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The 2-Stroke Garage => Turning Wrenches => Topic started by: 85RZwade on September 01, 2020, 09:18:07 AM

Title: Aluminum swingarm quest
Post by: 85RZwade on September 01, 2020, 09:18:07 AM
Aluminum swingarms come up from time to time; we all seem to want them, but they're hard to find and/or $$$. Jim recently posted a link to a site in Japan auctioning a ZRX400 arm that was relatively cheap, aluminum and designed for twin shocks. I've looked for years at and for Zephyr 550 arms.
I'm thinking of RDs, but information for any twin-shock bike is of interest.
Besides the DG, Calfab and custom-made beauties, what else is out there in the OEM world that people have used? What did it take to make it fit?
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 01, 2020, 09:32:37 AM
oem bolt in? pretty much: zero. I modded an fzr400 arm but its almost 4"  longer and required machining and welding.  :twocents:
Title: Re: Aluminum swingarm quest
Post by: oxford on September 01, 2020, 09:43:52 AM
From what I have seen recently the MotoLanna arms seem like the best deal for the money vs looks vs modifying it vs availability/lead times.  They are a little more modern looking so if you want that old school aluminum arm look it is probably something else.
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 01, 2020, 10:03:43 AM
^ this. or the one in the for sale section direct bolt in and do.
Title: Re: Aluminum swingarm quest
Post by: pdxjim on September 01, 2020, 11:36:02 AM
There are quite a few JDM bikes that look close.

Most are the 250-400 versions of the bikes we get here

ZR400, ZRX400 and XJR400 are the most obvious choices

Will likely require a bit to fit, but the buy in is certainly worth the gamble in my eyes
Title: Re: Aluminum swingarm quest
Post by: RDFL on September 01, 2020, 12:40:49 PM
Quote from: m in sc on September 01, 2020, 10:03:43 AM
^ this. or the one in the for sale section direct bolt in and do.
So that's where that thread is. anyone know if he has any made yet?
Title: Re: Aluminum swingarm quest
Post by: oxford on September 01, 2020, 01:01:37 PM
Just a little warning about those swingarms in the for sale section.  He genuinely seems like a good guy but when I got one of them like 2 years ago he was having health issues that may or may not be ok now.  This means communications on his end will drop off to zero if he has your money or not. 

Also the arm I received had the pivot holes where the bushing goes not bored straight to each other so you couldn't install the pivot bolt with out major binding.  I finally got a refund on it but it took a ruined set of bronze bushings, me having to machine bushings to prove it was the bores and not wrongly installed bushings, many photos and texts sent back and forth,  me having to send the swingarm back before a refund and like mentioned above some very long spurts of zero communication.  I had pretty much written off getting any money back.

I don't want to take anything away from them because it looked like a very nice arm and I would have loved to use it but there was now way I was going to take a chance on a replacement arm. 
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 01, 2020, 01:25:33 PM
Danny needs to make some 4130 ones. Just tossing that out there.

:whatever:

Title: Re: Aluminum swingarm quest
Post by: RDFL on September 01, 2020, 01:58:05 PM
Quote from: oxford on September 01, 2020, 01:01:37 PM
I do wonder why MotoLanna won't make one for RD's
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 01, 2020, 03:41:29 PM
Quote from: m in sc on September 01, 2020, 01:25:33 PM
Danny needs to make some 4130 ones. Just tossing that out there.

:whatever:
Oh, yeah! With a sexy curved brace below like an 80's superbike! Are you there, Danny? You'v been volunteered...
Title: Re: Aluminum swingarm quest
Post by: rodneya on September 01, 2020, 04:54:33 PM
Metmachex in the UK will make one, but at over 500 GBP plus shipping it is very expensive

Gigabikefactory is similar to the Motalana for a SR500 and will need mods. There is also a 3 month lead time.
https://japan.webike.net/products/23209961.html (https://japan.webike.net/products/23209961.html)

I have contacted Tractech Manufacturing in Niagra. He makes billet RD top triple clamps, fork braces and tach drive block offs.
He agreed to make a swing arm for my 350, but he is not fast. You could try contact him, more interested parties may add some speed to the process.
Title: Re: Aluminum swingarm quest
Post by: 27 Cycles on September 01, 2020, 06:17:49 PM
PM me..  I won't do aluminum arms but yes I build the arms just like you see on my bike and Mark's.  And a few others...😎
Title: Re: Aluminum swingarm quest
Post by: sav0r on September 01, 2020, 07:09:48 PM
Honest question, since I am likely below average age here, I don't have the sort of historic understanding RD's like many of you. I simply wasn't alive. But is the desire for an aluminum box section swing arm simply to achieve that DG (or other) look?

