Norwegian RD 350 YPVS hybrid build.

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mikkell
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Re: Norwegian RD 350 YPVS hybrid build.

#61 Post by mikkell » Wed Aug 17, 2016 10:30 am

ok Ime going to buy into this...i love committee built bikes...never mind the stand use a couple of bricks like the rest of us...lol now get back to the tank...take a long piece of white card and tape it upright to the rear of the seat ...then pivot it down the side of the tank at different heights and take pics from the side to show the "committee" the various combinations of how the tank and seat could look at differing angles...my 2c...mike

seahorse
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Re: Norwegian RD 350 YPVS hybrid build.

#62 Post by seahorse » Fri Aug 19, 2016 9:35 pm

Great build tommy. Good to see different designs that work. Particularly the tank.
It was always going to be a bit longer with the aftermarket swinarm Rz standard axle to axle is roughly 1370 the swinger will add about 60 mm or thereabouts.
I have a standard that measures the same about 1370 yet my hybrid lc with aprillia running gear including swing arm is 1430 axle to axle and rides realy well.
Looking at a standard RZ side on and your bike picture comparing the two the seat line is about perfect and the seat position correct, so you have done realy well.
The rake at the front looks extended out fractionally. I would be interested to know what the measurement is axle to axle in millimetres.
The rear hugger does hide the tire and wheel which we all want to see more of.
Maybe remove it and make a cardboard profile that you can work with then cut the plastic one down to suit.
Paint is a big question, I'd paint rims and frame black then maybe the later model red and white Yamaha colours. Or a goulwase blue yellow, but please keep it Yamaha colours.
Realy nice job, keep the good work up.
81 RD 250 LC Hybrid .Widened frame with Aprilia RS250 Back end & Front end, strokd RZ 421, Kennys TSA's, 31KVM26SS Carbs M-360 P-25 ALBA Ndl Pos 3, Air 1.3/4
81Rd350lc resto 2016
81 Rd250lc resto 2017
1999 ZRX 1100

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wolfman
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Re: Norwegian RD 350 YPVS hybrid build.

#63 Post by wolfman » Sat Aug 20, 2016 10:54 pm

Amazing work !
:smt026
84 RZ350 Spec II boost ports shaved head
Y boot 29mm PWKs billet manifold TDR Reeds Spec II pipes
Fox twin clicker JMC Braced swing arm
Tarozzi fork brace
Brembo 19 RCS Master ss lines blue spots EBC Vees
Spec 2 Full Fairing factory Solo Cowl

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TommyPettersen
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Location: Norway

Re: Norwegian RD 350 YPVS hybrid build.

#64 Post by TommyPettersen » Fri Feb 10, 2017 6:11 pm

Hi Guys.
Since it has only been a year since i last posted, i figured it is time to give an update on what is going on. And i have a problem that i could use some input on. As far as building this bike I only use time on it in the winter time since I have lots of other bikes to go thru in the summer/ride season. I am trying to start a business with vintage bikes and if all goes well I will be up and running next year. Usually I try concentrating on running bikes during the summer but I had a some that needed some work and that is why the hybrid has been sitting. As I write this I can tell you that I do have a 1980 Kawasaki z1300 sitting in my living room.. Best piece of furniture this living room ever had..
Anyway back to the hybrid. The only news is that I had the wheels powder coated satin black and they look good. New tires has been bought; Pirelli Angel ST 160/60/17 at the rear and 120/70/17 in front.
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TommyPettersen
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Re: Norwegian RD 350 YPVS hybrid build.

