Front Wheel Flex

[MrSteve]

The Problem:

I was fed-up with the constant truing of the front wheel.
Also tired of the constant flexing under the torque input during hard uphill
climbs and sprints.
Even hard cornering would flex the front wheel, rubbing the rim against the front brake.
To fix this problem, I flattened the dish.
Dish, of course, describes the offset built into the laced-up wheel, to accommodate
the width of the cassette.

Stock, the front wheels' spokes seemed too tight (about right) on the left (non-cassette side) side of the wheel
and too loose on the right (cassette) side of the wheel.

My Solution:

Today, I loosened the left-side spokes a bit and really tightened up the right-side spokes.
Then, of course, re-trued the wheel.
This moved the rim off- centre almost 2mm and greatly increased the
rigidity of the wheel.
After adjusting the rest position of the front brake, to match the front wheel's new
centre position, I went for a test-ride.

Conclusions:

What a difference.
I can climb familiar grades in one, two, even three taller gears than I'm used to.
No more front wheel flex.
-Or, drastically reduced flex.
In fact, top speed is better, steering is both more responsive, sensitive and direct;
the whole front-end feels much more solid.

I imagine that a solid disc front wheel would be ideal for the Cruzbike,
because of the extra stress that it must endure, beyond simply transmitting
drive and braking forces.

-Steve

 

[Hotdog]

It sounds like Cruzbikes might benefit from off centre rims, such as the Velocity Aerohead O/C. These allow you to even up the drive/non-drive sde spoke tensions without leaving the rim offset to one side.

 

[Mark B]

yakmurph wrote: I imagine that a solid disc front wheel would be ideal for the Cruzbike,
because of the extra stress that it must endure, beyond simply transmitting
drive and braking forces.

-Steve

A solid disc wheel would probably render it unridable in severe crosswind situations. :shock:

I wonder... Could it be the wheel was just improperly tensioned?

Mark

 

[MrSteve]

That Velocity rim looks good.

Yes, the wheel could very well have been incorrectly tensioned.
The aluminum rim may have had some effect on the spoke tension over time.

As to side-wind sensitivity?
I'm sure the solid disc wheel would be affected, but by how much?
The steering dampener -our legs- is very effective.

 

[Mark B]

yakmurph wrote:
As to side-wind sensitivity?
I'm sure the solid disc wheel would be affected, but by how much?
The steering dampener -our legs- is very effective.

I cannot give a qualified answer, but my experience has been that riders with "aero spoked" wheels always cry and complain on a windy day. I agree that our legs would derve to dampen the effects of the wind, but to what extent? While you're pedalling, I would assume the wind would be working against you. I could be wrong.

I'm going to stand by my original thought that the wheel was somehow not tensioned correctly. Inexpensive machine built wheels usually need to be touched up by the human hand sooner or later. I guess you could always redish the wheel back the way it was, retension everything and see what happens!

Mark

 

[MrSteve]

Quote: I cannot give a qualified answer, but my experience has been that riders with "aero spoked" wheels always cry and complain on a windy day. I agree that our legs would derve to dampen the effects of the wind, but to what extent? While you're pedalling, I would assume the wind would be working against you. I could be wrong.

This question is whispering to me for an answer.
I am imagining an experiment.
Fashioning a few discs of lightweight sheet material and transforming a spoked wheel
into a fully-faired wheel. Then experiencing the difference.

Yeah, it's been done countless times!
Coroplast is the material of choice, and I've read a lot about building fairings, tailboxes and wheel fairings using this material.
...Already done, countless times...well documented...but not by me, on my machine.

Time to look around for some spare wheels, for experimentation purposes, I think :!:

-Steve

 

[Mark B]

yakmurph wrote: This question is whispering to me for an answer.
I am imagining an experiment.
Fashioning a few discs of lightweight sheet material and transforming a spoked wheel
into a fully-faired wheel. Then experiencing the difference.

Yeah, it's been done countless times!
Coroplast is the material of choice, and I've read a lot about building fairings, tailboxes and wheel fairings using this material.
...Already done, countless times...well documented...but not by me, on my machine.

Time to look around for some spare wheels, for experimentation purposes, I think :!:

-Steve

Cool, be sure to post your progress and results!

Mark