The reason I ask is that from an engineering perspective I see no real benefit of a rectangular section swing arm on a twin shock bike. It just seems like extra material. An aluminum round tube swing arm would be lighter, and likely perform just the same.

If it's for nostalgia, I can understand that.
Title: Re: Aluminum swingarm quest
Post by: ace787 on September 01, 2020, 07:33:56 PM
look in the for sale section. 
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 01, 2020, 08:50:42 PM
Chris, I can only speak for myself, and I'll try to keep it short. From an engineering standpoint you're right, but I think it's that racing association: light is right. And I read an article once about humans developing tastes and preferences in their 20s, which explains my preference for the look of the OW01, RC30, any YZR500. Current Moto GP bikes are amazing, but their styling is a bit...organic for me.
I'm gonna look at Danny's bike some more now, once I find my reading glasses, and maybe a shawl. You kids get away from the thermostat!
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 02, 2020, 12:20:31 AM
I looked a little further into buyee, the buyer service in Japan. As luck would have it, the author bought an XJR400 swingarm and his story is pretty funny:

http://visor.vision/part-9-swingarm-debacle-2-when-buying-cheap-isnt/ (http://visor.vision/part-9-swingarm-debacle-2-when-buying-cheap-isnt/)

Maybe I should just buy a TIG welder. And a lathe. Vertical mill would be swell, and a bandsaw...
Title: Re: Aluminum swingarm quest
Post by: pdxjim on September 02, 2020, 02:42:29 AM
Hmmm...

I have bought tons of parts off Yahoo Japan.  When you're a JDM fan, it's pretty much the only game in town.

I always went thru a private middleman.  The guy I used was Drew "Moriwakiman" Jonsen, a British guy living in Japan. 

I would tell him my max bid, he would bid on the item and usually win.  He would then arrange shipping to his place in JP, then send it on to me here in the states. 

He charged 10% of the purchase price as his fee, and charged actual cost shipping.  Due to the inexpensive cost of the parts and relatively modest shipping charges, it always felt like a good deal.

I believe he is still in biz, but it appears he's dealing with some health issues at  the mo, and may be on hold.  Beware, we are friends on FB and he is a (sometimes heavy) drinker and a loose AF cannon.  Solid tho and has never let me down.

I have no experience with buyee, jauce, or any of the other online middleman services.

https://www.facebook.com/groups/unobtanium

https://twitter.com/moriwakiman?lang=en

I have also had good luck buying JDM bits from Naiomi at https://miyabeeplus.co.jp

They are a breakers and bike exporter in Chiba.  Great English communication, and I have a good friend in Seattle who has bought multiple containers of JDM bikes from them with no issue.

lots of parts on the site, and if there is something specific you are after they can usually get it without too much struggle.

They have had a booth at Mid-Ohio the last few years and are working hard to bring JDM bikes and parts to stateside buyers

Hope this helps.

Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 02, 2020, 09:48:52 AM
And there are many swingarms on eBay for less than $100...of course they're nearly all single-shock designs that would need the attention of the aforementioned TIG welder. This guy, however, knows that he has what some people want and has priced it accordingly:

https://www.ebay.com/itm/Kx-125-250-Aluminum-Alloy-Swingarm-Custom-Cafe-Racer-Bobber-Street-Tracker/193539394281?hash=item2d0fd8cae9%3Ag%3AUnIAAOSwjZlb3Qts&LH_ItemCondition=4 (https://www.ebay.com/itm/Kx-125-250-Aluminum-Alloy-Swingarm-Custom-Cafe-Racer-Bobber-Street-Tracker/193539394281?hash=item2d0fd8cae9%3Ag%3AUnIAAOSwjZlb3Qts&LH_ItemCondition=4)

Title: Re: Aluminum swingarm quest
Post by: m in sc on September 02, 2020, 10:20:48 AM
or just get the motolana arm and be done with it. minimal mods needed instead of fussing with all that. or,t he ones listed in the fs section. Im all for modding and making stuff fit, but after a debacle i had with jmc 10+ years ago,  id just go the other way and try to go domestic if a direct fit is available.  :twocents:
Title: Re: Aluminum swingarm quest
Post by: dusty350 on September 02, 2020, 01:58:31 PM
Metmachex, in the Uk, make some stunning swingarms, both standard fitment and bespoke to suit whatever you are building. Whenever I start a project now, I always budget for a Metmachex swingarm. Light, super strong, awesome looking too. Eccentric adjusters on these arms to suit Rgv wheel in an Lc;

