Bike fit question - Triathlon Week

11-29-2004, 02:32 PM

I'm a dedicated roadie and I'm dabbling in triathlons and time trials. I've
been borrowing a friend's P2K, but we'll be doing some off the same events
at the same time next year and I've gotta buy my own bike.

I know all about fitting a road bike. I know almost nothing about fitting a
tri bike. Are there any good rules of thumb like, if your frame size on
your road bike is X, your tri bike frame size should be Y? I heard one
today that said the combined length of your top tube (effective top tube)
and stem should be about 2 cms shorter than for your road bike. Can anyone
confirm that?

Any guidance will be appreciated.

Bob C.

11-29-2004, 02:58 PM

"psycholist" <[Only registered and activated users can see links. ]> wrote in message
news:cog4ib$2u0j$[Only registered and activated users can see links. ]...
> I'm a dedicated roadie and I'm dabbling in triathlons and time trials.
I've
> been borrowing a friend's P2K, but we'll be doing some off the same events
> at the same time next year and I've gotta buy my own bike.
>
> I know all about fitting a road bike. I know almost nothing about fitting
a
> tri bike. Are there any good rules of thumb like, if your frame size on
> your road bike is X, your tri bike frame size should be Y? I heard one
> today that said the combined length of your top tube (effective top tube)
> and stem should be about 2 cms shorter than for your road bike. Can
anyone
> confirm that?
>
> Any guidance will be appreciated.
>
> Bob C.

Try the following links:
[Only registered and activated users can see links. ]
[Only registered and activated users can see links. ]
[Only registered and activated users can see links. ]

11-29-2004, 03:53 PM

I ride a 55 or 57 cm Litespeed road bike. My tri bike is a Corima Fox with
a virtual 51cm top tube. I originally purchased a 55cm Litespeed Saber
triathlon specific frame when I first starting doing triathlons back in 2001
and found it was way to big for me. I'm 6'0" tall. I don't know about any
golden rules but a lot of it has to do with flexibility. I see riders who
like to ride nearly upright and others whose nose scrapes the front tire.
Slowtwitch.com has a bunch of articles on aero position vs. comfort vs.
power gain/loss depending on your setup. I bought my first tri bike before
I talked to my tri coach and he knew immediately that my bike was too big
when I went in for my first ramp test on the Computrainer.

You're lucky that you have a P2K to play with. Get it right or really close
the first time. The biggest thing I learned when it comes to tri bikes is
that it's easy to make a small bike "Bigger" with seat movement, aero bar
movement, and messing with the stem by turning it upside down, rightside up
or buying a longer/shorter one. It's extremely difficult to make a bike
that's too big for you "Smaller", by cramming your seat all the way forward,
bottoming out your stem against the headset, buying the absolute smallest
stem you can find to get the aerobars closer to you and last but not least,
attaching your armrests directly to your bullhorns with a welder so you can
get into a deeper aero position. I say this because I've done it all.

Good Luck

Aaron

"psycholist" <[Only registered and activated users can see links. ]> wrote in message
news:cog4ib$2u0j$[Only registered and activated users can see links. ]...
> I'm a dedicated roadie and I'm dabbling in triathlons and time trials.
I've
> been borrowing a friend's P2K, but we'll be doing some off the same events
> at the same time next year and I've gotta buy my own bike.
>
> I know all about fitting a road bike. I know almost nothing about fitting
a
> tri bike. Are there any good rules of thumb like, if your frame size on
> your road bike is X, your tri bike frame size should be Y? I heard one
> today that said the combined length of your top tube (effective top tube)
> and stem should be about 2 cms shorter than for your road bike. Can
anyone
> confirm that?
>
> Any guidance will be appreciated.
>
> Bob C.
>
>

11-29-2004, 05:47 PM

In article <cog4ib$2u0j$[Only registered and activated users can see links. ]>,
"psycholist" <[Only registered and activated users can see links. ]> wrote:

> I'm a dedicated roadie and I'm dabbling in triathlons and time trials. I've
> been borrowing a friend's P2K, but we'll be doing some off the same events
> at the same time next year and I've gotta buy my own bike.
>
> I know all about fitting a road bike. I know almost nothing about fitting a
> tri bike. Are there any good rules of thumb like, if your frame size on
> your road bike is X, your tri bike frame size should be Y? I heard one
> today that said the combined length of your top tube (effective top tube)
> and stem should be about 2 cms shorter than for your road bike. Can anyone
> confirm that?
>
> Any guidance will be appreciated.

