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SAB Heli Division - Goblin 700 Review
Traditionally known for rotor blades, SAB dives into the heli market with one of the most unique heli designs to date - the Goblin 700.
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There was a lot of excitement surrounding the release of the Goblin 700. It seems that when the designers at the Italian based company SAB decided to build a helicopter, they asked themselves "how can we make it different from anything seen before?" (but probably in Italian I'm guessing...). They certainly seemed to have figured that out with their new 700! There are many innovative features that stand the Goblin apart from any other heli out on the market, and this is very apparent from first glance. From the carbon fiber square tapered boom, to the "steampunk" array of belts and gears, and even the way the cyclic servos are laid out, the Goblin 700 doesn't disappoint.
With videos galore of team pilots Bert Kammerer and Tareq Alsaadi showing what the Goblin is capable of (and more recently Kyle Stacy), it is very apparent that this new design not only looks good, but also performs extremely well. I had been following the progress of the Goblin since the first batch was released, and after thinning my own fleet I got on the waiting list for the next batch. SAB has made a number of revisions since the first batch, and more still since the version I have, which shows that SAB is listening to its customers and continually improving their design. Did SAB stop there? Nope. If the 700 isn't your cup of tea, very soon SAB will have a whole family of Goblins, including a 500, 630, and 770! |
Kit Contents
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| Main Rotor Diameter: | 1568mm (with 690mm blades) |
| Main Blade Length: | 690 to 710mm |
| Tail rotor diameter: | 296mm |
| Tail blade length: | 115mm |
| Main shaft diameter: | 12mm |
| Tail shaft diameter: | 6mm |
| Spindle diameter: | 10mm |
| Weight including electronics: | 3470g (excluding batteries) |
| Transmitter: | Futaba 8FGS |
| Receiver: | Futaba R6203SB |
| Gyro: | Futaba CGY750 |
| Cyclic Servos: | Outrage Torque BL9180 |
| Tail Servo: | Outrage Torque BL9188 |
| Battery: | 12S 5000mah 40C SkyLipo |
| Motor: | KDE Direct 700XF-495 |
| ESC: | Castle Creations HV-160 V2 |
| Manufacturer: | SAB Heli Division |
| Available From: | HeliDirect |
| Price: | $999 |
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The box arrived safe and sound, packed in an outer shipping box with a little bubble wrap to stop it sliding around. The minimalist art gives no real impression as to what is inside, so all that was left was to open it! It appears as though just as much thought went into the packaging as the design. I was presented with six neatly packed boxes that would make any Tetris fan proud. On top of the boxes, nestled in the center, was the full color instruction manual. Picking up the manual first, I flicked through it briefly and found that everything was illustrated using 3D CAD drawings, as well as additional photos showing various electronics installations.
The first box I pulled out was box number 4. Opening box 4 revealed four foam trays, each wrapped in its own bag, that contained most of the aluminum parts for the heli. The foam trays had been cut specifically to accept the part it was holding, and looked great. The next box I pulled out was box number 6. This box contained the flat carbon fiber parts, such as the skids and side frames. Underneath box 6 was box 2, which contained the canopy and foam blade holder. The canopy is a work of art in itself, and painted by canopy experts "Canomod". The finish of the canopy was spectacular, Canomod really did an excellent job. There were two smaller boxes next to each other, 5 and 7. Box 7 was empty, and the manual showed that this was where combo parts were stored if they were offered. Box 5 contained bags of hardware, and finally box 3 contained the unique boom, blades, and tail blades. |
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Equipment Needed
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Choosing your equipment for a heli can be a very personal thing. There are many choices out there, and it helps to do a lot of research beforehand, and you can ask around and see what fellow flyers think. To get the Goblin in the air I needed to choose a motor, ESC, receiver, gyro, servos, and batteries.
