collapse

www.dimecitycycles.com


www.restocycle.com

www.CITYLIMITMOTO.com

www.jadusmotorcycleparts.com

www.bisonmotorsports.com

www.speedmotoco.com

www.cognitomoto.com

www.townmoto.com

www.sparckmoto.com

www.Moto-Madness.com

www.pistonsociety.com

www.steeltowngarage.com

GET DTT UPDATES ON FACEBOOK AND TWITTER

Author Topic: was a rupp roadster, now i dont know what to call it  (Read 14710 times)

Offline Hurco550

  • DTT SUPPORTER
  • *
  • DTT BOTM WINNER
  • *
  • Posts: 2984
  • Play Stupid Games, Win Stupid Prizes
Re: was a rupp roadster, now i dont know what to call it
« Reply #130 on: Jul 31, 2017, 16:12:28 »
Looked back and realized that the roadster wasn't like the blackwidow or scrambler, yeah thats totally different.  There is alot of power left in that motor to free up, almost to much.  Pull the governor, get a billet flywheel (the stock one will explode at high RPM), tighter springs, cone filter, exhaust, and throw a mikuni on there so its manageable.  The stock carb turns into an on/off switch at this point and its almost unrideable.  I need to get mine out of the shed
funny man, what you just wrote is my exact plans for the motor, plus I'll probably do a billet con rod while I'm at it. For now it's just a cone filter, jetted carb and pipe... because money, or lack there of lol once I get it together and going ill piece the hop up stuff together as funds become available

Sent from my SM-G920V using Tapatalk

Keep er' Between The Ditches!!!

1976 BMW R90/6 farkilitious: http://www.dotheton.com/forum/index.php?topic=74349.msg882477#msg882477
1975 RD350 Road Racer: http://www.dotheton.com/forum/index.php?topic=70652.msg833688#msg833688
1973 Ironhead Hardtail: http://www.dotheton.com/forum/index.php?topic=68135.msg788081#msg788081
1976 GT250 Rebuild: http://www.dotheton.com/forum/index.php?topic=64973.new#new
Full Custom Pit Bike: http://www.dotheton.com/forum/index.php?topic=66954.new#new
1971 Yamaha 90cc twin HS1: http://www.dotheton.com/forum/index.php?topic=70498.0
"Two strokes are the motorcycle equivalent to Thors chariot. Full of glory and memories of battles victorious" ~ von yinzer

Offline JSJamboree

  • DTT SUPPORTER
  • *
  • DTT BOTM WINNER
  • *
  • DTT BIKE OF 2016
  • *
  • Posts: 1068
  • Drink Local
Re: was a rupp roadster, now i dont know what to call it
« Reply #131 on: Jul 31, 2017, 16:16:44 »
funny man, what you just wrote is my exact plans for the motor, plus I'll probably do a billet con rod while I'm at it. For now it's just a cone filter, jetted carb and pipe... because money, or lack there of lol once I get it together and going ill piece the hop up stuff together as funds become available

Sent from my SM-G920V using Tapatalk



I cant say enough what a difference the mikuni made. Here is the kit that I put on mine.

http://www.ebay.com/itm/22MM-MIKUNI-CARB-KIT-PREDATOR-212-GX200-GX160-HONDA-CLONE-Drift-Trike-Mini-Bik-/252314674798?hash=item3abf20666e:g:10wAAOSwYlJW4GEm&vxp=mtr

Offline Hurco550

  • DTT SUPPORTER
  • *
  • DTT BOTM WINNER
  • *
  • Posts: 2984
  • Play Stupid Games, Win Stupid Prizes
Re: was a rupp roadster, now i dont know what to call it
« Reply #132 on: Jul 31, 2017, 16:33:37 »
I cant say enough what a difference the mikuni made. Here is the kit that I put on mine.

http://www.ebay.com/itm/22MM-MIKUNI-CARB-KIT-PREDATOR-212-GX200-GX160-HONDA-CLONE-Drift-Trike-Mini-Bik-/252314674798?hash=item3abf20666e:g:10wAAOSwYlJW4GEm&vxp=mtr
Yep, I have that saved on my watch list. I think iirc a Yamaha blaster carb is the same size mikuni, and van 2 be had for less coin yet

Sent from my SM-G920V using Tapatalk

Keep er' Between The Ditches!!!

1976 BMW R90/6 farkilitious: http://www.dotheton.com/forum/index.php?topic=74349.msg882477#msg882477
1975 RD350 Road Racer: http://www.dotheton.com/forum/index.php?topic=70652.msg833688#msg833688
1973 Ironhead Hardtail: http://www.dotheton.com/forum/index.php?topic=68135.msg788081#msg788081
1976 GT250 Rebuild: http://www.dotheton.com/forum/index.php?topic=64973.new#new
Full Custom Pit Bike: http://www.dotheton.com/forum/index.php?topic=66954.new#new
1971 Yamaha 90cc twin HS1: http://www.dotheton.com/forum/index.php?topic=70498.0
"Two strokes are the motorcycle equivalent to Thors chariot. Full of glory and memories of battles victorious" ~ von yinzer

Offline MotorbikeBruno

  • DTT SUPPORTER
  • *
  • Posts: 2543
    • Carb cleaning in MN
Re: was a rupp roadster, now i dont know what to call it
« Reply #133 on: Aug 07, 2017, 22:17:29 »
I love this thread!  8) 8) 8) 8) 8) 8)

Offline XS750AU

  • Posts: 318
Re: was a rupp roadster, now i dont know what to call it
« Reply #134 on: Aug 07, 2017, 23:38:14 »
Quote
I have thought about something similar,  but instead of full sheets, maybe some "x" braces in between the vertical ones.

