straight line in a hilly area and don’t mind the weight? This is your board.
Wanna carve effortlessly or live someplace with heavy traffic? Look elsewhere.

Special Thanks and Notes

This review would not have been possible without the kindness and help shown to me by the following people:
Marvin, Joseph, Tone, and everybody from Bay Area Eskate group (woo BAEskate!)
Last Mile SF

I try to write fair, unbiased reviews for fun, not profit. All equipment used is either borrowed or purchased. Hope you enjoyed reading!

Posted on by Sophia Tung

Acton Blink Qu4tro Prototype Preview (09/21/2017)

This review was originally published on September 22, 2017 and reflects my honest opinions at the time of publication. No part of this review has been redacted in any way. It has only been corrected for grammar and spelling.

Follow the discussion on Reddit here

If you want the TL;DR, see end of review

Introduction

Today (09/21/2017) I went over to Acton’s Headquarters in Santa Clara, California, and tested the Blink Qu4tro. I was invited the previous day via email, and the person I corresponded with was extremely nice and extremely prompt when responding. I’m writing this review for future Qu4tro owners as well as Acton engineers, who I’m also linking to this review.

When I got there, there were two other people there, as well as a huge number of engineers gathered around. We were taken to the back through their prototyping garage, which contained all sorts of boards in half built states, including another Qu4tro with its internals spilling out.

  • What we were allowed to test ride:
    Blink Qu4tro with “Avenue collaboration trucks” (these are a HUGE deal, I’ll come to that later)
  • Blink S2 with “Avenue collaboration trucks” (not as big a deal on the S2, but still big)
  • Blink Lite (original)

Let’s get the unimportant stuff out of the way first. Blink Lite was same old. The interesting stuff starts with the Blink S2.

S2

What they basically did was put the “Avenue collaboration trucks” that were meant for the Qu4tro on the S2. Peter allowed us to ride this S2 while they were trying to fix the Qu4tro. More on this later. I’d previously ridden a production S2 and owned an S for half a year so I know what the originals are like. This was nothing like the original. While everything electronic stayed the same, the ride quality was completely changed by the spring suspension. I won’t say it was ruined, but these trucks the way Acton has them currently configured are not meant to go on such a light board. You become completely disconnected from the road because you feel like it’s all you can do to hang on. Turning radius was also ruined, but more on that later. Bottom line, suspension trucks on the Blink S2 will only appeal to extremely select people and will ruin the board for the vast majority. I have a feeling this won’t make it to production.

Blink Qu4tro

Please keep in mind that what I tested was a prototype and that this review should not be construed as condoning of condemning the final product.

Hardware

The deck itself is constructed with three distinct sections. The front and back load bearing sections are constructed from cast aluminum. The mid section is constructed from seemingly the same material as the Blink extrusions. The deck itself is durable, but I don’t think anybody doubted that, but just for anecdotal evidence, I’m a 125lb girl and jumping as hard as I could on the deck felt like I was jumping on the floor. That is to say, it’s incredibly stiff. Some people will like that, some people won’t. In the end, it’ll be up to preference, but I don’t think it’s a huge deal. Compared alongside the Carbon GT’s 40″ deck, it seemed around 3″ shorter, so I’d say the deck is around 36-37″ in length.

What is a huge deal, however, is the weight. Due to the materials used, battery density due to power required, and just overall design decisions, the deck is heavy. Extremely heavy. And dense. Picking up the prototype feels like picking up one and a half Evolve Bamboo GTXs. If you imagine the weight of 1.5 GTXs but squeezed into a denser package, you’ll get the Qu4tro. I even struggled a bit to pick one end of it up to turn around. It’s that heavy. Peter says that they’re still attempting to make the whole package lighter, and that they’re using a different material than cast aluminum for the front and rear load bearing sections (he neglected to tell me what they’re switching to) so hopefully production models will be lighter.

Avenue “Collaboration” Trucks

Now you might be thinking that weight doesn’t matter if you’re never picking it up. You’d be wrong. Part of what makes a board good overall, especially for eskates, is weight and trucks, which brings me to my next point. This is a huge point. The new suspension trucks. These trucks… boy… where to start…

Let me start by saying that they’re not the same as the current Avenue longboard trucks that you can pick up from Avenue’s online store. The trucks on the prototype boards that we got to ride were actually hand made prototypes based on the Avenue trucks. They rode extremely high, and did not really play well with the hangars. This by itself probably wouldn’t have been too much of an issue, but combined with the weight of the deck and high center of gravity it forced, the board became basically uncarvable and unturnable. If you tried to carve, the bounce back from the springs would try to throw you off. If you tried to turn, the trucks would try to bounce back and you wouldn’t be able to turn. It wasn’t until I loosened the kingpin to basically unridable levels that I could turn 180 on a decently wide road, and even then, I could just barely do it. Basically, Acton needs to serious work on these trucks.