Motor After talking with a few flying buddies, I decided to contact Patrick Keogler at KDE Direct to ask him a few questions about their XF series of brushless motors. Patrick was very helpful, both in answering my questions and suggesting possible setups that I could use. So I ordered the KDE 700XF-495. This is a powerful motor (11,000+ watts), and I had watched the 600 version fly at IRCHA last year, which I was completely blown away with. Couple that with the customer service I got from KDE and it was a no brainer. The only caveat was that the canopy would need to be cut open to allow the motor to stick out a little, which didn't really bother me too much as it could only help with cooling. ESC I've been using Castle Creations ESC's for a while now, and I am a big fan of their PC software that lets you program every aspect of the controller. I chose the HV-160 V2, partly because of previous experience with Castle, and partly because this was one of the recommendations from SAB as well as Patrick at KDE. Servos While browsing servo options, it became apparent that the Torque servos from Outrage were very popular. I contacted Outrage, and they very graciously provided a set of servos for this review. The torque servos are ultra high speed and high torque servos, with an all aluminum case that helps dissipate heat, titanium coated gear train, helical gears, and brushless motor. The cyclic servos are the Torque BL9180, which can handle up to 8.4 volts and will swing 60 degrees in 0.10 with just over 245 ounces of torque. The tail servo, BL9188, again at 8.4 volts, will swing 60 degree in a staggering 0.034 with a little over 83 ounces of torque. Impressive stats for anyone! Gyro/Receiver I already had a Futaba R6203SB S.Bus receiver, and again it was a no brainer to pair it with a CGY750 flybarless gyro. Using the S.Bus features of both the gyro and receiver, I was able to cut down on wiring, but the biggest bonus is being able to adjust the gyro gains of the rudder, aileron, and elevator channels from my 8FGS. This has fast (no pun intended) become my favorite setup for helis, and I was excited to try it out on the Goblin. Batteries Again I already had some SkyLipo 5000mah 6S batteries, so decided to stick with those and ordered a couple more. They are only 40C, but watching a few videos online of similar powered Goblins convinced me that I would be happy with the setup for now. I decided to use a separate Lipo for the receiver, mainly to take advantage of a High Voltage setup. I had a two cell 2200mah lipo that I hadn't used yet, so it was volunteered for the job. As I came to appreciate later, this was a decision that would save me a lot of money and heart ache. |
Building
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| Building the Goblin is almost as fun as flying it. Almost. Every step of assembly is marked with a number that corresponds with a bag number, and in that bag are all the parts you need for the current assembly step. In fact, there are so many small ziplock bags in this kit that you will be stocked up for a long time afterwards! As mentioned earlier, the instruction manual is made up of 3D CAD drawings to aid you in the construction process, and is extremely easy to follow. Now here is where SAB breaks the mold yet again, this time with preassembled parts. SAB stresses that the preassembled parts in the kit are all built with threadlock, and that there is no need to take them apart. In many other kits it is necessary to take these sub assemblies apart in order to threadlock them back together, and is a necessary part of the assembly process. It is up to the builder to decide if they want to check up on SAB's promise that these parts have threadlock, and I am sure that many will double check for their own peace of mind. I did a little reading online to see what others had done, and found that the ones that had trusted in SAB had no problems, so I decided to follow suit and trust what SAB was saying. However, I did randomly select a part and disassemble it, only to find that the parts had indeed been assembled with threadlock. I'm happy to say that after many flights I haven't had anything loosen up, but this decision will ultimately be up to you. |
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The side frames went together extremely fast. One of the many unique features about the Goblin is how most of the electronics and mechanical parts are installed on an upper aluminum plate. This entire plate is removable via several screws, leaving the side frames behind, making replacing the side frames a two minute job. The photo above shows the completed side frames, just about everything else is installed on the aluminum base plate.
The motor drives the rotor head indirectly via a belt and pulley system. This pulley system also contains the one way auto bearing, which must be lubed (triflow) before installation. The tail is also belt driven, with a separate spring loaded belt tensioner that hangs below the main aluminum plate. The main gear is helical cut for extra strength and meshes directly with an aluminum pinion gear at the top of the motor pulley. There is no backlash on the pinion, nor the ability to adjust it, and it is important to use WD40 to lubricate these gears for the first few flights in order for them to break in. Do not be tempted to use an alternative lubricant, I saw first hand on another Goblin what a mess this created, plus it could shorten the life of your gears by causing excessive wear. It is worth noting at this point that the aluminum parts were beautifully machined, and I didn't encounter a single error during assembly.
