Is it ok ... ? :)

by kupepe   June 16, 2013  


I am currently riding a Boardman Team Carbon XL (Top Tube 58.5, Seat Tube 57). From my LBS I was told that the bike is essentially one size smaller than what I should had, when i was fitted on it, but its ok since one size smaller is better than bigger.Unfortunately Boardman does not create a bigger size so I took the bit smaller than what it should be frame.

Moreover, I was told that the seat tube size is not really important since the seat post can be adjusted accordingly vertically and that the size of the top tube is more important, since it cannot be adjusted, and any small corrections can be made with the size of the stem or a seat post with setback.

I got the opportunity to get a great frame for a new project with the following sizes

ST - 59 cc - 60.5 ct
TT - 58 cc
HT - 17.5

Taking into account that I am 1.92 m with a 86 inseam, the size of my current bike and the fact that i was told that I could easily take one size up if existed, will the size of the ST be ok for me ?

Thanx in advance

8 user comments

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I believe that your LBS is correct in placing more importance on the top tube length, and have faced similar dilemmas in the past due to my short-for-my-height legs. (I need a bigger frame than my height would indicate, thus have unfashionably little seatpost showing).

If you're thinking about a frame with a top tube shorter than what you have now, aren't you going to end up rather cramped and/or having to fit an overly long stem to compensate?

posted by ped [185 posts]
16th June 2013 - 9:58


If the TT is 0.5 shorter ... wont that compensate the fact that this frame has 17.5 HT tube while the one i got now is 18.5 ... ?

posted by kupepe [63 posts]
16th June 2013 - 10:11


Best solution to this is to draw the 2 bikes using graph paper (or Microsoft Visio if you have it). Use the known angles and draw to scale your current bike. Then draw the new one over it. You can then see the differences and where you need to compensate to arrive at the same position.

This all assumes that you are happy with your current position.

In theory, there is no difference between theory and practice, but in practice...

posted by notfastenough [3597 posts]
16th June 2013 - 10:32


Head tube height will determine how 'racy' the fit ends up, IMO if you go lower in head tube you might want to go longer in TT or as Ped mentioned you will end up getting a LNG stem. To be honest it's a pretty complex subject with lots of opinions. If you find you are suffering from pain etc fork out for a bike fit, it will be the best money you ever spend. Then you know where to put your money on a new bike as well. It's taken about a year and a half to 'dial in' my own fit but I know it probably still not 100%.

posted by Nzlucas [119 posts]
16th June 2013 - 11:05


is your inseam deffinately 86cm? because that would indicate you would need around a 56cm frame (on a trek for example) other bikes possibly smaller.

posted by Lost faith in t... [120 posts]
16th June 2013 - 11:16


Lost faith in the brand wrote:
is your inseam deffinately 86cm? because that would indicate you would need around a 56cm frame (on a trek for example) other bikes possibly smaller.

Kupepe may be a 'Otter' type; all body. I wear 32L jeans and am 6ft I've always been borderline overweight on the traditional BMI chart whilst still being slim. At 6ft3 is seems even more true for you; you might find that you leg length is indicating a smaller frame than your long body/height.
Unfortunately I don't have enough experience of different bikes to suggest if you should compensate small for legs or large for body. I'd be interested to hear what others have to say.

I am stronger than Mensa, Miller and Mailer, I spat out Plath and Pinter.

bikeboy76's picture

posted by bikeboy76 [1603 posts]
16th June 2013 - 13:14


I've not used it, but did see this site mentioned previously on the forum, which will allow you to get an idea of frame sizes that should be applicable for you

(if anyone has used it, it would be useful to know whether it worked for them and anything to be aware of...)

I got a basic bike fit similar to this before I bought my bike (it was refunded when I bought a bike from them)

posted by d_jp [117 posts]
16th June 2013 - 16:42


i do a lot of bike fitting at work, im trained with the trek project one "pro fit" that was reviewed on here i believe a while back. most people can go up or down a size depending on there arm length and leg length. it always seems easier to get the right size and then shorten or lengthen the stem slightly (normally no more than 20-30mm)

trek use an equation to workout what size bike you need which is really accurate however it is only for treks, we tend to find if your wanting a cannondale most people have to drop a size from the trek.

posted by Lost faith in t... [120 posts]
16th June 2013 - 22:05