The comforts of a carbon fiber frame

On Jul 21, 9:33*pm, Phil W Lee wrote:
James considered Fri, 22 Jul 2011 10:09:12
+1000 the perfect time to write:





Frank Krygowski wrote:
As many have said, comparing frame materials in bikes is tough,
because there are usually too many differences between any two bikes.
I'd love to see the results of a double-blind comparison test between
steel, aluminum, titanium and CF road bikes with otherwise identical
geometry and equipment. *Of course, the frame tubes would have to be
covered somehow. *I suspect the "experts" would be unable to tell much
difference.

Does "geometry" include tube cross section dimensions?

Of course, using tube dimensions appropriate to each material, the ride
qualities can be made very similar.

A friend has a Baum Ti frame that is very similar overall size and
geometry to my steel frame. *Comparing the two:

The Ti frame is lighter, by a few hundred grams.

The Ti frame cost 2-3 times as much. *He paid a lot for the name, IMHO ;-)

The Ti frame does not feel quite as stiff. *(My friend and I agree on this.)

Could I tell the difference in a double-blind comparison test if they
were equipped identically? *It would be tough. *Maybe, but probably not.

If the tube dimensions were identical, the comparison test would have
markedly different results. *With the same OD:

If the Ti tubes had a wall thickness of 0.38mm, the bike would be
slightly lighter, but far more compliant.

If the steel frame had tubes as thick as the Ti tubes (0.6-0.7mm?), it
would weight hundreds of grams more, but be very stiff indeed.

I guess what affects the possibility of adding vertical compliance most,
is the ability of the given material to flex repeatedly without
weakening, breaking or suffering plastic deformation. *CF may be more
suited to providing this than current metal offerings.

Possibly, but don't forget that the usual material of choice for
making springs is steel.
And if they are designed properly, and operated within their design
limits, steel springs can last a very long time, certainly well over a
century.
I've removed, checked and reinstalled springs older than that, at
fairly extreme ends of the size spectrum - watches and railway
locomotives!

CF hasn't been around long enough to find out if it can reach that
level of durability.- Hide quoted text -

- Show quoted text -

CF's been round the testing lab cycle machinery but where's that
information ?

On Jul 21, 8:09*pm, James wrote:
Frank Krygowski wrote:
As many have said, comparing frame materials in bikes is tough,
because there are usually too many differences between any two bikes.
I'd love to see the results of a double-blind comparison test between
steel, aluminum, titanium and CF road bikes with otherwise identical
geometry and equipment. *Of course, the frame tubes would have to be
covered somehow. *I suspect the "experts" would be unable to tell much
difference.

Does "geometry" include tube cross section dimensions?

If I were running the test, I'd say no; I'd choose frame tube
diameters (or similar dimensions) appropriate for the material.

FWIW, the two bikes I ride most are (old) standard diameter steel, and
"oversized" diameter aluminum. Also, the cool three speed I just
built up out of my junk box parts is 1970s Reynolds 531, "standard"
diameter.

Of course, using tube dimensions appropriate to each material, the ride
qualities can be made very similar.

Right. I've ridden an "old standard" diameter aluminum Alan frame,
and felt it flex like crazy beneath me.

I guess what affects the possibility of adding vertical compliance most,
is the ability of the given material to flex repeatedly without
weakening, breaking or suffering plastic deformation. *CF may be more
suited to providing this than current metal offerings.

I agree that affects the _possibility_ of vertical compliance. But my
bet is, if you actually measured vertical compliance of a range of
good quality frames, they'd all be so similar (and so small) that tire
deformation would swamp the differences.

But it would be interesting to read about a double blind test.

- Frank Krygowski

Frank Krygowski wrote:
On Jul 21, 5:49 pm, thirty-six wrote:
I can only assume
the supposed experts to which you refer were not competetive cyclists
or had only used smooth board velodromes.

They were magazine road testers who had spent years passed off as
"experts." As with almost all such magazine writers, we know nothing
about them. Yet many cyclists seem to take their every word as gospel
truth.

It is written therefore it is so.

Like ceramic bearings saving 10 Watts!

--
JS.

On Jul 21, 7:20*pm, AMuzi wrote:
landotter wrote:
On Jul 21, 10:07 am, Duane Hebert wrote:
On 7/21/2011 10:47 AM, landotter wrote:

On Jul 20, 11:46 pm, Anton *wrote:
You've probably been down this beaten path in rbt before but the
subject is new to me.
Basically recently I came by a claim that a CF framed bike rides on
narrow slicks
about is if it was an aluminum cross on 35-40 rubber. I always thought
CF was for
riders who values stiffness in their rides and don't mind parting with
the (hard earned?) $$$$
Would you care to comment
The feel might be exactly the same, but you need to use different
adjectives. A steel cross bike with 35mm rubber will be robust,
lively, yet damping. A CFRP bike will be icy, isolating, and dead.
Can you be more specific? *I don't think you're getting your point across.

You're right. I should have said "cloyingly icy".

I ride a classic steel bike in our brief summers and a
carbon fixie in the endless grey and cold season. *Wheels
are similar, rubber identical, both have mudguards & dynamo.
* Carbon bike's 8lb lighter.

Not so much difference in 'ride feel' as you might expect.
If I lowered the winter bike's handlebar to match the summer
bike, I doubt I could tell much difference.

The reason for CF in wet is that you don't want to subject steel
to the elements and to find out how well it resists rust?

Is that the reason aluminum took over the majority of the run of the
mill frames
these days supplanting steel despite steel being superior repair-wise?

My Ti road bike is so different in riding position and
equipment that a subjective 'road feel' comparison would be
a ridiculous exercise (which wouldn't stop a cycle mag pundit).