The motor is mounted to it's own separate aluminum mount. This mount is spring loaded against the main aluminum plate, which acts as a tensioner on the motor to pulley belt. There isn't a lot of room for the motor shaft, so it is necessary to cut it down to size per the instruction manual. I took one of the larger ziplock bags from the kit, and placed the motor inside it with the shaft poking through one of the corners. I then used a dremel with a cut off disc to carefully cut off the excess shaft, after measuring several times to make sure I had it right. The ziplock bag kept any fine metal particles from entering the motor case, which could possibly cause problems later on.
The motor mount was then installed into the side frames, along with the main mechanics, and I installed the motor belt before snugging down all the bolts. Another thing to consider is what size motor pulley you will need to use. The kit comes with a 22 tooth pulley, but after some calculations using Castle's ESC software, I realized that I would need at least a 24 tooth pulley in order to run 2200rpm governed. SAB has a myriad of different pulleys to choose from, so make sure you know which one you want when you order your kit! There is already some great info on the web about the Goblin's gear ratios, so I won't go into it here, suffice it to say that some research ahead of time really helps.
The only thing left to build at this point is the tail. There is no traditional tail hub, instead you have a carbon fiber "cage" that houses the tail rotor shaft and pulley. This is held to the boom with four belts, and can be adjusted by sliding it forward or backward on the boom to adjust belt tension. The tail blades grips are already assembled, along with the pitch slider, which greatly speeds up assembly (that is unless you want to check them yourself!).
The plastic inserts for the tail pushrod and servo were already glued in place, and only a small amount of work was needed to get the rest of the boom finished up. The paint finish on the boom was just as good as the canopy, but there were still a couple of very minor cosmetic flaws. These flaws were along the black part of the boom, and only noticeable upon close inspection. Speaking of the boom, it is one of the most obvious unique features of the goblin. That is no shroud you see in the photos, it's the actual boom. Made of carbon fiber, the boom is of a square, tapered design. This incredibly strong design means that boom supports are not required, and there is no horizontal fin. Some care must be taken when routing the wire from the tail servo, and a little dab of hot glue ensures it doesn't move around.
The boom has an aluminum shoe that slides onto the big aluminum plate sandwiched between the side frames. This is then held in place by two big nylon bolts through the top, as well as two cap head bolts through the side. Once the nylon bolts are snugged down with the included tool, a carbon fiber lockring is installed over the top to stop them from turning. The boom is designed to break away during a crash, and from some accounts that I've read so far this seems to work fairly well. In some earlier models incidence on the aluminum shoe was slightly off, resulting in the greater possibility of a boom strike, and after watching Mr Kammerer's video on how to check the blade to boom clearance, I found that I had plenty of clearance. This advisory from Bert was another great example of the customer service from SAB.
With the mechanics finished all too quickly, it was time to move on to the electronics installation! |
Electronics
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I know I must sound like a broken record when I keep mentioning "unique" features of the Goblin, but it simply can't be helped. Looking at how the cyclic servos are set up, you can't help but think of the word. The servos are laid down on their side, spaced evenly around the main shaft, and link directly to the swash with very short ball links. This arrangement just about eliminates any linkage play, and makes for a crisper feeling cyclic. Initially I installed the servos using the rubber grommets that we are all familiar with, but after reading more input from fellow Goblin owners, I decided to remove them and bolt the servos directly to their mounts. Supposedly this eliminates any play in the servo, making a more accurate cyclic. I used the included four way servo arm that came with the Torque servo. It is a very stiff arm, but must be trimmed down and the three unused arms need to be cut off. I made sure everything was centered before I started trimming the servo horn.
There is however a slight drawback to an otherwise impressive design. Once the servos are installed you can't remove or adjust the servo horns. Therefore, it is important to center your servos before installation. I did a dry run with my electronics setup out of the heli, and did all my centering on the table.
The goblin features a raised platform for installing your receiver and gyro. I ended up putting the controller for the CGY750 on the top, and my receiver underneath. The gyro sensor was installed on the underside of the main aluminum plate. SAB also provides a place for you to run your antennas, in my case one on either side of the boom. I later added a short piece of plastic tubing to help prevent any chafing on the antenna wires.
