Rolf wheels safety

[[email protected]]

I'm having a hard time visualizing this also.

I have two sets of rolf wheels vector pro and vector comp. Both are
incredibly stiff and strong, and I've never had any issuse with them. I
have been using the comps for commuting and probably have 15K miles on
them. The rear has a small ding in the sidewall, residual from hitting
a rock on the way to work last year. It has held up beautifully.

If the wheel 'folded' the spokes had to either be incredibly loose or
suffered a break from damage which allowed the wheel to fold.

We need pictures.

p.s. take the political discussion to another group please.

 

[Mike Jacoubowsky]

>> You keep saying this, and yet when I broke a spoke in mine, I was
>> still able to ride home without it rubbing on the brake. Yes, I had
>> to open up the brake (with the lever on the brake), but I didn't
>> have to remove the cable, or the pads. I did have to offset it
>> slightly to the side. And it's not as if I'm a lightweight guy (at
>> the time, about 185; fortunately a bit lighter now).
>
> So how well did your brake work when the QR was open. My old
> Campagnolo Record Brake just wobbles from side to side as it clamps on
> the rim as though nothing had changed. It is capable of swiveling
> from side to side with no change in cable length, something a dual
> pivot brake cannot do. It remains absolutely centered.
>
> Jobst Brandt

I will agree that a standard single-bolt sidepull will "follow" a badly
out-of-true wheel much better than a dual-pivot model, but I fail to see the
relevance to the original statement (which was essentially that evil,
low-spoke-count wheels will make it impossible to finish your ride if a
spoke breaks). We now seem to be switching gears to evil, dual-pivot brakes.

So much evil in the world... guess it just creates more opportunities for
good!

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA
<[email protected]> wrote in message
news:[email protected]...
> Mike Jacoubowsky writes:
>
>>>> The other day, a friend of mine had a nasty fall. She was using
>>>> Rolf wheels. I don't know the precise model. They have thin
>>>> round spokes arranged in pairs. There may be 20 or 24 spokes in
>>>> all.
>
>>>> From what we can work out, it appears that as she was turning at
>>>> no great speed, about a foot of the rim of her front wheel folded
>>>> over, causing the wheel to jam in the forks.
>
>>> From what you say it is not clear what sort of deformation the
>>> wheel had. Just riding along will not bend a wheel sideways, there
>>> being no side loads on bicycle wheels without some gymnastics on
>>> the bicycle. Are any spokes broken? I suspect this is a Rolf
>>> Vector Pro wheel with 14 spokes.
>
> http://www.craigslist.org/sby/bik/146415277.html
>
>>> With one broken spoke this wheel goes out of true enough that it
>>> will not pass through a dual pivot (the most common) type brake,
>>> these brakes not being able to follow a wobbly rim as former brakes
>>> did. Don't ride this sort of wheel unless you value fashion more
>>> than function.
>
>>>> Has anybody experienced anything like this?
>
>>> We need more details.
>
>>> With one broken spoke this wheel goes out of true enough that it
>>> will not pass through a dual pivot (the most common) type brake,
>>> these brakes not being able to follow a wobbly rim as former brakes
>>> did. Don't ride this sort of wheel unless you value fashion more
>>> than function.
>
>> You keep saying this, and yet when I broke a spoke in mine, I was
>> still able to ride home without it rubbing on the brake. Yes, I had
>> to open up the brake (with the lever on the brake), but I didn't
>> have to remove the cable, or the pads. I did have to offset it
>> slightly to the side. And it's not as if I'm a lightweight guy (at
>> the time, about 185; fortunately a bit lighter now).
>
> So how well did your brake work when the QR was open. My old
> Campagnolo Record Brake just wobbles from side to side as it clamps on
> the rim as though nothing had changed. It is capable of swiveling
> from side to side with no change in cable length, something a dual
> pivot brake cannot do. It remains absolutely centered.
>
> Jobst Brandt

 

[Llatikcuf]

[email protected] wrote:
> Eric Boo writes:
>
> http://www.physics.byu.edu/research/energy/htm7.html
>
> > So do you believe this, or do you consider this a joke?
>
> As you can see by reading it and seeing who authored it and on who's
> web site it resides.

BYU? That group believes some pretty weird stuff to begin with...

