The nipple bone conects to the... spoke bone.....

I recently bought an used bike, and the rear wheel apparently got damaged during shipping. The hub
is in good shape, so I decided to build a new wheel using the hub. But before I start, I wanted to
know a few things:

1 - I'm planning on using a Velocity Aerohead OC rim. Anyone knows how to calculate the spoke length
on off-center rims? Also, any warnings about this rim I should know about?

2 - The original wheel is very much overbuilt. Cross-3 on both sides with 14 gauge straight pull
spokes. Since its a recumbent bike, it can get by with a much lighter setup (no lateral forces from
off-saddle power-ups). So I'm planning on radial+cross-two, using lighter spokes. Does anyone have
any experience with DT Revolution 15-17 gauge spokes? They weight about 1/2 of the 14's, but do they
have an history of braking or stretching over time?

Cheers.

 

Joao de Souza <[email protected]> wrote:

> 2 - The original wheel is very much overbuilt. Cross-3 on both sides with 14 gauge straight pull
> spokes. Since its a recumbent bike, it can get by with a much lighter setup (no lateral forces
> from off-saddle power-ups). So I'm planning on radial+cross-two, using lighter spokes.

Recumbent rear wheels must be built *stronger* than those of a regular bike, because you cannot
"unweight" the wheels when running over bumps or potholes.

Cross-2 spoking is weaker to torsional loads than cross-3. If you have low gearing on your bike (and
most recumbents do), then you should consider using a pattern that is strong in torsion. If your
rear wheel is small in diameter (like 20") then it probably doesn't matter.

> Does anyone have any experience with DT Revolution 15-17 gauge spokes? They weight about 1/2 of
> the 14's, but do they have an history of braking or stretching over time?

They are reliable when built up to a tension they will sustain, but they should not be used on the
drive side of a rear wheel. They will stretch permanently before reaching an appropriate tension. DT
Swiss will tell you the same if you ask them.

Because they have 1/2 the cross-section of a 14ga spoke, they build a wheel that deflects twice as
much under side loads. Also, they "wind up" much more than thicker spokes, making them more
difficult to build with.

I use DT Revolutions or Sapim Lasers in two circumstances:
1) In a wheel with 48 or more spokes
2) On the non-drive side of a dished wheel

That is, when other factors limit the amount of tension I can put on each spoke, I will use thin
spokes to get more elastic range at the lower tension.

In your case I think you should stick to 14/15ga spokes, those proven to be the most reliable in
most circumstances.

Chalo Colina

 

joao-<< 1 - I'm planning on using a Velocity Aerohead OC rim. Anyone knows how

to calculate the spoke length on off-center rims? Also, any warnings about this rim I should know
about? >><BR><BR>

Using thr rods from a WS spoc calc tool, like any rim-598mm ERD< BTW-

Builds like a normal wheel. I add 1mm instead of 2 to the spoke calc, right to left.

<< So I'm planning on radial+cross-two, using lighter spokes. Does anyone have any experience with
DT Revolution 15-17 gauge spokes?
>><BR><BR>

Even on a 'bent, not a good idea. You will save a few grams and the wheel won't be as strong-use
14/15, three cross, build it well. Radial and 2 cross are an answer to a not asked question.
Besides, do 'bents somehow repeal the law of gravity??

<< They weight about 1/2 of the 14's, but do they have an history of braking or stretching over
time? >><BR><BR>

But 32 14g spokes don't weigh much to start....compared to the whole bike/rider package-

"conventional wheels built well' comes to mind.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

Chalo wrote:
>
> Recumbent rear wheels must be built *stronger* than those of a regular bike, because you cannot
> "unweight" the wheels when running over bumps or potholes.

Nope. Many people think that, but that's not the case. Most of the forces that untrue a wheel are
lateral, as in swinging the bike from side to side while either sprinting or climbing. I know a lot
of recumbent riders and racers who run on "underbuilt" wheels, and do fine. I currently own three
recumbents (two of which are for sale), and they all have spoke patterns that wouldn't last more
than a few miles on an upright bike, except for the rear wheel on the new one I mentioned. Yet I
commute on New York City streets with my recumbents, and their wheels require the same amount of
maintenance as my diamond frame bikes with much stronger wheels. A little fine trueing every couple
of months or so.

> Because they have 1/2 the cross-section of a 14ga spoke, they build a wheel that deflects twice as
> much under side loads.

As I mentioned, the side loads are much less than an upright bike.

But your post do confirm my suspicions that the 15/17 spokes might just be too stretchy. I'll stick
with the stronger spokes.

Thanks and cheers.

 

Joao de Souza <[email protected]> wrote:

> Chalo wrote:
> >
> > Recumbent rear wheels must be built *stronger* than those of a regular bike, because you cannot
> > "unweight" the wheels when running over bumps or potholes.
>
> Nope. Many people think that, but that's not the case. Most of the forces that untrue a wheel are
> lateral, as in swinging the bike from side to side while either sprinting or climbing. I know a
> lot of recumbent riders and racers who run on "underbuilt" wheels, and do fine.

Whatever, dude. I weigh 360 lbs, so wheel failures are not just hypothetical to me. I know from
observation that if I don't stand and unweight my saddle over bumps and holes, I trash wheels.

Hitting an edge (curb, seam, train track, etc.) at an angle other than 90 degrees can generate
momentary side loads far in excess of what swinging the bike can produce. Recumbents are as capable
of doing this as any bike (though perhaps more likely to dump their riders in the process).

I would not own a recumbent with less than 48 spokes in the rear wheel.

Chalo Colina

 

Chalo wrote:
>
> Whatever, dude. I weigh 360 lbs, so wheel failures are not just hypothetical to me. I know from
> observation that if I don't stand and unweight my saddle over bumps and holes, I trash wheels.

