Building a race bike

How does the wheelbase compare to a standard?
And also wheel distances from a central datum point.
Looks stretched out at both ends but with steeper steering maybe you get some of that back.
I'm sure you did your sums though. Top job.
 
Julian
From the top forward engine mount to the centre of (the bottom of) headstock looks to be very long, my SF measures 210mm (ish). what's yours?
Great project.

Piet, my spine frame weighs 12Kg, that's bare ... without swingarm.
 
chrisk said:
Julian
From the top forward engine mount to the centre of (the bottom of) headstock looks to be very long, my SF measures 210mm (ish). what's yours?
Great project.

Piet, my spine frame weighs 12Kg, that's bare ... without swingarm.
Click to expand...

Hi,

Just measured and exactly 210mm so spot on with yours which is interesting.  Probably just looks funny because it's bare.  (so do I  ;o)

My complete frame is made of 25CrMo4 and "light" with swingarm and brackets etc is 12.2kg and yes I am going for as light as possible,  even doing away with any unwanted engine casting sections like starter mount etc,  Imagine the weight reduction on the crank also at 63mm it will lose a hell of a lot of mass from the outer ring.  No flywheel either.
Not going for a weight goal, just "as light as possible" without puting the rider in danger.

Wheelbase as in the pics is 1450mm

J
 
Wheelbase of my SF2 with 45mm offset (from Jota) clamps is 1475mm. An SFC mock copy here has 1510mm, my mates trick frame for SF motor has 1370mm.
Great project Julian.
 
Just for fun I blended your photo with an image of the SFC, so the relations can be seen with a different view.

Super project!

Cheers Jens

 

Attachments

  • sc.jpg
    sc.jpg
    137.4 KB · Views: 110
  • jo.jpg
    jo.jpg
    153.1 KB · Views: 177
Thanks very much Jens,

Actually that is the look I am going for,  Early SFC styling,  Although I do like the Egli style of Marnix's bike, I think the early SFC is such a pure look.
Not sure If I will use side panels yet but probably.  Going to download that pic straight away and dream  :D ;)


Clem,
Yes the lower engine mount and swingarm mount was my idea as I think it will be a lot more rigid than the Egli design which I actually don't like very much, Just "feels wrong"
Ordered the shocks today,  nice light weight ally units Mmmmmmmm

J
 
Jens said:
Just for fun I blended your photo with an image of the SFC, so the relations can be seen with a different view.

Super project!

Cheers Jens
Click to expand...

Jens, what program does that type of drawing?

Julian, wow, that distance is amazing, must be an optical illusion that it looks so long.
 
chrisk said:
Jens, what program does that type of drawing?
Click to expand...

Photoshop can do it, I'm sure Gimp has also the needed features. Do not know about other ones, but there should be some.

The program has a function which finds/detects edges to create the outlines.

With some minor additional adjustments that function is quite helpful to create such an overlay image. Very suitable for this purpose I think

cheers, Jens


 
It's always dificut to judge from a pic as wheel sizes and for angles etc are are always different, even slightly, 

Shocks will be Falcon from England,  heard very good reports and they seem to be working on the Classic Manx as they are fitted to a lot of the front runners.

Am getting excited.
J

That centre stand is actually my new oil filter conversion,  do you think it's a bit low?  :D :D
 
What it does Chris is save on weight,

I workded out that oil in the engine weighs 1.2365kg but the device you see here is 0.896kg and what it does is scrape up all the oil dropped by the other bikes on the track so I don't need to fill the sump, and I use the scraped up oil in the engine before throwing it back out of the breather in the face of the persuing riders.  Clever eh!!

Don't know why anyone else didn't think of that before me.  I'm on Dragon's Den next week to sell the idea for about 500,000 for 1% of my company.  They will snap it up.

J
 
julian said:
What it does Chris is save on weight,

I workded out that oil in the engine weighs 1.2365kg but the device you see here is 0.896kg and what it does is scrape up all the oil dropped by the other bikes on the track so I don't need to fill the sump, and I use the scraped up oil in the engine before throwing it back out of the breather in the face of the persuing riders.  Clever eh!!

Don't know why anyone else didn't think of that before me.  I'm on Dragon's Den next week to sell the idea for about 500,000 for 1% of my company.  They will snap it up.

J
Click to expand...

When I raced Speedway, the bikes were a dead loss oil system, dumping oil on the track ..... Have a word to that big tall lanky blonde bloke, Simon Wigg, a fellow countryman of yours, I  think he'll love it. BTW, he has a great SOH, you'll love him.
 
chrisk said:
Jens, what program does that type of drawing?

Julian, wow, that distance is amazing, must be an optical illusion that it looks so long.
Click to expand...
Looks long because the top of the steering head and the bars are about 5 inches further forward on Julian's bike (due solely to the 23 deg rake)! Which means the tank can be mounted further forward and the seat/rider and thus move weight bias forward ... all of which are good!
Enjoying watching this project take shape. So with a 63mm stroke, what bore size will you run and thus, what capacity? Have you SFC Carillos been honed yet?
 
You must log in or register to reply here.
Back
Top