Beeweldmut
Been Around the Block
CR500 , 2 stroke hardtail chopper project
Damn that is like a boss.
Damn that is like a boss.
Beeweldmut said:Thanks I appreciate your encouragement. After a few weeks on this hardtail I might encourage you to not build a hardtail.
combustioncafe said:By the time I get around to it, I'll have at least 3 other bikes in the stable. Comfort would not be a main concern. A hard tail bike would be an occasional Saturday morning rider at the most for me. ;D
Nothing like the smell of two stroke burning. I bet that gets one million smiles an hour.Beeweldmut said:Yeah I'm kind of In the same boat. With 4 girls under 6 and 4 businesses to run I don't really have time for all day rides anyway. I'm just looking for some quick, cheap thrills out of a motorcycle.
burnin that bean oil, such a great smell.cafe mike said:Nothing like the smell of two stroke burning. I bet that gets one million smiles an hour.
indeed.Beeweldmut said:burnin that bean oil, such a great smell.
I've raced and ridden mostly 2strokes including a street legal HRC spec NSR250 and a Aprilia SR50 that could hold the front wheel of the ground until 40mph and topped out at 80. 2strokes on the street is like sex without a rubber, it just feels better.
cafe mike said:Are you for real. I have seen guys ride out of the wilderness on bailing wire and duct tape 30 miles when the shock mount broke on a quad. This guy is fine.
thats got a sexy looking cylinder headRyan Stecken said:
this is my 2nd stroke dream (after my RD)to restomod that husquarna cr 250...extremely rare extremely light.found a guy who just sold that one for 1500 euros....$$$
Walms said:You will want to beef the rear frame up a bit if you haven't done so already. With parallel tubes and no triangulation, it's going to fold up like a cheap suit on the first good impact of the rear wheel.
A quick and dirty way to determine what sort of weight you'd need to support, add your weight, the bikes weight, then double it for an impact load.
As an example, doing a 3rd gear wheelie then hitting a pot hole.
plagrone said:I have zero experience building frames, but I work on jets and fiddle with stuff in my free time, and like to think I have pretty good common sense when it comes to stuff like this... If it was me, I would put down tubes on either side of that first cross member in front of the tire to reinforce the long arc of the tail, however that kind of seems superfluous, but in building a custom frame I would lean towards over-building. Then again, I've never built a custom frame.
With that said, I think it will be fine.
I LOVE your build. It's simply batshit and awesome. Hope you make it to and do well at the show.
MORE PICTURES plz
Beeweldmut said:No it's been decided that a triangle is the only structure capable of supporting weight. Parabolic arches that are triangulated and gusseted are not capable. Must use straight lines and 90° angles or the bike will explode.
deviant said:I think the concern (at least from my perspective) is that your curved line is a catenary (hyperbolic cosine curve). The caveat with a catenary, is that it's strength is essentially sprung between two fixed points while it's load is uniform across the curve. A suspension bridge is an a example of a catenary. The St. Louis Gateway arch is an inverted catenary. In either example, the two endpoints of the curve are fixed points. The most common kilns I build are sprung arch kilns with a catenary as their roof. Any outward flex on the sidewall of the kiln, and the roof wants to cave in. It's paramount that the endpoints of the arch are fixed to give the arc it's strength. By nature a motorcycle frame doesn't have those anchors. Also in your design, you have introduced a 90 degree angle at the midpoint of the arc that creates the whole bottom of your frame. You designed a second arc over the rear axle that works counter to the arc at the base of the frame, but for that arc to strengthen the bottom arc, it would need to produce a biconvex shape. The tension between two arcs in a biconvex shape are what give them their strength. Your design may very well work, but I am not totally confident. Most point to triangulation to counter.