Would you consider it safe to assume that most riders are not as heavy as you?

Like I said, I've been riding recumbents nearly daily, on New York City streets (read: pothole
heaven), and my bents have 32-hole wheels, with radial lacing on the front wheels, and
radial/cross-two at the rear. The recumbent I recently bought has only 16 radial spokes on the
front wheel, and so far no problems. The bike was the daily training ride of a long time
professional racer, member of the US Olympic Cycling Team back in the 1970's, and someone who has
broken several world speed records on recumbents. He trained on this bike with these wheels over by
San Francisco for several years before selling it to me, and the wheels are still true. These are
facts, not theory.

 

Joao de Souza <[email protected]> wrote:

> Like I said, I've been riding recumbents nearly daily, on New York City streets (read: pothole
> heaven), and my bents have 32-hole wheels, with radial lacing on the front wheels, and
> radial/cross-two at the rear. The recumbent I recently bought has only 16 radial spokes on the
> front wheel, and so far no problems.

May you continue your run of trouble-free service from your wheels.

Understand that differences in spoke lacing pattern have no significant effect on a wheel's ability
to carry weight or sustain shocks or side loads, only on its resistance to torque loads. So
cross-two/radial lacing only makes a wheel "weaker" (compared to x3) in its ability to carry
drivetrain or hub brake torques, which may or may not be something you have to consider. If you
don't weigh much, don't use low gears much, and don't have disc or drum brakes, then
x2/radial should be as good a pattern as any for your use, if properly tensioned.

Things that will make a difference in wheel strength are rim weight and spoke count, and to a lesser
degree, spoke gauge and rim cross-section.

Since lateral flex is not something you are concerned about, you can use DT Revs or the like, just
not on the flatter (drive or disc) side of a dished wheel. FWIW, I find 15/17ga spoke a trifle
easier to build with than 14/17. They seem to wind up less. 15/16ga spokes are easier yet and still
quite light and elastic.

Chalo Colina

 

Joao de Souza <[email protected]> wrote in message news:<[email protected]>...
> Chalo wrote:
> >
> > Whatever, dude. I weigh 360 lbs, so wheel failures are not just hypothetical to me. I know from
> > observation that if I don't stand and unweight my saddle over bumps and holes, I trash wheels.
>
> Would you consider it safe to assume that most riders are not as heavy as you?
>
> Like I said, I've been riding recumbents nearly daily, on New York City streets (read: pothole
> heaven), and my bents have 32-hole wheels, with radial lacing on the front wheels, and
> radial/cross-two at the rear. The recumbent I recently bought has only 16 radial spokes on the
> front wheel, and so far no problems. The bike was the daily training ride of a long time
> professional racer, member of the US Olympic Cycling Team back in the 1970's, and someone who has
> broken several world speed records on recumbents. He trained on this bike with these wheels over
> by San Francisco for several years before selling it to me, and the wheels are still true. These
> are facts, not theory.

Yo, Joao-

Is that the Calfee/Markham Stiletto?

FWIW: I have a 36-spoke rear wheel built with 14/15 double-butted spokes (cross-three) on a Sun M14A
"aero" rim. It held up fine under my 215-ish pounds on the back of my Lightning recumbent. It never
needed truing. I retired it after several years due to rim wear.

Personally, I think you should go with 32, 14/15 gauge spokes on a "semi-aero" rim. Lacing pattern
is optional- except I wouldn't build an all-radial rear wheel. ;-)

Jeff

 

Joao de Souza <[email protected]> wrote:
>Chalo wrote:
>>Whatever, dude. I weigh 360 lbs, so wheel failures are not just hypothetical to me. I know from
>>observation that if I don't stand and unweight my saddle over bumps and holes, I trash wheels.
>Would you consider it safe to assume that most riders are not as heavy as you?

That's not the point, though. Your lighter weight makes suboptimal wheel designs less unsafe;
conversely, Chalo Cholina's weight makes it easy to verify which designs _are_ suboptimal. But that
doesn't mean they're not suboptimal even for someone of your weight.
--
David Damerell <[email protected]> Distortion Field!

 

On 26 Jun 2003 15:00:25 +0100 (BST), David Damerell <[email protected]> wrote:

>That's not the point, though. Your lighter weight makes suboptimal wheel designs less unsafe;
>conversely, Chalo Cholina's weight makes it easy to verify which designs _are_ suboptimal. But that
>doesn't mean they're not suboptimal even for someone of your weight.

Well, that depends on if you're optimising for load carrying capacity or something else, like weight
or rolling resistance or whatever. Or at least, it's not a given that optiomal for Chalo is also
optimal for others.

Jasper

 

Jeff Wills wrote:
>
> Yo, Joao-

Yo right back at Yo! ;-)

> Is that the Calfee/Markham Stiletto?

Nope, but close. Its Freddy Markham's old Gold Rush. He rides the Stiletto prototype pretty much
exclusively now, so he decided to sell the older bike. The Stiletto isn't for sale yet, but they are
taking orders.

> Personally, I think you should go with 32, 14/15 gauge spokes on a "semi-aero" rim.

That's what I'm doing. The Velocity Aerohead OC is semi-aero, its one of the lightest rims I
could find, and its pretty affordable to boost. The aero factor isn't as important on a bike with
a low seat such as the GRR, since nearly the entire top half of the wheel is fully behind the
rider's draft. But I decided on this rim since the off-center profile reduces the amount of
dishing of the wheel.

> Lacing pattern is optional- except I wouldn't build an all-radial rear wheel. ;-)

Wuss. ;-)

Cheers.