rgv 250 vj21 swing arm conversion into rz

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graham heise
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rgv 250 vj21 swing arm conversion into rz

#1 Post by graham heise » Mon Aug 20, 2018 7:52 am

Wanting a bit of information about the rgv swing arm conversions. i know of a vj21 swing arm at a reasonable price. From some forum searches i understand this swing arm with a conversion kit is a similar fit to the vj22 bannana arm. Besides the cool look of the vj22 arm are there any advantages with either the vj21 or vj22 swingarm.
Other then the swing arm what other parts from the rgv are required. I'm contemplating this conversion along with r6 front end and sv650 rear wheel. I wish to do this for performance.
yamaha fanatic.

hondaror
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Re: rgv 250 vj21 swing arm conversion into rz

#2 Post by hondaror » Mon Aug 20, 2018 9:42 am

Not a good move if you like the nimble feel of the stock RZ. Fatter wheels slow down steering response. In my opinion, the only reason to change wheels would be for tire selection, 17".

The aluminum swingarm advantage, lighter weight, beefier look, to house larger tires.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

RuZty
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Re: rgv 250 vj21 swing arm conversion into rz

#3 Post by RuZty » Mon Aug 20, 2018 5:52 pm

Not disagreeing with the theory of larger tires slowing the handling down but I completed the swap you describe late last year and the only thing I lost was turning circle when pushing the bike around. The bike does not feel any less nimble and gains the advantage of more/better tire choice, more rigid forks, vastly improved brakes, better wheel control and is actually a couple of pounds lighter, biased more to the front.
Consider that the 120 front and 150 rear are the same sizes used on the RGV 250 and Aprilia RS250, neither of which are described as truckish.
It also must look pretty cool besides just to me because I have come back to find people taking pictures of it twice.

To answer your questions, make sure you get the RGV suspension link, main pivot seal cups, and axle. Depending on your plans for a rear wheel and brake you may not need the rear brake hardware, I didn't use it. Ditto the shock, I used a Penske. Tyga do an optional bracket for the RGV to mount a Brembo rear caliper, but most modern wheels won't (easily) take a rotor that small. I can't comment on VJ21 vs VJ22.
Front end is pretty straight forward depending on the components you choose, basically bearings and spacers.
Sprocket alignment will drive you mad, I went to great pains to square everything up and then took the engine out for a rebuild and it was way off when it went back in. If you crack the engine mounting bolts and plates loose you can move the engine all over the place, focus on getting the wheel centerlines on the same plane first and then deal with confirming the engine position before you adjust sprocket offset.
It's not a bad job, but it's not as simple as bolt off/bolt on and go, the devil is in the details to end up with a safe and enjoyable ride.

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Questo vecchio rz
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Re: rgv 250 vj21 swing arm conversion into rz

#4 Post by Questo vecchio rz » Mon Aug 20, 2018 7:01 pm

Having Ridden other similar swaps, when done correctly nothing but Sublime.
Aside from the mentioned turning radius when a given a direct comparision if stick vs swap the ease of lighting quick transitions is diminished to a degree, But nothing proving detrimental. as let's face it on a stock bike with 90 & 100 tires and very narrow triples, it's obvious transitions with wider tires and increased triple width... but that's where it all ends.
The massive increase of a radial tire footprint is a huge advancement and in my case confidence inspiring. It truly is a night and day difference..
As many of us have advised, do your homework,ask questions and make sure you have ALl the correct parts to allow you proper geometry and range of motion and wheelbase,centered wheel, chain clearance etc..
Use all NEW bushings and a ride height adj shock.
If you take short cuts and do it inproperly with the front or back, the bike will be awful to ride.
Done right...it nothing but wonderful.

Note* I'm not by stating that a bike with stock bias-ply tires cannot be hustled around rapidly very fast but all things being equal the modern is just that modern and modern is just ;that..advancements with benefits.
the one and the only thing that sets a small motorcycle from yesteryear apart from today's is the advancement in Tire technology it far exceeds what it was in the 80s or even the 70s. the multi compound modern tires are a motorcyclists dream
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graham heise
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Re: rgv 250 vj21 swing arm conversion into rz

