Hub brake and low spoke number

  • Thread starter =?ISO-8859-1?Q?G=FCnther?= Schwarz
  • Start date



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=?ISO-8859-1?Q?G=FCnther?= Schwarz

Guest
Yet another question regarding wheels: I'm about to get a second
wheelset for my trike with 406/20" wheels all around. The rear wheel
without brake was already done with 24 bladed spokes by Johann Rödel:
<http://www.xn--gnther-schwarz-gsb.de/Pictures/ice11.jpg>
Special spokes with a double bent instead of a head. So the spoke holes
in the hub do not have to be widened. I use these spokes since quite
some time on another wheel and I have no reason to complain about them.

The front wheels have drum brake hubs (Sturmey Archer X-FD, 90mm
diameter as compared to 74 mm for the hub on the picture above,
<http://www.sturmey-archer.com/hubs_fh_XFD.php>). I'm considering a
similar spoke pattern here, 24 spokes laced 2x in a 36 hole hub.

My question: will 24 spokes be enough for a 20" wheel with hub brakes?
Light rider, light luggage, no off road riding and most certainly no
drops, but quite regular high speed descents including heavy breaking
at corners. That's the fun part with a trike basically.

Günther
 
L

landotter

Guest
On May 29, 5:31 pm, Günther Schwarz <[email protected]> wrote:
> Yet another question regarding wheels: I'm about to get a second
> wheelset for my trike with 406/20" wheels all around. The rear wheel
> without brake was already done with 24 bladed spokes by Johann Rödel:
> <http://www.xn--gnther-schwarz-gsb.de/Pictures/ice11.jpg>
> Special spokes with a double bent instead of a head. So the spoke holes
> in the hub do not have to be widened. I use these spokes since quite
> some time on another wheel and I have no reason to complain about them.
>
> The front wheels have drum brake hubs (Sturmey Archer X-FD, 90mm
> diameter as compared to 74 mm for the hub on the picture above,
> <http://www.sturmey-archer.com/hubs_fh_XFD.php>). I'm considering a
> similar spoke pattern here, 24 spokes laced 2x in a 36 hole hub.
>
> My question: will 24 spokes be enough for a 20" wheel with hub brakes?
> Light rider, light luggage, no off road riding and most certainly no
> drops, but quite regular high speed descents including heavy breaking
> at corners. That's the fun part with a trike basically.


I'd worry more about overheating, but perhaps that's unwarranted.
Sounds like your toddler is pretty fast. ;^)
 
J

jim beam

Guest
� Schwarz wrote:
> Yet another question regarding wheels: I'm about to get a second
> wheelset for my trike with 406/20" wheels all around. The rear wheel
> without brake was already done with 24 bladed spokes by Johann R�del:
> <http://www.xn--gnther-schwarz-gsb.de/Pictures/ice11.jpg>
> Special spokes with a double bent instead of a head. So the spoke holes
> in the hub do not have to be widened. I use these spokes since quite
> some time on another wheel and I have no reason to complain about them.
>
> The front wheels have drum brake hubs (Sturmey Archer X-FD, 90mm
> diameter as compared to 74 mm for the hub on the picture above,
> <http://www.sturmey-archer.com/hubs_fh_XFD.php>). I'm considering a
> similar spoke pattern here, 24 spokes laced 2x in a 36 hole hub.
>
> My question: will 24 spokes be enough for a 20" wheel with hub brakes?
> Light rider, light luggage, no off road riding and most certainly no
> drops, but quite regular high speed descents including heavy breaking
> at corners.


i hope you don't experience heavy breaking at corners. braking, yes.
breaking, no.

> That's the fun part with a trike basically.
>
> G�nther


check out mavic mtb disk wheels and check their spoke count - some have
only 18.
 
H

Hank Wirtz

Guest
On May 29, 5:07 pm, landotter <[email protected]> wrote:
> On May 29, 5:31 pm, Günther Schwarz <[email protected]> wrote:
>
>
>
>
>
> > Yet another question regarding wheels: I'm about to get a second
> > wheelset for my trike with 406/20" wheels all around. The rear wheel
> > without brake was already done with 24 bladed spokes by Johann Rödel:
> > <http://www.xn--gnther-schwarz-gsb.de/Pictures/ice11.jpg>
> > Special spokes with a double bent instead of a head. So the spoke holes
> > in the hub do not have to be widened. I use these spokes since quite
> > some time on another wheel and I have no reason to complain about them.

>
> > The front wheels have drum brake hubs (Sturmey Archer X-FD, 90mm
> > diameter as compared to 74 mm for the hub on the picture above,
> > <http://www.sturmey-archer.com/hubs_fh_XFD.php>). I'm considering a
> > similar spoke pattern here, 24 spokes laced 2x in a 36 hole hub.

