Kai City RC

Tamiya requires the use of LiFe batteries in all their official Gran Prix and Challenge Cup races held at various venues around Japan. So if you're planning to enter then you have to use their batteries. They also only allow the use of NICAD, Nimh or LiFe at their circuits. Kyosho also do a similar thing with their official races, even requiring the use of their "LiPO Battery Protector" during charging. LiFe batteries are relatively expensive from a voltage and mAh capacity standpoint. But they are seen as a safer technology, particularly where younger hobbyists are involved. They also have a longer lifespan than typical Lipo packs. Although they lack the voltage of a 2S Lipo pack, they can be quite punchy if charged/discharged in the right manner (lots of amps!). Perhaps their biggest advantage is their light weight. In a Vintage Class race during last year's Yokomo Offorad Festival I won the B Main with a LiFe Powered Optima. The race regulations stipulated NICAD, NiMH or LiFe. I opted for less volts, but lighter weight.

Without the chain guide/front brace and battery tray installed there is a whole lot of flex in the chassis. However, with it in place, it's surprisingly sturdy! What little flex remains isn't anything to worry about. I've not got an original to compare it with, so can't say for sure if they've changed the specifications. Overall the buggy seems sturdy enough, despite being mostly plastic. I think the weak point will be the steering. The thin wire joining the steering bell cranks together tends to bend on hard crashes - I've bent the one in my 870c twice now! Thanks for watching. Your support is very much appreciated. 😊

Although it comes pre-assembled (Yokomo state they did this to mimic how it was originally sold) there is some disassembly required to fit the motor and electronics. I ended up taking the gearbox apart out of curiosity. I would have liked to build the entire kit myself, but understand why Yokomo went in the direction they did. That said, over here the retail price is exactly the same as the superior 870c. Overall I feel that buggy is better value for money. The 834B sure does look cool though and I look forward to running it.

I don't have the HG shocks on my Beetle, but I've seen others with them fitted and they *just* clear the body - no need to modify the cut lines.

Thanks! I've had a few people tell me my videos are the reason they got addicted to vintage Kyosho re-releases. 🤣 Now, if only Kyosho would realize I'm acting as an ambassador for the brand and perhaps send a few perks my way! 😀

That is correct, the low friction belt used in the Optima Mid (and now Optima Pro) is slightly longer.

Interestingly, in the re-release Optima Pro manual there is a section on setting the belt tension. It says the weight of the buggy (without battery) when held vertically by the bumper is the correct tension for the belt. The Optima Pro manual can be downloaded from the Kyosho homepage. 👍

Seems the pictures I originally posted didn't work.

Super excited for the latest addition to the Vintage Series from Kyosho. The Optima Pro arrives in late May, along with a new Lazer based 4WD kit with Dirt Master styling. 👍 IMG_6304.webp IMG_6303.webp

Thanks for the replies. 👍 I plan to head to the circuit later today to confirm what motor can be run. I'm probably going to go with either the Dirt Tune or GT (whichever is permitted) for the extra torque and better cooling. The rules also state that you can run a different machine in each round, so I'm planning to prep three machines - the Genova, Dirt Master and S1 RM. The plan is to compete with a different buggy in each round to keep things interesting. CoreRC are not very common over here and the track I run at prefers to spec "slower" motors for the races (usually silver cans). But while the speeds might not be so high, the races are no less fun. Nevertheless, it would be good to use a motor with a built in fan! We have to build custom mounts to install them on the DT-02 and Grasshopper.

Thanks for the responses! I'm a huge fan of the Kyosho Legendary series and it would be great to run a Turbo Scorpion or Tomahawk. But they aren't really suited to indoor high grip carpet tracks. Likewise, I love the looks of the BBX, the Blitzer and Wild One. It would be great to see them out on the track, but perhaps not the best choice for racing. I'm leaning towards the Dirt Master, Genova or S1 RM. What about motor? The regulations are either 540 silver can, OP.68 Sport Tune or Dirt tune. (I need to clarify the race regulations, as the text states "Dirt Tune" but the item code given is OP.779, which is the GT Tune.) According to Tamiya's website, here's how they stack up: Sports Tune 23T 350gf･cm and 18300rpm @ 7.2V GT Tune 25T 500gf･cm and 19,000rpm @ 7.2V Dirt Tune 27T 37.24mN･m and 17,000rpm @ 7.2V The latter two also have the benefit of replaceable brushes. What's would you consider more important - turn, torque or rpm?

I'm after some ideas for what to run in a new race series being held at my local indoor, off-road carpet track. If you're familiar with my channel you'll know I raced in both the DT-02/03 and TT-02B Race series last year. This year a new race series will be held and these are the regulations. 🤗 Must be RWD with the motor mounted behind the rear axle. Must use the kit supplied body, gearbox and spur. Must use either a Sport Tune or Dirt Tune motor Gear ratio must be 8.0:1 or above. Control tires are Tamiya Square Pin Spike front and rear. Aside from that, new or old anything goes! A few notes about the races. Small(ish) indoor high grip carpet track, narrow lanes, jumps and banks. Races are generally 3 to 5 laps and points are awarded depending on finishing order. Death Match style rules.There are NO MARSHALS. Flip over or get stuck and you're out! Some of the "suggested" chassis include the DT-03, Wild One, Blitzer Beetle, BBX, Ultima, Turbo Scorpion, Dirt Master and Genova. (based on what is commonly run at my track, the latter two will likely be the most popular choice.) I'm not very competitive and I enjoy racing just for the fun of it. Nevertheless, I took 2nd place overall in the TT-02B Cup and I'll admit it's nice to cap of a fun nights' racing stood on a podium. 😁 So if you were in it to win it, what would you run and why? (Here are some links to our recent races)

So far no word on spares for the 870c here in Japan. I doubt they’d release a buggy without parts support, but until I can order spares (if needed) it is making me hesitant to run the 870c on the track!

Blue is the best color for the Tomahawk! (I may be biased ) And I thought I was addicted to the Legendary series, with about 15 kits in total! 😅 But you've taken it to the next level! Quite the collection! 👍🤩

It’s due here in Japan on the 15th. I’m not in any hurry to build it. Still haven’t built my JJ Ultima! 😅 Next build for me will be the Super Dogfighter. 👍