I've done a bit of bike testing for Cycling Plus recently, so I've
gotten the opportunity to test some very nice bikes made of a variety
of materials.
I've found that it's very hard to make general judgements about "7005
oversize aluminium", since like any material, you can make really good
high quality frames with a pleasant ride out of it, or you can make
heavy unresponsive frame out of it, or something with unpredictable
handling.
I think the best judge is you yourself. Try to find a nice Reynolds
tubed bike to compare with. Also try to find a much more expensive
aluminium bike to compare with (one of the batter Cannondales springs
to mind as a benchmark). Ride them around, noting how they feel. That
way you'll know from what you feel as your ride how the bike compares
with the others. Make sure you spend enough time to adjust them up to
your tastes before riding them, otherwise you may spend the entire
ride thinking "this seat feels too far forwards".
Things to try:
Ride with no hands or with your hands on the tops of the bars near the
stem to see how stable the handling is.
Take the bikes around corners as fast as you dare to see if they
responds to your shifts in weight and turning in a way that you find
predictable.
Aim for potholes to see how well the bike absorbs bumps. For this
test, you'll want to try to see if you can get the same size tire
inflated to the same pressure so you're judging the frame, not the
tire.
--
-Myra VanInwegen
Myra.Va...@cl.cam.ac.uk http://www.cl.cam.ac.uk/~mvi20/bike/
GoFar: The UK's Independent MTB Webzine http://www.gofar.demon.co.uk/
The big difference between most steel frames and alu frames are of course,
as you said, the weight. But in general there's also quite a big difference
considering the response. Usually alu-frames respond better than steel
frames, and so that would be a good reason, as well as the weight, for you
to buy the alu-frame.
The bad thing about alu-frames (in general) is that the "life-length" is
shorter comparing to steel frames. Alu frames are also easier to break. I
have had an alu frame this year, with which I have done a lot of races in
Sweden, where I live. At the end of the season the frame broke, a few
centimetres above the fork. But it had been through a lot, and until it
broke I think it was better than a steel frame. On the other hand, I don't
think the steel frame would have been broke.
So, if you ride a lot on a bit roughy roads, I'd advice you to look for a
steel frame. But if you do not ride so much, and when you ride, you do it on
nice roads, I think you should go for the alu-frame.
I'm Swedish and do not usually speak any other languages than Swedish, so
you have to excuse my bad English
// David Johansson
da...@mds.mdh.se
Graham Errington skrev i meddelandet ...
>I haven't had a road bike for about eight years (which is one of my biggest
>regrets) and i want to get back into road riding.My last bikes were a
>Reynolds tubed 531 with a Shimano 105 groupset and a 653 with a Campagnolo
>groupset.
>I decided that i wanted a new road bike and i went into a few local bike
>shops and i got quite a shock at the prices,they seem to have risen out of
>proportion.
>Anyway looking around i came across a Fausto Coppi Lombardia for under
>£500,i understand that they are built with Aluminium tubes which is lighter
>than the Reynolds tubed bikes that i was last used to .
>Has anyone got one of these bikes that can offer any advice on how good a
>deal it is or can anyone with experience of modern frames impart any
>advice.(The tubing is 7005 oversize aluminium)
>Cheers
>Graham Errington (UK)
>
>
Hum, I think your English is lots better than many people who speak it
natively!
>The big difference between most steel frames and alu frames are of course,
>as you said, the weight.
Is it? I know that alu frames are supposed to be lighter than steel
frames, but can anyone put some numbers on this? I mean, take a top
class alu frame like a Cannondale, and the same size Reynolds 853
frame by a good builder. What's the weight difference?
>But in general there's also quite a big difference
>considering the response. Usually alu-frames respond better than steel
>frames, and so that would be a good reason, as well as the weight, for you
>to buy the alu-frame.
I think what you're saying here is that alu frames don't bend: they
are very stiff. Thus if you stand up to pedal, the bike doesn't flex
at the bottom bracket, it just jumps forward.
I think this is probably a valid generalization. You can build alu
frames that flex, but the more they flex, the more fatigue they get,
so they break faster. Thus to have a long life for an alu frame
requires that it be pretty stiff.
You can make steel frames stiff, by using large diameter tubes. But
you can also make it very flexible if you want.
But even with alu there are still differences. Carefully butted tubing
allows thinner walls in the middle of tubes, allowing a bit of flex,
without the concetrations of stress that you'd have in unbutted tubes
that flexed. In the women's bike test I did for Cycling Plus a couple
of issues ago, the one steel bike in the test had a completely
unbending frame, while the two alu frames flexed just a little
bit. And I have an old (10 years old) alu MTB that doesn't flex at
all. It has a very harsh ride, which is only partly compensated by its
fatter tires.
Now, do you really want your bike to be as stiff as you can get it?
While you may love the feeling of the bike simply jumping forward when
you stand up to pedal, the tradeoff is that it offers a much rougher
ride. If sprinting performance is not top priority for you, but
long-distance comfort is, it might be worth looking for a bike that
flexes a bit more. Which most likely means getting a steel bike,
unless someone figures out how to build an alu bike that flexes more
without breaking.
>The bad thing about alu-frames (in general) is that the "life-length" is
>shorter comparing to steel frames. Alu frames are also easier to
>break.
I'm not sure this is true. While steel can be flexed an infinite
number of times without fatigue (if the amount it flexes is small
enough), and alu fatigues a tiny bit every time it flexes, I don't
know if this translates in real life to a shorter life for alu
frames. Yes, you hear tales of alu frames breaking, but then I know of
plenty of people who have broken their steel frames as well. I know of
no tests or controlled studies that show steel frames having a longer
life than alu frames.
