Scrapheap challenge Mk 3 hybrid (finished)

[nikfubar]

Well here goes this is my third hybrid, this is what I've got so far.
Of the forum a F2 frame & engine with matching numbers. Don't think the engines ever been out the frame, so unmollested, whipped the head off and no signs its ever been seized and still on standard pistons ;D
A mint NC35 single sided swing arm and new wheel.
Ducati monster front end.



Great run into first problem with the forks. On the yokes the back of the fork legs are in line with the centre of the shaft, on RGV yokes the back of the legs are in line with the front of the shaft. This pushes the forks back towards the frame 30mm from standard and reduces the turn. Also to fit taper head bearings I need 26 x 48 x 15 & this size isn't made. Boll*cks anyone any ideas.

[guiri]

hi nik,can the stem be removed from the yokes ? as in have a new one made that you can get a bearing for...or can you have a shim made to increase the shaft diameter,you can weld it in situ so you have no play in it..(nitrogen freeze fitting is a bit far fetched for your home mecanic..lol.)..as my old dear sez there´s more than one way to skin a cat........john

[nikfubar]

I have considered having the stem pressed out and 1mm machined off to suit the bearings but the main problem is the stem is set too far forward in the yokes which restricts the lock to lock turning. Also considered changing the yokes, RGV top yoke fits but the bottom one is 2mm too small and I don't think there would be enough meat left if they were machined out

[midlifecrisisrd]

Feb 17, 2010 8:53:44 GMT 1 nikfubar said:

I have considered having the stem pressed out and 1mm machined off to suit the bearings but the main problem is the stem is set too far forward in the yokes which restricts the lock to lock turning. Also considered changing the yokes, RGV top yoke fits but the bottom one is 2mm too small and I don't think there would be enough meat left if they were machined out

You could get a set made from spondon, would look really good.

Steve.

[nikfubar]

That's a good idea, but how much would it cost?

[Niz]

Just bought a set off him for my 4LO hybrid with RGV - USD forks , cost me £275 they came all anodized and I must say they look fantastic. He makes a top job.

[nikfubar]

Decided to sell the Ducati forks, not worth the aggro

Bought this ;D GSXR 600 K4 front end, sweet and easy to fit ie: off the shelf taper bearings.



Got a bit further with the rear end, cut and opened up the frame to take the swing arm. Welded patches over the cuts to hold them open.




Once the arm was in, fitted a tube to the headstock and pulled a line through to the centre of the wheel to check it lined up with the centre of the frame at the arm mount. It does so all straight and true.





Can anyone tell me the dimension from the centre of the grab rail lower mount to the centre of the wheel on an F2, on centre stand so I can set the hight of the swing arm.

[bare]

So far so good!
I'm left wondering if the pore old Valvie frame will have the torsional Rigidity to hold that single sided swinger pivot steady, once in use ?
Flexi Flyers was a nick name for these bikes when they were current.

[nikfubar]

Yeah know what you mean I was wondering the same thing too. Plan to beef up the frame, remember a thread somewhere, where this was done.

[nikfubar]

Well it was raining all day Sunday so got a bit more done
Cut out and replaced the top and bottom suspension and engine mount tubes. Also de-lugged and removed redundant metalwork from the back end.





After all that cutting and welding I thought I'd better check everything for alignment again so fitted the swing arm and wheel, put the lines through, checked centre line then both sides of wheel rim and it appears I am now 1mm off centre so I will have to grind 1mm off the right hand swing arm bush and insert a 1mm spacer on the chain side.





Can't do a lot more on the frame untill my new machined swing arm spindle arrives so I decided to strip the engine. It's never been apart before, it all came apart so easy even the flywheel ;D well happy with what I found, good crank, no signs of seizure, gearbox and selectors were perfect even the clutch basket has no ridges.




Now I've re-assembled the empty cases put the barrells and head back on it's a lot lighter to lug around, fitted it back in the frame ready to weld on the rear engine mounts.

[bryan]

wouldnt you be better dropping some plumb bobs from 2 points each side of the frame at the front and back and marking on your bench, then half way between this would give you an accurate centre line to drop centre plumb bobs too.
Something like the inside of the frame where the plastic infills go and the swing arm bolt holes.

