hondapower
New Member
Hey guys. New member here. Use the site a lot for reference for my 1972 cb100. Recently put together a cb100 that is in good shape and all stock. After riding it, I'd like to upgrade the suspension. I've done some research and know that it is not particularly cheap or easy, but the prospect of having a small street legal 4 stroke with modern suspension is really appealing. I've got some questions.
Forks:
Seems like the easiest thing is to swap triples that take 31mm forks (cb250 triples or similar). However, there don't seem to be any good 31mm forks. Finding one with disc brakes is really hard it seems.
The harder thing to do seems to be swap anything larger than 31mm (tube diameter).
The guys who ride xr100's face the same problem and solve it by pressing custom steering stems into either kx80/85/100 triples or cr80/85 triples and then running the modern dirtbike forks (or anything else that fits the triple either 35 or 37mm I think). Xr100's use the same steering stem bearings as cb100's. I don't know if the stem is the same height or not, but assume that it is similar.
Does anyone know if the kx/80/85/100 swap used on xr's can be done to a cb100?
Further, the swap obviously raises the front of the bike substantially. Assuming the forks can be swapped, how do you all think the difference in overall fork height can be compensated for? My thoughts are: lower the forks in the triple (can't lower much), run a 17" kx80 front wheel, and raise the rear.
Shocks:
The raising the rear part I am unsure about. I assume that I could get an inch or so of height simply from longer shocks (Hagons?) and not screw up the geometry of the bike too much. My guess is that drum brake connections would be the first limiting factor raising the rear. Anyone have experience with this?
Thanks for the help. I just think that a cb100 with inverted forks (or not if from a '97 kx) and a disc brake would be awesome. And even if the new forks chop the bike out a little it will probably be ok. I'd love to hear some suggestions. I'll post pics of the base cb100 soon.
Forks:
Seems like the easiest thing is to swap triples that take 31mm forks (cb250 triples or similar). However, there don't seem to be any good 31mm forks. Finding one with disc brakes is really hard it seems.
The harder thing to do seems to be swap anything larger than 31mm (tube diameter).
The guys who ride xr100's face the same problem and solve it by pressing custom steering stems into either kx80/85/100 triples or cr80/85 triples and then running the modern dirtbike forks (or anything else that fits the triple either 35 or 37mm I think). Xr100's use the same steering stem bearings as cb100's. I don't know if the stem is the same height or not, but assume that it is similar.
Does anyone know if the kx/80/85/100 swap used on xr's can be done to a cb100?
Further, the swap obviously raises the front of the bike substantially. Assuming the forks can be swapped, how do you all think the difference in overall fork height can be compensated for? My thoughts are: lower the forks in the triple (can't lower much), run a 17" kx80 front wheel, and raise the rear.
Shocks:
The raising the rear part I am unsure about. I assume that I could get an inch or so of height simply from longer shocks (Hagons?) and not screw up the geometry of the bike too much. My guess is that drum brake connections would be the first limiting factor raising the rear. Anyone have experience with this?
Thanks for the help. I just think that a cb100 with inverted forks (or not if from a '97 kx) and a disc brake would be awesome. And even if the new forks chop the bike out a little it will probably be ok. I'd love to hear some suggestions. I'll post pics of the base cb100 soon.
)!