redmarque

Only a small update for now... My ducati monster... :D Opps! franken VFR is coming on nicely... Picked up the main engine carrier bushes on the weekend, so a few more tubes cut and fitted. Had an inital quote for the custom yoke too - £500! <_< Going to see if I can leave work early this week to visit the machine shop and discuss options. (one of the engineers has built grasstrack bikes before, so hopefully I can get someone excited about making bikes) I'm hoping that simplifying the design will bring the machining cost down. Has anyone used http://www.emachineshop.com? Keep riding! :thumbsup: Redmarque

Yes that's right Tok. Zero is fork fully extended. So normal pre-load should be at about 25-30mm. I should be able to change this as the front shock top mounting will be adjustable for ride-hight. What does the curve for normal tele forks look like?... don't know? Though I imagine pretty disgusting in comparision.. :pissed: I'll have to check whether the FFE software can calculate it? As for progressive - the graph shows a steady increase in anti-dive upto full travel. (If mr foale's maths is correct) also the rising-rate linkage will increase the force on the spring the further it's compressed too. P.S. if MR Ohlins is reading this, I could really do with a nice pair of shocks to test with? :blink:

Been pondering the anti-dive on my design... Arion seemed to thing it may produce about 5% anti-dive in initial suspension travel which got me very worried :unsure: At the time i hadn't got my laptop with the FFE software installed.. but I picked it up this evening and went over the design again. Here are the graphs for anti-dive, rake, trail and wheel trajectory. lets say that sag is 25-30 mm and over all suspension movement is 120mm (same as standard VFR) As you can see the anti-dive after 30mm goes upto 50% in the next 60mm of travel. If the base link is shorted by 5mm anti-dive goes up to 60% in the same distance. phew! :thumbsup: what a relef! :D

Not sure if any of you guy's read thekneeslider interesting article on a vfr over there! :D The Kneeslider

Great Arion! this is just the type of input I've been looking for! hossack suspension is really an unknown quantity. I agree that to adjust the weight bias using a custom swingarm would be the best solution as I don't really want to increase the wheelbase or rake\trail :blink: Will just have to see how it works with the VFR swingarm first. On your advise I am going to re-address the anti-dive situation. Tok Tokkie has suggested 60% anti-dive? I think I will try and calculate how much BMW used by scaling up the pic and entering in FFE software. On another note. My copy of the VOSA MSVA Inspection Manual arrived yesterday! :huh: It's the UK Vehicle & Operator Services Agency Motorcycle Single Vehicle Approval Inspection Manual. ( yawn ) basically when you build a one-off bike in the UK it has to undergo an engineers report before they will alocate a Identification Number and allow a Registration number to be assigned to it. 29 Chapters of rules and regs about how high the lights are allowed to be, where the number plate can go. if any of the parts will cause injury, brake testing and exhaust noise etc. Great bed time reading! I can see why most people use an existing frame and modify it saves loads of hassle! :rolleyes:

Interesting. I'm wondering how the frame geometry was decided, including: wheel base, rake, trail, front/rear weight bias, anti-dive proportion. Judging from the front suspension arm angles (close to parallel), it may produce about 5% anti-dive in initial suspension travel. Was that your aim? HI Arion, ah the 'magic' numbers! There is no real mystery on how the dimensions came to me. Firstly i wanted the wheel base as short as possible, the VFR engine and many v-twins are very long front to back so I initally drew the front wheel as close to the forward cylinders as possible allowing for flex under heavy braking. The vfr swingarm length was already decided for me by Mr Honda. So that's the overall wheelbase! Rake - don't know if any of you guy's have read Tony Foale's Motorcycle Handling and Chassis Design? Anyway in Tony's book he tried a few experiments with rake and trail on a BMW with various rake angles, Standard - 15 Degrees and zero. He noted that the bike was just as stable with 15 or 0 rake but experienced telescopic fork judder. (tele's were pretty naff then) One thing he did notice is that steering was quicker with a steeper rake.. hence the fashion for GP/Race bikes to have steeper rakes than 5-10 years ago. I guess I wanted to see what an even steeper rake would handle like? especially with vfr power. Trail - the most determining factor on stability and a motorcycles self-centering effect. shorter trail - less effect -but less stable. longer - more effect - more stable. I've design the trail to be 96mm at the moment as this about the same as a CBR600RR - known for impressive cornering. Anti-Dive - perchased a copy of Tony's FFE (Funny Front End) Software for this. I didn't want the first ride to be too dangerous so the current geometry is pro-dive bias so that it didn't feel really unfamiliar (the lengths of suspension arms can be altered to change this later) disclaimer : I am no expert on this ! it's a trial by fire approach! Your input would be most apreciated! :thumbsup:

Just going right back to the beginning for a moment... is the front wheel in the pic destined to be there on the final product? If so, may I suggest a Marchesini three-spoke rear wheel to match... (yep, I'm the master of the unlimited budget suggestion ). How gorgeous is this bike??? I'd normally take an RC45 over an RC30 any day, but this bike sure makes me stop and think. Not sure why but finding a VFR 6 spoke at a reasonable price is quite hard in the UK :rolleyes: , so yes this is a cbr600f4 front. Uses the same 296mm disks and hollow axle. If the design proves a success mr credit card might take a bashing. :rolleyes: Would be fab to have a lovely set of Marchesini's of any type! :salesman: RC30-45 lovely! Make mine an NR750! :thumbsup:

