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.