(https://live.staticflickr.com/65535/50298702606_34ff973055_4k.jpg) (https://flic.kr/p/2jCHZUs)20171015_161428 (https://flic.kr/p/2jCHZUs) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

Standard fitment Lc wheel, with straight pull chain adjustment;

(https://live.staticflickr.com/65535/50298021733_e3226e2662_4k.jpg) (https://flic.kr/p/2jCEvvg)20190325_163451 (https://flic.kr/p/2jCEvvg) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

Lc arm to take Rgv wheel with straight pull adjusters;

(https://live.staticflickr.com/65535/50298021133_81a1f60f5b_4k.jpg) (https://flic.kr/p/2jCEvjV)20190831_093607 (https://flic.kr/p/2jCEvjV) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

And the first Rd aircooled arm to take an Rgv wheel, with straight pull adjusters;

(https://live.staticflickr.com/65535/50298700936_bfb77a60f9_4k.jpg) (https://flic.kr/p/2jCHZpE)20200812_142049 (https://flic.kr/p/2jCHZpE) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

Great people to deal with - Garry and his partner Tamsyn. Garry has been welding swingarms since he left school, and is a top guy ;D

Dusty
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 02, 2020, 02:39:22 PM
had one on my rz, the quality was  :nana:
Title: Re: Aluminum swingarm quest
Post by: oxford on September 02, 2020, 02:48:55 PM
Quote from: 85RZwade on September 02, 2020, 09:48:52 AM
And there are many swingarms on eBay for less than $100...of course they're nearly all single-shock

Problem I found with the single shock swingarms is length.  Most of them are long compared to what is on a vintage twin shock bike.  Mark had mentioned this above with the FZR arm.  A lot of them are not very easily modified to get the length down.  Unless you are looking for a project they are not worth it.

I played this game with a Kawi h1 and a Yamaha secaII swingarm.  I cut the arm to length and welded in custom eccentric adjusters.  Then cross bracing near the pivot had to be cut out and a new one put in because the tire was too close.  It was also getting a little close on the sides from the arm tapering in but it made it.  This was also a steel arm, not aluminum which made things a little easier.

On Edit, here is the link to that bike with the swingarm.  It looks like all the pictures are up but have the photobucket water mark.  Note, the swingarm pics are of version 1, version 2 was remade and was a little longer.  The cross brace didn't have to come out but was modified.  You can see version 2 in the later pics.

http://kawi2strokes.com/forum/viewtopic.php?f=16&t=6302
Title: Re: Aluminum swingarm quest
Post by: RDFL on September 02, 2020, 02:49:07 PM
Quote from: dusty350 on September 02, 2020, 01:58:31 PM
Metmachex, in the Uk, make some stunning swingarms, both standard fitment and bespoke to suit whatever you are building. Whenever I start a project now, I always budget for a Metmachex swingarm. Light, super strong, awesome looking too. Eccentric adjusters on these arms to suit Rgv wheel in an Lc;

(https://live.staticflickr.com/65535/50298702606_34ff973055_4k.jpg) (https://flic.kr/p/2jCHZUs)20171015_161428 (https://flic.kr/p/2jCHZUs) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

Standard fitment Lc wheel, with straight pull chain adjustment;

(https://live.staticflickr.com/65535/50298021733_e3226e2662_4k.jpg) (https://flic.kr/p/2jCEvvg)20190325_163451 (https://flic.kr/p/2jCEvvg) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

Lc arm to take Rgv wheel with straight pull adjusters;

(https://live.staticflickr.com/65535/50298021133_81a1f60f5b_4k.jpg) (https://flic.kr/p/2jCEvjV)20190831_093607 (https://flic.kr/p/2jCEvjV) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

And the first Rd aircooled arm to take an Rgv wheel, with straight pull adjusters;

(https://live.staticflickr.com/65535/50298700936_bfb77a60f9_4k.jpg) (https://flic.kr/p/2jCHZpE)20200812_142049 (https://flic.kr/p/2jCHZpE) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

Great people to deal with - Garry and his partner Tamsyn. Garry has been welding swingarms since he left school, and is a top guy ;D

Dusty
Beautiful bikes, I have lusted after Meymachex arms for a long time.
Title: Re: Aluminum swingarm quest
Post by: rodneya on September 02, 2020, 02:51:15 PM
Quote from: m in sc on September 02, 2020, 02:39:22 PM
had one on my rz, the quality was  :nana:

So is the price by the time you get it landed in North America.
Id love one of them.
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 02, 2020, 03:06:26 PM
totally worth it. Sorry, they are really just awesome.

has anyone contacted billymack on his int he for sale section?

http://www.2strokeworld.net/forum/index.php?topic=2326.0
Title: Re: Aluminum swingarm quest
Post by: pdxjim on September 02, 2020, 07:42:38 PM
I still think seriously about a Metmachex arm for my LC.

