The second picture is a 750 frame with atlas offset

thanks for the efort, a little confused though in the 2nd picture , it shows the rake as 28 degrees does it not?

madass140 wrote:thanks for the efort, a little confused though in the 2nd picture , it shows the rake as 28 degrees does it not?

You can ignore that if you like, it is the effective rake with respect to the ground, the frame rake hasnt been altered, its still 27deg. Basically as the back of the bike gets higher that angle gets smaller or conversely if the front gets higher the angle will increase.

ok, thanks, so we now know what the trail is with the Atlas yoke on the 750 frame is, now the trail of using the Atlas yokes on the 28 degree 850 frame is????

did we determine the what the trail would be using the early Atlas type yokes with the 2-1/4" offset on the 850 frame???

Using a Roadrider 100/90-19 (13.3" radius) it comes up 4.47" ground trail. 3.95" real trail.

http://www.tonyfoale.com/progs/castor1.exe

Thanks Bob, now over to the experts, would this be considered ok ????

using Foales calulator with these measurements
28 degrees (850)
2-1/4" offset (Atlas or early Commando)
4.10 x 19 K81 345mm Radius ( I just measured it)

ground trail 118.71
Real trail 104.81

I see someone mentioned 850s have alittle over a degree built into the yokes. Im assume using a straight yoke would yield quicker steering response?