It’s not all bad. I was assured by the engineering team that the spring curvature would resemble the Avenue ones more, which should mean less ridiculous spring and lower center of gravity, which in turn should help with reducing the effects of the weight which again in turn enables better carving and turning. I’ll believe it when I see (ride) the production trucks.

Remote

The remote was surprisingly nice. It uses a thumbwheel system with **no** deadman trigger, and was not sensitive at all. The version of the remote I tested was definitely 3D printed, but it had a nice feel and heft to it. There’s an indicator light on the bottom top facing side of the remote that blinks to indicate battery life and board status. It’s akin to the status indicator of the Yuneec E-go remotes, which is to say that getting your current status while riding by reading colors and counting blinks will get annoying. Right underneath the indicator light is the on/off switch. Connection, as with the other Blink series boards, is instantaneous. There’s no mode switching on the controller *still*. Mode switching has to be done from the app.

Ergonomics of the remote is mostly ace, or at least the part you grip is ace. I’m not sure why they’re keeping the top and bottom portions that stick out if the controller doesn’t act as a pull handle anymore, as all it does now is look weird and keep the controller from comfortably fitting in my pocket or purse. There were no controller related cutouts while I was riding the board hard. (There were definitely points where I lost control completely but I’ll get to that later)

Technical Testing

As much as I was able to, I tried to do as scientific of tests as possible. I was only able to measure extremely limited measurements, but I’ll do my best to describe to you results of my tests as best I can.

Acceleration

Acceleration curves on Normal mode was nice and easy. Acceleration on Pro mode was still nice, definitely feels more like the Raptor 2 acceleration curve and not the “Extreme G-Force” acceleration on the GT modes on Evolve boards. I think Acton nailed this aspect of the board’s UX, but I could see myself missing the exhilaration of the GT mode’s full power at 0 seconds. Peter says that’s not the market they’re targeting, so I’m not going to argue with that.

The dozens of times I went from full standstill to max speed, there were only a couple of times where it felt like the acceleration curve was uneven. I could chalk it up to prototypes not having the fully completed power delivery system, but that and other issues I’ll describe later makes me worried.

Top Speed

My speedometer said 22mph. That’s on the 88mms Acton had on the demo board. Compared to the 27mph measured on my CGT with 97mms on the same exact course. 3 repeated tests produce the same results. It’s “fast enough” for most people, but definitely not the fastest.

Braking

In normal mode, braking was fine. It slows you down to a complete stop pretty gradually, so you don’t have to worry about being thrown off. At the same time, don’t expect the braking to save you from oncoming traffic if you’re trying to stop at an intersection and you don’t know how to footbrake. In pro mode, braking **at full charge** will **shut down the board**. This happened twice. Once before the Facebook live stream, and once during the Facebook live stream. If you were watching, I was all the way at the end of the road near the turnaround and an engineer had to run and fetch the board. As I explained to both Peter and the engineers, this happens on the Blink S and Blink S2 and can *easily* be fixed with an overcharge resistor. The resistor would convert energy into heat which you can pipe into the all metal frame of the Qu4tro. This issue is even more crucial with the Qu4tro because instead of two motors pumping regen charge into the system, there’s now four. Twice the amount of power, twice the likelyhood of shutdown. I stressed this point to Peter and the engineering team there multiple times since there’s such a huge increase in risk of death. **They said they’d fix it**. If they don’t by launch time, y’all know it’s not because I didn’t try.

Stress Handling

After the shutdown incidents, they didn’t let me back onto Pro mode, so I ran the rest of the tests in Normal mode. Stress handling, where you accelerate to full speed then brake to a complete stop, is often used to test systems such as eskates where large amounts of power is transferred to and from various parts of the system. Doing this in Normal mode revealed no problems, but of course our concern here is Pro mode.

Turning Radius

Please see my thoughts above on the truck setup. No accurate tests could be performed.

Drag Race

I didn’t get to directly race the two boards against each other, but I did let the Acton engineers try the CGT. I’m not sure if they knew that Mandarin was my native language, but they were talking amongst themselves after trying the CGT and the phrases “insane acceleration”, “way faster”, and “crazy” got thrown around a lot so I’m going to assume they were reasonably impressed. I did find it strange that they apparently had no idea companies like Evolve or Enertion even existed. It seems to me that if you’re going to build a product that’s supposed to compete in this kind of market, you’d at least try stuff from other companies… Anyways, from my personal testing, there’s really no comparison. Both acceleration and top speed on the CGT blows the Qu4tro away.

Suspension Trucks

See my earlier section on this. I will add though that they were actually quite stable at high speeds. Might have to do with the weight of the board though.

That’s it

Feel free to ask me any questions in the comments and I’ll try my best to answer.