Uh-oh - where's the ToroCharger drive belt gonna go??? :rolleyes: Was the projector headlight clearance issue caused by the Hossack set-up (centrally mounted shock)?? Those headlights certainly need some depth. Not only is the assembly quite long (at least 150mm, or 6" for the metrically-challenged) but the lens itself needs some clearance as it will melt anything plastic that's too close. I'm juggling projector lens headlights myself. One more thing - don't rush it just coz we're so demanding of pictures :salesman: I owe the collective a heap of pics, but I'm having to just go on with things according to plan, although the temptation is there to slap things together just for photos - oh, hi there AB, the pics are on the way!! :unsure: ToroCharger installs on the right side of the engine if my memory serves? :rolleyes: so don't worry! Yep got it in one Projector headlight rear end would get hit buy the hossack fork - headstock supports. a traditional headstock is alot nearer the tank! :blink: Point taken Phantom, I 'attached' the tubes just to see what it would look like, after a hour of measuring, profile cutting, getting it wrong and remaking - it's nice to see some results :D

I am truly honored! :thumbsup: to my post being moved to "Featured Modifications!" Big thanks to everyone at VFRD! :D

Now I know you guys love pictures.... loft insulation foam has other uses. :joystick: I've had do ditch the projector headlamp for now as i couldn't find enough space! Next job is to cut air intakes for the ram air system each side. apologies for the state of my garage... i'm not so worried about you seeing the mess after checking out vfrriders cool project! :thumbsup: Promised a while ago to post pic of the front mudguard plug. Painted it with 'reface' a special polyester high build filler/sealer which won't react with fibreglass gel coat. please don't ever try normal car paint as the chemical reaction makes a right mess! Fork jig still needs stops welded on to position tubes correctly. More updates and pics soon.... Redmarque :blink:

Yes Sir Mr tok tokkie!! Your wish is my command! :thumbsup: will cut some card circles and tape up the thottle bodies asap! :blink: FANTASTIC offer to CNC! Tok. That would be ace! I really liked your triple clamp a very professional job! Can you deal with autocad dxf files? as I don't think i can write G codes! :wheel: Is the "aegis" the raw code that will control your CNC mill? Would be very happy to pay for materials and shipping! :D and your guaranteed a ride and a place to stay when it's finished! The tube profiles in paper (shown on forks) are created using a free piece of software called tubemiter which can be found here http://www.ozhpv.org.au/shed/tubemiter.htm Just input the size of the tube and wall thickness of both tubes to join plus the angle and it will print the profile on A4 paper using any printer - makes the job much easier! :D The two tubes you can see joining the sub-frame to main frame still need to be cut. the middle section will be welded to the mainframe with bushes to hold the sub-section. - Will post some more pics when cut to show the idea, so unfortunatly it's not articulated but will make changing sub-frames easy. could always do a full touring sub-frame with luggage/rack points built in and a nice coffy seat! If i'm going to design some hangers and pegs for my project bike, it would be really good to make them as replacement for standard 5th Gen ones, then everyone can have lovely rear sets? :idea3:

Thanks guy's! Adjustable pegs does seam the most logical way to go. I've been trying to keep the cost down, so cnc machined is out of the question at the moment. i've sourced a pair of hangers and pegs from cbr600 f3 which I could fit to an adjustable back plate. Gear linkage might be an issue. as the connector rod hits the sproket cover! Yep would really love a ToroCharger! I think I better get the machine running first! :D

Hi all! Another installment in the development of a frankenviffer. it's been a while but i've made some progress... most of the frame tubes are tacked together. designed and cut/tacked the rear sub-frame Cut tubes and made a jig for the hossack forks Made a wood frame to hold the Sv650 upper fairing in place plus mocked up some 'handle bars to check positioning. Engineering drawings are at a local engineers. i'm now waiting on costings for bearing holders, bushes, steering head bearing mounts, more sub-frame bushes and front /rear shock mountings. Hoping for some encouragement from you guys on the build! :thumbsup: If you could move the foot pegs on your 5th gen where would you like them? I've been debating 40mm up from stock? :idea3: Redmarque :blink:

Alot of posts about seats flying around... Here's my frankenviffers seat - 2 inches taken out of middle section and 3 from the back. leather is from an old horse saddle. i'm liking the look of the sargent though might take some more foam off the sides?

Cheers for that. I think that a power commander 3 is the way to go, athough this looks very interesting? http://www.bgsoflex.com/megasquirt.html DIY fully programable fuel injection system.

Yep it's special. There was some conjecture about it, as the motor looks more V-Max than VFR800... I thought about using 2 vacuum cleaner hoses, (bit like a Kwak ZXR750) porting it though the existing snorkel hole and flapper valve - as you can see there should be enough room without the standard headstock. surely a bit more clean air can only help! Were the Oz guys using a power commander?

Top of frame coming together - turned bushes hold tubes in place on threaded rod - airbox wil need a little diet to fit. Has anyone tried ram air modification with a VFR?

Just have the cleanest bike out there to make up for it! Its what I do! Man, if that Hossack front end is invisible, sign me up for one Yeah OK, invisible in real life just not in CAD! whole bikes just a load of parts at the monent 'just have to piece them together ! :goofy:

How did you guess? Yes I read - or tried to read as best i could, Tony Foales book. i'm trying to emulate his contruction methods as they seem to work. He did some great experiments with rake and trial which is where I got the 15 degrees from. apparently the trail is the most contributing factor on stablity. The nice thing about a hossack frontend is being able to change the geometry more easily. Tony has also produced FFE software which makes calculating upright and link lengths a doddle. on another point - I like your bettle sound idea was thinking of calling the bike scarab but your bettle sounds better!

Hi all, Just thought I'd see what's your opinon on my frankenviffer. In the process of Jigging the engine. frontends going to be hossack based.