OzVMX Forum

Clubroom => Tech Talk => Topic started by: Noel on September 06, 2009, 09:26:02 pm

Title: steering Geometry
Post by: Noel on September 06, 2009, 09:26:02 pm

I've had this in my head all day and need some help,
what is the effect of running leading axle forks as trailing axle forks
apart from looking wrong,
XZ550 Yamaha's had this and last year I saw it intentionally done on a pre75 Bultaco running on the dirt track
at Jack Hogg, ridden by a young guy but the bike was set up by his father,( he was fast)
does it have the same effect as de-raking the steering head? or the opposite effect, or is it some thing else,
Cheers
Noel

Title: Re: steering Geometry
Post by: jimson on September 06, 2009, 09:35:27 pm

I think it would have the same effect as de raking the steering head :-\ .but the forks would have to be from the same period as the bike one would think.jimson

Title: Re: steering Geometry
Post by: mx250 on September 06, 2009, 10:44:03 pm

It's late but if I get my head around this correctly putting the axle behind the sliders increases the trail making the bike more stable in a straight line and greater reluctance to turn :-\

Title: Re: steering Geometry
Post by: Lozza on September 06, 2009, 11:28:54 pm

100% correct.

Title: Re: steering Geometry
Post by: JC on September 07, 2009, 07:43:40 am

Also puts more weight on the front wheel cos it shortens the wheelbase.

Title: Re: steering Geometry
Post by: DR on September 07, 2009, 10:22:02 am

this isn't a new trick..if you remember rightly the Hatta forks that Kawaskai used on a few pre'75 (f5/f7/f8) models allowed for 3 way adjustment. Axle inline, leading axle and trailing axle ;)

(http://www.cyclechaos.com/wiki/images/5/55/Hatta_Fork02.jpg)