Well, having logged another
150 miles or so on the Calfee with the 36° conventional wheel
set I'm confident the initial handling issues with our tandem
have been resolved.
We joined a local club for
a short 50 mile ride near Rome, Georgia, today and this was the
first time that we had the Calfee out for a ride on something
other than the loop rides that we ride from our home. Again,
the Calfee does not disappoint. Although we didn't encounter
any significant climbs or descents, the moderately rollling terrain
on a variety of different road surfaces in various stages of
repair -- from smooth as glass fresh asphalt to rutted and crumbling
chip-seal -- all felt great on the Calfee: even the occassional
big jolts at bridge crossings. The tandem also felt rock solid
and spirited on the several short, out-of-the-saddle climbs.
Again, it's hard to describe the
actual ride characteristics in a meaningful way other than to
note the tandem is just so darn comfortable while still being
spry and nimble when you push it hard.
So, what about those low
spoke count racing wheels?
As John Lydgate wrote, "You
can please some of the people some of the time and all of the
people some of the time, but you can't please all of the people
all of the time.
At this point I must conclude
that, for whatever reason, this particular set of low spoke count
racing wheels are simply a poor choice for us. I'm not sure if
it's just my expectations based on over a decade of riding tandems
fitted exclusively with very robust 36° wheel sets or if
perhaps it's just my riding style.
My dealer and the manufacturer
have shared a number of Emails regarding my findings with the
wheels and they too have simply concluded that we are apparently
better served by wheels that have less lateral deflection. It's
noteworthy that they freely admit the design objective was to
build the lightest and fastest tandem wheels, not the stiffest.
However, they did note I was
purportedly the first owner who ever reported an unacceptable,
adverse impact on the handling of a tandem fitted with their
wheels: a dubious distinction to be sure. The latter makes me
wonder how many folks are simply unaware of how their tandems
might handle with a stiffer, conventional wheel set? Oh well,
not really my concern...
There was obviously some concern
as to whether or not it was a fair comparison, e.g., same size
tires, same psi, same skewers, etc. My initial answer was an
unequivocal YES. Although, on reflection I did recall the low
spoke count racing wheels were fitted with a set of 700x23 Vredestein
Fortezza SE tires inflated to 145psi, whereas the conventional
wheels were fitted with a set of 700x23 Vredestein Fortezza tires
inflated to 145psi. While I initially considered doing a re-test
with the 'exact' same tires I realized that the 'juice just wasn't
worth the squeeze' as the handling issues I experienced could
not have been caused by the ever-so-slight differences that could
exist in how these two tires casings were made.
For the record, the comparison
wheel set was as follows:
Front: White Industries MI5
hub, 36°, laced to Velocity Fusion rims with Sapim 2.0mm
Leader spokes tensioned to 126 Kgf.
Rear: White Industries MI6
disc hub, 36°, laced to Velocity Fusion rims with Sapim 2.0mm
Leader spokes tensioned to 126 Kgf.
Total weight with Titanium
cassette carrier: 1,950 grams
Why No Naming Names?
readers of my journal and related posts have asked why I have
not come right out and identified the brand name and model of
the low spoke count racing wheels that I evaluated. It's a good
question and one that I wrestled with a bit.
In short, I do not have an
axe to grind with these wheels: they simply don't work well for
us. Moreover, handling is a rather subjective matter and given
that hundreds of tandem teams have been using these wheels for
several years now, the prima fascia evidence seems to suggest
my issues with the wheels represent an issue with me and my hyper-sensitivity
to bike handling, and are not a problem with the wheels.
Therefore, I have elected not
to name names so as not to add any fuel to the brand debate and
would note it's not all that hard to establish which brand of
wheels I have been using by those who are interested or in the
market for wheels like these.
Once all was said and done, I finally disclosed the first set
of low-spoke count racing wheels to have been '08 Rolfs. We've
since sold the '08 Rolfs and acquired a set of '07 Rolfs with
the 34mm deep section rim and they seem to be a bit more robust
than the '08's. However, they're still not nearly as laterally
stiff as a set of conventional wheels or even a set of Topolino
Technology AX 3.0-T wheels that were subsequently acquired.
All Disc Hubs Are Created Equal:
turns out there may not be enough clearance between the Calfee's
left rear chain stay and the 203mm rotor mounted to the White
Industries MI6 disc hub's rotor mount. What I discovered was
that when the rotor is bolted up to the MI6 there is not
more than 1mm of space between the rotor and the Calfee's
chain stay rotor recess.
Further investigation did reveal
that this particular MI6 hub was a little out of spec in that
instead of the rotor mounting face being the International Standard
(I.S.) spec. of 15.25mm from the inside face of the drop-out,
it was ~14.8mm. Admittedly this is only a little bit of variability;
however, when you're dealing with tight tolerances a little can
seem like a lot.
Interestingly enough, the 20mm
thread-on disc adapter that we used on the low spoke count racing
wheels provided adequate clearance.
Although I opted not to bother
the folks at Calfee with this as I merely saw it as a component
integration / selection issue, the tight clearance did become
a topic of discussion on the Hobbes tandem discussion list. While
various different list members weighed in with observations on
their own disc clearance dimensions I felt compelled to note
that the variability one can see in disc installations is substantial,
which is why I chose to include the photo of the also quite narrow
disc clearance on our Ventana off-road tandem to give some context
to the Calfee's disc clearance. While other tandems may have
very wide rear stays or perhaps narrowed disc rotor mounts to
create larger gaps between the stays and disc rotors, the bottom
line is you don't need a lot of clearance for the disc rotor,
you just need enough clearance. My comments were
apparently reinforced when I discovered that Craig Calfee had
weighed into the discussion with the following observations /
comments disc interfaces, hubs, and the like and it's pretty
We like the chainstay
to be as fat as possible there so the stiffness of the chainstay
is as high as possible for solid brake feel.
The clearance between
rotor and chainstay does not have to be very much at all. The
[disc rotor to chain stay] clearance may vary from 1.5 to 3 mm
on our frames.
There is an International
Standard for locating the disc mounting
surface relative to the inside surface of the dropout. It's 15.25
mm. If [disc hubs] are designed for IS (International Standard)
then [they] always clear.
Thread on adapters [can
also] be selected to achieve this distance. There is quite a
bit of leeway with the Avid caliper if you don't have the exact
I personally like the
hubs that don't use threaded adapters: [the threaded adapters]
can be very difficult to remove.
Regardless, this discovery
simply reaffirmed my plan to go ahead with having one more set
of wheels built for our Calfee... the final set of wheels that
will be our "do-all" wheels as there's just no reason
to have different sets of wheels for our needs. As for my solution,
I'll simply go with a White Industries Daisy tandem hub with
left-side threading for a thread-on disc adapter. Given that
the 20mm thread-on adapter used with our low-spoke count wheels
gave us enough clearance for the disc, I should be able to use
it on the new wheels.
The Daisy Hub / Velocity Deep-V wheelset with thread-on disc
rotor does provide about 2mm of clearance for the rotor, which
is acceptable given that our frame is unpainted. The thread-on
disc isn't my first choice, but it seems to be the most flexible
in terms of managing rotor off-set.
On the bright side, when we're
not using the disc the wheel set will be a bit lighter. However,
the down side is that we'll once again be faced with the use
of a thread-on disc adapter. In the past these worked just fine
until I went to remove one after a full season of use, at which
point things got interesting. I'm told the newer disc rotor "donuts"
incorporate features that make removal less dramatic and I hope
that's the case.
So, why did you bring up
this disc clearance issue?
It was my hope that others
might also benefit from this information which is why I have
shared my experiences and discoveries as candidly and openly
as I have in this journal.
The point in bringing up the
rotor clearance was, in fact, something that I thought would
be of interest given that discs on tandems, even though relatively
common, still create issues and questions. As some readers have
noted in their posts to the Hobbes list, their perceptions regarding
disc spacing is based on what they've seen on their own tandems,
e.g., custom installations using narrow disc adapters or perhaps
tandems with very wide chain stays and larger gaps between the
stays and rotors. My own comfort zone is around 3mm - 5mm. As
already noted, you don't need a lot of space around the disc
rotor and stay, you just need enough. For me, and having gone
into this cold I've simply learned that not all I.S. disc hubs
are created equal and being off by .5mm where 1.5mm of spacing
is needed can grab your attention.
Moreover, and remembering that
my journal is intended to educate those who may venture down
a similar path in the future, the point in bringing up these
little nuances is to illustrate some of the things others might
want to take into consideration as they work up their specifications
with a dealer or builder, and/or what to think about as they
make certain component choices.
Again, there are work arounds
-- simple workarounds -- that would allow me to use the MI6 hub
on our Calfee if I was committed to keeping these wheels: a washer
between the hubs end cap and drop-out adds 1.0mm: problem solved.
Of course, I could also request a replacement hub that has the
exact I.S. spacing of 15.25mm.
Following publication of this edition of our Journal I have heard
from other Calfee owners who have also experienced some very
tight quarters between the caliper, rotor, and stays. Calfee
states so long as the rotor is not rubbing no worries. However,
consumer perspective seems to be that it's disconerting to have
it that close and that invariably the rotor will chip any paint
on the inboard side of the left stay during rear wheel removal
Are these things normal
issues that come up with all tandems?
Hey, I've said before and I'll
it say again: custom and high-end tandems take a bit of a different
mindset than buying production models. You may think that it
shouldn't be that way, but it is. Custom and one-off tandems
are just that: one of a kind. They aren't built to suit a wide
range of potential buyers they're built for a specific client
and will often times have features that make them a bit different.
Frankly, I've been having a ball going through the discovery
process with the new tandem. It may not seem like that to some
readers, but to me there has been new knowledge and information
at every turn that has often times even challenged a lot of what
I thought I knew while searching for answers to my own questions,
e.g., low spoke wheel stiffness and their influence on handling,
Also, it's interesting to see
how new and different things work. For example, this is our third
road tandem with a rear disc and our fourth different rear disc
installation (our '02 Erickson started off with a Hope disc and
was converted to an Avid BB7 Road). Each of these installations
was a one-off custom job with all kinds of unique tweaks or machined
parts that made them work. Therefore, in looking at how this
particular disc installation was designed, it's really the first
one that really conforms to I.S. standards.
Am I happy about having to
use the thread-on disc adapter? Not really but, then again, I
had already resigned myself to using a thread-on disc adapter
with the low spoke count wheels since that's how they are made.
Therefore, I can't be too upset or disappointed about the use
of the thread-on adapter at this juncture. However, you can bet
your boots that I'll make a point of removing it now and again
just to make sure that it will come off.
So, what's next?
gone ahead an ordered up a 3rd and hopefully final set of wheels
built for the Calfee. In addition to the rear hub change, this
wheel set will most likely use my all-time favorite: a pair of
Velocity Deep-V rims laced to the White Ind. hubs with double
butted (2.0mm x 1.8mm) spokes. This, of course, this brings up
the reason that I posted the photo of a Deep-V sitting on a scale
at the top of this entry.
As you can see, this Deep-V
weighs in at 577 grams, which is consistent with two other spares
I have here at the house. I recently sent a note to Velocity
USA to mention that the Deep-V rim weights listed on their Web
site seemed a bit on the low side @ 520 grams compared to the
last five that I'd purchased which weigh in at 577 grams. I also shared a Web site that depicted my
3 rims sitting on a calibrated scale.
The Velocity rep stated he'd
pulled a silver anodized Deep-V rim off the shelf and weighed
it to be 522 grams. He went on to note the anodized and machined
rims would have different weights than, say, powder coated and
non-machined rims, and that the number of spoke holes also factored
into the rim's weight. However, to establish the catalog weight
they randomly pulled a number of different Deep-V rims to come
up with the average weight and that average is purportedly what
they based their catalog weight against.
The latter was interesting,
but it seemed to ignore the point that my three (3) 577 gram
Deep-Vs with their anodized with machined sidewalls still falls
well off the "average". I would note that someone from
the Hobbes list had just recently purchased a pair of silver
Deep-V rims with 24h spoking where the rims weigh 525 grams and
530 grams, respectively. Therefore, I must conclude that what
Velocity is using is the average weight of the base-model / silver
rims and not an average of rims that represent the full line.
We received our new set of White Ind / Velocity Deep-V wheels
in May and the spare rim weighed in at 520 grams on the dot.
So, it would appear the current Deep-Vs are per spec, which is
a good thing.
Someone who has been following
my experiment with lightweight wheels who read this update asked
a very good question: Why not 32° instead of 36° for
the next set of wheels? Since it seems relevant to anyone following
my journal, I though I'd share my reply...
Having had my eyes opened quite
dramatically by my little experiment with tandem racing wheels,
I think I've cured myself of the allure of uber-light wheels
for teams like us (285#) who will not be racing or competing
in time trial events. If we were doing non-technical time trials
we'd likely reap a tangible and quantifiable benefit by using
the low-spoke count racing wheels because in that application,
every second counts. Of course, at least based on our experience,
if they were technical time trials I'm not sure we'd save any
time by white knuckling and taking sub-optimal lines through
Therefore, at this point and
given that what we're talking about are every-day wheels that
will need to contend with pot holes, mountain descents, touring
and will otherwise rack up about 3,000 - 5,000 miles per year,
I'd rather opt for the added durability, strength, and better
value of the more robust 36° deep section wheel set similar
to what we've ridden for the past decade.
Will they be as light and aero
as they could be? yes and no. Yes, they will be as light as a
set of wheels like these can be but, no, they won't be as light
as a set of racing wheels and that's the bottom line. We really
don't need racing wheels since all they would afford us would
be a short-lived performance boost that made going the same speeds
a bit easier.
Would the 32° deep section
wheels be just as durable and robust? Perhaps... but I'd hate
to guess wrong and find that out during a tour or after hitting
a pot hole at a tandem rally. And, remember, the Fusion wheel
set was built with straight gauge 2.0mm spokes instead of the
butted 2.0mm / 1.8mm. Therefore, anything I will gain in stiffness
from the deeper section Deep-V rim will be somewhat off-set by
going back to double-butted spokes. It warrants mention here
that we've subjected our tried-and-true 36° Deep-Vs to a
lot of abuse over the years and they've stood up to some really
hard hits that have left the rims dented and deformed, but good
enough to get us home. This outstanding history with the 36°
Deep-Vs a major driving force in the decision process for me
(if it ain't broke, don't fix it).
Therefore, at least for us,
we'll just have to work harder at being stronger riders to off-set
the performance hit we'll take for having those four extra spokes
and that slighter heavier rim. Frankly, that's probably not a
bad strategy given that one of the reasons we ride is to keep
fit and healthy.
Bottom Line: The trick to wheel
selection is matching your needs to the available technology.
I don't think there is a right or a wrong answer, but there's
certainly a different answer for many teams based on their needs
and expectations. 36° wheel sets are a no-brainer for most
lightweight teams and at this point I think I could use a no-brainer:
this stuff has made my head hurt and left a huge hole in my wallet.
Best of intentions; however, I was once again lured by the intrigue
of technical innovation during the Tandems East Expo where Rafe
Schlanger of Topolino Technology pitched his 1,520 gram Carbon
Core Series AX 3.0-T wheelset. So, after selling the '08 Rolfs
and swearing off racing wheels we've now jumped back in with
both feet given the $1,359 MSRP of the Topolino wheels. To make
matters worse, we picked up a set of new old stock (NOS) '07
Rolf Prima Vigor tandem wheels so that we could see if the '08's
were perhaps a step backward and to see how they would compare
to the Topolino AX 3.0-Ts.