Am I thinking straight here?

[Bigtallfatbloke]

Is my bike sizing logic correct here:


My current bike has a 64cm seat tube measured from the centre of the Bottom bracket to the top of the tube (seat clamp). This gives me a top tube length of 58.5cm measured from the centre of the seat tube to the centre of the front tube. It gives me top tube>crotch clearance of 9-10cm.

I used to ride with a 11cm stem but felt over stretched. I reduced the stem to 10cm and things are better. So I guess my total reach is 58.5 + 10 = 68.5cm ?


Ok…with me so far?...

On the new bike I am about to buy the frame size choice I need to make is either a 60cm or a 63cm measured from the the centre of the Bottom bracket to the top of the tube (seat clamp) again. The 60 cm frame gives me a top tube length of 57.3cm measured from the centre of the seat tube to the centre of the front tube. So to achieve the same ‘reach’ I reckon I will need a 12cm stem. 57.3 + 11 = 68.3 ( the .2 I can live with)…make sense??

The 63cm option gives a top tube length of 58.3cm so I reckon a stem length of 10cm would work??

Assuming I am correct in the way I am thinking here? why would I need a 63cm frame over a 60cm frame? Isn’t it all just added weight to push up the hills?

I know it has an impact on bar height, is there really so much difference between the bar height range on 60,63 & 64 cm frames??

 

[Crackle]

It's not directly comparable though as your Galaxy will have an entirely different geometry. This bike will have a more stretched feel than the Galaxy anyway. I've said this before but go and sling your leg over some similiar bikes.

If you don't I would say, if you get one too big it's too big. If you get one slightly smaller than you should, you can compensate without compromising the bike.

 

[Aperitif]

I have been reading your stuff bigtfbloke and I dunno...go and sit on some! I realise the problem is availability of your size in shops.
Take a look here - it might help?

I'm 6'2" and I just measured my Look KG361 which is 'racing' (I use the word loosely) geometry, carbon and a comfy but a bit wibbly wobbly downhill at speed...don't know if it will help your thinking but...
OK. Seat tube centre of crank to top of tube 60cm
Top tube 57.5cm
Stem 120mm
Saddle height from lounge floor (my 'bike shed') 106cm
Top of top tube to floor 83cm
My inside leg 84cm+/- a gnats
Armpit to tip of fingers - ish (measured with Stanley's finest) 68cm +/-
A wierd collection of measurements but hey!

Of course - you could always have a ride on it and tinker about if finding rideable examples is a prob.

 

[Bigtallfatbloke]

..so my thinking is about right then? ...I have decided on this frameset...it's jus tif it should be A 63 or a 60? There is nowhere I can sit on this bike before buying...and none of the lbs stock bikes in these sizes in any brand...just smaller size spesh, giant or treks every where and even then asking fro a test ride is like asking them to get out of bed...it's just not on their agendas.

 

[Aperitif]

No - I meant to try my bike as a sample!

 

[Bigtallfatbloke]

thanks for those measurements. My inside leg is 86cm and I am 6' 3" tall. So based on one of the 'simpler' formulas of calculating frame size on that link you posted I should take 2/3 of my inside leg which will give me th efrane size I need...which puts me on a 57 or a 58cm...erm...which either means you are on a bike which is way to big for you or the formula is Bollox....I reckon a 60cm on a 120 stem should do it for me...but then again this issue with bar height is bugging me...a 63cm will let me use a highe rbar hieght right?

I think I may jus tend up having to take aflyer on this which is a seriously expensive risk if wrong. I am getting no respeonses to e mails to the frame builder or dealer...basically I think they either dont give a shoot or dont know.

One question that I wan tto ask is why is it that a an Orbea onix frame size 60 is definatly my size (according to the dealer), yet the kinesis frame builder says 63cm....could it be that Orbea dont make a 63cm...hmmm I am smelling another rat here....it has a very similar smell to the Bianchi dealers who insisted 61 was what I needed...which jus thappens to be bianchis max size...I reckon it's all BS....now...where's the number for that swimming club?

 

[Gary D]

Btfb,
This is obviously worrying you!
My recommendation would be to get yourself fitted/measured for your perfect fit by someone that really knows what they are doing. Then spec a frame around your measurements. I think if you don't, you will be constantly worrying if you made the right choice.

I will tell you a story........

I recently went to Paul Hewitts in Leyland for a fitting session. I had already bought my bike and assumed that the shop had "fitted" me properly for it. They seemed to know what they were doing so I had no reason to doubt that they had done it properly. I honestly expected to go to Hewitts with my bike just to get the positioning "fine tuned". More of a confirmation really with a few millimetres adjustment here and there.

