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 Post subject: Frame Modification for Straight Pipes
PostPosted: Thu Apr 12, 2018 11:10 pm 
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Tried searching, but couldn't find it.

Just need to know how much space is required for straight upper/rear cylinder pipes.

I guess, if I had aftermarket pipes, I could measure the pipe bellies, but I dont. The size probably isn't much different than straight pipes. But, what do I know?

Does anyone know the widest diameter on a straight pipe? Please post or PM me.

Thanks!


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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Tue Apr 17, 2018 10:44 pm 
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you have a subframe. you can measure it.

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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Wed Apr 18, 2018 12:32 am 
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giron wrote:
you have a subframe. you can measure it.

Please don't post in any of my threads.

Your posts are not helpful, and are unwanted.

Thank you.


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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Wed Apr 18, 2018 12:37 am 
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A great pipe fabricator gave me the info. :smt006

I'll be posting ideas in my project bike thread.


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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Wed Apr 18, 2018 12:48 am 
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Location: Joliet,Illinois
on the Yamaha TSI spec, the largest diameter on the uppers is 110 mm.

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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Wed Apr 18, 2018 1:02 am 
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Gary Papesh wrote:
on the Yamaha TSI spec, the largest diameter on the uppers is 110 mm.

Thanks, Gary! :smt006

The number I was given for a stock engine is close to 100mm.

I'll try to leave some extra space, just in case.


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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Wed Apr 18, 2018 11:00 am 
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it is an open forum :smt006 :smt006 :smt006 :smt006

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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


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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Wed Apr 18, 2018 3:33 pm 
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Location: Germany
110 is not the biggest bellys and you need enough space between each pipe and the surrounding parts.
I'd calculate with a 125 mm pipe dia and some 20-30 mm clearance (remember that they get hot if you're ever going to use it outside a museum).
Between the pipes you should also have enough space for dislocations caused by vibrations. 10-15 mm should do the job here.

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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Wed Apr 18, 2018 5:18 pm 
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MK wrote:
110 is not the biggest bellys and you need enough space between each pipe and the surrounding parts.
I'd calculate with a 125 mm pipe dia and some 20-30 mm clearance (remember that they get hot if you're ever going to use it outside a museum).
Between the pipes you should also have enough space for dislocations caused by vibrations. 10-15 mm should do the job here.

Thanks, Martin!

That's definitely more than I anticipated. So, 20+125+10+125+20=300mm or 11.8 inches.
The 2 rails are 1 inch each, so the subframe width would be 13.8 inches total.

I was hoping to keep the total width to 12 inches, to match the frame width at the center cast pieces.
So, 20+100+10+100+20=250mm or 9.84 inches. 11.84 inches total width.

Not sure how much this would affect performance, but maybe it would be okay, since I'm not building a race bike. I'd also like all 4 pipes to be as short as possible, without decreasing performance too much. Your input is greatly appreciated.

(I promise, I'm working on the cap and filler neck drawings!) :smt001


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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Thu Apr 19, 2018 10:13 am 
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Well nobody said the subframe needs to go around the pipes.
The RG guys often use one with a single tube in the middle supporting the upper tubes.
https://www.pinterest.de/pin/4360751763 ... 5176625605

And even if you use the standard layout it does not mean you have the support at the location with the widest cones. Have a look at existing stuff, often it's still in the region of the region of the diverging cone.

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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Thu Apr 19, 2018 2:38 pm 
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Very interesting photo, Martin. Doesn't look like much room for rear wheel travel, but must be enough.

I clearly remember seeing one of Wolfgang's custom subframes. Really not even a subframe, just a single support for the pipes. I think it had a carbon self-supporting tail/seat section.

Still have some thoughts about chopping the whole subframe and making a new one. It would also be nice to buy an aluminum subframe (and tail) from a different bike and fit it to the RZV frame and run the pipes through that. I'm just not knowledgable about what would work, and would prefer not to copy someone else's nice work. Not good for them, or for me.

Actually, I'm hoping that if I can fit the pipes between the rails, I could also raise them up higher over the rear tire, and under a taller seat/tail. Sitting on my stock RZ500 is uncomfortable because the seat and footpegs are so close.

I'm not sure what I will be able to accomplish, and I will compromise my ideas to get the bike finished - but I love trying to make my moto dreams come true. Every time I see those titanium relay arms, it puts a HUGE smile on my face! :smt003


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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Thu Apr 19, 2018 4:13 pm 
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Location: Germany
This is what I did some 5 years ago:
Aluminum subframe for my race 350 before and after a crash.
And a concept with a subframe made of 1.5 mm sheet that also serves as an airbox.

Later I refined it and by now my aluminum welding got better, too.


Attachments:
hilfsrahmen_2_121.jpg
hilfsrahmen_2_121.jpg [ 95.7 KiB | Viewed 325 times ]
hilfsrahmen_1_crashtest_177.jpg
hilfsrahmen_1_crashtest_177.jpg [ 83.54 KiB | Viewed 325 times ]
heckteil_selbsttragend_1_5mm_klein_180.png
heckteil_selbsttragend_1_5mm_klein_180.png [ 106.81 KiB | Viewed 325 times ]

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 Post subject: Re: Frame Modification for Straight Pipes
PostPosted: Thu Apr 19, 2018 4:21 pm 
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I wanted to attach a bit more detail pics, but got the message about the board quota being reached.

@admin: Could you please enhance that? I promise not to post any junk, just interesting RD stuff ....

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