The Castle ESC proved to be something of a challenge. No matter which way I oriented the ESC I could not get it to sit flat on the ESC mounting plate. Others had installed it at a slight angle with a single zip tie holding it in place, but I wasn't happy with this solution. I wanted as much of the ESC sitting on that aluminum plate as possible in order to help dissipate heat. After a lot of head scratching I finally figured out a way that I was happy with. For it to work I temporarily removed the plastic clamshell case from the ESC, and using a dremel sanding drum I carefully cut away some material directly below the battery input wires. I then attached a thin strip of double sided adhesive tape to the top of the ESC, and mounted it upside down to the aluminum plate. I then wrapped a velcro tie around the whole thing to keep it in place. I was happy with this method for two reasons. The first was that it placed the ESC's heatsink in direct contact with the aluminum plate, which itself has cooling fins on the bottom. The second reason was that this also placed the ESC cooling fins directly in the opening of the canopy, ensuring air travelled through the fins. The reason the material was cut away from the clamshell was to allow the wires to curve upward, and not rub on the edge of the aluminum plate. I later cut and added some fuel tubing to the ESC wire as an extra precaution. You can see in the first photo below where the plastic needed to be trimmed to allow the wire to travel up and over the front of the ESC plate.
This also meant that the motor wires would not fit through the hole in the side frames that were designated for those wires. This was not an issue, as I simply looped the wires around the back and down around the side frame. I glued a square piece of the soft fuzzy side of velcro to the inside of the canopy just to make sure there was no chafing on the motor wires.
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Flying
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There were a few things I needed to do before I could really fly the Goblin the way I wanted. I "guesstimated" some throttle curves so that I could fly with the governor disabled while I set up the CGY750. I use linear pitch curves, so once I had set the pitch range mechanically, there was very little to do in the radio. I mixed in a little expo on the aileron and elevator too, just until I got used to the heli. I made sure that I had the WD40 handy to lube the gears, and headed out to the flying field.
After spraying the main and pinion gears with some WD40, I lifted off on the first flight. It was incredibly smooth, but I didn't get to enjoy it too much as I was concentrating on setting up the gyros. I limited my first few flights to just three minutes, until I had a better idea of how much my batteries were getting used. I spent the first three or four flights tuning the gyro and checking that everything else was still tight. I did some gentle forward flight, and progressed into faster forward flight to test the tail. Everything seemed good at the end of day one, but I still hadn't really flown the Goblin.
Now that the gyros were dialed in pretty good, I activated the governor mode on the Castle HV160. It's worth noting that there is a certain amount of setup that needs to be performed on the ESC itself, and if not done correctly you will not get the performance you are expecting. From my initial flights I found that with my gyro set nicely for higher head speeds, lower headspeeds would induce a little wobble. With this in mind I kept my rpms pretty close together, with normal mode at 2000rpm, idle up 1 at 2100 and idle up 2 at 2200. With the 24t motor pulley, the Castle software was happy governing at 2200.
After a few more flights of testing and tweaking, I felt confident enough to put a real flight on the Goblin. A little more relaxed, I flew the Goblin through most of what I could do. One of the first things I noticed was how quick it was to respond to pitch inputs, the KDE 700 is a monster motor and pulls the Goblin through the air as though it weighs next to nothing, and those Torq cyclic servos are extremely quick and precise. The tail blew my mind as well. With the Torq servo on the tail as well, combined with the CGY750, the tail is lightning fast and stops instantly with no bounce at all. It just starts and stops exactly where you want it.
Because of the sleek nature of the Goblin, it is one fast heli! I couldn't believe how quickly it would climb, and high speed passes were a lot of fun. With the canopy wrapped around most of the mechanics, blending in with the boom (that doesn't need any external boom supports), the Goblin is very aerodynamic and it certainly shows in the air. It tracks as straight as an arrow, and rolls are very axial. That being said the Goblin is also a 3D monster, with that much power you can flip flop the Goblin around without any worries of bogging the motor. The HV160 and KDE 700 seem to be a great match for each other, I don't recall a single moment when I thought "uh oh, too much collective just bogged the motor". However, after a little down the deck smack, there is that inevitable grin that comes from a high speed pass, especially when your heli is faster than most of the planes out at your field...
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Video/Photos
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This video below shows me getting more comfortable after about 20 flights.
To see what a real pro can do with the Goblin, you should watch this video of SAB team pilot Bert Kammerer.