[nikfubar]

Thanks for that, I take your point but at the moment I don't think I can get much more accurate as I centred the line between the front down tubes the swing arm lugs and centre of wheel rim. Then double checked with a straight edge eather side of the rear wheel.

Please correct me if I'm wrong but it's all about wheel allignment, I've now got the taper bearings for the yokes, so if I fit the forks and front wheel then clamp two straight edges across the front wheel so they run parallel to the back wheel, as long as the measurement between the straight edge and the rim are the same both sides they should be perfectly alligned
I will then see how accurate my bits of string are ;D

[bryan]

I know you dont have tyres but this should still work.
www.motorcyclistonline.com/howto/string_align_motorcycle_wheels/index.html
As the rear wheel is wider, wouldnt it be better to use them on the rear wheel and check lines with the front wheel as it will fit between them.

[bryan]

as you havnt takern anything off the swing arm or its mounts on the frame, shouldent it be central anyway Nick.

[nikfubar]

The tw*t that sold me the front end lost all three yoke nuts so had to buy new ones £42.00 what with that and the taper bearings @ £30.00 ouch




Then had to fabricate a new yoke stop with a fixing point for the steering damper.






Next I've fabricated a new rear engine mount because I mullered the old one getting it off.




Put the empty cases back in and welded on the rear mounts.



Fabricated the fixing point for the shock lower linkage and welded it on.






My new stainless steel swing arm spindle finally turned up, now I nearly have a rolling chassis ;D




Got a nice condition CBR 600 RR shock, problem is because the NC35 shock position is offset the new shock resovoir fouls my new sub-frame so I'm going to try and mount it backwards as photo. Trouble is the top mount is going to be a nightmare, might try a single sided mount

[sidney]

looks cool cant wait to c more of it oh and will u eva use that bloody renthal sprocket hanging on the wall lol ;D

[nikfubar]

The sprockets for my Aprilia RSVR, gone down 1 tooth on the front, the one on the wall is 2 teeth up for the rear. Got to see if i can keep the front wheel on the ground before I fit it, if not it goes on the bay.

Wait for next installment and I will change back ground ;D

[sharpyg]

looks great Nik, fancy popping over to do mine ?

[bubba]

looks a great job!, nice neat welding cant wait to see more,

[nikfubar]

Thanks ;D Invested in a mig welder for this build. The last two I've done I used my old arc welder, when you go over to mig it's so easy to get nice welds.

[seanrd]

Looks really smart that What Mig welder are you using?

[nikfubar]

It's a Sealey mighty mig 100XT mark 2 turbo

I use 0.6mm wire and CO2 as it gives you more time to build up a neat weld than the 0.8mm wire.

[nikfubar]

Well got a fair bit done in the last 2 months
Finished modifying the frame with additional bracing, that should stiffen the bugger up ;D
Also fabricated the single sided shock mount & welded on new mounts for the rear sets & subframe. Also moved the side stand mount forward as it fouled the gear change.

Thought I'd change the background as well for those of you who are fed up with looking at that sprocket on the wall







Also finished the heavily modified Mito rear sub-frame.



This now houses a Gel battery laid flat, a RS125 oil tank & some of the electrical components.




Now I got me a rolling chassis



Put the engine casings in & fitted the tank, seat unit. Now I'm ready to have some pipes made. ;D

[scott]

very nice m8,love the extra bracing on the frame

[seanrd]

Getting a bit handy with that welder!! Cracking work, really looks good

[gadget]

Cracking build so far nick, really like the bracing on the frame, looks a little 'Ducati'esc.

[nikfubar]

Pipes are progressing nicely, they are Mick Abbey design ;D

[nikfubar]

Yeah so do I ;D Slinger is making these

[Norbo]

WOW this is turning in to some bike . LOVE and i mean LOVE the frame mods . and your going for 2 up i side as well with the pipes should fit in well with the look of the bike .

[nikfubar]

Cheers Norbo ;D got no choice but to run GP style exhausts with the single sided arm. A pair of your carbon F2 cans should look the dogs, stuck on the end at high level.