Building a race bike

Thanks Marnix, you should pop over some time and take a look, you would enjoy yourself and my coffee is great! 😀
Thank you all for your comments, hopefully it will work 🤣🤣

J
 
More progress,
Final welding done,
Made a strengthening ring in spring steel last night and tacked it all on then shrunk it to tension and re temper it. You can see in some of the pics the tension has actually "threpenny bitted the band which is what I hoped for, however if I was making more I would re-design it slightly as this part took a lot of time last night and could have been saved on a CNC.
Basically finished other than some finishing touches, Massively lighter than the stock setup, I will weigh it this weekend but it's not a matter of "it feels a bit lighter" it is chalk and cheese, really a big difference. And the diameter is much small er as you can see so a double win.
Test fitted here with everything inside and tight. Really happy with it.
Tested the reverse "slip" with a big bar also and it's working a treat, there are extra springs in the kit to adjust the slip load which is a cool idea.
Regards,
J
 

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Vince said:
Engine cutout and no clutch downshifts here we come.
Click to expand...
Hi Vince.

A. Its a race bike,
B. You still get a fair bit of engine braking as it has to have enough backload to disengage the clutch springs,
C. Almost every Ducati and modern Hyperbike has one as standard

Not really worried of any problems in that area.
Besides, I won't be riding it :LOL::ROFLMAO:
 
Surely you will give it a run, someone needs to test it. As much fun as it sounds banging hard down gears on the road into bends with these bikes is a bit over the top. Bit different on the dirt where it's softer to land. I have a Recluse fitted to my Husky, been around odd clutches for a while. Brake and power sliding is done a lot. Been watching those Supersports blokes backing them in, it does look like fun.
 
The problem is the torque reaction from engine braking (and to a lesser extent the rear brake) has a tenancy to lift the rear wheel, (built in anti-squat to counteract the front end drop) however as the bike is heavier than the wheel the wheel tends to lift, (sprung and un-sprung weight ratios) so releasing all braking effect and slowing the wheel more than the speed of the bike, as the wheel then lands the wheel then locks, and ends up going into an oscillation which is really not funny on a very fast bike, especially so on an extremely light one travelling as fast as possible at any given moment, (hopefully fast and light will both be features on this bike) In earlier GP days people like Biaggi had really big issues with this exact problem, hence the use of slipper clutches, it's certainly not my invention. I simply want this bike to be as powerful and light as it possibly can be and as rideable as it can be, therefore every trick in the book.
Jules
 
Vince said:
Engine cutout and no clutch downshifts here we come.
Click to expand...
Hi Vince,
I misunderstood your post I think.
Engine cutouts etc are forbidden in our class of racing. In the UK we have to also run drums and no discs, in Belgium Holland and Germany we can run period discs and period calipers but electronic shifts etc are strictly a no no.
A good thing I think.
Regards,
J
 
Probably gentler on gearboxes in the long run. We have a few modern bikes with power shifters on rides in the past, they now turn up on Laverdas, I miss the scary explosion like gear changes though.
 
Many years back I was making a single seat race car with a turbocharged Yamaha FZR750 motor, this had an air shift up and down, the only manual action was to select neutral. Wild :oops::D
 
julian said:
Hi Vince,
I misunderstood your post I think.
Engine cutouts etc are forbidden in our class of racing. In the UK we have to also run drums and no discs, in Belgium Holland and Germany we can run period discs and period calipers but electronic shifts etc are strictly a no no.
A good thing I think.
Regards,
J
Click to expand...
It’s interesting how we still debate the pros and cons of allowing ‘modern inventions’ into ‘classic’ racing. I’m not sure we will ever get to the point where everyone agrees what is and isn’t acceptable. By coincidence, I was reading some old Motorcyclist Illustrates from the 1970’s recently and Ray Knight was bemoaning some of the ‘cheating’ that was going on in supposedly ‘Production Racing’ back then. The arguments were not dissimilar to what many of us are now using in respect of classic events, and I dare say in another decade or so there will be similar arguments about whether a certain type of battery, electric motor or management system is a legitimate option on your old Energica superbike. 🤔
 
My favourite story was I forget its name but it was a, Buckets Racing just remembered. It was I think limited to 100cc or so and was an attempt at cheap racing, fast forward a couple of years and they were sneaking HRC programmable ignitions in all kinds of crazy expensive hidden mods to win.
 
Hopefully the rules won't change before Julian has his machine card. Here they no bikes permit bikes without engine/frame combinations that were not sold as a unit back in the day, those with current machine registration cards can continue. So no more home-made frames, tribsa, vincati, suzi engine in tz frame etc etc. Where this shit comes from I have no idea, nor what the purpose is. The guys racing "old" classes (before full faired became standard) are generally engineer types who have always played around like this, even back in the day. It seems they want a gentlemanly silhouette show.
 
Tippie said:
Hopefully the rules won't change before Julian has his machine card. Here they no bikes permit bikes without engine/frame combinations that were not sold as a unit back in the day, those with current machine registration cards can continue. So no more home-made frames, tribsa, vincati, suzi engine in tz frame etc etc. Where this shit comes from I have no idea, nor what the purpose is. The guys racing "old" classes (before full faired became standard) are generally engineer types who have always played around like this, even back in the day. It seems they want a gentlemanly silhouette show.
Click to expand...
I agree it is an odd rule, takes away the ingenuity. Imagine then actually the Britten could not race Under those rules?
 
Agree! Remember 1971 when Phil Read won the world championship on a private TD2 Yamaha with Cheney frame and Dunstall disc brakes. Those bikes would be banned from classic racing as they deviate from the production racers of their period ...
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A mate who is deep in historic two-stroke Yamahas has build up a close to original replica.

Cheers,
Jo
 
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