No one has yet mentioned that finding a good local bike sho that deals
with time-trial bikes is probably your best bet.

--Harold Buck

"I used to rock and roll all night,
and party every day.
Then it was every other day. . . ."
-Homer J. Simpson

11-29-2004, 06:25 PM

Always a good answer ... assuming you can find a "good" bike shop where the
people who do fitting actually know as much as they should. The nearest
bike shop to me is 45 miles away. Last time I was there they bragged to me
about their "fitting station." They took me over to the corner to see it.
It was a bike on a trainer in front of a mirror. Well, it was a start I
suppose.

After reading the articles at slowtwitch.com, I'm sure I know substantially
more on the subject that any LBS I've visited within a 50 mile radius of
where I live. Thanks for those links Williamsdrew! I knew the principle
about simply rotating your position forward (maintaining leg to back and
back to arm angles). I didn't know how to translate that into a new tt
frame. The articles really helped. Probably kept me from jumping at a
closeout special that would have been too big.

Bob C.

"Harold Buck" <[Only registered and activated users can see links. ]> wrote in message
news:[Only registered and activated users can see links. ].giganews.com...
> In article <cog4ib$2u0j$[Only registered and activated users can see links. ]>,
> "psycholist" <[Only registered and activated users can see links. ]> wrote:
>
>> I'm a dedicated roadie and I'm dabbling in triathlons and time trials.
>> I've
>> been borrowing a friend's P2K, but we'll be doing some off the same
>> events
>> at the same time next year and I've gotta buy my own bike.
>>
>> I know all about fitting a road bike. I know almost nothing about
>> fitting a
>> tri bike. Are there any good rules of thumb like, if your frame size on
>> your road bike is X, your tri bike frame size should be Y? I heard one
>> today that said the combined length of your top tube (effective top tube)
>> and stem should be about 2 cms shorter than for your road bike. Can
>> anyone
>> confirm that?
>>
>> Any guidance will be appreciated.
>
>
> No one has yet mentioned that finding a good local bike sho that deals
> with time-trial bikes is probably your best bet.
>
> --Harold Buck
>
>
> "I used to rock and roll all night,
> and party every day.
> Then it was every other day. . . ."
> -Homer J. Simpson

