Air head scrambler,fun and games

mikeyboy

Well-known member
UKGSer Subscriber
Joined
Jul 14, 2010
Messages
8,662
Reaction score
453
Location
Overland and classic,vale of belvoir,Melton Mowbra
A few months ago I posted on some twin shock scramble/ISDE style bikes we were building,
Well the MK1 prototype,hit the road last weekend after much faffing and modding ,mainly around the issues we had with the rear end,initially I offered it for sale but having ridden the bike I decided to keep it as it put a big smile on my face:blast
Here it is in its nearly finished state,prior to commissioning.
 

Attachments

  • 9CD193A3-670C-49CA-BA86-A4C31EC7232E.jpg
    9CD193A3-670C-49CA-BA86-A4C31EC7232E.jpg
    256.5 KB · Views: 484
  • 520D74F9-2B22-4DA9-8DDC-FF59F52FE3B7.jpg
    520D74F9-2B22-4DA9-8DDC-FF59F52FE3B7.jpg
    257.8 KB · Views: 468
  • FC210CEC-37C0-4820-A6F9-B0D63315DA72.jpg
    FC210CEC-37C0-4820-A6F9-B0D63315DA72.jpg
    258 KB · Views: 503
  • A22EC21D-1644-42AE-884D-3806CD1A5C40.jpg
    A22EC21D-1644-42AE-884D-3806CD1A5C40.jpg
    249.3 KB · Views: 470
The engine is a 79 RS ,so I guess it would maybe make 50 BHP on a dyno,
On the road the bike was fast,very fast ,this would be down to the bevel box I fitted,it would top out at around 100 mph
I put it on the scales and it was 180kg..
So the list of improvements,hmmm
The front brake is shit,I always knew it would be,we will see if it beds in.
However,as the smallest master cyl available for the bmw perches is 12mm and the caliper prob needs 10mm,some development may well be needed.
But with an old school mentality,who needs brakes ,
Let’s spend money on fun,,,:blast
I pulled the motor back out,and paid a visit to Richie Moore.:D
Some omega high comp pistons,
And a 324 degree cam.
That should spice things up a bit:bounce1
 

Attachments

  • 740CAF01-2912-4AFF-AE0A-DB40991FC36E.jpg
    740CAF01-2912-4AFF-AE0A-DB40991FC36E.jpg
    235.8 KB · Views: 461
  • E3AAD524-A53C-4DD2-BF96-F4826D61A69A.jpg
    E3AAD524-A53C-4DD2-BF96-F4826D61A69A.jpg
    247.3 KB · Views: 461
  • B142DE9B-D63C-48CF-8161-07896CCB7DFB.jpg
    B142DE9B-D63C-48CF-8161-07896CCB7DFB.jpg
    234.5 KB · Views: 460
I'm not surprised it put a smile on your face,it's making me smile just drooling over the photos.
Cracking bit of kit,well done:D
 
The mental arithmetic tells me I’ll have 16 degrees more duration on the cam,
And compression will go from a nominal 9.5 to 1 to somewhere over 11 to 1
I’ll take it for a dyno run once it’s bedded in,but potentially,
,the motor could be pushing out 65 to 70 bhp.:cool:
 
I’m interested in what you are going to do to improve the front brake,mine is crap as well,standard DR350 disc and caliper. Larger disc and softer pads will be my first job,then I ll look at the master cylinder.
 
Took this for a run on Saturday with the upgraded pistons and cam,took it gentle as it needs bedding in/setting up properly,but,
All I can say is wow,
This is the engine that bumw should have built for the gs bikes,
It goes like stink,huge torquey lump.:bow
 


Back
Top Bottom