strong axles

Hi,

Just thought I’d throw something out about axle design. One design that I think
would be really cool to see made, but haven’t yet seen, is a one-piece steel
axle/hub with a hexagonal shaped axle to fit Odyssey’s hex shaped pinch-BMX
crank arms. The one-piece design has always been attractive, but although an
engineering drawing does exist for production of one with splined axles, it is
actually really difficult to do because of interference between the flange and
the spline cutting tool. Grinding a hex shape into the axle would be much
easier, I think.

Does anyone have a metal lathe and want to experiment with this? (or has anyone
done this already?) I think that this might be fairly straightforward and
relatively stronger than a 4-square taper (though not as strong as splines), and
once the design was worked out, might be a fairly inexpensive CNC operation.

The crank type I’m thinking of can be seen at
<http://www.odysseybmx.com/cranks/crk_blkwidowpro.htm>. As usual it’s too long
for most unicyclists but I think that they could be cut shorter and re-drilled.

Any opinions on this?

-Kris.


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Re: strong axles

— Leo White <Leo.White@tesco.net> wrote:
> Speaking of strong axles … (and also cranks)
>
> Has anyone some quantitative data on the survivability of axles - I haven’t
> broken enough

I’m not sure that this would be informative: a badly landed 1 foot drop can put
as much force on an axle as a properly landed 5 foot drop. Dan Heaton has landed
7 foot drops on a Suzue hub with relatively mediocre cranks! (but he weighs
around 120 lbs I think).

> Is the main advantage of a splined hub that the hollow cranks are less prone
> to bending?
>
Splines are way stronger because overall diameter of the axle is larger, and
forces are more efficiently distributed. They also allow you to rotate your
cranks, instead of the tire, to redistribute tire wear, and mean that you don’t
need press-fit bearings because all the crank units slide on until they hold the
bearings in place. Generally the crank arms are stronger as well.

> P.S. Kris just how many axles/cranks/rims have you totalled so far??

I had tons of problems originally because I was riding on homemade splined
cranks that basically sucked (around 6 broken). Rims were a big problem last
year because of filming (around 6 broken), but on regular rides I had no
problems. I’ve broken 3 pairs of tubular BMX crank arms. Since I’ve gone to a
24" doublewide, I’ve had no problems with axles or cranks, but am now breaking
spokes occasionally. I guess it’s always the weakest link that goes!

-Kris.


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RE: strong axles

> (don’t let Semcycle fool you–their axles are the same size as the Suzue where
> it counts.)

Pardon me. Not that Semcycle has attempted to fool anybody, but there is a
marked width difference. This could affect whether or not it will fit your
cycle. Unfortunately one of Geoff Faraghan’s re-heat treated Semcycle hubs could
not fit into my carbon MUni, so I had to go back to the Suzue. In future it will
be replaced by one of the newer splined hubs which, I’m told, will match the
dimensions of the Suzue.

Allow me to add to Chris’ list:

> Profile (or other splined, large diameter axles)
Telford re-heat treated Semcycle
> Suzue Semcycle Deluxe
Schwinn? (this is an estimate of where it would fit)
> Taiwanese el cheapo

Stay on top, John Foss, the Uni-Cyclone http://www.unicycling.com

“Sometimes there just aren’t enough rocks.” – Forrest Gump

RE: strong axles

One very strong axle that wasn’t mentioned:

The DM ATU axle is much stronger than any other axle except the new Profile one.
Unfortunately though, it isn’t sold separately from a DM unicycle. This axle has
survived dozens to hundreds of >5 foot drops with no damage at all.

-Kris.