-nate

 

[Phil, Squid-in-Training]

Mike Jacoubowsky wrote:
>> With one broken spoke this wheel goes out of true enough that it will
>> not pass through a dual pivot (the most common) type brake, these
>> brakes not being able to follow a wobbly rim as former brakes did.
>> Don't ride this sort of wheel unless you value fashion more than
>> function.
>
> You keep saying this, and yet when I broke a spoke in mine, I was
> still able to ride home without it rubbing on the brake. Yes, I had
> to open up the brake (with the lever on the brake), but I didn't have
> to remove the cable, or the pads. I did have to offset it slightly to
> the side. And it's not as if I'm a lightweight guy (at the time,
> about 185; fortunately a bit lighter now).

With the paired-spoke design, truing a buddy's wheel after a spoke broke was
trivial. Loosen the offending spoke's companion, and the ride can be
completed. She switched out the wheel soon after.

--
Phil, Squid-in-Training

 

[[email protected]]

Mike Jacoubowsky writes:

>>> You keep saying this, and yet when I broke a spoke in mine, I was
>>> still able to ride home without it rubbing on the brake. Yes, I
>>> had to open up the brake (with the lever on the brake), but I
>>> didn't have to remove the cable, or the pads. I did have to
>>> offset it slightly to the side. And it's not as if I'm a
>>> lightweight guy (at the time, about 185; fortunately a bit lighter
>>> now).

>> So how well did your brake work when the QR was open. My old
>> Campagnolo Record Brake just wobbles from side to side as it clamps
>> on the rim as though nothing had changed. It is capable of
>> swiveling from side to side with no change in cable length,
>> something a dual pivot brake cannot do. It remains absolutely
>> centered.

> I will agree that a standard single-bolt sidepull will "follow" a
> badly out-of-true wheel much better than a dual-pivot model, but I
> fail to see the relevance to the original statement (which was
> essentially that evil, low-spoke-count wheels will make it
> impossible to finish your ride if a spoke breaks). We now seem to be
> switching gears to evil, dual-pivot brakes.

This isn't a sliding scale. Dual pivot brakes cannot go off center
and if the wow in a Wheel exceeds pad clearance, the wheel binds.
There is no fudging there. You can always open the QR, but then you
have no brake. That's all I'm saying.

> So much evil in the world... guess it just creates more
> opportunities for good!

Why try to overstate the case to make some point? I know we aren't
getting off dual pivot brakes so it isn't a choice. **** happens!

>>>>> The other day, a friend of mine had a nasty fall. She was using
>>>>> Rolf wheels. I don't know the precise model. They have thin
>>>>> round spokes arranged in pairs. There may be 20 or 24 spokes in
>>>>> all.

>>>>> From what we can work out, it appears that as she was turning at
>>>>> no great speed, about a foot of the rim of her front wheel
>>>>> folded over, causing the wheel to jam in the forks.

>>>> From what you say it is not clear what sort of deformation the
>>>> wheel had. Just riding along will not bend a wheel sideways,
>>>> there being no side loads on bicycle wheels without some
>>>> gymnastics on the bicycle. Are any spokes broken? I suspect
>>>> this is a Rolf Vector Pro wheel with 14 spokes.

http://www.craigslist.org/sby/bik/146415277.html

>>>> With one broken spoke this wheel goes out of true enough that it
>>>> will not pass through a dual pivot (the most common) type brake,
>>>> these brakes not being able to follow a wobbly rim as former
>>>> brakes did. Don't ride this sort of wheel unless you value
>>>> fashion more than function.

>>>>> Has anybody experienced anything like this?

>>>> We need more details.

>>>> With one broken spoke this wheel goes out of true enough that it
>>>> will not pass through a dual pivot (the most common) type brake,
>>>> these brakes not being able to follow a wobbly rim as former
>>>> brakes did. Don't ride this sort of wheel unless you value
>>>> fashion more than function.

>>> You keep saying this, and yet when I broke a spoke in mine, I was
>>> still able to ride home without it rubbing on the brake. Yes, I
>>> had to open up the brake (with the lever on the brake), but I
>>> didn't have to remove the cable, or the pads. I did have to
>>> offset it slightly to the side. And it's not as if I'm a
>>> lightweight guy (at the time, about 185; fortunately a bit lighter
>>> now).

>> So how well did your brake work when the QR was open. My old
>> Campagnolo Record Brake just wobbles from side to side as it clamps
>> on the rim as though nothing had changed. It is capable of
>> swiveling from side to side with no change in cable length,
>> something a dual pivot brake cannot do. It remains absolutely
>> centered.