Sorry for not getting back to you sooner. Refer to the attached photo, the top section (red line) is in compression, meaning it is being pushed from both ends.  The current structure is not good in compression, much better in tension (being pulled at the ends). Cross braces also work well in tension but not compression, so I would suggest a solid sheet welded along the red line is the best option, but if you wanted to make some cool cut outs down the middle of the sheet then go up a thickness or 2! The current structure will behave a bit like a house of cards, once it goes it will go quickly.
The orange line is of secondary concern, and would just stiffen up the headstem, so you could cut a few seconds off your lap times  ;D. That area is in tension so cross braces would be OK.
Hope this helps.
Love what you have done so far.
“Engineering is the art of being approximately right rather than exactly wrong.”

Yamaha XS750-2D
Yamaha XS896
Husaberg FE550
Yamaha TT250
Yamaha IT200N

Online Popeye SXM

  • Posts: 52
  • Also used for MX
Re: was a rupp roadster, now i dont know what to call it
« Reply #135 on: Aug 08, 2017, 00:04:02 »
 The current structure is not good in compression, much better in tension (being pulled at the ends). Cross braces also work well in tension but not compression, so I would suggest a solid sheet welded along the red line is the best option, but if you wanted to make some cool cut outs down the middle of the sheet then go up a thickness or 2! The current structure will behave a bit like a house of cards, once it goes it will go quickly.
The orange line is of secondary concern, and would just stiffen up the headstem, so you could cut a few seconds off your lap times  ;D.

I love this project, but I agree, It could collapse, very quickly, say after a bump or two?

Offline Hurco550

  • DTT SUPPORTER
  • *
  • DTT BOTM WINNER
  • *
  • Posts: 2984
  • Play Stupid Games, Win Stupid Prizes
Re: was a rupp roadster, now i dont know what to call it
« Reply #136 on: Aug 08, 2017, 11:25:20 »
Sorry for not getting back to you sooner. Refer to the attached photo, the top section (red line) is in compression, meaning it is being pushed from both ends.  The current structure is not good in compression, much better in tension (being pulled at the ends). Cross braces also work well in tension but not compression, so I would suggest a solid sheet welded along the red line is the best option, but if you wanted to make some cool cut outs down the middle of the sheet then go up a thickness or 2! The current structure will behave a bit like a house of cards, once it goes it will go quickly.
The orange line is of secondary concern, and would just stiffen up the headstem, so you could cut a few seconds off your lap times  ;D. That area is in tension so cross braces would be OK.
Hope this helps.
Love what you have done so far.

I love this project, but I agree, It could collapse, very quickly, say after a bump or two?

Thanks guys for the input! It really is appreciated. I am not, and do not claim to be an engineer, I'm just a welder that has access to 2d cad software and a waterjet ha. I plan to do a strip on the top and front as described, as well as one for good measure between the two bars of the "hardtail". They wont be just plain strips, they will have a few spots for flared holes as well as slots where I can weld them in to connect to the cross gussets. Even though I did a wood mockup a while back, there are still things that I would change now that I have this one made up and tacked together. But oh well, I will make this one work. Thanks again for the input, it didn't fall on deaf ears!

« Last Edit: Aug 08, 2017, 11:30:13 by HURCO550 »
Keep er' Between The Ditches!!!

1976 BMW R90/6 farkilitious: http://www.dotheton.com/forum/index.php?topic=74349.msg882477#msg882477
1975 RD350 Road Racer: http://www.dotheton.com/forum/index.php?topic=70652.msg833688#msg833688
1973 Ironhead Hardtail: http://www.dotheton.com/forum/index.php?topic=68135.msg788081#msg788081
1976 GT250 Rebuild: http://www.dotheton.com/forum/index.php?topic=64973.new#new
Full Custom Pit Bike: http://www.dotheton.com/forum/index.php?topic=66954.new#new
1971 Yamaha 90cc twin HS1: http://www.dotheton.com/forum/index.php?topic=70498.0
"Two strokes are the motorcycle equivalent to Thors chariot. Full of glory and memories of battles victorious" ~ von yinzer

Offline XS750AU

  • Posts: 318
Re: was a rupp roadster, now i dont know what to call it
« Reply #137 on: Aug 08, 2017, 19:14:26 »
Sensational, this is going to be good  ;D
“Engineering is the art of being approximately right rather than exactly wrong.”

Yamaha XS750-2D
Yamaha XS896
Husaberg FE550
Yamaha TT250
Yamaha IT200N