Around $700 shipped from the UK, so really not that bad.
Title: Re: Aluminum swingarm quest
Post by: IR8D8R on September 04, 2020, 04:43:31 PM
The Metmachex Engineering website says "As from 2017, Metmachex no longer makes swing arms". Which confused me...

Then there is metmachexswingarms.com which advertises swingarms. They are apparently a spinoff. ...sort of.

I surmised that the son of the company founder left to pursue other business: "Billet World" whose site has some outstanding bike porn https://www.billetworld.co.uk/. (I am not completely sure what products Billet World has to offer except maybe a complete RD LC with some re-engineered parts made from billet and machined billet aluminum parts on request. There is not really a product list).

...and then the Metmachex owner sold the swingarm IP to the current operator of the swingarm manufactory (ex-employees) who named the business Metmachex Swingarms and continued the line. That doesn't entirely explain the current status of Metmachex Engineering which retains the name. Does all that make any difference? Probably not. I just thought it was interesting.

Straight-pull slotted chain adjuster RD 400 swingarm is $783.49 before shipping. All their arms are either 590 or 550 British pounds except the LC at 516.66 (excluding VAT). They make them for quite a few bikes but not the AC RD 350 (which was what I was looking for in the first place).
90 minutes I will never get back.

IR8D8R
Title: Re: Aluminum swingarm quest
Post by: RDFL on September 04, 2020, 05:21:57 PM
There is also Trac Dynamics - https://tracdynamics.com/collections/yamaha-swingarms/products/yamaha-rd-350-400-swingarms
Title: Re: Aluminum swingarm quest
Post by: bitzz on September 04, 2020, 05:28:42 PM
I've known Denis Curtis of CMR Racing for many years. He's the guy that makes the frames for the "Team America" FJs and TZs.
I needed a swingarm for a TZ350G, that I of course wanted since I am making it, made to custom dimensions... but that's another story... and he convinced me to make it in 4130 chrome moly.
The Chrome moly is more elastic than aluminum. All swingarms bend/twist and the steel ones return to original shape faster than aluminum. All the cool kids are using chrome moly swingarms. 
In the end, he built the swingarm for me (in and out, including the design, took 3 months) and I am happy with it and the price. Nice piece: 1x2 rec tube, billet swing arm pivot, supplied taper bearings, BEAUTIFUL welding, takes up to a 150 tire, 1-1/2" longer than stock.
I am looking at building a RD-LC this winter and thinking about running a GSXR based shock... soooooo I need another custom swingarm
If there is any interest I could ask him to make some more
Title: Re: Aluminum swingarm quest
Post by: dusty350 on September 05, 2020, 09:00:37 AM
Regards Metmachex - a quick history. Bill Ryde was/is the owner and founder of Metmachex. He has a son - Dean Ryde, who worked with his Dad in the firm. They did general engineering work as well as Motorcycle swingarms. Dean is a great machinist, but most of the welding was done by employee Garry Gratton. Dean is quite a difficult person to deal with to be honest - I bought my first swingarm from him in 2015, and he was an arse when the spacers were wrong. Got sorted in the end. In 2017, Dean left to start his own business - Billet world, but his Dad wouldn't let him carry on with the swingarm side, instead selling that to Garry, and his missus, Tamsyn. As said, Garry has been welding since he left school and started with Bill. Garry and Tamsyn are a joy to deal with, and my hybrid 400 swingarm is just stunning. I took the frame up to Derby when I collected the swingarm, and Garry did some minor alterations whilst I was there. Couldn't be more friendly and helpful, and I doubt you will find a better made swingarm anywhere;

(https://live.staticflickr.com/65535/50104472558_320c358f7a_4k.jpg) (https://flic.kr/p/2jkyw5w)20200712_124039 (https://flic.kr/p/2jkyw5w) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

The cross section;

(https://live.staticflickr.com/65535/50105284972_ea301e3e4c_4k.jpg) (https://flic.kr/p/2jkCFzE)20200712_124524 (https://flic.kr/p/2jkCFzE) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

(https://live.staticflickr.com/65535/50112082292_44a52389cb_4k.jpg) (https://flic.kr/p/2jmewbQ)20200714_122516 (https://flic.kr/p/2jmewbQ) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

I took a plastic catch tank with me as I wanted something a bit nicer. He knocked these up for me;