— John Foss <john_foss@asinet.com> wrote:
> > (don’t let Semcycle fool you–their axles are the
> same
> > size as the Suzue where it counts.)
>
> Pardon me. Not that Semcycle has attempted to fool anybody, but there is a
> marked width difference. This could affect whether or not it will fit your
> cycle. Unfortunately one of Geoff Faraghan’s re-heat treated Semcycle hubs
> could not fit into my carbon MUni, so I had to go back to the Suzue. In future
> it will be replaced by one of the newer splined hubs which, I’m told, will
> match the dimensions of the Suzue.
>
> Allow me to add to Chris’ list:
>
> > Profile (or other splined, large diameter axles)
> Telford re-heat treated Semcycle
> > Suzue Semcycle Deluxe
> Schwinn? (this is an estimate of where it would fit)
> > Taiwanese el cheapo
>
> Stay on top, John Foss, the Uni-Cyclone http://www.unicycling.com
>
> “Sometimes there just aren’t enough rocks.” – Forrest Gump


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RE: strong axles

I am a little curious about the reasons for re-heat treating the hub. What
were the properties he was looking for? Greater Rockwell hardness? Reducing
internal stress?

-----Original Message----- From: John Foss [mailto:john_foss@asinet.com] Sent:
Wednesday, November 01, 2000 10:05 AM To: ‘Chris Reeder’; ‘Leo White’
Cc: ‘unicycling@winternet.com’ Subject: RE: strong axles

> (don’t let Semcycle fool you–their axles are the same size as the Suzue where
> it counts.)

Pardon me. Not that Semcycle has attempted to fool anybody, but there is a
marked width difference. This could affect whether or not it will fit your
cycle. Unfortunately one of Geoff Faraghan’s re-heat treated Semcycle hubs could
not fit into my carbon MUni, so I had to go back to the Suzue. In future it will
be replaced by one of the newer splined hubs which, I’m told, will match the
dimensions of the Suzue.

Allow me to add to Chris’ list:

> Profile (or other splined, large diameter axles)
Telford re-heat treated Semcycle
> Suzue Semcycle Deluxe
Schwinn? (this is an estimate of where it would fit)
> Taiwanese el cheapo

Stay on top, John Foss, the Uni-Cyclone http://www.unicycling.com

“Sometimes there just aren’t enough rocks.” – Forrest Gump

Re: strong axles

Geoffrey, Are the Telford hubs available for purchase and how much would they
cost? thanks, Jeffrey

On Fri, 3 Nov 2000 00:23:40 -0800 “me” <me@here.com> writes:
> Telford Design has analyzed many hubs and would rank them in the
> following order::
>
> Profile - 3/4" (19mm) CrMo steel , good heat treating, splined Advantages -
> Very strong, for heavy muni & trials, Profile is well respected and holds up
> to professional BMX and Mtn bike riders. Disadvantages - Very expensive,
> heavy, shortest crankarm is 165mm(currently)
>
> Telford - 17mm NiCrMo steel, very good heat treating, tapered Advantages -
> Superior steel and proprietary heat treating creates strongest 17mm axle
> available. Holds up to heavy muni Disadvantages - If you are Bruce Bundy,
> after 10-12 months of trials use and ruining a couple sets of crankarms, it
> will break.
>
> Suzue- 17mm CrMo steel, ok heat treating, tapered Advantages - Decent CrMo
> steel, reasonable price, good for street, light muni Disadvantages - Heat
> treating a little brittle, breaks under moderate muni
>
> Semcycle- 17mm NiCrMo steel, poor heat treating, tapered Advantages - Superior
> steel, but… Disadvantages - Flawed heat treating negates superior steel,
> causes failure between bearing and hub flange
>
> Schwinn- 5/8"(15.8mm) Cr steel, no heat treating, tapered Advantages - Better
> steel than Taiwan Disadvantages - Breaks
>
> Taiwan- 17mm ?? steel, no heat treating, tapered Advantages - Cheap
> Disadvantages - Breaks
>
> Geoffrey Faraghan Telford Design muni@telford-design.com
>
>
> Dibble, John <John.Dibble@us.luxfercylinders.com> wrote in message
> news:9D2E4E2FD8C9D211BFC600A0C9B6B17F8B5144@ALPHA2
> > I am a little curious about the reasons for re-heat treating the
> hub. What
> > were the properties he was looking for? Greater Rockwell
> hardness? Reducing
> > internal stress?
> >
> > -----Original Message----- From: John Foss [mailto:john_foss@asinet.com]
> > Sent: Wednesday, November 01, 2000 10:05 AM To: ‘Chris Reeder’; ‘Leo White’
> > Cc: ‘unicycling@winternet.com’ Subject: RE: strong axles
> >
> >
> > > (don’t let Semcycle fool you–their axles are the same size as the Suzue
> > > where it counts.)
> >
> > Pardon me. Not that Semcycle has attempted to fool anybody, but
> there is a
> > marked width difference. This could affect whether or not it will
> fit your
> > cycle. Unfortunately one of Geoff Faraghan’s re-heat treated
> Semcycle hubs
> > could not fit into my carbon MUni, so I had to go back to the
> Suzue. In
> > future it will be replaced by one of the newer splined hubs which,
> I’m told,
> > will match the dimensions of the Suzue.
> >
> > Allow me to add to Chris’ list:
> >
> > > Profile (or other splined, large diameter axles)
> > Telford re-heat treated Semcycle
> > > Suzue Semcycle Deluxe
> > Schwinn? (this is an estimate of where it would fit)
> > > Taiwanese el cheapo
> >
> > Stay on top, John Foss, the Uni-Cyclone http://www.unicycling.com
> >
> > “Sometimes there just aren’t enough rocks.” – Forrest Gump
>
>
>


