In article <[email hidden]>,
[email hidden] says...
Quoted message said:I have read a lot lately about the necessity to undertake
correct 'sizing' when purchasing a bike, which of course I
agree with. However the advice is a bit hit and miss in
that, today, I visited 5 reputable dealers in my area with
the intention of buying a bike. Every single one if them
merely said that correct sizing involved my standing with
slight clearance over the crossbar and having the saddle
at a height where my toes were in contact with the ground.
This, I was told, was the correct way to ascertain size.
Now, not many shops that I know (and many are long
standing, reputable dealers) have fitting machines/jigs
etc so in the absence of these how on earth do I know what
the correct size is?
I tried a Trek 1500 today and was able to apply the above
criteria to both the 56 and 58 cm frames, of course with
the latter having less seatpost pin out. I am 5 feet 11
(and a bit) tall - which is the correct size and what, in
practical terms, are the criteria for correct size?
And I thought cycling was just about riding your
bike........
Cheers
S
Now there are others more qulified than I, however, as they
all seem to be either down the pub or in bed, I will give
you a starter[1] for 10. Bikes (or bicycles) come in many
different flavours to do many diffrent jobs. Unsupprisinly,
the sizing will be diffrent for each type. So, first
question, what do you want to do on your new bike. Commute,
if so, will that be a fast commute or a slow pootle commute.
Will it be a train commute with a bit/some/a lot of riding
at one/both ends? Race? ok, will that be on the road, or off
the road, or perhaps a combination of the two? Tour? wil
that be weekend tours or full blown round the world tour, so
soemwhere inbetween. Enough. this isn't an exustive list but
you get the picture. You mention a Trek, without looking I
don't know whether the modle you looked at was a mountian
bike a hybred or a road bike. However, one of the primary
measurements you will be interested in is the distance
between the saddle and the peddal when the crank is inline
with the seat tube. There are mathematical formulea to work
this out but a good starting point is with you sitting on
the saddle, you should be able to comfortable rest your heel
on the lower peddal with a slight bend in the knee. But as
the seat post is normally adjustable in the seat post, this
can be moved to suit you on a wide varity of frame sizes.
Next up (and my personal starting point!) is the stand over
hight. this is the distance between your dangley bits and
the top tube. On a road bike this only needs to be
confortably clear, (say a couple of
cm), on a mountin bike, this distance can't really be to
big, say a couple of feet for safety... ok, sensibly 10
to 15 cm, though bike manufactures have done alsorts to
lower the standover hight these days igh all manor of
bent top tubes (one way to look at this, is it's one les
tube for you to bend 🙂 next up is the saddle to the
handle bars distance. Starting point here is with your
elbow on the noes of the saddle your fingertips should
reach the bars. whether you want the saddle above the
bars, in line with the bars or below the bars is personal
prefference and depends on what your goals are, but you
should considier this when you buy a frame. OK, got all
that. Good. In summary, the for a saftey bike[2] you will
have three contact points with the bike, your hands, your
feet and the soft squigy bit between your legs. it is the
relationship between these that is important to comfort
and power[3] whether you can reach the floor while in the
saddle is a safety issue, but is also important. A good
bike shop would tell you this, and the advise you
recieved is more akin to that which would be dished out
to a parent buying a toy bike for a child.
HtH
1. It is only a starter, theres a whole scince out there
specialisingt in thsi stuff.
2.A safety bike is what you probably consider as a 'normal
bike' with a dimond frame. there is of course no such
thing as a normal bike and everyone in this ng knows
(whether they'll admit it or not) that the the continume
of refinement goes from Ordenaries (penny farthings)
through safety bikes all the way to recumbents
3.Again, as is known by all of this parish, the dark side is
he only true place of comfort and power availale to the
pedal cyclist.
--
.paul
If at first you don't succeed... Skydiving is probably not
the sport for you.