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Conclusion
| So far I'm a big fan of the Goblin. SAB seem to have their ear to the ground, and are listening to feedback from pilots and continue to improve upon the design. They did have a few bumps in the road initially, and issues have been addressed and problems solved. I have no doubt that we will continue to see great things from SAB as time goes on. In the mean time I will thoroughly enjoy my 700. I see my Goblin and I progressing together, myself improving on my skills, and the Goblin giving me the confidence to push myself further. It really is a joy to fly, and to anyone who is on the fence about getting one themselves - do it! |
| Pros | Cons |
| Innovative Design | Servo needs to be removed to adjust horns |
| Extreme performance |
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| Looks and feels great! |
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Discussion
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Aug 07, 2012, 06:35 PM
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Southern California
Joined Feb 2006
1,993 Posts
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Oops...see my post below. I hit the button twice!
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Latest blog entry: Soapbox time
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Aug 07, 2012, 06:36 PM
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Southern California
Joined Feb 2006
1,993 Posts
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Bellissimo, amice!
That is one good-looking Italian there, bro. Beyond cool. |
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Latest blog entry: Soapbox time
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Aug 08, 2012, 10:41 AM
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Rocky Mount, NC
Joined Apr 2001
5,663 Posts
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Awesome review Chris, thanks for posting! I've watched videos of the Goblin 700 for a few months now and even though I don't fly 3D, my jaw hit the floor in watching what this heli is capable of. It's too bad it's not designed for my style of flying as I'd love to have one. A hobby shop owner near me had assembled one but not yet flown it and I was facinated with its construction and belt-drive layout.
Thanks again, and enjoy! |
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Latest blog entry: Chaos 600 ESP build
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Aug 08, 2012, 12:13 PM
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Oak Ridge, NC
Joined Jun 2006
1,163 Posts
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Quote:
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Aug 08, 2012, 12:20 PM
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Rocky Mount, NC
Joined Apr 2001
5,663 Posts
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Quote:
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Latest blog entry: Chaos 600 ESP build
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Aug 08, 2012, 06:08 PM
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Nampa, ID
Joined Oct 2009
487 Posts
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I though I saw Bruce Jenner on TV the other day with one of these.
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Aug 08, 2012, 07:23 PM
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Oak Ridge, NC
Joined Jun 2006
1,163 Posts
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Aug 09, 2012, 06:23 AM
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United States, NC, Stokesdale
Joined Jul 2006
241 Posts
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Im not a heli guy, but watching that thing fly gives me a chubby.
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Aug 10, 2012, 08:15 AM
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Dayton, OH
Joined Oct 2006
868 Posts
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RE: Bruce Jenner
Recent article on Bruce Jenner and featuring his Goblin, in part.
http://www.esquire.com/features/bruce-jenner-0612 And while it's clear the Goblin is a marvel of engineering performance and will set the direction of our helis in the future, I must say that even after all these months, its bionic dragonfly look still has me left a little cold. 
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Last edited by FNFAL; Aug 14, 2012 at 07:49 AM.
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Aug 12, 2012, 03:13 AM
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United States, MO, Springfield
Joined Jul 2010
2,956 Posts
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nice i might have to get a red one
every one knows red makes it go faster |
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Aug 19, 2012, 06:07 PM
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Joined May 2012
552 Posts
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Wow, that Kammerer dude has me GREATLY humbled...that was one of the better reviews for ANYTHING I've seen in quite some time. Wouldn't get one of these for my flying style, but they do look like a winner!
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Aug 19, 2012, 11:16 PM
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Mali, Tombouctou, Timbuktu
Joined Aug 2012
391 Posts
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Not at all keen on the cosmetics of this thing, even though it's a little different than the norm', and would probably pick the Gaui x7 over it if and when I decide I want a 700.
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Aug 23, 2012, 12:11 AM
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Oak Ridge, NC
Joined Jun 2006
1,163 Posts
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Aug 23, 2012, 12:36 AM
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Mali, Tombouctou, Timbuktu
Joined Aug 2012
391 Posts
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I need to thin down my fleet before I even think about it though, as I'm already lacking space in this one bedroom accommodation. Will be closely watching this thread.... Subscribed. |
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