In fact, the only study I know, which tried to
mimic real-life stresses on a bike, and the alu frames lasted far
longer than the steel ones!
http://www.damonrinard.com/EFBe/frame_fatigue_test.htm
There are monay criticisms of this report, so I would take it with a
big lump of salt, but it goes to show that it is not a foregone
conclusion that "steel lasts longer than alu".
What certainly is true, is that if an alu frame breaks, it takes very
little time from beginning to end. If steel frames break, you get
plenty of warning. In general you'll feel the frame acting funny, and
if you heed the warning and look carefully at your bike, you'll find
the crack and it won't break under you.
Graham Errington wrote in message ...
Graham Errington <g...@clara.co.uk> wrote in message
news:uH4S3.2073$Ad3....@nnrp4.clara.net...
<snip>
> Anyway looking around i came across a Fausto Coppi Lombardia for under
> Ł500,
<snip>
Many Italian manufacturers have gone into aluminium in a big
way since Cannondale started sponsoring an Italian team and
selling their bikes in Italy.
At the lower end of the market, Italian aluminium frames are
no better than cheapo Taiwanese aluminium frames, and will
therefore weigh not much less than a Reynolds 531 frame. This
is because cheap to mid-range alu frames are made of plain
gauge tubing. In particular, this is true of the Lombardia
which you are looking at.
I wouldn't worry about all the `aluminium gives a hard ride'
rubbish that we read in the cycling press. Damon Rinard's tests of
flexibility of frames have shown that the frame has almost no effect
on the ride quality: that depends more on the tyres, the tyre
pressures, the saddle and the riding position - the latter determines
how much weight you support on your hands and how much on the
saddle.
The frame will probably last a good long time, although you should
realize that if you crash it then you cannot repair it. I would be
more concerned with the quality of the groupset and finishing kit.
Below 500 quid there could be one or two cheapo components which
are responsible for increasing the weight of the bike substantially
beyond what is really necessary. If you don't mind carrying around
an extra pound and a half of weight, that's clearly no problem.
Marco
That's excactly what I'm saying. And of course it depends on what priority
you have. If you prefer comfort for a long ride, it's, as you say, better to
not have that stiff frame, but in the sprint, I'm glad you agree with me in
this, it's a lot better with a stiff frame. I'm an elite cyclist and I do
ride a lot of long races (<240 km). Of course you want to have comfort
during the miles, but almost every race it all depends on the sprint the
last 200 meters. So, let's ask us this question: Do I want comfort during
the race or do I want the comfort after the race, in the results list.
The question for me has an easy answer, of course I'll go for the second
alternative. But I know, I know... It's not that big difference between the
frame types, but I think you see what I'm trying to say.
Anyway, we shouldn't argue about this too much, at least I shouldn't. It
seems like you know a lot about bike frames, actually I'm quite impressed.
But I also hope that you agree with me in that what frame type you use and
what components (shimano, campa or mavic) you have on the bike, it's all a
matter of taste...
Concidering my knowledges about frame types, I base it all on my own (and
friends) experience. I haven't had the luck to do real testes. But I want to
share some of my experience with you. Until last year I had only rode steel
frames. They didn't break, they were in good shape when I sold them, and so
on. But they weren't very stiff. Las season my team (4 cyclists) had a so
called b-contract with Bianchi. Two of them broke, among those two, my own.
But I wouldn't say really that it took short time from the end of the
braking to the end (what the "end" means I'm not sure. Maybe that is when
it's all broken into two peaces). However, from the beginning in my case, I
was able to use the bike for about one month further. Until that moment it
hadn't been broke completely either, but it wasn't a frame I was willing to
use at more races.
The original writer should stick to Myra's advices, based on more facts and
statistic. But it still is a tough choise. Do concider what you want to use
the bike for, and than come back. Hoopefully Tyra than can give you the
final advices, and I won't say a word. It feels like I would only make you
more confused than you already are (which should be the case, since you like
cycling... as I do)
// David
da...@mds.mdh.se
I don't know what Damon Rinard was testing here, but there are some
vast differences in frames. Comparing a Cannondale racer to a 531
steel Audax bike with thin diameter tubes with thin walls is like
comparing a very stiff thing with a very flexible thing. No way was it
down to the tires!
Similarly, comparing a 10 year old alu MTB (with straight gauge tubes)
to my new Roberts Rough stuff, with *exactly* the same tires, it's
again a vast difference. You'd have to be dead not to feel it.
Maybe he was comparing good quality racing bikes to other good quality
racing bikes. In which case, he was comparing things which are
designed to be stiff, and he might have a point.
I think you're over-estimating my knowledge. I'm no real expert. I
don't design frames, and I haven't tested all that many yet.
I do however, read an awful lot, and I think about what I read in
relation to my experiences with bikes. Then I form a theory, and
that's what I write. I port here partly to affirm that it makes
sense. I'd be quite happy if, say, some metallurgist or bike designer
came back to me and pointed out something that was wrong. So far no
one has, so I think I'm probably not too far off.
You did raise one point, which I'd like more info on. I wrote that if
alu frames do break, they break quickly, while steel frames generally
give you more warning (more time from the initial crack to breaking
under you). You wrote:
>Las season my team (4 cyclists) had a so
>called b-contract with Bianchi. Two of them broke, among those two, my own.
>But I wouldn't say really that it took short time from the end of the
>braking to the end (what the "end" means I'm not sure. Maybe that is when
>it's all broken into two peaces). However, from the beginning in my case, I
>was able to use the bike for about one month further. Until that moment it
>hadn't been broke completely either, but it wasn't a frame I was willing to
>use at more races.
I presume these Bianchi frames wre alu? And exactly what was wrong
with them? Were there actual cranks in them, and you continued to ride
them while they were cracked???