New build Kyosho Triumph.

[Coelacanth]

I got around that, at least with the Optima series, by installing aluminum rear arms for the Tamiya TF-02, which are an almost perfect swap for stock Optima/Turbo Optima/Mid rear arms, but are exactly 5mm longer. AsiaTees.com even has them in black anodized aluminum so they'll almost look stock. With these arms, you just need a few spacers on either side of your hubs to eliminate side-to-side play and you can use either 65.5 or 68mm CVD's. I have this setup on 3 of my cars. (It's also hella cheaper than Pargu's alloy arms.)

http://www.ebay.ca/itm/BLITZ-CNC-ALUMINUM-ALLOY-REAR-LOWER-ARM-WITH-PINS-FOR-TAMIYA-DF02-DF-02-/390571261337?pt=Radio_Control_Parts_Accessories&hash=item5aefdc7d99

I don't know about the Triumph rear arms, though...are they similar to Optima arms, or closer to Ultima arms?

[losiXXXman]

I've never held a Triumph, but I'm pretty sure its arms are longer than Ultima, and ProXL Ultima. FWIW, Tamiya DB01 rear Uni's are 64mm, and available from many of the Asian aftermarket suppliers, as well as the genuine Tamiya ones. I've been thinking of trying them out. I think they may work as I have to limit droop on my Ultima to keep bones from popping out, so it seems that a little bit of extra length will still fit. I got the idea from a discussion in the Yoke forum where someone was using them as a replacement for the really expensive Yoke Uni's.

[Coelacanth]

Sounds like a good idea to try out. At least with CVD's, I seem to think Tamiya's units (or was it HPI?) are the reverse of Kyosho's; i.e. with Kyosho's, the ball ends are on the axles, the cup ends are on the dogbone ends. I think Tamiya has the ball ends on the bone side and the cup ends are on the axles. That wouldn't really matter unless you were trying to mix & match (which I ended up doing to get a narrow enough track width for CYANide). And the Tamiya axles would be straight 5mm diameter axles with crosspins instead of tapers?

[rccars4sal]

Triumph rear arms are slightly longer than opt mid rear arms, and slightly shorter than lazer zx zxr rear arms. Pretty much right in the middle of the 2.