>
> > My question: will 24 spokes be enough for a 20" wheel with hub brakes?
> > Light rider, light luggage, no off road riding and most certainly no
> > drops, but quite regular high speed descents including heavy breaking
> > at corners. That's the fun part with a trike basically.

>
> I'd worry more about overheating, but perhaps that's unwarranted.
> Sounds like your toddler is pretty fast. ;^)- Hide quoted text -
>
> - Show quoted text -


Bill Baka is Gunther's secret love child.
 
J

JeffWills

Guest
On May 29, 2:31 pm, Günther Schwarz <[email protected]> wrote:
> Yet another question regarding wheels: I'm about to get a second
> wheelset for my trike with 406/20" wheels all around. The rear wheel
> without brake was already done with 24 bladed spokes by Johann Rödel:
> <http://www.xn--gnther-schwarz-gsb.de/Pictures/ice11.jpg>
> Special spokes with a double bent instead of a head. So the spoke holes
> in the hub do not have to be widened. I use these spokes since quite
> some time on another wheel and I have no reason to complain about them.
>
> The front wheels have drum brake hubs (Sturmey Archer X-FD, 90mm
> diameter as compared to 74 mm for the hub on the picture above,
> <http://www.sturmey-archer.com/hubs_fh_XFD.php>). I'm considering a
> similar spoke pattern here, 24 spokes laced 2x in a 36 hole hub.
>
> My question: will 24 spokes be enough for a 20" wheel with hub brakes?
> Light rider, light luggage, no off road riding and most certainly no
> drops, but quite regular high speed descents including heavy breaking
> at corners. That's the fun part with a trike basically.
>
> Günther


20" wheels already require fewer spokes since the rim is a smaller and
more rigid circle (duh!). The greater angle from the flanges to the
rim will also make the wheel stronger. On the other hand, trikes put
far greater lateral stresses on the whole wheel:
http://home.comcast.net/~jeff_wills/aerocoupe/pages/river08.htm
I think 24 spokes is adequate for your wheels, but I have no idea what
will happen if you are simultaneously braking and cornering. I've had
wheels collapse when skidding sideways- I wouldn't want to experience
that at high speed.

Jeff
 
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=?ISO-8859-1?Q?G=FCnther?= Schwarz

Guest
landotter wrote:

> On May 29, 5:31 pm, Günther Schwarz <[email protected]> wrote:


>> My question: will 24 spokes be enough for a 20" wheel with hub
>> brakes? Light rider, light luggage, no off road riding and most
>> certainly no drops, but quite regular high speed descents including
>> heavy breaking at corners. That's the fun part with a trike
>> basically.

>
> I'd worry more about overheating, but perhaps that's unwarranted.


Actually that is something to worry about. But then I suspect that the
spokes do not contribute much to cooling. So reducing the spoke number
most probably won't have a noticeable effect.

> Sounds like your toddler is pretty fast. ;^)


As the Germans say: There's a child in every man.

Günther
 
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=?ISO-8859-1?Q?G=FCnther?= Schwarz

Guest
jim beam wrote:

> � Schwarz wrote:


>> My question: will 24 spokes be enough for a 20" wheel with hub
>> brakes? Light rider, light luggage, no off road riding and most
>> certainly no drops, but quite regular high speed descents including
>> heavy breaking at corners.

>
> i hope you don't experience heavy breaking at corners. braking, yes.
> breaking, no.


LOL, a classic error not noticed by spell checkers.

> check out mavic mtb disk wheels and check their spoke count - some
> have only 18.


The rim is taken from a Vuelta BMX wheelset with disk brake hubs. I
still ask on rbt as such wheels are quite uncommon and I simply have no
experience with them.

Günther
 
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=?ISO-8859-1?Q?G=FCnther?= Schwarz

Guest
JeffWills wrote:

> On May 29, 2:31 pm, Günther Schwarz <[email protected]> wrote:
>> Yet another question regarding wheels: I'm about to get a second
>> wheelset for my trike with 406/20" wheels all around. The rear wheel
>> without brake was already done with 24 bladed spokes by Johann Rödel:
>> <http://www.xn--gnther-schwarz-gsb.de/Pictures/ice11.jpg>
>> Special spokes with a double bent instead of a head.