Jobst Brandt

 

[Mike Jacoubowsky]

> With the paired-spoke design, truing a buddy's wheel after a spoke broke
> was trivial. Loosen the offending spoke's companion, and the ride can be
> completed. She switched out the wheel soon after.
>
> --
> Phil, Squid-in-Training

Phil: For wheels with conventional spoke nipples, that's true. But for
designs with recessed spoke nipples, which require a different tool than
normal, and removal of the tire/tube/rimstrip for access, it's a bit more of
an ordeal. Of coures, that has nothing to do with standard vs paired
spoking.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com


"Phil, Squid-in-Training" <[email protected]> wrote in
message news:55E%f.10654$IZ2.9252@dukeread07...
> Mike Jacoubowsky wrote:
>>> With one broken spoke this wheel goes out of true enough that it will
>>> not pass through a dual pivot (the most common) type brake, these
>>> brakes not being able to follow a wobbly rim as former brakes did.
>>> Don't ride this sort of wheel unless you value fashion more than
>>> function.
>>
>> You keep saying this, and yet when I broke a spoke in mine, I was
>> still able to ride home without it rubbing on the brake. Yes, I had
>> to open up the brake (with the lever on the brake), but I didn't have
>> to remove the cable, or the pads. I did have to offset it slightly to
>> the side. And it's not as if I'm a lightweight guy (at the time,
>> about 185; fortunately a bit lighter now).
>
> With the paired-spoke design, truing a buddy's wheel after a spoke broke
> was trivial. Loosen the offending spoke's companion, and the ride can be
> completed. She switched out the wheel soon after.
>
> --
> Phil, Squid-in-Training
>

 

[[email protected]]

Mike Jacoubowsky wrote:
>
> Phil: For wheels with conventional spoke nipples, that's true. But for
> designs with recessed spoke nipples, which require a different tool than
> normal, and removal of the tire/tube/rimstrip for access, it's a bit more of
> an ordeal.

For rolf wheels this is true on the high-end wheels. The low and mid
range wheels still use conventional nipples, albeit in a paired-spoke
design.

 

[Jasper Janssen]

On 13 Apr 2006 03:23:31 GMT, [email protected] wrote:

>As I have mentioned here in the past, I rode an MA-2 rim in the Alps
>in the rain until its sidewalls were a mere 0.5mm thick with no wheel
>strength problem, although I dared not use the front brake descending
>the Stelvio in pouring rain. As soon as things dried up I was back to
>full brake performance descending in the Dolomites. I have a cross
>section of that rim in my collection.

Why are thin wall rims more dangerous when wet than when dry?

Jasper

 

[Jasper Janssen]

On 14 Apr 2006 03:21:01 GMT, [email protected] wrote:

>This isn't a sliding scale. Dual pivot brakes cannot go off center
>and if the wow in a Wheel exceeds pad clearance, the wheel binds.
>There is no fudging there. You can always open the QR, but then you
>have no brake. That's all I'm saying.

But even if the single-pivot will follow the wow & flutter, wouldn't it
still drag on the side of the rim while doing so?

How come dual-pivot can't follow, don't they still attach to the
frame/fork on a single bolt around which they can pivot to follow the rim?

Jasper

 

[Art Harris]

Jasper Janssen wrote:

> Why are thin wall rims more dangerous when wet than when dry?

Because there's more grit when it's raining, and therefore faster wear.
If the braking surface is close to failure, you don't want to do heavy
braking in the rain.

Art Harris

 

[[email protected]]

Jasper Janssen writes:

>> As I have mentioned here in the past, I rode an MA-2 rim in the
>> Alps in the rain until its sidewalls were a mere 0.5mm thick with
>> no wheel strength problem, although I dared not use the front brake
>> descending the Stelvio in pouring rain. As soon as things dried up
>> I was back to full brake performance descending in the Dolomites.
>> I have a cross section of that rim in my collection.

> Why are thin wall rims more dangerous when wet than when dry?

Oops! It is rain that indirectly wears rims to death, in that granite
slurry grinding paste gets into the braking interface. It was rain on
every major descent on that tour of the Alps that wore an essentially
new MA-2 down to 0.5mm wall in about 2500km. I realized that the
descent of the Stelvio in the rain would most likely cause a rim
failure using the front brake, the one where the rim was dangerously
thin. As I said, as soon as it was drier, in the Dolomites, I braked
with the front wheel as always and was sure that it was no hazard.

http://tinyurl.com/agnvh
http://tinyurl.com/9ah2r

For me, there is no more exhilarating road than the Stelvio and I have
seen many!

http://webcam.popso.it/stelvio.php?PASSOEST

Try this one early in the morning (9hrs difference).