11-29-2004, 06:25 PM

"Alo" <[Only registered and activated users can see links. ]> wrote in message
news:SLNqd.485770$D%.468976@attbi_s51...
>I ride a 55 or 57 cm Litespeed road bike. My tri bike is a Corima Fox with
> a virtual 51cm top tube. I originally purchased a 55cm Litespeed Saber
> triathlon specific frame when I first starting doing triathlons back in
> 2001
> and found it was way to big for me. I'm 6'0" tall. I don't know about
> any
> golden rules but a lot of it has to do with flexibility. I see riders who
> like to ride nearly upright and others whose nose scrapes the front tire.
> Slowtwitch.com has a bunch of articles on aero position vs. comfort vs.
> power gain/loss depending on your setup. I bought my first tri bike
> before
> I talked to my tri coach and he knew immediately that my bike was too big
> when I went in for my first ramp test on the Computrainer.
>
> You're lucky that you have a P2K to play with. Get it right or really
> close
> the first time. The biggest thing I learned when it comes to tri bikes is
> that it's easy to make a small bike "Bigger" with seat movement, aero bar
> movement, and messing with the stem by turning it upside down, rightside
> up
> or buying a longer/shorter one. It's extremely difficult to make a bike
> that's too big for you "Smaller", by cramming your seat all the way
> forward,
> bottoming out your stem against the headset, buying the absolute smallest
> stem you can find to get the aerobars closer to you and last but not
> least,
> attaching your armrests directly to your bullhorns with a welder so you
> can
> get into a deeper aero position. I say this because I've done it all.
>
> Good Luck
>
> Aaron
>
>
> "psycholist" <[Only registered and activated users can see links. ]> wrote in message
> news:cog4ib$2u0j$[Only registered and activated users can see links. ]...
>> I'm a dedicated roadie and I'm dabbling in triathlons and time trials.
> I've
>> been borrowing a friend's P2K, but we'll be doing some off the same
>> events
>> at the same time next year and I've gotta buy my own bike.
>>
>> I know all about fitting a road bike. I know almost nothing about
>> fitting
> a
>> tri bike. Are there any good rules of thumb like, if your frame size on
>> your road bike is X, your tri bike frame size should be Y? I heard one
>> today that said the combined length of your top tube (effective top tube)
>> and stem should be about 2 cms shorter than for your road bike. Can
> anyone
>> confirm that?
>>
>> Any guidance will be appreciated.
>>
>> Bob C.
>>
>>
>
>

Thanks Aaron. Good advice.

Bob C.

11-29-2004, 07:10 PM

psycholist wrote:
> I'm a dedicated roadie and I'm dabbling in triathlons and time trials. I've
> been borrowing a friend's P2K, but we'll be doing some off the same events
> at the same time next year and I've gotta buy my own bike.

Hey, knowing you are nearby, are you planning on doing the sprint
triathlon in Clemson in May? That's the goal I'm shooting for, if I can
work through a hip problem I get when I run. I've always enjoyed open
water swimming, but I'm going to have to find someone to teach me some
form so I'm not so terribly slow.

Pam

11-29-2004, 07:35 PM

psycholist wrote:
> I'm a dedicated roadie and I'm dabbling in triathlons and time trials. I've
> been borrowing a friend's P2K, but we'll be doing some off the same events
> at the same time next year and I've gotta buy my own bike.
>
> I know all about fitting a road bike. I know almost nothing about fitting a
> tri bike. Are there any good rules of thumb like, if your frame size on
> your road bike is X, your tri bike frame size should be Y? I heard one
> today that said the combined length of your top tube (effective top tube)
> and stem should be about 2 cms shorter than for your road bike. Can anyone
> confirm that?
>
> Any guidance will be appreciated.
>
> Bob C.
>
>
You might look at slowtwitch.com/ tech section/ bike fit. Seems to be a
lot of good information there.

11-29-2004, 08:27 PM

"pam_in_sc" <[Only registered and activated users can see links. ]> wrote in message
news:[Only registered and activated users can see links. ]...
> psycholist wrote:
>> I'm a dedicated roadie and I'm dabbling in triathlons and time trials.
>> I've been borrowing a friend's P2K, but we'll be doing some off the same
>> events at the same time next year and I've gotta buy my own bike.
>
> Hey, knowing you are nearby, are you planning on doing the sprint
> triathlon in Clemson in May? That's the goal I'm shooting for, if I can
> work through a hip problem I get when I run. I've always enjoyed open
> water swimming, but I'm going to have to find someone to teach me some
> form so I'm not so terribly slow.
>
> Pam
>

I've probably told you about getting hit by the car 2 years ago. Shattered
my hip, broke my pelvis and ankle, and on and on. I don't run anymore.
Actually, I can (miraculously enough) ... but I certainly wouldn't do it for
fun and excitement.

I've got some friends who like to get together and enter as relay teams at
area triathlons. I do the bike leg. My bike leg at the triathlon in
Greenwood this past summer would have put me on the podium (in my age group)
at the state TT championships which were held the same weekend on much
flatter terrain in Charleston. But I've been borrowing a friend's bike. My
idea is to get my own bike and get serious about time trialing. My "racing
age" this year is 50. I think I might be able to do quite well in that
agegroup. But it's a gulp to think about spending a couple thousand bucks
to find out.