(https://live.staticflickr.com/65535/50126303791_f25aae1cc8_4k.jpg) (https://flic.kr/p/2jnupK6)20200718_152651 (https://flic.kr/p/2jnupK6) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

And due to the wider Rgv wheel, and subsequently wider swingarm, we needed to extend the top shock mounts. He did these on his lathe and welded them onto the frame;

(https://live.staticflickr.com/65535/50105053661_c0cab3c9ee_4k.jpg) (https://flic.kr/p/2jkBuPx)20200712_112736 (https://flic.kr/p/2jkBuPx) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

(https://live.staticflickr.com/65535/50104472858_0685c69572_4k.jpg) (https://flic.kr/p/2jkywaG)20200712_121338 (https://flic.kr/p/2jkywaG) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

(https://live.staticflickr.com/65535/50112082832_b14b3bfbe4_4k.jpg) (https://flic.kr/p/2jmewm9)20200714_122443 (https://flic.kr/p/2jmewm9) by dusty miller (https://www.flickr.com/photos/167361504@N05/), on Flickr

Bill Ryde still runs Metmachex engineering, but the swingarm side is a separate entity.

Dusty ;D
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 05, 2020, 09:22:51 AM
Thank you all for chiming in! This thread has produced some GREAT information  :patriot:
Title: Re: Aluminum swingarm quest
Post by: sav0r on September 05, 2020, 11:25:06 AM
Between the members here couldn't we do a run of aluminum swing arms?

I could machine the dropouts, shock mounts, chain guard bung, and the butt joints on the tubing. Somebody will have to bend the tube, do the welding, and machine the front tube to fit bushings. A jig should also be made.

I'd a guess that a minimum run of like 5 or 6 would be required, but given that this thread continues to march on that should be doable?
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 06, 2020, 08:14:25 AM
Oh, my. This has just taken a tantalizing turn... I would be in for an RD350 arm for sure.
Title: Re: Aluminum swingarm quest
Post by: sav0r on September 06, 2020, 07:18:23 PM
With fall just around the corner this is really the perfect time, IMO, to organize a project like this. If anybody is interested, either in purchasing an arm, helping fab, or both, send me a PM. Let's try to get it going.
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 06, 2020, 07:27:38 PM
and heat treating to be done correctly.

Title: Re: Aluminum swingarm quest
Post by: RDFL on September 06, 2020, 07:49:17 PM
Why reinvent the wheel, like I said in another thread someone with the equipment and skills could do what ever needs to be done, added to the motolanna and sell them.
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 06, 2020, 07:58:06 PM
i agree. a motolana arm modded for an rd ready to bolt in would be very useful and prob way cheaper.

or

4130.


:whistle:
Title: Re: Aluminum swingarm quest
Post by: sav0r on September 06, 2020, 08:17:37 PM
If I was going to design an arm for myself I'd use a thin wall 4130 that's slightly smaller in ID than the stock thick wall tube. I'd bend it, then flatten it slightly in the press so that the oval shapes thick section would be oriented laterally. This would make an arm that was both lighter and stiffer than the stock arm. For what though? There's no real reason to do it, so I've not done it. And I personally prefer the look of the round tube swing arm.

People seem to like that retro/monoshock look though.

As for heat treating, given the loads a twin shock arms sees, it simply isn't needed. Though I do agree it would be ideal.
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 06, 2020, 08:28:42 PM
should on the aluminum, just good practice. But as said, prob not needed.
Title: Re: Aluminum swingarm quest
Post by: rodneya on September 06, 2020, 09:19:05 PM
Quote from: m in sc on September 06, 2020, 07:58:06 PM
i agree. a motolana arm modded for an rd ready to bolt in would be very useful and prob way cheaper.

or

4130.


:whistle:

Only problem is Motolana does not offer longer lengths
Title: Re: Aluminum swingarm quest
Post by: oxford on September 06, 2020, 10:37:41 PM
Quote from: rodneya on September 06, 2020, 09:19:05 PM
Only problem is Motolana does not offer longer lengths

How long are you looking for?  Pretty sure they are +1 for a 400 and would be +2 for a 350.
Title: Re: Aluminum swingarm quest
Post by: rodneya on September 06, 2020, 11:00:35 PM
Quote from: oxford on September 06, 2020, 10:37:41 PM
Quote from: rodneya on September 06, 2020, 09:19:05 PM
Only problem is Motolana does not offer longer lengths

How long are you looking for?  Pretty sure they are +1 for a 400 and would be +2 for a 350.