Jobst Brandt

 

[[email protected]]

Jasper Janssen writes:

>> This isn't a sliding scale. Dual pivot brakes cannot go off center
>> and if the wow in a Wheel exceeds pad clearance, the wheel binds.
>> There is no fudging there. You can always open the QR, but then
>> you have no brake. That's all I'm saying.

> But even if the single-pivot will follow the wow & flutter, wouldn't
> it still drag on the side of the rim while doing so?

Yes, but it is insignificant, especially if you are descending, as I
have done in such situations, going as fast as ever with full braking
ability.

> How come dual-pivot can't follow, don't they still attach to the
> frame/fork on a single bolt around which they can pivot to follow the rim?

What kind of brakes do you have? Just try and move the caliper from
side to side. You'll get the message. The entire purpose of the dual
pivot is to be absolutely centered. This had to be done because the
higher mechanical advantage of these brakes requires smaller pad
clearance, and that could only be done if the pads always retract
reliably centered. As you may have seen, Campagnolo went back to a
single pivot rear brake with a lower mechanical advantage and larger
pad clearance so that the dragging brake syndrome of climbing while
standing could be avoided.

The rear wheel being more flexible (narrow flange spacing) wobbles
elastically when climbing (the top of the wheel deflecting to the same
side as the bottom) causing brake drag. The response was for racers
to open the QR on dual pivot brakes and climb with no rear brake, the
clearance being too great for braking. After the climb, forgetting to
close the QR, made it a descent with only one brake.

I was surprised at that insight by Campagnolo after their Delta brake
debacle.

Jobst Brandt

 

[Lou Holtman]

[email protected] wrote:

>
> What kind of brakes do you have? Just try and move the caliper from
> side to side. You'll get the message. The entire purpose of the dual
> pivot is to be absolutely centered. This had to be done because the
> higher mechanical advantage of these brakes requires smaller pad
> clearance, and that could only be done if the pads always retract
> reliably centered. As you may have seen, Campagnolo went back to a
> single pivot rear brake with a lower mechanical advantage and larger
> pad clearance so that the dragging brake syndrome of climbing while
> standing could be avoided.
>
> The rear wheel being more flexible (narrow flange spacing) wobbles
> elastically when climbing (the top of the wheel deflecting to the same
> side as the bottom) causing brake drag. The response was for racers
> to open the QR on dual pivot brakes and climb with no rear brake, the
> clearance being too great for braking. After the climb, forgetting to
> close the QR, made it a descent with only one brake.
>
> I was surprised at that insight by Campagnolo after their Delta brake
> debacle.

I doubt if that was the reason. Campagnolo say it's for better
modulation/balance front-rear and I think it's just a little lighter.

Lou
--
Posted by news://news.nb.nu

 

[Jasper Janssen]

On 14 Apr 2006 22:31:40 GMT, [email protected] wrote:
>Jasper Janssen writes:
>
>>> As I have mentioned here in the past, I rode an MA-2 rim in the
>>> Alps in the rain until its sidewalls were a mere 0.5mm thick with
>>> no wheel strength problem, although I dared not use the front brake
>>> descending the Stelvio in pouring rain. As soon as things dried up
>>> I was back to full brake performance descending in the Dolomites.
>>> I have a cross section of that rim in my collection.
>
>> Why are thin wall rims more dangerous when wet than when dry?
>
>Oops! It is rain that indirectly wears rims to death, in that granite
>slurry grinding paste gets into the braking interface. It was rain on
>every major descent on that tour of the Alps that wore an essentially
>new MA-2 down to 0.5mm wall in about 2500km. I realized that the
>descent of the Stelvio in the rain would most likely cause a rim
>failure using the front brake, the one where the rim was dangerously
>thin. As I said, as soon as it was drier, in the Dolomites, I braked
>with the front wheel as always and was sure that it was no hazard.

Right. I should have thought of that -- so it's not necessarily dangerous
of itself, just more likely and quicker to get the wall thickness of the
rim down under safe levels. Inasmuch as half a mm is safe in the first
place... I don't think *I*'d knowingly do serious descents with a rim like
that on the front. Then again, I like descending, but I prefer ones that
are a little less exciting -- and I don't like going up

>http://webcam.popso.it/stelvio.php?PASSOEST
>
>Try this one early in the morning (9hrs difference).

So in US early morning or Italian early morning? I'm actually in the same
timezone as Italy, but I'm rarely behind a computer early in my morning.
Early in the US morning would be early afternoon over here, though, that
sounds doable.

