Project Chassis Choice

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evan_calgary
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Project Chassis Choice

#1 Post by evan_calgary » Thu Apr 07, 2016 2:53 am

Hi All,

Mind is running again and although i'm still finishing up my current projects I usually get rolling on the next one at this stage. I would like to put together a big bore RZ based twin and throw it in an aluminum framed chassis. Something with a bit more modern geometry but not totally modern. Tossing around a few ideas but curious if there are any other ideas here.

RS250 Aprilia (MK1)
FZR400

I'm likely shipping in the frame so I would prefer something with a removable subframe.

I have a 90 ZX7 frame but think that is likely a bit large and bulky. They over-stiffened the thing on their hunt for the perfect package.

I'm really not married to keeping it all 'Yamaha'. Just looking for something interesting.

No issues with welding up mounts although really wish had AC TIG for alum.

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South_Oz
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Re: Project Chassis Choice

#2 Post by South_Oz » Thu Apr 07, 2016 3:26 am

Its been done before but RGV and RG frames make good hybrids. RGV VJ22 frames have removable rear sub frame, not so the 21.

Theres probably a good reason its been done many times before.

I will be moving to a place with dirt road frontage in a year or 2 and am thinking a TRD style of bike might be fun to build/ride.

Dave
RZ 250 85 (Waiting)
RZ 250 85 (Parts)
RGV VJ21 250, Australian Speed Record Holder, MPS/G 250, 140.5 MPH
BMW R1100S 99 (Its Red)
BMW R1200GS (Its BIG)


http://www.dlra.org.au/index.htm" onclick="window.open(this.href);return false;

evan_calgary
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Re: Project Chassis Choice

#3 Post by evan_calgary » Thu Apr 07, 2016 3:46 am

Thanks SouthOZ. That is another good choice. From what I have read, the Aprilia Chassis was really more of just an overall upgrade to the handling package of the RGV thus the thought on the RS. They are readily available from Japan (Miabi) for around 350USD landed. Since the frame will likely be shipped in I will probably go with a modernish I-4 front end.

RuZty
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Re: Project Chassis Choice

#4 Post by RuZty » Thu Apr 07, 2016 6:44 am

I have a TZR250 3MA chassis for which I have similar long term plans, but I was originally thinking an RZ500 motor. I lucked out and bought it locally from a guy with the same idea, but a big bore 350 will be much cheaper and easier. The TZR125 4DL is the same frame but the engine mounts on the bottom of the frame spars are shorter, simplifying a 350 install. The tanks interchange between the two, I have both. Let me know if you have any questions.

MK
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Re: Project Chassis Choice

#5 Post by MK » Thu Apr 07, 2016 7:36 am

How about creating a frame by using existing frames?

Just recently I welded the front end of a CRF450 to a Zero e-bike. May 22'nd the bike will have it's first race - I'm eager if that'll last ...
I told the owner next time we're gonna use a big bike frame , cut out the steering head and re weld the left/right frame halfs to an appropriate width. The steering head will be custom made in a lathe to fit the desired forks.
You could use that idea, too. Advantage: you're not fixed to ccm, brand or year. Just pick what is cheap and does the job.
Bye
Martin

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giron
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Re: Project Chassis Choice

#6 Post by giron » Thu Apr 07, 2016 12:26 pm

I made a mistake or I was ripped off by getting the wrong recommendation. RGVSteve did the work for me and he advice me not to use the TZR250 3XV frame. This is the same reason I recommend not using a frame that came with "V" engine like the VJ22.

You will be much better with a TZR250 3MA frame. A parallel engine goes into a frame that took a stock parallel engine not a V shape engine.

RGVSteve will be doing another project for me. This time I will follow his advice. I have a RZ350 engine that will go into a TZR250 3MA frame.

Myabee plus also sells the TZR250 3MA frame in Yahoo Japan. I picked up both of my TZR250 3MA frame for a dollar a piece.
The shipping was what got me $300.00 EMS. You can have it shipped by ship and is a little cheaper.
1991 3MATZR250SP
!993 3XVTZR250SP
1996 RGV250(Lucky Strike)
1994 MC28SP
1995 MC28SP
1996 MC28SP
1985 RG500(Walter Wolfe)
1984 IT490
1985 RZV500R
1985 NS400R
1985 NS400R
1997 VFR750
1992 FZR1000
RGV400
TZR500
TZR350
1990 RZ350
1971 Porsche911S

evan_calgary
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Re: Project Chassis Choice

#7 Post by evan_calgary » Thu Apr 07, 2016 12:31 pm

Interesting thoughts Giron. I heard about the issues with the pipes was it? In the 3XV chassis. Sounded like it was basically not possible.