How wrong was I????

What Paul does is firstly takes some reference dimensions off your current bike set up. Then he sits you on a multi-adjustable jig, which looks like one of those training/fitness bikes, using your own saddle and with your cycling shoes on. He then adjusts things and puts you in the "ideal" position based upon what you have told him your requirements and problems are. Another set of dimensions are then taken and compared. These could then be used to spec your ideal frame.

The thing that absolutely knocked me sideways was that we found that my saddle was over 40mm too low and 27mm too far forward. The overall reach was wrong and the drop between the saddle and the bars was also out by 17mm. Apart from that it was fine (in reality, I should have probably been sold the next frame size up in the first place).

The point is that the bike never actually felt uncomfortable but I occasionally suffered from shoulder and neck pain which I just put down to riding technique rather than fit. However, as was explained to me, I was riding in a very cramped up position. It also meant that my pedaling effort was inefficient as my knee position was all wrong relative to the pedal spindle. They adjusted my bike to these new dimensions as best they could and off I went.

Low and behold, the first ride I did which was 70 miles - guess what? - no shoulder pain I have since done a 40 and another 70 miler all with no problems. It does actually feel a nicer bike to ride.

I know it is a fair jaunt for you and it also costs £50 but for my mind it was money very well spent. I think it would be for you as well just to get it right first time.

Hope this helps.

 

[Bigtallfatbloke]

...you make a lot of sense...I will take a look at his site. The reason I havent done thisa before is that I had my heart set on the Bianchi, then the Orbea now the Kinesis...also I only have £1300 so I can get a better spec bike if I assemble it all myself online. I'm not sure if I like th elook of th eHewitt bikes either to be totally honest, although I now they are superb quality....call me shallow but I want to look at it and dribble every day!

 

[Aperitif]

Good advice Gary - also, don't forget the bike show coming up. It might be worth the wait to plug all the experts there 'face to face' - might get you somewhere (and it would be a touchy feely bikey thing to do!)

www.cycleshow.co.uk

 

[Gary D]

...you make a lot of sense...I will take a look at his site. The reason I havent done thisa before is that I had my heart set on the Bianchi, then the Orbea now the Kinesis...also I only have £1300 so I can get a better spec bike if I assemble it all myself online. I'm not sure if I like th elook of th eHewitt bikes either to be totally honest, although I now they are superb quality....call me shallow but I want to look at it and dribble every day!

You don't have to buy a bike from Hewitts to use the fitting service - I didn't. You just get the £50 off the price of a new bike if you do. He gives you a bike "diagram" with all of the measurements on which you can basically use as you wish. Also, Hewitts not only do their own brand bikes but lots of other high end stuff as well ie Look, Colnago etc and they also do Kinesis and Orbea so you might be surprised. I don't think many shops can match his for bike porn

I think it has already been mentioned, but Epic Cycles in the wilds of Worcestershire sell all 3 makes of bike you like (as well as Wilier which you might like) and I am pretty sure I saw a proper fitting jig there when I visited them. However, I can't vouch for their fitting capabilities - maybe someone else can? They certainly were prepared to spend a lot of time talking to me even though I wasn't in a position then to place an order.

The thing with Hewitts is that I have only ever read positive comments about him and the service he provides. An aquaintance who is a life long experienced cyclist also recommended him.

Get fitted first - then buy the bike that fits. I wished I had.

Gary.

 

[Bigtallfatbloke]

...bike show...yeah I might do that...thanks for the offer to ride your bike, only heefrow is a long way for me and I have a serious allergy to the M25 which the docs insist is incurable.

I was just poking around on the Hewitt site...it all seems perfect, except that he's on the dark side of the moon...oops sorry I mean north of Manchester

I did see this though:

http://www.hewittbikefitting.co.uk/cgi-bin/trolleyed_public.cgi?action=showprod_BIAMEGAPROXL60

...I know nought about this frame...I assume is a steel job and not seriously damaged...maybe it'll do me...but then again I have to have that kinesis and ...oh bugger it...has anybody got a pill I can take for bike lust?

 

[Aperitif]

One other thing - this morning I measured my other bike - also 'traditional' geometry and the top tube length is the same as the Look. The size (it's a Veneto, which is Orbea BTW) stamped in the alu is 56cm! (C to C of seat tube/ axle...)
130mm stem (+10mm longer than the other bike)
106cm floor to top of saddle.
The frame is Altec2 and jingles a bit but is extremely comfortable fit.
So the answer is: You're either thinking straight - or sloping
Bummer!