What is your typical and atypical Ti bike usage?

On Jul 21, 7:39*pm, Duane Hebert wrote:
On 7/21/2011 12:20 PM, AMuzi wrote:



landotter wrote:
On Jul 21, 10:07 am, Duane Hebert wrote:
On 7/21/2011 10:47 AM, landotter wrote:

On Jul 20, 11:46 pm, Anton wrote:
You've probably been down this beaten path in rbt before but the
subject is new to me.
Basically recently I came by a claim that a CF framed bike rides on
narrow slicks
about is if it was an aluminum cross on 35-40 rubber. I always thought
CF was for
riders who values stiffness in their rides and don't mind parting with
the (hard earned?) $$$$
Would you care to comment
The feel might be exactly the same, but you need to use different
adjectives. A steel cross bike with 35mm rubber will be robust,
lively, yet damping. A CFRP bike will be icy, isolating, and dead.
Can you be more specific? I don't think you're getting your point
across.

You're right. I should have said "cloyingly icy".

I ride a classic steel bike in our brief summers and a carbon fixie in
the endless grey and cold season. Wheels are similar, rubber identical,
both have mudguards & dynamo. Carbon bike's 8lb lighter.

Not so much difference in 'ride feel' as you might expect. If I lowered
the winter bike's handlebar to match the summer bike, I doubt I could
tell much difference.

My Ti road bike is so different in riding position and equipment that a
subjective 'road feel' comparison would be a ridiculous exercise (which
wouldn't stop a cycle mag pundit).

I went from a Cro-Moly steel sport tour to a cF road bike. *While my
feeling is that the CF is stiffer and certainly lighter, like you say,
the bikes are so different that it wouldn't make sense to even try to
compare.

To the OP, If you're shopping for a bike, I would suggest that you buy
the best bike in your price range based on whatever you consider
warrants value. *If it's between a CF, TI, AL or whatever, test ride them.

Ok, I've to check if that is even an option in my neck of woods.
The last two purchases ("fitness" (flatbar cross) and 29"er)
were "leap of faith" kind of deals.

With two riding family members and two bikes I'm covered for now,
but I may ponder something lighter for my wife (she's pregnant
and her 29er weighs a ton - not a good combination).

Me thinks a light 26"er would be an easier find than another 29"er
as light or lighter than 29er.

That or a touring bike, though given the hostile position
of the local DMV officials towards bikes on public roads
a front suspended bike seems a better idea.

If these folks are ever helped out of the office (I don't think they'd
commit seppukku on their own will, they typically need a helping hand
here)
the idea of a touring bike will become more attractive.

If you're just interested in opinions, I'm sure you'll get a bunch of
opinions here.

I see I like to have options in case I'd need to have an "emergency
bike shopping".

On Jul 22, 4:40*am, Anton Success wrote:

That or a touring bike, though given the hostile position
of the local DMV officials towards bikes on public roads
a front suspended bike seems a better idea.

If these folks are ever helped out of the office (I don't think they'd
commit seppukku on their own will, they typically need a helping hand
here)
the idea of a touring bike will become more attractive.

Care to give details on the hostile DMV officials?

- Frank Krygowski

On Jul 21, 11:15*am, Frank Krygowski wrote:


For anything similar to a classic frame design, vertical frame
deflection is very small compared with vertical tire deflection.
There's no way just switching to CF is going to give you an extra
(say) 3mm vertical travel in response to road shocks. *But a wide tire
can do that.

Have you ever used a cf seatpost?

On Jul 22, 1:22*pm, RobertH wrote:
On Jul 21, 11:15*am, Frank Krygowski wrote:

For anything similar to a classic frame design, vertical frame
deflection is very small compared with vertical tire deflection.
There's no way just switching to CF is going to give you an extra
(say) 3mm vertical travel in response to road shocks. *But a wide tire
can do that.

Have you ever used a cf seatpost?

Nope. But a seatpost isn't part of a frame. I was talking about
frame deflection.

- Frank Krygowski

On 22 jul, 20:51, Frank Krygowski wrote:
On Jul 22, 1:22*pm, RobertH wrote:

On Jul 21, 11:15*am, Frank Krygowski wrote:

For anything similar to a classic frame design, vertical frame
deflection is very small compared with vertical tire deflection.
There's no way just switching to CF is going to give you an extra
(say) 3mm vertical travel in response to road shocks. *But a wide tire
can do that.

Have you ever used a cf seatpost?

Nope. *But a seatpost isn't part of a frame. *I was talking about
frame deflection.

- Frank Krygowski

Frank you doing it again. Cervelo makes a CF frame thats deflects a
couple of mm.

Lou

On Jul 22, 1:56*pm, Lou Holtman wrote:
On 22 jul, 20:51, Frank Krygowski wrote:





On Jul 22, 1:22*pm, RobertH wrote:

On Jul 21, 11:15*am, Frank Krygowski wrote:

For anything similar to a classic frame design, vertical frame
deflection is very small compared with vertical tire deflection.
There's no way just switching to CF is going to give you an extra
(say) 3mm vertical travel in response to road shocks. *But a wide tire
can do that.

Have you ever used a cf seatpost?

Nope. *But a seatpost isn't part of a frame. *I was talking about
frame deflection.

- Frank Krygowski

Frank you doing it again. Cervelo makes a CF frame thats deflects a
couple of mm.


Don't be silly. If it's "anything similar to a classic frame design"
it's infinitely rigid.
In fact my newly constructed frame made from coat hanger wire is a
classic double diamond, therefore infinitely rigid.

DR