#65 Post by TommyPettersen » Fri Feb 10, 2017 6:16 pm

Anyways over to the problem. It is about the rear shock. Years ago when I began this build I did not plan on it going so extreme. My plans includes mostly modifications and improvements rather than all these alterations. So in the beginning I bought an R6 shock that so many else has been using on the RD. When I later decided to use the zxr400 swingarm with linkage, that R6 shock could not be used since the Kawasaki linkage will only work with a shock with a fork in the lower end. At that time I began look for a Kawasaki shock. At that time I had also decided on using the Gsxr tail, and to make for a clean look I wanted a shock without a reservoir. Since the reservoir would stick out and ruin the lines of the bike. I then settled on a Kawasaki zzr600 shock. It is known for being saggy and weak on that bike so I figured it would work great on a light weight RD. Anyway the ZZR shock fitted but it was a really long shock.. too long even with the shock mount move upwards in the bike. So I began searching again. In the end I have found a Suzuki 600 Bandit shock. It fits good, has decent travel and no reservoir. So what is wrong?.. It is too hard. I cannot move it at all. With all weight loaded up on the bike, it will not compress at all. I have a found a company here in Norway which can make any spring I would like but where do I start? I have read a great deal on shocks and it seems that when shocks have a shorter working range, it can have a spring that is twice the stiffness of a shock with slightly longer working range. Then there is some choice’s with the linkage as well. The zxr400 was used in racing back in the day and so there were linkages with different ratio on the arm pushing the shock up. I just bought one that should give me a longer arm that will make the shock compress more easy. I guess this is the first thing I need to check, if there is a difference with this linkage. But if I do need to have a weaker spring made, how much weaker should I make it? Do you think it is a good idea to check the zzr600 spring, and use that as a starting point of making a new one for the Bandit shock?
Bandit Shock
Bandit Shock
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RuZty
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Re: Norwegian RD 350 YPVS hybrid build.

#66 Post by RuZty » Fri Feb 10, 2017 8:19 pm

How did you decide where to mount the ZXR400 shock linkage to the RZ frame?

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TommyPettersen
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Re: Norwegian RD 350 YPVS hybrid build.

#67 Post by TommyPettersen » Fri Feb 10, 2017 9:04 pm

There has been other Rd`s built with that rear swing arm using that linkage. It fits the Rd/Rz frame brackets.
This is an old picture but it show some of the linkage with bracketry..
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hondaror
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Re: Norwegian RD 350 YPVS hybrid build.

#68 Post by hondaror » Sat Feb 11, 2017 4:49 am

The linkages designed for that specific shock and the mounting points must all be the same spaced distances. Any slight changes in the linkage lengths and/or mounting points make for drastic changes in lever ratios. Hence, you cannot compress your shock. It is not the spring.

Factors: Swing arm length, shock length, linkage lengths, linkage and shock mount positions. Then there's the shock itself, internal valving or dampening, fluid weight, spring rate. You can't just throw any swing arm on and stick any shock in it. These are all concerns to be considered. This is where your math and knowledge of levers, ratios, fulcrums comes into play.
Rory
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RuZty
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Re: Norwegian RD 350 YPVS hybrid build.

#69 Post by RuZty » Sat Feb 11, 2017 6:59 am

On the picture on page 3 it shows the dogbones (connected to the swingarm) and the relay arm (connected to the frame) making an angle of about 150 degrees. If you look at the suspension on a ZXR400 this angle will be close to 90 degrees, it needs to be for the suspension to work properly. If you look at the popular RGV swap the adapter plates relocate the pivot point for the RGV relay arm to preserve (as closely as possible) the RGV linkage geometry. It has to account for the fact that the shock mounts at a different height in the RZ frame, but it maintains the correct angles of the linkage.
You are concerned that the shock is too stiff, but a Bandit 600 spring is only about 20% stiffer than a stock RZ spring. The reason it feels stiff is because the linkage is way past its effective angle, and this will only get worse as it compresses, to the point where it goes solid if it had enough travel for the angle to go to 180.
Just because the parts will bolt together doesn't mean they work together. You can correct this by finding where the shock and relay arm mount on a ZXR400 relative to the swingarm pivot and duplicate that location on your RZ frame. You will likely have to accommodate a different shock location which will mean different length dogbones to keep the angles right.
Another thing to consider when modifying shocks is that if you are making big changes to the spring rate you should be considering if it is still valved correctly to damp the new spring. Spending money to half modify a second hand OEM shock is counterproductive. If the spring rate is correct and it fits it will be better than a stock RZ shock just because it is newer, but beyond that is a step backwards.
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MK
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Re: Norwegian RD 350 YPVS hybrid build.

#70 Post by MK » Sat Feb 11, 2017 3:42 pm

What you need is to measure the realtive position between the linkage points and hack it into a multi body simulation like ADAMS.
That's what I do for a living and there is a free student edition you could use:
http://www.mscsoftware.com/page/adams-student-edition" onclick="window.open(this.href);return false;

I ran simulations in the past for RD350's and RD500 swingarm versions.
If you happen to need an extremely different spring in your shock, then it's extremely likely that your damping will be way off.
The best solution is always to weld in some new brackets that enable you to use the stock donor linkage with the stock donor frame mount positions.
Another sensible alternative: scrap the linkage and do a direct shock to swinger connection. In that case your upper shock mount will need to be reworked. The advantage here: if you make the swing attachement adjustable, you can optimize the point with keeping the same spring/damper.
Bye
Martin

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