just aquired two vintage road racing bikes a triumph and a norton

[motorpig]

I just aquired these two bikes and am an avid motorcrosser.. I know nothing about these bikes except that my uncle raced them on raod flat tracks. there are no triumph or norton markings and i need help identifying what they are. I know one has a custom race frame from track racing frames, and i believe its the norton. the other has a tranny marking of AXTELL . I have engine numbers from both one is p11124705 and the other is NC 02798. both have dual amal carbs. andy help would be greatly appreciated...dave

[Bomber]

Try google!

[L.A.B.]

I have engine numbers from both one is p11124705 and the other is NC 02798. both have dual amal carbs. andy help would be greatly appreciated...dave

p11124705

P11 124705 ?

You didn't say which number is  Triumph and which is Norton, however "P11" is a Norton/Matchless hybrid model, and the serial number 124705 would tie in with it being a P11 from 1968.
The P11 had a Norton 750 Atlas engine in a lightweight frame derived from the Matchless G85CS scrambler and it was really a desert racer rather than a road racing model.

http://en.wikipedia.org/wiki/Norton_P11
http://www.nortonownersclub.org/history/atlas-hybrids-2

NC 02798

NC would be the date code prefix for a 1969 model Triumph built in October 1968 and serial number 02798 would also fit in with a Triumph made at that time-but the model type was normally stamped as well as the date code and serial number?   



   

[motorpig]

thankyou for the start ...the info given makes the norton with a custom race frame and the other would be the triumph..how do i figure out what the cc of the triunph is . the norton is a 750 which im guessing from what you posted..thanks again LAB..

[L.A.B.]

how do i figure out what the cc of the triunph is .

A Triumph twin of that period would normally have been either 500cc or 650cc and the engines look slightly different, so I suggest you look at some Triumph images and see if you can decide which is type it is?

If you can measure the stroke (place a pencil or rod etc. in a spark plug hole and measure the distance the piston moves between BDC and TDC)  a 650 will be 82mm, and a 500 is 65.5mm.