#5 Post by graham heise » Tue Aug 21, 2018 6:14 am

Thanks for the replys gents. Rory I know what your saying about the flickability of the stock set up. I have a stock set up bike (with some suspension mods) and it has very fast steering.
I thought about doing this conversion before and at the time i was concerned about ground clearance running 17 inch wheels. through some pm's with petro's he pretty much convinced me the conversion was worth while.
I have contanplated a rz engine into a 2ma tzr but haven't found a suitable doner bike. I do have a spare rz roller and now this swing arm has come up.
The swingarm is bare and has no connecting parts or axle. i would need to come up with thses parts plus wheel etc and thats just the rear end.
You guys have offered some great advice here and i will look through some more build threads and see whats parts are around to start gathering.
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hondaror
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Re: rgv 250 vj21 swing arm conversion into rz

#6 Post by hondaror » Tue Aug 21, 2018 10:38 am

Having a second bike to play with is a great luxury. It does not matter what you do to it, you always have the stock based bike to ride. That's when you really notice the difference between the two.

Both of Steve's bikes are modified, but one, way more then the other, and they feel very different. Have fun with it. I'll be building my bikes very different from one another, but keeping them all shod with skinny wheels. The radical one, will be the RZ into the SV650.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

RuZty
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Re: rgv 250 vj21 swing arm conversion into rz

#7 Post by RuZty » Tue Aug 21, 2018 12:10 pm

hondaror wrote:Having a second bike to play with is a great luxury.
Not as great as 3rd, 4th, 5th, 6th......... [smilie=mf_bounce8.gif]

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nokturnal
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Re: rgv 250 vj21 swing arm conversion into rz

#8 Post by nokturnal » Tue Aug 21, 2018 5:21 pm

RuZty's bike handles likes its on rails and switches direction just by thinking...

Flickability is retained, with better stability.

I personally would prefer to have both standard and a hybrid...
:smt017

mikkell
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Re: rgv 250 vj21 swing arm conversion into rz

#9 Post by mikkell » Sat Nov 10, 2018 2:16 am

Hey Graham i did this swap 10 years ago to an F2 then sold the bike, well i missed it !.... it handled very neutral and was so flickable...my mate now owns it but wont sell it back to me...so i had another f2 roller in the shed for the last 5 years and last week was time to make a move when a roller vj22 came up with everything on it. so here we go again....on the subject of the "chain run" i had 5-6mm machined off the rear hub and that sorted mine.

p51mustang
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Re: rgv 250 vj21 swing arm conversion into rz

#10 Post by p51mustang » Thu Mar 21, 2019 1:01 pm

well I am running a rgv vj21 rear swingarm with a 150 and vj22 front end adopting them to the RZ was easy it took some time do all of it having to order every thing from over seas My bike runs vary clean in the turns no plowing of any sort I am all so running vj23 rear wheel and a vj22 front wheel in all my work my bike is under 300 pounds it sat on the scale at 280 with fuel I will work on some pics for you if you would like to see my set up its all vary simple

Thanks Larry
1984 RZ350
1978 RD 400
1979 Daytona

p51mustang
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Re: rgv 250 vj21 swing arm conversion into rz

#11 Post by p51mustang » Thu Mar 21, 2019 1:09 pm

PS the R6 stuff is cheeper but is much heavier

Thanks Larry
1984 RZ350
1978 RD 400
1979 Daytona

gpaddict
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Re: rgv 250 vj21 swing arm conversion into rz

#12 Post by gpaddict » Thu Mar 21, 2019 11:24 pm

Yes, photos please!
tuned to Paris Hilton specs............rich and retarded!

MK
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Re: rgv 250 vj21 swing arm conversion into rz

#13 Post by MK » Fri Mar 22, 2019 9:33 am

I actually run one RD with the VJ22 banana and one RD with the VJ21 straight swinger.
Both run a 160/60 rear and both feel much better than stock at high speed cornering.

One of it is a race bike solely run on kart tracks, where agility and quick steering is mandatory.
On my home track the absolute track record is in the 51.x s region (German Championship Supermoto professional rider).
Most hobby riders on Supermoto bikes are around 1 min or in the high 50's at best.
I'm a 50+ old fart doing solely track days and I run 55.2 s - now can you tell my again, why the swinger and the wide tire is to blame for being so extraordinary slow?
Bye
Martin

p51mustang
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Re: rgv 250 vj21 swing arm conversion into rz

#14 Post by p51mustang » Sat Mar 23, 2019 10:11 pm

I will try some photos
1984 RZ350
1978 RD 400
1979 Daytona

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