size knowledge

[johnnyh]

as I scour the various ad sites, ebay and the like, looking for a potential purchase, I am getting a little confused over size.

I ride around on a Giant Boulder MTB at the moment, 19" I believe, but it seems the road/touring type bikes give a measurement in cm's.

Is there a way of working out which sizes are going to fit the bill, or am I best going to Halfrauds and sitting on a couple to gauge size?

 

[montage]

just use a inches to centimeter calculator on google
19" seems a tad small for a road bike so definately worth getting sized out, but try the LBS rather than Halfrauds.

 

[johnnyh]

I thought about using the LBS, but then I would feel guilty were I not to buy the bike from them... damned conscience

Halfords on the other hand I have no problem in using - after all I have spent many notes on car bits in there.

 

[johnnyh]

ps - if it is any help, I am 5'8" with a 30" inside leg...

 

[wlc1]

54cm I'd say

 

[Sittingduck]

I guess everyone's different and you would need to try some out or get fitted. I am 5'9" with a 29" inside leg and I have a 55 Hybrid with sloping top tube. Would NOT want to go larger for my next bike though. I am thinking if getting a road bike and think a 54 would be spot on.

Good Luck!

 

[johnnyh]

that kind of fits with a "rule of thumb" that I found online, so 54 is the target. (unless I decide to stop the bargain hunt and buy new - but then budget would limit me at the moment... that said new and shiny.... gah! )

 

[chris667]

If you are really serious, lots of bike shops charge for fitting, which they refund if you buy a bike from them.
Don't know any that do it around you, though.
I'm about your size and I ride a 54cm traditional (non-compact) frame, but it's much better if you can try the bike before you ride it.

 

[jimboalee]

54cm - That's with a HORIZONTAL toptube

 

[fossyant]

54cm - That's with a HORIZONTAL toptube

Yup about right....

You'll still need to check the bikes out as compact frames vary.

I have 22" road bikes (56cm) and a 17" MTB.... my new bike is looking like a 54cm - semi compact frame !

 

[roadiewill]

Sorry for the hijack here, but when you measure a traditional frames toptube you just measure the actual toptube. But when you measure a compacts toptube you measure from the centre of the headset to the centre of the seatube to get the quivalent toptube length... right?

 

[postman]

It is a nightmare.Try being 6' 4" with a 35" inside leg. But the best thing about this site. There is always someone to offer help. As i found out this week. Thanks BTFB (with photos also).Now thats help.

 

[roadiewill]

and to de hijack this thread, heres a pretty useful site to get you sized up:
http://www.competitivecyclist.com/z...TRO_LINK=NOREDIR&CLEAR_RESULTS=TRUE&SITE.CODE=

 

[Radius]

To give another example, I'm 6'2" and my road bike is just about right at 59cm, but my commuter / hybrid (sloping top tube) is 21" and too small really...tonnes of seat post showing.

 

[youngoldbloke]

Sorry for the hijack here, but when you measure a traditional frames toptube you just measure the actual toptube. But when you measure a compacts toptube you measure from the centre of the headset to the centre of the seatube to get the quivalent toptube length... right?

Wrong! Both are measured (or should be) centre to centre, but in the case of the sloping/compact top tube often a 'virtual' top tube measurement is given,this being the measurement of a horizontal line from the centre of the headset at the junction with the top tube, to the point at which it meets the (projected) centre line of the seat tube (use a spirit level, this point will be at some point on the seat pin). Of course, this point will also give you the 'virtual' seat tube length, allowing comparison to be made with 'traditional' frames.