Motolana arm is for a SR500, not and RD. It is 1/4 inch longer than the RD350 arm according to the internets.
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 07, 2020, 08:08:45 AM
im pretty sure nathan told me his was a bit longer than that on his 350. .02
Title: Re: Aluminum swingarm quest
Post by: rodneya on September 07, 2020, 01:03:47 PM
Dimensions for the Motolana that I found posted online a while back. No guarantee they are accurate.
length to mid adjustment 18.25"
Pivot spread 8.28"
axle spread 7.25"
Title: Re: Aluminum swingarm quest
Post by: oxford on September 07, 2020, 01:36:50 PM
Based on this picture I see 18.5" from pivot to axle.

I have a 400 arm on my bike and it measured around 16.5" from pivot to axle. 

Nathan reported the moto lanna to be 1" longer than stock 400. 

I have no real idea on what is what other than what the arm on my bike measures.

(https://uploads.tapatalk-cdn.com/20190424/340b633493b28f073d7a3a52adf56a74.jpg)
Title: Re: Aluminum swingarm quest
Post by: RDFL on September 08, 2020, 05:54:18 PM
What Tracs look like now. -- (https://i.imgur.com/W8PF9K8.jpg)
Title: Re: Aluminum swingarm quest
Post by: sav0r on September 08, 2020, 06:43:47 PM
It looks great, but it's an absolutely silly design.
Title: Re: Aluminum swingarm quest
Post by: oxford on September 08, 2020, 07:13:24 PM
Quote from: RDFL on September 08, 2020, 05:54:18 PM
What Tracs look like now. -- (https://i.imgur.com/W8PF9K8.jpg)

I had that picture in my head and couldn't remember who made it.  I can't believe they use solid bar stock and mill pockets in it. 
Title: Re: Aluminum swingarm quest
Post by: Jspooner on September 08, 2020, 08:27:50 PM
Quote from: sav0r on September 08, 2020, 06:43:47 PM
It looks great, but it's an absolutely silly design.

What's silly about it. It's kind of ingenious if you think about it and I'll bet it's not as heavy as you think it also might be less time to make that way. I like it.
Title: Re: Aluminum swingarm quest
Post by: sav0r on September 08, 2020, 08:43:12 PM
It's almost certainly heavier and weaker than a tubular design. They could have at a minimum done some actual shape optimization on those pockets. It's ingenious because they realized they can minimize their mill and weld operations to maximize their profit. Otherwise it's an inferior product. For the record, I don't actually see that arm on their site for RD's, or any other model for that matter. So maybe they have since discontinued it?
Title: Re: Aluminum swingarm quest
Post by: RDFL on September 08, 2020, 09:14:56 PM
Other way around it replaced the one pictured on site.
Title: Re: Aluminum swingarm quest
Post by: suey1958 on September 08, 2020, 10:21:14 PM
Very Nice looking design in my opinion,...I like it :clap:
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 09, 2020, 01:23:50 AM
+1 for the Motolanna
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 09, 2020, 07:08:06 AM
just looking at the 2 designs, the motolanna arm is going to be stronger where it matters.  the curve in the leg, the strengthening ribs on the outsides, etc. very well done, much more elegance of function of design. the trac arm is pretty clunky buy comparison. but, to be honest, on an rd, no one will ever come close to testing the strength of either. 
Title: Re: Aluminum swingarm quest
Post by: SoCal250 on September 09, 2020, 11:50:23 AM
Quote from: m in sc on September 09, 2020, 07:08:06 AM
the trac arm is pretty clunky...
That's exactly how I was going to describe it. Clunky looking
Title: Re: Aluminum swingarm quest
Post by: pdxjim on September 09, 2020, 12:31:04 PM
Quote from: SoCal250 on September 09, 2020, 11:50:23 AM
That's exactly how I was going to describe it. Clunky looking

Yup, and on a 2T twin with no torque, keeping everything as light as possible, and just strong enough is key.

Alloy has the bling, but in this application, chromo is the way to go.

Title: Re: Aluminum swingarm quest
Post by: sav0r on September 09, 2020, 03:07:57 PM
Can anybody provide me the dimensions of the rectangular tube stock on the DG or similar swing arm?
Title: Re: Aluminum swingarm quest
Post by: RDFL on September 09, 2020, 03:19:19 PM
Quote from: suey1958 on September 08, 2020, 10:21:14 PM
Very Nice looking design in my opinion,...I like it :clap:
Me too, looks way better than their original.
Title: Re: Aluminum swingarm quest
Post by: RDFL on September 09, 2020, 03:22:06 PM
The Motolanna and the Trac both look clunky the Trac less to me. The original Trac looked really clunky but tuff.
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 09, 2020, 03:39:06 PM
having have seen both in real life, im going to have to disagree that the motolana looks clunky by comparison.  either way, regarding the square stock, just use off the shelf.  https://www.onlinemetals.com/en/buy/aluminum/1-5-x-3-x-0-125-aluminum-rectangle-tube-6061-t6-extruded/pid/7021

Title: Re: Aluminum swingarm quest
Post by: oxford on September 09, 2020, 05:26:44 PM
Quote from: sav0r on September 09, 2020, 03:07:57 PM
Can anybody provide me the dimensions of the rectangular tube stock on the DG or similar swing arm?

