Bike sizing

Jonny Shoe
Jonny Shoe Posts: 217
edited May 2008 in Road beginners
Hi,

I have seen a lovely Bianchi for sale very near me, and the guy selling it says that he is 5'11" and that the bike, which he says is 55cm, fits him well. I have seen the pictures and there is definately room to bring the seatpost up a bit, I am nearly 6'1" and would like to know the opinion on whether it would be an ok fit, or would I have to put a longer stem on, or whether the bike is completely out the question? I plan to look at it on Saturday or Sunday but would like to go there having some knowledge of sizing.

Thanks,

Jonny

Comments

  • John.T
    John.T Posts: 3,698
    If it is a 55cm with a sloping TT you may be OK. If a horizontal one I would say it is too small. TT length is a more important measurment as you can only fit a bit longer stem. 13 or 14cm is the max for it not to steer like a barge.
    My Fleet.
  • Jonny Shoe
    Jonny Shoe Posts: 217
    Thanks, I am not sure on the top tube length etc. I expect that I will go and have a look at it as it is less than a mile and a half away, and will give it a test ride, but what things should I try and observe to decide whether it is too small or not when I give it a small test ride?
    I will mainly be using it for out and out racing rather than commuting etc. so I don't mind it being a bit compact.

    Thanks,

    Jonny
  • John.T
    John.T Posts: 3,698
    If you will be racing on it then you will probably need a bit longer bike than you would use as a comuter. You need to be able to get the bars to a comfortable but low enough height. You need to be comfortable on all bar positions, tops, hoods and drops. You must be able to reach the brakes from both the hoods and the drops easily. Too short a bike will compromise some of these. For racing you must get the saddle the right distance behind the BB, you can not use this to cover a short TT as you will loose power and comfort. By all means give it a good try but if you have any doubts then walk away. An ill fitting bike is never a bargain.
    My Fleet.
  • Jonny Shoe
    Jonny Shoe Posts: 217
    Hi,

    Thanks for the advice! What do you mean by getting the saddle the right distance behind the BB, and the bit about TTs?

    Thanks,

    Jonny
  • John.T
    John.T Posts: 3,698
    The most common way of setting the saddle position is to have the notch under your knee cap verticaly above the pedal spindle when the crank is horizontal facing forward. This is considered a starting point only but will be somewhere near for most riders. Proper time trial bikes will differ from this but we are not discussing these.
    TTs are top tubes, that is the tube from the head tube to the seat clamp. This length defines the 'room' you will have on the bike. As I said you can adjust this 'room' with different stem lengths but not by too much.
    You don't say what type of racing you intend or how much experience you have so I have to be a bit general with advice but you can never perform to your best if not comfortable on the bike. You will also not be able to control it as well, not good in a bunch.
    My Fleet.
  • antonylp
    antonylp Posts: 33
    Take a look at this article re. bike sizing

    http://www.edinburghbicycle.com/resourc ... ike_sizing
  • Jonny Shoe
    Jonny Shoe Posts: 217
    Hi,

    Oops I thought you were referring to Time trials as against toptubes. In that first part, it seems like a foreign language to me :P please could you break it down more simply, which notch etc.?
    I should hopefully be doing 10 mile time trials, and Category 4 group racing, but it will all depend on how much I can find as local as possible. I have had no experience in road racing at all but have done a couple of years of XC cycling and did about 3 race series. Standard wise I was managing a 30 minute 10 mile road ride on my XC bike, before I sold it, but I would be unsure how to relate that to road cycling as it is very different.

    Thanks,

    Jonny
  • morrisje
    morrisje Posts: 507
    Take a tape measure when you try out the bike. At 6'1'' you would need a bike with a virtual horizontal top tube length of 57 or 58cm

    Also try riding out of the saddle. If your knees are almost hitting the handlebars and you feel that you want to be more forward then it's too small.
  • jon208
    jon208 Posts: 335
    I think it may depend on the model but Bianchi bikes seem to come up a bit on the small side. I'm also 6'1" and recently bought a Via Nirone Alu/Carbon. I tried a 59 and a 61 but ended up going for the 61 as it felt better when I tested it. I had a bit of a worry a few days after buying it that it was too big but it feels fine to ride. When compared to a friends 58 Spesh Allez it is the same size, indeed when you take t atape measure to it it comes up smaller than the dimensions Bianchi give. I did a 63 mile Wetherby to Scarborough ride last Sunday and the bike felt ace.


    Jon
  • Jonny Shoe
    Jonny Shoe Posts: 217
    Weird, I have heard a couple of others saying they came up a bit long... The guy who is selling it is 5'11" and he actually had to swap the stem with a shorter one, so now he has put the longer one back on, which is what I will test it with. I am just below 6'1" so that isn't even 2 " taller than him so I would have thought it may be ok, but obviously the proof is in the riding.

    It is a Bianchi Via Nirone 7 Alu/Carbon 06 so not the same style as the new ones.

    Thanks,

    Jonny
  • Jonny Shoe
    Jonny Shoe Posts: 217
    Weird, I have heard a couple of others saying they came up a bit long... The guy who is selling it is 5'11" and he actually had to swap the stem with a shorter one, so now he has put the longer one back on, which is what I will test it with. I am just below 6'1" so that isn't even 2 " taller than him so I would have thought it may be ok, but obviously the proof is in the riding.

    It is a Bianchi Via Nirone 7 Alu/Carbon 06 so not the same style as the new ones.

    Thanks,

    Jonny
  • jon208
    jon208 Posts: 335
    Only thing to do is give it a bash and see if it feels right I suppose. The bike is ace by the way, I'm really pleased with mine. Hope it's the mandatory celeste :wink:
  • Jonny Shoe
    Jonny Shoe Posts: 217
    Nope...it's the Blue and white one, looks nice though.

    Thanks for the advice guys it has been very helpful, I will take it into consideration when I try it but obviously if it feels right, then Bob's your uncle!

    Thanks,

    Jonny
  • Slow Downcp
    Slow Downcp Posts: 3,041
    Jonny Shoe wrote:
    Weird, I have heard a couple of others saying they came up a bit long... The guy who is selling it is 5'11" and he actually had to swap the stem with a shorter one, so now he has put the longer one back on, which is what I will test it with. I am just below 6'1" so that isn't even 2 " taller than him so I would have thought it may be ok, but obviously the proof is in the riding.

    It is a Bianchi Via Nirone 7 Alu/Carbon 06 so not the same style as the new ones.

    Thanks,

    Jonny

    I have the same model, and I think it may be a little small for you. I'm 6' and ride a 57cm, which works well for me. As said, you can raise the saddle and lengthen the stem but then there may be an issue with too big a height drop between saddle and bars.
    Carlsberg don't make cycle clothing, but if they did it would probably still not be as good as Assos
  • Jonny Shoe
    Jonny Shoe Posts: 217
    Hi,

    I went and had a look at the bike, and on appearence and looking at me on it, it certainly looks a bit small...however the postioning was right, it was comfortable and my my knees weren't near the bars when I stood up, or overlapping my elbows ridiculously when on the drops so I have bought it, especially at the price it was!
    It should prove to be a nice nippy machine, and if after a few races it does appear to be a tad small, well...I will sell it on again!

    Can't wait to get out on this thing!

    Jonny

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