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Re: strong axles

Speaking of strong axles … (and also cranks)

Has anyone some quantitative data on the survivability of axles - I haven’t
broken enough (1 and that was a cottered Pashley on my old Muni adaptation). I
know there are many variables in the equation (tyre size/crank length/landing
technique/repetetive abuse/rider weight) but who’s broken what? I’ve seen
Taiwanese, NK and Susue tapered hubs broken … … has anyone broken a
splined DM or Profile hub?

Is the main advantage of a splined hub that the hollow cranks are less prone
to bending?

Here’s some data from me to kick off :

DM tapered axle up to 40" drop 180lbs 140mm cranks 2.2" tyre - survived Susue
axle up to 30" drop, ditto, ditto, ditto survived

As I’ve bent cranks or bottled any higher drops so far then my stats end there.

Leo White

P.S. Kris just how many axles/cranks/rims have you totalled so far??

Re: strong axles

Hi, John,

I see what you are saying. The flanges on the Semcycle Deluxe axles are spaced
farther apart than on the Suzue axles. Since the distance between the square
tapered faces is the same, this means the Semcycle Deluxe offers less room for
bearing holders. I actually had to grind down a pair of lollipop bearing holders
to make them thinner the first time I tried a Sem Deluxe hub. I assume the
bearings are also slightly farther apart on the Sem Deluxe, but on steel frames
like mine it’s easy to bend the forks a bit to acommodate for this.

What I was actually referring to in my last post is the shaft diameter. Many
people believe that because the Semcycle Deluxe is a larger diameter through the
middle section (between the hub flanges) that it is a stronger axle. In reality,
the place where axles break is between the hub flange and the crank arm. And in
the case of both axles, the diameter at that point is 17mm.

Thanks for adding to the list. Geoff has done some nice work in producing better
standard axles.

Chris

Profile (or other splined, large diameter axles) Telford re-heat treated
Semcycle Suzue Semcycle Deluxe Schwinn? (this is an estimate of where it would
fit) Taiwanese el cheapo

Re: strong axles

Telford Design has analyzed many hubs and would rank them in the
following order::

Profile - 3/4" (19mm) CrMo steel , good heat treating, splined Advantages - Very
strong, for heavy muni & trials, Profile is well respected and holds up to
professional BMX and Mtn bike riders. Disadvantages - Very expensive, heavy,
shortest crankarm is 165mm(currently)

Telford - 17mm NiCrMo steel, very good heat treating, tapered Advantages -
Superior steel and proprietary heat treating creates strongest 17mm axle
available. Holds up to heavy muni Disadvantages - If you are Bruce Bundy,
after 10-12 months of trials use and ruining a couple sets of crankarms, it
will break.