I'm not sure what you are wanting to do with the info but be aware that some of the swingarms are using extrusions not simple box tubing.  I am pretty positive that the DG arms did use tubing though.
Title: Re: Aluminum swingarm quest
Post by: sav0r on September 09, 2020, 06:35:35 PM
I was just curious. The answer was mostly provided in the online metals link.
Title: Re: Aluminum swingarm quest
Post by: RDFL on September 09, 2020, 07:12:26 PM
(https://i.imgur.com/AxFpySd.jpg)
Title: Re: Aluminum swingarm quest
Post by: SoCal250 on September 09, 2020, 07:19:34 PM
Quote from: sav0r on September 09, 2020, 03:07:57 PM
Can anybody provide me the dimensions of the rectangular tube stock on the DG or similar swing arm?

Chris, I just measured a MotoCarrera arm that I have here. It's 1"x2" tube, and the pivot tube is 1.5" OD
Title: Re: Aluminum swingarm quest
Post by: sav0r on September 09, 2020, 08:47:32 PM
Quote from: SoCal250 on September 09, 2020, 07:19:34 PM
Quote from: sav0r on September 09, 2020, 03:07:57 PM
Can anybody provide me the dimensions of the rectangular tube stock on the DG or similar swing arm?

Chris, I just measured a MotoCarrera arm that I have here. It's 1"x2" tube, and the pivot tube is 1.5" OD

Thank you!
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 09, 2020, 11:58:07 PM
grade of aluminum is everything, and overall shape. hence the shape of the motolana arm makes it very strong. 6061 t6 box will do just fine as well. i mean, they were made in the 70s, and affordably sold, i would venture to say thats equivalent to what was used. .02
Title: Re: Aluminum swingarm quest
Post by: pdxjim on September 10, 2020, 02:00:14 AM
6061 is the current cheap bicycle frame material dujour, and has been for the past 20 years.

Too bad the demand isnt greater, because those same fantastic Chinese robot welders could be knocking out RD swingarms dirt cheap.

There are six chapters to this vid. It's worth watching them all.




Title: Re: Aluminum swingarm quest
Post by: rodneya on September 10, 2020, 01:09:02 PM
Not mine, but the Motolana doesn't look clunky at all
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 12, 2020, 01:33:57 AM
I suspect the Giga

https://japan.webike.net/products/23209961.html (https://japan.webike.net/products/23209961.html)

And the Motolanna super tuff w/welded shock mounts

https://www.motolanna.com/ourshop/prod_448876-Swingarm-Aluminum-Alloy-SuperTuff.html (https://www.motolanna.com/ourshop/prod_448876-Swingarm-Aluminum-Alloy-SuperTuff.html)

Are the same item. Is it just me?
Title: Re: Aluminum swingarm quest
Post by: pdxjim on September 12, 2020, 01:51:20 AM
Quote from: 85RZwade on September 12, 2020, 01:33:57 AM
I suspect the Giga

https://japan.webike.net/products/23209961.html (https://japan.webike.net/products/23209961.html)

And the Motolanna super tuff w/welded shock mounts

https://www.motolanna.com/ourshop/prod_448876-Swingarm-Aluminum-Alloy-SuperTuff.html (https://www.motolanna.com/ourshop/prod_448876-Swingarm-Aluminum-Alloy-SuperTuff.html)

Are the same item. Is it just me?

They are def close, but the dropouts aren't the same.
Title: Re: Aluminum swingarm quest
Post by: Cdffiredad on September 12, 2020, 02:21:23 AM
https://www.facebook.com/549685025368762/posts/1398045710532685/
Here's another I saw in a Facebook group the other day for LC models. Maybe he would do AC swingers as well?
Title: Re: Aluminum swingarm quest
Post by: pdxjim on September 12, 2020, 03:21:07 PM
That LC swinger looks pretty ruff.

