swingarm, Radian or braced stock

[xstim]

Any thoughts on how a stock braced swingarm (in the traditional bent tube under on legs) would compare to a Radian swingarm. I am making a Cafe, I don't mind the old school looks but do want a good set up.
I am also open to a third option.
Cheers
Tim

 

[dwyatt]

Consider an arm from the TX750. Only made them a year or two, back in the 1970's. It is exactly the same design, but with larger diameter tubing. Strong, but a direct bolt-on and very subtle way to get where you're going and usually inexpensive. I went this route and enjoy correcting folks that insist on telling my I should have done something to the swingarm to avoid flexing.

 

[5twins]

As a third option, yes, you might consider the swingarm from the old TX750 twin if you can find one. About the easiest swap out there, it pretty much bolts right in. It's identical to the 650 one in almost every way - length, width, axle size, pivot bolt - but with one major difference - nearly 1/4" larger diameter tubes. It looks stock unless you park next to a 650 with the original arm in place, then you'll notice.

 

[ady66]

The TX 750 has a drum brake and a torque arm mounted on the underside of the swingarm. If you have a disc rear brake you'll have to weld a new mounting bracket on the top of the swingarm and extend the torque arm slightly (25 mm or so) to clear the rear shock. I did this conversion on my '79 SF and it does otherwise bolt straight in. I was however disappointed that it still won't out-handle a YZF.

 

[xstim]

Hey, thanks guys.
It does seem hard to make an old, well very old, bike ride like a new one but we keep trying.

 

[MrBillohnooo]

I am working on modding a early 80's aluminum YZ monoshock arm to accept dual shocks. The pivot is the same diameter/width, on needle bearings. It is also about 4" longer, and will accept a massive tire. It will not clear the stock passenger peg mount brackets. The axle will work. I should be done next week with it. I will post pics when done.

 

[xstim]

How is that Alum swingarm comming along?

 

[MrBillohnooo]

I have the shock mounts welded on, using clevis mount bottom attachment shocks...nos marzocchi units. doing the swap to a rd400 rear wheel at the same time. waiting on a sprocket right now. Should have it together soon. Will post pics as promised when done as promised.

 

[pa23driver]

so dwyatt, i'm building a street use cafe racer, do you think the tx750 swingarm would make a huge difference on the road?

 

[dwyatt]

It should, the stocker is a bit weak, however, if you aren't going to ride all that hard, may not be a big difference. Be sure to change out the plastic pivot bushings for bronze or needle bearings, that's the biggest difference for the street.

I finally got my bike on the track and didn't notice any flex problems using the TX750 arm. I found mine on eBay and it came with a rear wheel as well, all for about $125.

 

[pa23driver]

well my previous bike was a 2006 v-max, an absolute blast on the straight-line but a bitch in the curves, i also rode a roadstar around for a while (handled great, just didn't have the ground clearance) with this build i'm looking to tear up some corners on the street with no intention of ever putting her on the track. so far i've got needle bearings where ever you can put em, progressive 14.5 shocks in the rear, progressive fork springs in the front, and fork brace

i guess i'm asking is the swingarm worth $45 shipped for street use, and will the stock 18 inch spoked wheel fit without modification?

i really appreciate your input seeing as how you've tracked your skoot. BTW beautiful build you got there.

 

[5twins]

I felt a big difference at all speeds with the TX750 arm - and I still haven't swapped out the plastic bushings yet. That's the thing about many of these TX750 parts. The motors were bad so many times you get chassis parts that are like new with only a few thousand miles on them because the motors crapped out. $45 is cheap for one of these arms now that people know they fit 650s. I should have kept my mouth shut, lol, at least until I was able to latch onto a few cheap.

The 650 wheel will swap right in or use the 750 one. I swap back and forth between 650 and 750 rear wheels as I wear tires out. I have the 2nd wheel ready to go with new rubber. I also have them geared differently, 32T on one, 33T on the other.

 

[pa23driver]

well, i went ahead and took the plunge, i'll give both the stock and tx750 swingarms a shot seeing as how the stock swingarm is being powder coated as we speak. atleast i know i can recoup my costs if i don't find a difference.

sorry to hijack the thread, but i hope xstim found the discussion informative.

 

[dwyatt]

Yeah, I agree, for $45 you'll get a better handling bike and the satisfaction of knowing you made a good build decision. Don't go by me though, I turned a 25 year old $1000 bike into a 28 year old $7000 bike, but it's way cool. Another advantage of the TX 750 wheel is that it has much larger brakes,so should stop better, but finding new shoes and spokes is more difficult. I went with 18" front and rear, but don't runa speedo, so no worries on that up front.

The longer rear shock will help, both is better ground clearance and better weight distribution. I went more extreme in this area, but mine was built for the track.

 

[pa23driver]

well so far i've turned a $600 bike into a $3000 project (counting tools) so i feel ya. it's been a blast though. right now i'm looking to keep the character of the stock bike intact, just add some handling improvements. i plan on keeping her around for a while - i've never had this much fun working with a motorcycle - down the line after i've experienced it for what it is i'll add further improvements.

the roads around here are terrible, northern michigan winters raise hell with the roadways, so anything more than this upgrade will be negated by the shitty surfaces, unless i decide to track it.

 

[dwyatt]

It is all consuming, before you know it, you're addicted.

 

[5twins]

I thought brake shoes for the TX750 wheel would be a problem as well but it turns out they're not. Yamaha continued using that shoe on different models, including some Viragos, all the way up through the '90s. Contact 3M at 650 Central, he can set you up with some.

 

[dwyatt]

Spokes were my issue, I was too lazy to keep looking, so went with the XS wheel. Still have the 750 hub, so may use it at some point.

 

[gggGary]

Color me shallow but putting on a TX750 swing arm is like peeing in dark pants. It will give you a warm feeling but no one will notice. This may be heresy but I have even thought of DIY bracing a stock swing arm just so it looks trick.

 

[aldo5468]

Kinda depends on the "look" that you as the owner/rider want - I have pages of changes in my little log book to the Heritage Special I bought last Spring, mostly the usual reliability-improving suspects like new fuse holders, relay for ignition coil power, long clutch pushrod w/ new seal, fork brace, etc., plus a few cosmetics like bobbing the turn signal stalks, but strive for a "near stock" look, so the TX750 swingarm (w/ bronze bushings and central grease fitting) meets that criterion for me. Can't really say how much it might have improved handling, cuz I still have to replace tires, rear shocks and ball bearings in steering stem with tapered ones. Also think I'll go to an 18 inch rear wheel.