[fslflint]

hey guys.

this is gonna act as a place holder as I gather parts and information for my build. I will update as I get parts and draw out the concept. this bike will be my first attempt at frame fabrication. the original name for this build was gonna be Jack the Ripper, not sure if I'm gonna stick with it or not

synopsis:
the aim is to build a bike that will be tailored to me and me alone. it will be a purpose built bike that is made to shred twisty back roads. maybe I will take it to the track someday. this bike will be functional first and foremost. if it turns out to be ugly, well then so be it.

geometry:
the geometry will be rather agressive. these are preliminary numbers, that is why I have given a range. once I setup my jig I will decide on what they will be exactly
rake: 21-22 degrees
trail: 3.25"-3.5"
wheelbase: 52"-53"
offset: 1.2"

components:
I will be fabricating many of the components as one off pieces. the pieces I don not fabricate myself will most likely be modified by me.

Frame: big tube 4130 aircarft tube or box section. I got it narrowed down to two concepts.

Motor: most likely it will be an RC51 plant, but we will see about that next week. also looking at a rotax v990 (aprilia rsv1000)

Front forks: 01 gsxr750. revalved and resprung eventually

Rear suspension: undecided, open to suggestions

triples: made by me. woot. they're gonna be pretty neat

wheels: custom cut from aluminum blanks by me

front brakes: dual perimeter setup designed and fabricated by me, most likely with a radial master

rear brakes: possibly a single perimeter rotor? not sure

calipers: most likely I will be using modified buell ZTLs, but I am also looking at machining my own billet calipers

Tank and tail: custom made by me. lookin into making a fiberglass setup. (if I can get around that pesky ethanol eating the resin thing)

things I need before I actually get started
rear suspension. I have a fox shocks double clicker kickin around. I haven't decided if I'm gonna try and set that up for this build or just go with a newer shock from a late model bike and respring it? it might be cheaper to get something off ebay.

swingarm: still not sure if I want to go with an rc swingarm with the rc motor.it does have the pivot on the engine case, so it might be the easiest way..... but hell, what part of this build is easy? might build a tubular swinger

the biggest part I need is a titled neck. I really prefer a steel one though. so that kinda cuts down on my options

a garage. lol. well actually I'm just collecting parts right now. once everything is collected I will probably rent a garage and build the bike as fast as possible.



I will be updating this thread with my rough concept drawings soon enough.

and to all you haters out there NO, I am not building my version of a GC-1000 or a hack built buell1125r. the concept and vision for this bike was in my notebook and in my head long before I had ever even heard of either of those bikes.

progress is gonna be slow until I have everything in place and ready. then I hope it will move pretty fast

what do you guys think?

 

[fslflint]

I say do a single-sided tubular swinger! If your gonna go ground up, do it right!!!

Can't wait to see it!

I'm thinkin of doin a custom single sided setup, but with the single perimeter brake mounted on the open side and a solid caliper mount. that would be different, not sure it would be functional. but it would deffinatly be different.

I was gonna post my concept pics right away, but my sketch book is in that car and my wife took the car to work. so thats a no go.

 

[fslflint]

this is the first concept I drew specifically for a v-twin powerplant. its sole purpose was for looks. scale really is nonexistant. it was done while at work.

this concept was done with allot more attention to the actual scale of the wheels, rake angle and wheelbase. the rest of the dimensions are just based off of visual ratios.

also remember that no matter what the tubular construction of the frame looks like it will be boxed for maximum strength

side note, I HATE belly pans. so there will not be one on this bike unless it is an underbody exhaust/muffler. I just drew them in the pics for some visual balance and to cover the fact that I am worthless when it comes to drawing an engine



my wheels
3.5x17 and 6.25x17. 20lbs and 24lbs respectively

 

[Scrapyard]

Very cool. I like the over all attitude of it. Do you have a desired weight you're looking to build it to? Cause right now, it's heavy I didn't realise how much those wheels weighed. They look cool though.

I would recomend using the Twin Clicker. You'll have a far better range to work with then going with a factory shock. You could respring a stocker, but you'll just be masking the issue down the road. Where as the twin clicker has a far bigger range of dampening adjustment.

 

[fslflint]

Very cool. I like the over all attitude of it. Do you have a desired weight you're looking to build it to? Cause right now, it's heavy I didn't realise how much those wheels weighed. They look cool though.

