haderz Posted August 17, 2009 Report Share Posted August 17, 2009 difference in geometry with a 24 inch trials and a 24 inch jump bike. i realy dont know the difference so please help! Quote Link to comment Share on other sites More sharing options...
Revolver Posted August 17, 2009 Report Share Posted August 17, 2009 Jump bike - low BB, short CS, sharper HA (i think) so it can take higher forks, shorter in general.Trials bike - raised BB, around 30, longer CS, 380 or so, slacker HA to take lower forks, longer - 1030 or so. Quote Link to comment Share on other sites More sharing options...
sstein Posted August 17, 2009 Report Share Posted August 17, 2009 Jump bike - low BB, short CS, sharper HA (i think) so it can take higher forks, shorter in general.Trials bike - raised BB, around 30, longer CS, 380 or so, slacker HA to take lower forks, longer - 1030 or so.The jump bike actually has longer chainstays and a slacker head angle, but you are right about the lower bb. Also the head angle has nothing to do with the length of fork going to be used, only how sharp the steering should be, a jump bike headangle is usually a 69 degree and trials are 72 degree. Quote Link to comment Share on other sites More sharing options...
Trials Punk Posted August 17, 2009 Report Share Posted August 17, 2009 With revolver and sstein on corrections.Headangle: As said, not alot to do with the length of forks. A 70 deg head angle would provide more stable steering at higher speeds, also more control for taps. A steeper head angle such as a 75 deg, would be less stable at speed but more responsive for slow speeds, such as spins and front wheel manouvers such as switzerland squeakers, pivots etc.BB: A lower BB, as on a jump bike will make the bike more stable to balance in the air and on land, it also lowers your point of gravity for more responsive turning at speed, also by lowering your centre of gravity manuals can sometimes feel nicer. A higher BB, as on most modern trials frames makes it slightly harder to balance, but alot nicer on the rear wheel.Chainstays: Longer chainstays, more common on jump bikes aid control when going up lips, will be harder to get to the balance point of a manual but once there it will be more controlled and easier to keep. Shorter chainstays are better for back wheel control, bunny hops and manuals come up easier although are then harder to control.I think the trials bikes of days gone by, pashley, giant team trials had more, what we would consider now jump bike geo. Not saying they had bike jump geo, but that they leant towards dirt more than trials bike geos do now.I hardly ever post on here, not sure why I was inspired to write all that................meh. (no guarantee its right). Quote Link to comment Share on other sites More sharing options...
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