Jasper

 

[Jasper Janssen]

On 14 Apr 2006 22:46:05 GMT, [email protected] wrote:
>Jasper Janssen writes:

>> How come dual-pivot can't follow, don't they still attach to the
>> frame/fork on a single bolt around which they can pivot to follow the rim?
>
>What kind of brakes do you have? Just try and move the caliper from

Well, V-brakes, actually. More of a tourer style than a racer thing. I do
have single-pivot road and drum brakes in the collection, but I don't
think I've got dual-pivot.

>side to side. You'll get the message. The entire purpose of the dual
>pivot is to be absolutely centered. This had to be done because the
>higher mechanical advantage of these brakes requires smaller pad
>clearance, and that could only be done if the pads always retract
>reliably centered.

Ok.

>As you may have seen, Campagnolo went back to a
>single pivot rear brake with a lower mechanical advantage and larger
>pad clearance so that the dragging brake syndrome of climbing while
>standing could be avoided.

Do Campy compensate for that in the lever or does it just change the MA of
the total system?

>I was surprised at that insight by Campagnolo after their Delta brake
>debacle.

Well, they *do* have some brains over there.

Jasper

 

[[email protected]]

Jasper Janssen writes:

>>> How come dual-pivot can't follow, don't they still attach to the
>>> frame/fork on a single bolt around which they can pivot to follow
>>> the rim?

>> What kind of brakes do you have?

> Well, V-brakes, actually. More of a tourer style than a racer
> thing. I do have single-pivot road and drum brakes in the
> collection, but I don't think I've got dual-pivot.

>> Just try and move the caliper from side to side. You'll get the
>> message. The entire purpose of the dual pivot is to be absolutely
>> centered. This had to be done because the higher mechanical
>> advantage of these brakes requires smaller pad clearance, and that
>> could only be done if the pads always retract reliably centered.

> Ok.

>> As you may have seen, Campagnolo went back to a single pivot rear
>> brake with a lower mechanical advantage and larger pad clearance so
>> that the dragging brake syndrome of climbing while standing could
>> be avoided.

> Do Campy compensate for that in the lever or does it just change the
> MA of the total system?

I haven't measured them recently but all hand levers in the past were
4:1 if you consider the crook in the lever to be its length. Prior to
dual pivot brakes, calipers were 1:1. I don't think the hand levers
have changes although there are brakes other than caliper brakes that
have a different ratio levers. For these, a gizmo called a travel
agent is offered so that brake types can be interchanged.

http://www.bikemannetwork.com/biking/p/CXSP/BR0411

>> I was surprised at that insight by Campagnolo after their Delta
>> brake debacle.

> Well, they *do* have some brains over there.

I'm not sure what moved them to do this but it could have been an old
timer who said "we never had that problem in the old days with 1:1
calipers." I often wonder whether you can find as good a bicycle
engineer as the one Tullio had. The one who cam up with all his
excellent products that became the standards of the industry. The
whole Campagnolo business arose from these designs that worked
immensely better than prior hardware.

Jobst Brandt

 

[David L. Johnson]

On Sat, 15 Apr 2006 08:57:41 +0200, Lou Holtman wrote:


>> The rear wheel being more flexible (narrow flange spacing) wobbles
>> elastically when climbing (the top of the wheel deflecting to the same
>> side as the bottom) causing brake drag. The response was for racers
>> to open the QR on dual pivot brakes and climb with no rear brake, the
>> clearance being too great for braking. After the climb, forgetting to
>> close the QR, made it a descent with only one brake.
>>
> I doubt if that was the reason. Campagnolo say it's for better
> modulation/balance front-rear and I think it's just a little lighter.

I think it was the reason. You can see racers (those who use Shimano)
reach back to do up the quick-release as they come to the top of a big
climb.

One thing that Jobst did not mention in this context is that Campy brake
QRs are not as easy to release as Shimano, being on the brake lever rather
than on the brake. I usually use two hands, and am standing in front of
the bike, to release the QR. It can be done while riding, but it is not
easy, since you have to push the pin in while slightly depressing the
lever. OTOH, once open the rider can leave the QR open, since you can
still stop with an open Campy QR (it increases lever travel instead of
opening the caliper directly).

So, for Campy there was an added incentive to fix the drag problem with
these flexy wheels and tight clearances. And their new brakes do exactly
that. Their press rationales are marketing.

--

David L. Johnson

__o | "Business!" cried the Ghost. "Mankind was my business. The
_`\(,_ | common welfare was my business; charity, mercy, forbearance,
(_)/ (_) | and benevolence, were, all, my business. The dealings of my
trade were but a drop of water in the comprehensive ocean of my
business!" --Dickens, "A Christmas Carol"