I would recomend using the Twin Clicker. You'll have a far better range to work with then going with a factory shock. You could respring a stocker, but you'll just be masking the issue down the road. Where as the twin clicker has a far bigger range of dampening adjustment.

the wheels will weigh less than half that when cut and finished.

I am aiming for 350 lbs dry. with how heavy the rc powerplant is thats a pretty lofty goal. I'll do my best

 

[fslflint]

something like this when finished

 

[Scrapyard]

That's right. Yeah I like those.

Well, how set are you on using 4130 as apposed to aluminum? Figure any modern Vtwin is going to weigh in close to 150lbs. If you can keep the weight of the frame down to 20 or so lbs your goal will be that more obtainable with the right frame config. With your current idea I would say your closer to a 40 lbs outcome for your frame.

 

[fslflint]

1.5" 4130 steel tubing with .058" wall thickness only weighs .893 lbs per foot. I'm figuring between 15 and twenty linear feet of tubing for the frame. plus gussets, boxing and billet mount points. I'm hoping to keep it under 30 lbs.


I may go with 2" tubing with a similar wall thickness. I haven't made my final decision yet.


also haven't decided on a bender yet either. its really down to two right now. the jd squared one. it cost $295.00 and another 300 or so for the required dies. and the other option is the carey bender, its cost about 450 with one set of dies.

hell I might just make my own

 

[Scrapyard]

If you can make a bender, that's the way to go. And you're in a position where you can make your own dies, so you're that much ahead of the game.

That's a thin wall bud. I'm a bit hessitant to run a wall that thin on a streetbike. It can be done with everything braced porperly, but that's still hella thin. Look into .068 or better. Remeber, a streetbike has to contend with a lot more abuse then a race bike. Pot holes, cracks, rebri and small animals . Also you have to be very carful bending something that thin. It will want to crimp. But that will deffinatly get you down in the weight you're looking for.

I was thinking if I go steel or 4130 for mine. 1.25x.095. Still gives you around a lbs per foot and has enough strength to take daily abuse. Getting the weight down is all in the geometry of the frame. The more triangulated the beter obviously. And the less material needed.

 

[fslflint]

yeah its thin, but it will be boxed aswell. the frame will be kinda like the spondon tlr, but all the openings will be covered with .058 4130 cold rolled sheet. each triangle will have a triangular shaped piece of steel covering it, welded (or brazed) on all edges. it will be boxed on the inside too.

I might go with .095 thicness, but I really think its overkill.

another option I am looking into is a steel delta box style.

 

[chandler]

a 6.5 inch rim. so thats a 200 tire. how much carving does a 200 do ? wouldnt a 170 or 180 be ideal or was it rims before design came final ?

 

[fslflint]

I may be able to go with a 190 tire with the 6.25" wheel.
the rims I bought were advertised as a 3.5x17 and a 5.5x17. when they arrived the rear was 6.25". so after emailing them back and forth for a while I finally decided just to stay with the 6.25" wheel as the company who they get there wheel blanks from doesn't even make a 5.5" wheel (which I verified). I can through on a gixxer rear if I want to.


on the plus note I am trying to see if they will contribute to the charity build for putting me through so much trouble. go to chromeplating.com thats them. lots neat powdercoating and chrome effects (the black chrome looks pretty neat)

 

[Scrapyard]

6.25" isn't bad honestly. You got a good selection of tire to use with that. From 180-210 works without distorting the profile too much. So Score on that one.

I could still carve the mountain switchbacks with 200 on a 7 inch with out problem.

That's gona be a beefy frame though. I want to see this thing. DW man.

 

[fslflint]

I'm trying to get a more complete concept drawn up in the next couple day. it will probably be the last one before I get my motor. then it will be back to the drawing boards for a while. anybody have access to an rc51, I would like to know how high the bottom of the engine sits from the ground on a stock RC. if anybody wants to contribute there artistic talents for the concept, have at it. just realize that I have 100% veto rights.

also, anybody have a copy of tony foales book they aren't using anymore? I have good grasp (I think) of steering geometry and chassis design, but I don't want to miss out on a chance to learn from the best.

also, to anybody who is planning on buying a top triple from me (or a set of triples) be happy to know that you will be funding my build. maybe I should make some stickers. lol.