$399 plus shipping from China.
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 12, 2020, 05:11:26 PM
lc arm will bolt into an aircooled frame. but yeah, not my cup of tea there at all.
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on May 01, 2021, 12:42:28 AM
Yeah, I know it's been awhile. Sometimes I need time to make hasty decisions... I ordered a Motolanna swingarm tonight, for my AC RD350 frame. Gas tank arrived from Striker1423 yesterday, and the top end is in the capable hands of Mr. Ritter. Need to figure out wheels and front suspension next, but no more purchases tonight!
Title: Re: Aluminum swingarm quest
Post by: stresa on May 01, 2021, 08:37:56 AM
A friend of mine has just finished his Motolanna swingarm built into his 1A2 RD250 race bike.
It was an easy conversion, only needed some shims and distances.
(https://up.picr.de/41098281cl.jpg)
(https://up.picr.de/41098282yl.jpg)
Regards Uwe
Title: Re: Aluminum swingarm quest
Post by: 78rd420 on May 03, 2021, 06:51:16 PM
Ok if one was going to buy a Motolanna for a 78 400 which one??Welded or machined?Or does it matter machined looks better but dont want shock problems thanx
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on May 04, 2021, 12:04:42 AM
For my 350 frame, I chose the welded because I liked the look better. Just personal preference.
Title: Re: Aluminum swingarm quest
Post by: stresa on May 05, 2021, 04:01:10 AM
I bought the Motolanna one and the one from Webike because of the same reasons as 85RZwade. Optics.
We use them in race bikes so weight advantage is another point.
I don't see how the welded shock mounts are a disadvantage against the machined ones.
Regards Uwe
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on May 05, 2021, 09:20:21 AM
On a slightly different note: when I placed my order a few days ago, the standard turnaround time was stated as 2-8 weeks PLUS possible additional delays due to Covid. Got an email this morning that it has shipped!  :cheerleader: :whoop: :celebrate:
Title: Re: Aluminum swingarm quest
Post by: stresa on May 05, 2021, 09:29:22 AM
Quote from: 85RZwade on May 05, 2021, 09:20:21 AM
On a slightly different note: when I placed my order a few days ago, the standard turnaround time was stated as 2-8 weeks PLUS possible additional delays due to Covid. Got an email this morning that it has shipped!  :cheerleader: :whoop: :celebrate:
Had the same experience last fall. The delivery time was much shorter as announced
Regards Uwe
Title: Re: Aluminum swingarm quest
Post by: Rhino363 on June 24, 2021, 05:29:12 PM
Has anyone gotten the motolana swingarm and installed it on a RD400 yet? Anyone have any pics or info on the install ?
Thanks
Title: Re: Aluminum swingarm quest
Post by: Striker1423 on September 26, 2021, 09:34:01 AM
Bump for curiosity on the Motolanna arm for an RD350. :)
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 26, 2021, 10:48:32 AM
RD pivot bushing slid right into the bearings supplied in the Motolanna. The 'arm is narrower at the pivot than the RD piece, so I made two spacers, I think they ended up at 7.3mm each. Done   :gentleman:
Title: Re: Aluminum swingarm quest
Post by: Striker1423 on September 26, 2021, 03:31:10 PM
How did everything line up? Stock chain length etc? Shock mount?
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 26, 2021, 04:53:09 PM
Shock mounts are right on. Chain length and alignment are going to be different for me than most, or maybe anybody else, as I'm using the TDR rear wheel I got from Jim. That fitment has to wait until I get a sprocket carrier (Hey Evan, found that sprocket carrier?). At present, the TDR wheel is soaking it's nipples in penetrating oil to ease disassembly prior to accepting the YZ490 rim I bought for it.
I'd try the RD wheel in there for educational purposes, but the hub lives in Canada now with Uncle Rodney (at least I think he still has it).
Title: Re: Aluminum swingarm quest
Post by: Striker1423 on September 27, 2021, 09:05:37 AM
Ok, well, I am sticking with the stock swingarm for now, but am definitely considering the motolanna in the future. It's the cheapest option that should look pretty good considering the stockish look of my bike.
Title: Re: Aluminum swingarm quest
Post by: m in sc on September 27, 2021, 10:34:24 AM
i'll definitely be getting a motolana arm for the 72 r5 at some point because it certainly doesn't need it. But, it needs it. 
Title: Re: Aluminum swingarm quest
Post by: Striker1423 on September 27, 2021, 11:04:11 AM
Quote from: m in sc on September 27, 2021, 10:34:24 AM
i'll definitely be getting a motolana arm for the 72 r5 at some point because it certainly doesn't need it. But, it needs it.
Absolutely. my thoughts exactly.
Title: Re: Aluminum swingarm quest
Post by: 85RZwade on September 27, 2021, 02:56:05 PM
 :agree: