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TIRES! |
If you have
read our "Tire" article before, you will now find that our tire
article has been edited down to fewer and fewer choices over the years given
the frustrating limited and rare availability of Avocet Fasgrip tires, the thin
sidewall of the Panaracer Pasela tires, and associated lack luster sales. We do have great tires for tandems though!
Several factors
should be considered when selecting a tire for your tandem. Since no one tire
will "DO ALL" and "BE ALL", sacrifice is
necessary. For example one cannot expect to ride on a narrow light fast road tire
with a team weight of 450 - 500 pounds, at least not very far. Other
considerations in tire selection include rough pavement or the desire to load
the bike down for touring and any other special needs. Using the wrong tire for
the job will result in great frustration and it won't be a fun nor safe day.
The purpose
of this article is to share my personal experience and that observed of other
teams having different needs than that of what I perceive for myself.
Subjective information is shared concerning ride quality and comparisons made
with respect to sidewall durability, tread life, handling, ability to handle
heavy loads, and the negative effects of gravel and or rough pavement.
Discussions about tread compounds, threads per inch and the like will be reserved
for the bicycle science type lists.
Tread on
bicycle road tires has absolutely no useful purpose on wet or dry pavement as
it is impossible to hydroplane a bicycle tire unless you exceed 120 mph. The more
rubber you have in contact with the road the greater the traction. Tread is
useful in situations where the riding surface is loose or soft and one
generally does not encounter this on the road. Tread on road tires will
decrease traction, increase rolling resistance, add vibration, and create
noise. People are so ingrained to tires having tread from their automobile
knowledge that its existence on bicycle road tires is deeply rooted in
marketing efforts in my opinion.
My
experience includes the use of several tires from various manufacturers, some
currently in production and others that are now history. The tire
recommendations and thoughts are based on current availability and my first
hand knowledge and should not be considered to be all inclusive by any means as
other options may exist to which I am not privy nor knowledgeable.
Tire Width, The Great Dilemma
Most of us
want to go fast and do so efficiently making it natural to contemplate narrow,
light and expensive tires. Selecting the proper tire width for the weight and
task is probably the most misunderstood element in the determination process. I
made a posting to the T@H list back in May of 2000 where I alluded to common
misconceptions about running narrow "fast" tires as you will read
below.
Original Post: Time to put another set of tires on the tandem ('98 C'Dale RT1000). Been running Conti. GP 3000 700 x 28's. Switching to same tire but in a 25c width.Input from others running 25c tires? too narrow? wear characteristics?Been getting 1000-1500 miles from 28c, rotating every 500 miles, frontTo rear and changing direction of rotation. Subject: Re: [T@H] Tire sizeDate: Thu, 11 May 2000 15:15:27 -0500 Robert, We have gone through a couple sets of Conti GP 3000 with the first pairinstalled for the 750 mile Paris Brest Paris event last August.Fortunately, these tires improved the comfort of the ride as compared tothe old Super Sport 100's, something we strongly desired for an eventthis long and the French road texture. We have a couple of stories about PBP '95 and '99 posted on our website. We barely made it to 2000 mi on the rear tire before hitting the cordsand 3000 miles on the front. They seem to wear about 30% faster thanthe regular Grand Prix model. 25mm tires can be a bit narrow and likely have a higher rollingresistance than the 28mm width unless one is able to run them atextremely high pressure. It seems I recall an optimal tire pressureinflation chart that showed I would need to run something like 145 psiwith 25mm tires versus 120 psi with the 28mm width. The narrow tires may look fast, feel fast, sound fast, but I am not sosure they are. Mark and Sue Johnson~~~~Precision Tandems~~~~
The Continental Grand
Prix 3000 tire referenced above is no longer available.
Below is the chart
referred to in the above post. You can see that extrapolation is necessary for
all but the lightest teams. The chart refers to total weight of the ready to
ride team and loaded bicycle. Before you
look at the chart, be aware that there are weight differentials in many cases
with different tandem teams as outlined in the following examples and formula
applications.
To calculate the weight
for a given tire or wheel on a multi seat bicycle, consider the following formula
with its basics taken from a post on T&H by Mike Breaux on 04/01/04:
Front
weight = [(captain weight x (rear compartment + chainstay)) + (stoker weight x
chainstay)] / wheelbase or more simply total weight - rear weight
Condition
one
Captain 150#'s & Stoker 150#'s
Rear Weight = [(150 x 24) + (150 x (24+27))] / 69 = 163#'s
Front Weight = [(150 x (27+18)) + (150 x 18)] / 69 = 137#'s
So on an evenly weighed team, the rear wheel holds more weight / more pressure.
Condition two
Captain 170#'s & Stoker 120#'s
Rear Weight = [(170 x 24) + (120 x (24+27))] / 69 = 143#'s
Front Weight = [(170 x (27+18)) + (120 x 18)] / 69 = 147#'s
In the above example, the same pressure would be used.
Condition
three
Captain 170#'s & Stoker 50#'s
Rear Weight = [(170 x 24) + (50 x (24+27))] / 69 = 96#'s
Front Weight = [(170 x (27+18)) + (50 x 18)] / 69 = 124#'s
So with a stokid, the front holds more weight than the rear and it makes sense
to adjust the tire pressure accordingly.
Condition four
Triplet Weights 170#'s, 45#'s, 50#'s &
front 24", middle 27", rear 27" and chain stay 18"
Rear = [(170 x 24) + (45 x (24+27)) + (50 x (24+27+27)] / 96 = 107#'s
Front = [(170 x (27+27+18)) + (45 x (27+18)) + (50 x 18)] / 96 = 158#'s
Click on the image to
enlarge
Questions to ask yourself
when selecting a tire
A person's mindset is also
a factor in deciding what tire is best suited for the team. The questions below
should help sort through your concerns.
1) Are you into fast
sport or competitive riding?
2) What is your team
weight? ..under 275? ..over 350?
3) Would you prefer
durability (longer wear) at the expense of added weight and increased rolling
resistance? Gram counters and competitive or fast sport riders will invariably
say no.
4) Are your roads
excellent, good (occasional problem but can avoid the bad spots) or poor
(unexpected hits, too many to miss)?
5) Are you a careful
captain and take it easy over railroad tracks and rough spots or do you hammer
through everything to prevent loss of speed?
For simplicity, please
allow me to make some generalizations for the purpose of categorizing teams and
tire recommendations. Since categorizations won't fit every team, I will now
apologize ahead of time but at the very least some thought should be
stimulated!
A Team = Go fast
hammerhead racer types that count grams, willing to spend money to save weight,
interested in greatest efficiency and not concerned about shortened tread life
as a result. These teams are usually very fit, ride a large number of miles,
ride in competition or do fast sport riding. Team weight is often near 300 pounds
or less.
B Team = Possibly new to
tandems, getting in better shape, weight is dropping, not competitive all the
time but may be with the right crowd but does not necessarily seek it out in
order to have a "good" ride.
These teams will sometimes stop and smell the roses. Longevity and durability and reasonable
performance from a tire is expected by this team and does not mind spending a
little extra for a quality tire. These
teams are often seen enjoying and riding fine equipment. Team weight varies greatly but is often
between 300 and 350 pounds.
C Team = Into smelling
the roses, prefer longevity and durability. Not interested in average speed or
saving a few grams. Does not mind being passed. May prefer a more expensive
quality tire or something quite basic.
Working on long term goals of exercise, possibly weight loss but not
always, and improved health.
TIRE RECOMMENDATIONS
Please note that all
tires discussed are assumed to be 700C unless otherwise noted.
"A" TEAMS under
300 Pounds:
Consider a 25 or 28 mm
width tire with either a Kevlar or wire bead.
Both widths are available in the tires discussed below. The Kevlar bead permits folding for ease of
carrying a spare and it also saves weight.
The steel bead may be a better choice for those that ride in conditions
where long term braking generates more rim heat.
Folding Tires: Our
favorite is the Continental Grand Prix 4-Season as they have a low rolling
resistance and corner well.
Wire Bead Tires: Our
absolute favorite tire is the personally time tested Continental Ultra
GatorSkin. Having personally ridden
these tires for more seasons than fingers on one hand, I can report zero
sidewall failures nor S-bends in the casing.
Longevity, handling characteristics and ride comfort are quite good with
this tire but reliability is the main feature that causes me to continue to use
these particularly on our triplet and quad given the very precious cargo
aboard! These tires are full size
meaning the width numbers are accurate and sometimes conservative once the tire
has and stretched out. A 28mm tire may
measure 29mm once inflated a number of times which may lead to clearance problems
with older pre 2006 Alpha Q carbon forks.
Lightweight teams would likely opt for the 25mm width if the Ultra
GatorSkin is the tire of choice since they are 'full' size.
Budget tires would
include the Continental UltraSport in a 28mm width.
A narrow rim is preferred
for 25 mm tires such as the Shimano Sweet 16, Rolf Prima Vigor, Bontrager
Tandem Wheels, Velocity Deep V, Velocity Fusion, or the Velocity Aerohead
rims. Use of a narrow 25 mm tire on a
fairly wide rim common to many modern tandems such as the Velocity Dyad or FiR
models will unnecessarily expose the sidewall to road debris and the lowered
profile increases the propensity for pinch flats.
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Continental Grand Prix 4-Season |
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Continental Ultra Gatorskin |
"A" TEAMS Up To
350 Pounds:
A 28 mm width tire is
recommended with either a Kevlar or wire bead.
The remaining foldable
Continental tire to consider in a 28mm width is the Grand Prix 4-Season with
its Dura Skin sidewall protection.
The wire bead
Continental tire to consider is the Ultra Gatorskin. The Ultra Gatorskin provides extra sidewall protection and a
longer wearing tread than the now discontinued Ultra 2000.
A Team summary: Use the folding
Continental Grand Prix 4-Season if you have the extra money and want the
ultimate in performance and don't mind the cost. For a budget tire take a look at the Continental UltraSport.
I have personally ridden
the Ultra GatorSkins the past 5+ years and have been pleased with them in all
aspects. We usually get 2000-2400 miles out of a rear tire before cords are
exposed while running 120 psi with a team weight of 295 pounds. Teams that climb a great deal or those with
greater weight should expect fewer miles. Ride quality of the Ultra GatorSkin
is excellent and tread wear good with excellent sidewall life as I have had
zero failures to date. The Continental tires discussed here are basically slick
(as desired) as they have very little tread with some siping as shown in the
pics above.
"B" TEAMS
300-350 Pounds:
Now that the Conti Ultra
2000 is no longer made, consider the Continental Ultra Gatorskin 28 mm width
tires for low rolling resistance and good performance. You will feel confident
running these tires if you sometimes enjoy good solid or somewhat aggressive
cornering. If you are a bit more laid back, smell the roses, not into
competitive riding and certainly favor tread life longevity, consider the IRC
30mm Tandem tire. The characteristics and expected life of the Continental
tires are discussed under A Teams above.
The IRC Tandem tire is a
very comfortable tire due to its width and extra tall peaked profile. The
downside of this tire is increased rolling resistance, a slight hum as you ride
due to the inverted tread design and cornering feels less than secure while
riding aggressively. Expect 2500 miles out of this tire on the rear and more if
you are a light team. This tire has a lot of rubber on it! We also recommend it
for those riding on poor roads.
The Continental 28mm
width Ultra GatorSkin is our favorite for a team weight of 350 pounds and
upwards. We personally use these on
our triplet, quad and quint!
"C" TEAMS Over
350 Pounds:
Jumbo teams and those on
triplets are advised to remove their tires every 700 miles and check the bead
edge where the rim can actually cut and wear through the protective tape and
into the cords. The defect starts to appear due to tire flex at the edge of the
rim which will lead to sidewall failure and blowout. I personally replace both tires after 700
miles regardless when used in this application.
That said, my favorite
tires for teams in this weight range include the 30mm IRC Tandem Tire and in
particular the 28mm Continental Ultra Gatorskin. We have used the Gatorskin on
triplets, quads and quints at 140 psi and find the sidewall wear at the rim
junction is far less than that of other tires.
For 26" wheels
often used with Jumbo teams, triplets, quads and longer bikes, consider the
1.5" IRC Metro Duro is a nice wide tire capable of doing some gravel
stints, has excellent wear quality and a high pressure rating of up to 100 psi
and that is unusual for a very wide tire! It is basically a smooth tire with
siping.
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IRC Metro Duro 26" |
IRC Tandem Tire |
Continental Ultra Gatorskin |
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