I remember a link was posted some time ago about a tail mounted radiater. anybody know where that is? the bike is gonna be a monoposta, so why not put the rad there? still debating it.

I am looking for info about the exhaust HRC ran on the GP rc-51s. I have not decided on an exhaust yet. over everything else I will want something functional... and I want to make it myself. so I was thinking of running a single pipe from each cylinder, equal length if possible. dump the rear cylinder out under the tail and the front cylinder under the right footpeg.

lotsa scattered thoughts right now. still gettin ready for this. should be entertaining to watch anyways

 

[fslflint]

its late and I should be in bed, but instead I am screwing around with line drawings trying to figure out my frame geometry. ha, who needs sleep anyways.

heres one. its pretty close to buell geometry. a few months ago I said I was just gonna copy the geometry from the 1125r. well, the more I thought about it the more I decided I wanted a shorter wheelbase.

so the forks I have are 720 mm long from the axle centerline to the top. (atleast thats what it says on some website. they aren't right beside me to measure, so I'll take there word for it)

21 degrees of rake. 3.19" trail. 52" wheelbase. 31.5" seatheight.


for the motor in this drawing I just took a sv650 motor rendering that I already had and scaled it up 5 percent and rotated it back 5 degrees to approximate the size and position of an rc51 motor..

its pretty rough. I'll work on it more tomorrow

 

[fslflint]

Cool. And damn that's a short bike. That's gona fall into turns

I wanted something compact and light weight. wheelbase is the easiest thing to change if I don't like it. a little longer swinger and I'm back in business.

anybody have a buell they'll let me take out for a spin. in theory I like the steep rake, but I haven't ridden a bike with rake and trail numbers quite that extreme.

as it sits the frame tubing itself, not including welding, gussets and hardware is right around 23 lbs. so I'm probably lookin at a 30-35 lb frame. hhhrrmm. not sure I like that.

the x bracing looks kinda cool, but I'm not 100% sold on it just yet. its gonna be boxed anyways.

my eval period on the software I was using ran out last nite. its ok, I wasn't real impressed with Rhinoceros anyways. I gotta see about finding something else to work with. solidworks hopefully.

 

[cyclic]

You could loose some of the cross tubing buy using a slightly larger oval tubing ala aircraft tubing. Or close up the frame a little and use a simple plate to close up the opening kind of "I" beam style. You could even just do it perimiter style tubing with a thin plate inside and outside with dimpled holes connecting them welded together. I'll see if I can find a pic of what I'm talking about.

http://www.lightracing.com/v1b/includes/articles/FlareHoleArticle_4x4Garage.pdf

Basically take the complete plate make two of them and dimples the holes toward each other and close them up with a piece of tubing connecting them.

 

[fslflint]

You could loose some of the cross tubing buy using a slightly larger oval tubing ala aircraft tubing. Or close up the frame a little and use a simple plate to close up the opening kind of "I" beam style. You could even just do it perimiter style tubing with a thin plate inside and outside with dimpled holes connecting them welded together. I'll see if I can find a pic of what I'm talking about.

http://www.lightracing.com/v1b/includes/articles/FlareHoleArticle_4x4Garage.pdf

Basically take the complete plate make two of them and dimples the holes toward each other and close them up with a piece of tubing connecting them.

I would like to use some streamlined tubing, but it is a bit cost prohibitive.

a big misconception with flared hole gussets is that it makes them stronger. it doesn't. it increases lateral rigidity. the overall strength of the material is still limited by how much material is there.

thats not to say that they don't have there uses. in fact I was already figuring out where I could use them appropriately.

I'm gonna work on the frame over the next few day. the above design has too much tubing. its abit over complicated. I've been lookin at the mondial frames (sexy bikes by the way).

anybody else have pics of tube framed RC's go ahead and post em up. I am finding that they are few and far between comapared to tube framed ducatis and TL's

I wanted to use all three motor mounts, it seems that only the rear two+the swingarm pivot may be necessary.

this is from a dutch rc51 fighter build thatis in progress. he is using a mondial frame (how the hell did he get ahold of one?)

 

[Scrapyard]

Tale this and start drawing line

 

[ZrO-1]

That frame is perfect, but that radiator is HUGE