Suzue- 17mm CrMo steel, ok heat treating, tapered Advantages - Decent CrMo
steel, reasonable price, good for street, light muni Disadvantages - Heat
treating a little brittle, breaks under moderate muni

Semcycle- 17mm NiCrMo steel, poor heat treating, tapered Advantages - Superior
steel, but… Disadvantages - Flawed heat treating negates superior steel,
causes failure between bearing and hub flange

Schwinn- 5/8"(15.8mm) Cr steel, no heat treating, tapered Advantages - Better
steel than Taiwan Disadvantages - Breaks

Taiwan- 17mm ?? steel, no heat treating, tapered Advantages - Cheap
Disadvantages - Breaks

Geoffrey Faraghan Telford Design muni@telford-design.com

Dibble, John <John.Dibble@us.luxfercylinders.com> wrote in message
news:9D2E4E2FD8C9D211BFC600A0C9B6B17F8B5144@ALPHA2
> I am a little curious about the reasons for re-heat treating the hub.
What
> were the properties he was looking for? Greater Rockwell hardness?
Reducing
> internal stress?
>
> -----Original Message----- From: John Foss [mailto:john_foss@asinet.com] Sent:
> Wednesday, November 01, 2000 10:05 AM To: ‘Chris Reeder’; ‘Leo White’
> Cc: ‘unicycling@winternet.com’ Subject: RE: strong axles
>
>
> > (don’t let Semcycle fool you–their axles are the same size as the Suzue
> > where it counts.)
>
> Pardon me. Not that Semcycle has attempted to fool anybody, but there is a
> marked width difference. This could affect whether or not it will fit your
> cycle. Unfortunately one of Geoff Faraghan’s re-heat treated Semcycle hubs
> could not fit into my carbon MUni, so I had to go back to the Suzue. In future
> it will be replaced by one of the newer splined hubs which, I’m
told,
> will match the dimensions of the Suzue.
>
> Allow me to add to Chris’ list:
>
> > Profile (or other splined, large diameter axles)
> Telford re-heat treated Semcycle
> > Suzue Semcycle Deluxe
> Schwinn? (this is an estimate of where it would fit)
> > Taiwanese el cheapo
>
> Stay on top, John Foss, the Uni-Cyclone http://www.unicycling.com
>
> “Sometimes there just aren’t enough rocks.” – Forrest Gump

Re: strong axles

Here’s my 2c worth.

Of the axles I’ve tried, here’s from best to worst (don’t let Semcycle fool
you-- their axles are the same size as the Suzue where it counts.)

Profile Suzue Semcycle Deluxe Taiwanese el cheapo

Leo White wrote:
>
> Speaking of strong axles … (and also cranks)
>
> Has anyone some quantitative data on the survivability of axles - I haven’t
> broken enough (1 and that was a cottered Pashley on my old Muni adaptation). I
> know there are many variables in the equation (tyre size/crank length/landing
> technique/repetetive abuse/rider weight) but who’s broken what? I’ve seen
> Taiwanese, NK and Susue tapered hubs broken … … has anyone broken a
> splined DM or Profile hub?
>
> Is the main advantage of a splined hub that the hollow cranks are less prone
> to bending?
>
> Here’s some data from me to kick off :
>
> DM tapered axle up to 40" drop 180lbs 140mm cranks 2.2" tyre - survived Susue
> axle up to 30" drop, ditto, ditto, ditto survived
>
> As I’ve bent cranks or bottled any higher drops so far then my stats
> end there.
>
> Leo White
>
> P.S. Kris just how many axles/cranks/rims have you totalled so far??


Chris Reeder reed8990@uidaho.edu