Here's a tip for helping to develop form in the water. Try using a pull
buoy (that's what they were called when I was swimming competitively many
years ago). They're little styrofoam things you put between your knees or
ankles to neutralize your legs during the swim. It helps you learn to
smooth out the upper part of your stroke and ride at the proper level in the
water. A kickboard is great for helping your kick.

Hmmm. In thinking about it, a good swim kick is like good cycling form in
that it starts from the hip. I had a cycling coach who told me to "spin
from the hip." I had a swimming coach who said my kick should "come from
the hip." Interesting.

Bob

12-03-2004, 02:05 PM

I’m a long time roadie also planning to compete in a few triathlons in 2005. I
have completed a few dualtlons/biathlons. I ride my “traditional” road bike 90%
of the time. I still enjoy group rides with my roadie friends. They’re already
suspicious of me since they found out I swim and run. They don’t enjoy me
showing up for the group ride on my tri-bar bike. Kidding, but most of by bike
training is with other roadies.

I have a road bike set up with profile aero x bars. The question that I have
yet to get a good (informed/educated) answer to is, “ If I ride a traditional
road bike 90% of the time when training, does changing to a “true” tri set up
help me on race day?” I know, from experience the tri bike set up makes me
rotate my hips forward, extending my hamstrings, and I use more gluts to produce
power. The two setups work the leg muscles differently. I think I can go faster
on a bike with road geometry (moderate seat tube angle/ top tube) with aero bars
than a true tri geometry because that’s how I train. I guess this is related to
specificity/muscle memory. I’m considering going to a tri fit guru with both my
bike to get fit. Know of any in SC? I would like to know what he recommends for
me. The slow twitch links are helpful. I’m not convinced that a tri bike will
help me for sprint-international distance tri’s. If you find a good link with
answers please share it. Rick

psycholist wrote:

> I'm a dedicated roadie and I'm dabbling in triathlons and time trials. I've
> been borrowing a friend's P2K, but we'll be doing some off the same events
> at the same time next year and I've gotta buy my own bike.
>
> I know all about fitting a road bike. I know almost nothing about fitting a
> tri bike. Are there any good rules of thumb like, if your frame size on
> your road bike is X, your tri bike frame size should be Y? I heard one
> today that said the combined length of your top tube (effective top tube)
> and stem should be about 2 cms shorter than for your road bike. Can anyone
> confirm that?
>
> Any guidance will be appreciated.
>
> Bob C.

12-03-2004, 07:18 PM

"Rick Anderson" <[Only registered and activated users can see links. ]> wrote in message
news:[Only registered and activated users can see links. ]...
>
> I'm a long time roadie also planning to compete in a few triathlons in
> 2005. I
> have completed a few dualtlons/biathlons. I ride my "traditional" road
> bike 90%
> of the time. I still enjoy group rides with my roadie friends. They're
> already
> suspicious of me since they found out I swim and run. They don't enjoy me
> showing up for the group ride on my tri-bar bike. Kidding, but most of by
> bike
> training is with other roadies.
>
> I have a road bike set up with profile aero x bars. The question that I
> have
> yet to get a good (informed/educated) answer to is, " If I ride a
> traditional
> road bike 90% of the time when training, does changing to a "true" tri
> set up
> help me on race day?" I know, from experience the tri bike set up makes me
> rotate my hips forward, extending my hamstrings, and I use more gluts to
> produce
> power. The two setups work the leg muscles differently. I think I can go
> faster
> on a bike with road geometry (moderate seat tube angle/ top tube) with
> aero bars
> than a true tri geometry because that's how I train. I guess this is
> related to
> specificity/muscle memory. I'm considering going to a tri fit guru with
> both my
> bike to get fit. Know of any in SC? I would like to know what he
> recommends for
> me. The slow twitch links are helpful. I'm not convinced that a tri
> bike will
> help me for sprint-international distance tri's. If you find a good link
> with
> answers please share it. Rick
>
<<SNIP>>

IMO opinion, it would be worth switching to the tri-config on race day, even
if you lacked prep time on it.

