Wondering about frame stiffness of this Nimbus coker.
I remember comments about the standard Coker frame – that if you have installed brakes and you try to ride it uphill, the brakes will rub due to flex of the frame.
Can anyone comment on stiffness of the Nimbus coker in this situation (brakes, pedaling uphill).
At first glance it looks similar to the Hunter frame. I remember an old post by a mechanical engineer who said the design of the Hunter frame didn’t make much sense, mechanically.
But closer inspection of the Nimbus frame reveals that the rear section is braced to the front in a way that forms triangles on the left and right. Seems like this should reduce front-back flex.
But I haven’t convinced myself that the shape of the frame is strong for reducing sideways flex, since the rear section forms a square with the axle.
There’s a triangle on top too, from the seat tube to the two side tubes, maybe that does something about side-side flex.
I suspect the person who said the Hunter design didn’t make sense was Joe Rowing, who designed the Blizzard frame design used by the Nimbus 36, because he thought the design of the Hunter looked nice but wasn’t sensible mechanically.
Having said that, even people with the Hunter coker frame seem to think it’s okay for braking, especially compared to the stock coker frame, the improved Nimbus design should be better.
Haven’t got the brakes full working on mine yet so I can’t accurately comment but the frame did seem extremley stiff when i tried loading it a little to see how it behaved. If I do have any problems in this department i think it will be due to the stock coker rim rather than the frame flexing.
No, it was this thread. I remember it because I had just purchased a Hunter, and while I couldn’t understand all of the physics mumbo jumbo, my actual riding experience was telling me the frame was super strong, no flex. Four and a half years later, I still come to the same conclusion. It’s bombproof. I love my Hunter, although it’s been neglected lately. Time for a Turkey Day ride, I think.
I went for my first ride with brakes on my Nimbus 36er today. I had no problems at all with brakepads rubbing on the rim. The frame seems good and stiff.
Not so - the important factor in controlling wheel flex is the width of the hub, rather than the rim itself. On my original custom coker I had a standard Suzue hub and it flexed like crazy. After changing to a wide hub this problem was fixed completely.
Airfoil rim and 14 guage spokes
Shortened KH seatpost (exta short)
T7 handle
The new KH freeride seat
127mm aluminium cranks
Smooth tyre (TA is it called?)
Magura break
UDC wide hub
Just took it out for a quick spin this morning. Wow! Compared to my coker (short person’s coker frame, standard rim, 12 guage spokes and 140mm cranks) it flies. It’s so light and very nippy. Coker = cart horse. Nimbus = young colt. or perhaps coker = tractor. Nimbus = sports car.
And I love the handle. Having it there where my hand sort of naturally falls after engaging in ‘arm flapping’ or ‘sticking your arms out to balance or turn’ type behaviour, instead of having to rumage around under my coat, moving anything that I might have in my pocket out of the way, to reach my KH handle.
I’m reserving judgement on the seat until I take her out for a long run.
That’s good to hear as i have the stock rim but the wide cromo coker hub.
Cathwood, I’m just hooking up the brakes on mine atm, do you have your handle down the prong of the T7 as far as it will go? I’m worried about damaging the brake or the pipe running to it if i drop the uni.
Well, I felt that if I was going to spend a rediculous amount of money on a unicycle I didn’t need, I might as well have it the perfect colour. Yes Roger did it.
Thanks for the pictures Cathy, yours is a real beauty. We’re a couple of low rollers. (low seat that is)
I looked over that last close-up for what Roger did to lower your post, it looks like the post holder may be drilled out allowing the lower rail adapter screw head to lower into the recess, what a nice touch. If I try again for a rail adapter mount, I may make it with that trick.
I saw some talk of having the seat lowered… I was looking on unicycle.com and there was something about the MAX/MIN leg length. My measurements are about 32 in. With these measurements it would mean getting the seat lowered, correct? Also, how do you factor in the length of your cranks to the height of your seat?
you want to have your legs almost fully extended when riding, most people ride with 150’s or 125’s so you count that plus half of the wheel size, then add how much higher the seat is.