MK, Building my own frame is a bit over my head at this point as I do not have AC tig for aluminum and would not trust my own work at this point from an engineering strength perspective. There are also major headaches here about making a custom frame and insurance will be crazy expensive.

Looks like Myabee prices continue to edge up and up.

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Re: Project Chassis Choice

#8 Post by MK » Thu Apr 07, 2016 4:19 pm

It's not that difficult and if you recycle the steering head with the VIN of the donor bike, you can still insure it as maybe a custom ZX7R.
If you can't do the welding on you own, you need to find someone qualified enough.
The attached project was off road only and I already welded a widened swinger for that guy that still lives after heavy usage.
Attachments
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Bye
Martin

evan_calgary
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Re: Project Chassis Choice

#9 Post by evan_calgary » Thu Apr 07, 2016 4:33 pm

That is pretty intense Martin! I guess It might be worth taking a shot. I am really scared of the level of engineering that *should* go into frame modifications though.

It would be a really great excuse to get an AC TIG welder as well :)

dinamos
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Re: Project Chassis Choice

#10 Post by dinamos » Fri Apr 08, 2016 12:55 am

Martin, you made a "Frankenframe".

Nice

roger

evan_calgary
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Re: Project Chassis Choice

#11 Post by evan_calgary » Fri Apr 08, 2016 1:19 am

Is that some sort of buggy or 3-wheeler at the back of the thing????

MK
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Re: Project Chassis Choice

#12 Post by MK » Fri Apr 08, 2016 3:24 am

Nope, it's a Zero off-road e-bike with a CRF450 front end.
As an excuse I have to mention that I wasn't involved with the concept, just with the welding. My expectation is that it may fail when doing big jumps (which is planned).
That's why I already have plan B (if the owner survives the crash due to the broken frame ...).
Bye
Martin

evan_calgary
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Re: Project Chassis Choice

#13 Post by evan_calgary » Fri Apr 08, 2016 12:20 pm

Right right. You mentioned that at the start. The rear section just appeared very wide. Having ridden moto I cant' say I would want to ride a frankenframe that heavily modified. Cool idea but....not confidence inspiring to me.

I'm not against your idea MK but I htink for now I will stick with a prodo frame that does not need to be heavily modified (at least from the initial plan.

Think the RS250 Aprilia frame is still near top of the list.

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giron
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Re: Project Chassis Choice

#14 Post by giron » Fri Apr 08, 2016 12:50 pm

Check out nkracing.com

Nigel uses a TZR250 3ma frame
1991 3MATZR250SP
!993 3XVTZR250SP
1996 RGV250(Lucky Strike)
1994 MC28SP
1995 MC28SP
1996 MC28SP
1985 RG500(Walter Wolfe)
1984 IT490
1985 RZV500R
1985 NS400R
1985 NS400R
1997 VFR750
1992 FZR1000
RGV400
TZR500
TZR350
1990 RZ350
1971 Porsche911S

MK
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Joined: Sat Nov 26, 2005 11:44 am
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Re: Project Chassis Choice

#15 Post by MK » Fri Apr 08, 2016 2:30 pm

Evan, I (still) have the same thoughts about that project.
I did another frame and swingarm for that guy and he's still alive.
That's why he picked me for this "advanced" mod.
He promised he'd start slowly and check for cracks in the welds before doing "full performance" heats.

But I also learned a little bit from this: Honda CRF frame welded pretty nice (Better than a Suzuki swinger I did some time ago).
If it's clean and pre-heated, it's not a big thing to modify a frame.

That's why I came up with the idea to simply cut a big bike frame in three pieces (left/right/steering head), shorten where necessary and weld it together in the right position.
Doing a frame-rig is not too complicated and a friend of mine has done his own (steel) frame:
http://forum.rd350lc.de/viewtopic.php?t=21837" onclick="window.open(this.href);return false;
http://forum.rd350lc.de/viewtopic.php?t=25477" onclick="window.open(this.href);return false;

If I ever feel to upgrade my race RZ, you will see me doing this in the future.
Saves you searching the world for expensive old and narrow frames and you have a one-off bike that nobody else has (at least until you publish pics and details - after that people usually start to build replicas)
Bye
Martin

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