* You get to support your weight on your bones rather than hold yourself up
with your arms. I think you will notice the difference in your shoulders
when runing.
* While I have used aero bars on a road fit, I could not sustain it for
long; the hip angle is wrong (for me).
* True - - the specific conditioning of that position would be lacking but,
but if you are fit and flexible you are your own best judge of whether that
is an overriding factor.

If you were proposing a time trial (no swim or run) my answer might be
different.

TTFN,

rsquared

12-07-2004, 09:45 AM

Thanks for the feedback. As with the original poster I'm trying to learn what
works for me, and why, as I began to compete in tris/duals. My longest ride
leg to date is 22 miles. My road bike w/ aero bars worked fine for that. I hope
to try a tri geometry bike some day. I agree with with your comments regarding
hip angle, it's different and can be uncomfortable. I can work around it for the
distances i'm currently riding. Question- How do you fit a tri bike? For road
bike geometry you start with the saddle positioned so that a plumb line dropped
from your knee is centered over the pedal spindle (cranks parallel to the
ground). This is a neutral position and is adjusted for rider preference. You
then (assuming proper lenght top tube) adjust the stem lenght/height once the
saddle is positioned correctly. How do you position the saddle with the steep
tri geometry? Knees have to be forward of the pedal spindle. Is there and
advantage in transitioning to the run, or for power/efficiency ? It's been a
while since I visited slowtwitch.com and I don't recall how they set a riders
position over the pedals. Think i'll review their recommendations again. I''m
kind of old school in my thinking about "correctly" setting up the riders
position over the pedals. I know I have a lot the learn about my tri set up.
rick

rsquared wrote:

> "Rick Anderson" <[Only registered and activated users can see links. ]> wrote in message
> news:[Only registered and activated users can see links. ]...
> >
> > I'm a long time roadie also planning to compete in a few triathlons in
> > 2005. I
> > have completed a few dualtlons/biathlons. I ride my "traditional" road
> > bike 90%
> > of the time. I still enjoy group rides with my roadie friends. They're
> > already
> > suspicious of me since they found out I swim and run. They don't enjoy me
> > showing up for the group ride on my tri-bar bike. Kidding, but most of by
> > bike
> > training is with other roadies.
> >
> > I have a road bike set up with profile aero x bars. The question that I
> > have
> > yet to get a good (informed/educated) answer to is, " If I ride a
> > traditional
> > road bike 90% of the time when training, does changing to a "true" tri
> > set up
> > help me on race day?" I know, from experience the tri bike set up makes me
> > rotate my hips forward, extending my hamstrings, and I use more gluts to
> > produce
> > power. The two setups work the leg muscles differently. I think I can go
> > faster
> > on a bike with road geometry (moderate seat tube angle/ top tube) with
> > aero bars
> > than a true tri geometry because that's how I train. I guess this is
> > related to
> > specificity/muscle memory. I'm considering going to a tri fit guru with
> > both my
> > bike to get fit. Know of any in SC? I would like to know what he
> > recommends for
> > me. The slow twitch links are helpful. I'm not convinced that a tri
> > bike will
> > help me for sprint-international distance tri's. If you find a good link
> > with
> > answers please share it. Rick
> >
> <<SNIP>>
>
> IMO opinion, it would be worth switching to the tri-config on race day, even
> if you lacked prep time on it.
>
> * You get to support your weight on your bones rather than hold yourself up
> with your arms. I think you will notice the difference in your shoulders
> when runing.
> * While I have used aero bars on a road fit, I could not sustain it for
> long; the hip angle is wrong (for me).
> * True - - the specific conditioning of that position would be lacking but,
> but if you are fit and flexible you are your own best judge of whether that
> is an overriding factor.
>
> If you were proposing a time trial (no swim or run) my answer might be
> different.
>
> TTFN,
>
> rsquared