>> The front wheels have drum brake hubs (Sturmey Archer X-FD, 90mm
>> diameter as compared to 74 mm for the hub on the picture above,
>> <http://www.sturmey-archer.com/hubs_fh_XFD.php>). I'm considering a
>> similar spoke pattern here, 24 spokes laced 2x in a 36 hole hub.
>>
>> My question: will 24 spokes be enough for a 20" wheel with hub
>> brakes? Light rider, light luggage, no off road riding and most
>> certainly no drops, but quite regular high speed descents including
>> heavy breaking at corners.


> 20" wheels already require fewer spokes since the rim is a smaller and
> more rigid circle (duh!). The greater angle from the flanges to the
> rim will also make the wheel stronger. On the other hand, trikes put
> far greater lateral stresses on the whole wheel:
> http://home.comcast.net/~jeff_wills/aerocoupe/pages/river08.htm


Nice trikes. I wasn't aware of these.

> I think 24 spokes is adequate for your wheels, but I have no idea what
> will happen if you are simultaneously braking and cornering. I've had
> wheels collapse when skidding sideways-


Ups, did this happen on or off road? I suspect that the 622 (?) rear
wheel did give up, not the small front ones. Collapsing wheels are a
concern for BMX guys doing big jumps and such. I would not expect such
a thing in normal road riding even with low spoke count wheels.

> I wouldn't want to experience that at high speed.


Skidding sideways at high speed will give you already enough to worry
about. IME the trike is out of control once the rear wheel looses
traction.

Günther
 
J

JeffWills

Guest
On May 29, 10:55 pm, Günther Schwarz <[email protected]> wrote:
> >http://home.comcast.net/~jeff_wills/aerocoupe/pages/river08.htm

>
> Nice trikes. I wasn't aware of these.


Well, considering we went out of production 22 years ago, only
produced 12, and we were based in Southern California, I'd be
surprised if you *were* aware of them!

>
> > I think 24 spokes is adequate for your wheels, but I have no idea what
> > will happen if you are simultaneously braking and cornering. I've had
> > wheels collapse when skidding sideways-

>
> Ups, did this happen on or off road? I suspect that the 622 (?) rear
> wheel did give up, not the small front ones. Collapsing wheels are a
> concern for BMX guys doing big jumps and such. I would not expect such
> a thing in normal road riding even with low spoke count wheels.
>


On road, and one of the 20" front wheels collapsed while skidding.
Since the rear wheel was sliding, it didn't get as much sideways
pressure and it survived OK.

> > I wouldn't want to experience that at high speed.

>
> Skidding sideways at high speed will give you already enough to worry
> about. IME the trike is out of control once the rear wheel looses
> traction.
>


Well, my point is that a high-speed turn is already going to put a lot
of sideways thrust on the wheel, in the direction that it's weakest.
If the sideways thrust causes the wheel to collapse, the trike may
just fall to the pavement or it could flip. One situation is bad, but
the other is deadly.

Jeff
 
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=?ISO-8859-1?Q?G=FCnther?= Schwarz

Guest
JeffWills wrote:

> On May 29, 10:55 pm, Günther Schwarz <[email protected]> wrote:
>> >http://home.comcast.net/~jeff_wills/aerocoupe/pages/river08.htm

>>
>> Nice trikes. I wasn't aware of these.

>
> Well, considering we went out of production 22 years ago, only
> produced 12, and we were based in Southern California, I'd be
> surprised if you *were* aware of them!


There is lot of information on recumbents on the web, and the number is
different trike designs is limited.

>> > I think 24 spokes is adequate for your wheels, but I have no idea
>> > what will happen if you are simultaneously braking and cornering.
>> > I've had wheels collapse when skidding sideways-

>>
>> Ups, did this happen on or off road? I suspect that the 622 (?) rear
>> wheel did give up, not the small front ones. Collapsing wheels are a
>> concern for BMX guys doing big jumps and such. I would not expect
>> such a thing in normal road riding even with low spoke count wheels.
>>

>
> On road, and one of the 20" front wheels collapsed while skidding.
> Since the rear wheel was sliding, it didn't get as much sideways
> pressure and it survived OK.
>
>> > I wouldn't want to experience that at high speed.

>>
>> Skidding sideways at high speed will give you already enough to worry
>> about. IME the trike is out of control once the rear wheel looses
>> traction.
>>

>
> Well, my point is that a high-speed turn is already going to put a lot
> of sideways thrust on the wheel, in the direction that it's weakest.
> If the sideways thrust causes the wheel to collapse, the trike may
> just fall to the pavement or it could flip. One situation is bad, but
> the other is deadly.


Thanks for sharing your experience. This is the information I was
looking for. So I might better stay with 36 spokes on the front. On the
rear it's too late as the wheel is already done and mounted. I will
report on rbt if it behaves badly. For the first 500km or so it worked
just fine, and I like the dynohub.

Günther