Is a Radian swing arm a worthwhile upgrade from the stock RD400 one?
Robakun has done it.
Went ahead and got one local (off eBay), complete w adjusters, 2 axles and swing arm pivot bolt. Looks like it's 3 inches longer than my RD swing arm, from pivot to mid axle. 19.5 inches vs 16.5 stock arm. Wonder if this is too long? I could probably cut off about 1 inch in length, and elongate the axle holes if I had too. The swing arm pivot and axle widths look the same (eyeballing it w a tape measure). I'll have to relocate the shock mounts forward and inward, but that should not be difficult. Anyway, this is all a ways down the road from being mounted up. Just collecting parts :clap:
3 inches longer may be too much of a good thing, at least if you are planning to use the stock rear fender, chain guard, seat etc. I guess it will also tame any wheelie tendencies quite a bit. I have never ridden a 400, but have owned and ridden 2 RD 350s, which have a shorter swing arm and wheelbase than the 400. With a race type seat, and maybe a longer tank, it may still look fine with 3" longer swing arm, especially if you plan to use some of the longer expansion chamber exhausts. Stock exhaust may also create problems when fitting a longer swing arm, at least it does on the 350. The mufflers are dimpled for rear axle/ nut clearance.
Yeah, I was thinking of going with a tracker type seat, and altering or changing (or eliminating) the rear fender. It came with shortish chambers that end about 3-4 inches beyond the rear axle. Might make it easier to get to the axle and chain adjusters? Anyway, no final decisions yet.
Quote from: pdxjim on August 28, 2022, 11:39:40 AM
Robakun has done it.
I see that irk_miller also has a Radian swing arm, but his is a 350.
I have an fzr400 aluminum arm on my 350s framed hybrid. Its 4" longer than a stock 350 arm, so the same length about. I like it. and yes, it def helped keep the wheelies under control.