While my mind is in “Review Stuff” mode, I thought I’d ask about other peoples’ Nimbus II frames; in particular the clearance between the frame and the top of the tyre.
My 24" has just over half an inch between the 24x3" Halo Contra tyre and the frame; perfectly enough for mud clearance and whatever gets hurled at it.
My new 20" however has at most about 3 millimetres between the top of the frame and the 2.5" tyre. It doesn’t rub, but it’s a bit strange as to why it’s that close.
It was really scary when I took it out for its first major spin; a stone somehow got stuck up the post, and was making a horrible din before I stopped and pried it out. That scared me, thinking my nice new uni was falling to bits on me already…
Other peoples’ unis don’t seem to have this feature. What’s the difference? Are the tolerances of Nimbus II frame sizes amazingly lax? Or am I the first person to have a sawn-off uni?
I’m sorry I can’t help you there but do you have any photos of your Nimbue II/Yuni frame? I’d really appreciate if you posted some because I need ideas for the frame I’m getting built.
>peoples’ Nimbus II frames; in particular the clearance between the frame
>and the top of the tyre.
>
>My 24" has just over half an inch between the 24x3" Halo Contra tyre and
>the frame; perfectly enough for mud clearance and whatever gets hurled
>at it.
>Are the tolerances of Nimbus II frame sizes amazingly lax?
Maybe they are. I have the same MUni (frame, rim, tyre) as you do. The
tyre is hardly worn down yet. My clearance between the frame and the
top of the tyre is 8 mm so significantly less than yours - though
still enough. My side clearance is 3 - 4 mm (most protruding end of
the knobbies), what’s yours?
The side clearances on both sizes of Nimbus II frames are about 8mm, like yours. I doubt there’s much that can go wrong with that, really; you’d hope they’d make it so it fits a tyre, and the length is so short even a large relative error will still be quite small.
your frame definatly is a bit on the short side, if it catches stones then thats not good. it can even cause faceplants when offroad. get back in touch with roger, he might be able to exchange it if you ask nicely.
from what i’ve seen nimbus ii / Yuni frames certainly do have a bit of variation in them,
the clearance on my nimbus II /onzatyre/montyrim/profilehub trials uni is just over one inch the rims should be the same diameter or the tyres wouldn’t be interchangable.
perhaps you could find someone with a freestyle nimbus ii who’d like to swap frames.
when i decided on my freestyle unicycle frame i went for the sem xl wide frame. because my nimbuss i was realy big.
if unicycle.com/.uk.com graded the frames and used the smaller ones for freestyle unicycles and the larger ones for trials then everybody would be happy.
mine is actualy a bit lop sided. but it dosen’t make any diference to ridability.
>The side clearances on both sizes of Nimbus II frames are about 8mm,
>like yours. I doubt there’s much that can go wrong with that, really;
>you’d hope they’d make it so it fits a tyre, and the length is so short
>even a large relative error will still be quite small.
>
>It’s just the top clearance that is strange.
Are you talking to me? My side clearances are less than yours, but my
top clearance is more. I’ll put a pic and some text on my web site
tomorrow (no CF card adaptor today).
BTW your tyre seems brand new with all those little rubber “poles”
still sticking out. With more wear from riding, the top clearance will
automatically increase
phil <phil.cwbab@timelimit.unicyclist.com> wrote:
> My 24" has just over half an inch between the 24x3" Halo Contra tyre and
> the frame; perfectly enough for mud clearance and whatever gets hurled
> at it.
> My new 20" however has at most about 3 millimetres between the top of
> the frame and the 2.5" tyre. It doesn’t rub, but it’s a bit strange as
> to why it’s that close.
2.5 tyre is pretty big. in a 20 inch frame. You might also find that your
“24” inch frame is actually a 26 inch frame as a 24x3 is nearly a 26.
> Other peoples’ unis don’t seem to have this feature. What’s the
> difference? Are the tolerances of Nimbus II frame sizes amazingly lax?
Tolerances all depend on what tyre you put in the fram, and the clearence
your having problems with under the crown is directly realted to the trye
size and shape. I’ve been runnning a 700x54 ( or 29inch) tyre in a N2
28inch frame, with decent clearance. Pics are in the shed at www.uk.unicyclist.com.
