Franx2

Hi there

Does anyone know how the frame sizes work for road bikes?

Is it the same principle as mountain bike - i.e. BB to top of head tube? - or is there a different way? For some reason, road bikes seem to be in centimetres, and MTBs in inches, although whether it's a straight conversion, I don't know...

I'm 5'10''. 75kg, and average in build. The mountain bike I ride at the moment is a Scott Endorphin (Medium) - not sure of the size in inches, as it's not here to measure, but it'll be around 18'' I think.....

Any ideas?

JTaylor

http://bbs.scoobynet.co.uk/forumdisplay.php?f=37

Franx2

Not that sort of bike.....

JTaylor

OK, sorry Frank

Dave T-S

It is the same measurement, but it's not a straight conversion, due to differing frame geometry between road and MT bikes.

Your 18" MTB would straight convert (x 2.54)to around 46cm, whereas for your height you would probably want in the region of 52-54cm for a roadie.

Having said that, there is a recent trend to go for smaller compact road bike frames with a longer stem and it can vary from brand to brand so the only way is to go try bikes to see if they suit you/size properly

Jonathan Davies

I agree with Dave T-S on the whole. Road frames are bigger than MTB frames, which are made to have more clearance (for you) and to allow a rider to move around the bike much more. An MTB should give you a few inches clearance below the nutbag, for instance.

A road frame should be longer and taller, cos your road position is generally static and you want a good comfortable stretch. You can't really guess your road size from an MTB frame.

RB5-Black

I'm the same height and weight as you are and ride a 54CM Specialized Allez Sport as my training/Winter bike at the moment so 54 will do you fine.

Brendan Hughes

I rode a 23.5in road bike, but would be expected to ride a 19in MTB if I'd use it anywhere other than on the flat.

rob878

Just keeep in mind that different manufacturers measure differently, from memory (which is terrible) some frame sizes are measured from the centre of the bottom bracket to the top of the top tube, where as others measure from the centre of the bb to the centre of the top tube.

Just make sure you try before you buy as translating one size from one manufacture to the other could leave you with an ill sized frame.

B0DSKI

iTrader: (17)

I'd say u need about a 54-56cm i'm 6ft 3 and i ride a 59cm Bianchi SL3 but i like a fair amount of seat post exposed, depends on what u like, my S Works M5 is only a 19" frame but as u can see it's got a fair old bit of seat post out
http://i3.photobucket.com/albums/y88...I/IMG_0044.jpg

Franx2

Nice bike there

Thanks for that I was thinking towards a 52-54cm, which I had a feeling would be the right size, although i could do to try a few different ones as well. I'm slightly undecided as to whether I should build it up from scratch, which is undoubtedly the more expensive option....as I found with my mountain bike ...., or to try and find a good second hand one, which I'd prefer, as I'd like it sooner rather than later.

I did wonder about that thing with the Specialised road bikes and others - low top tube must somehow alter the measurements, but I wouldn't know which way.

Any ideas on where to find a good second hand one? E-bay? there's loads on there - mostly time trial ones and oldies though

Jonathan Davies

Ebay has some real bargains I reckon.

Get a good Italian or British steel frame with Campag components - Campag are the best (they say) for retro-compatibility, so you can upgrade bits and bobs without having to change the lot. Shimano are less good for that.

I like a nice steel frame.

Aztec Performance Ltd

iTrader: (234)

Ebay looks good for s/h bikes. Some very good ones on there at a fraction of the original price.

Will get alot more for your money that way.

Are you replacing your mountain bike or keeping it?

anc-sti

If you 5'10, 52-54cm is a little small but it depends on you leg size really.
I'm 5'11 and have a S-works epic in the Large size and my road bike is 58cm which was fitted professionally. I think with a 52-54cm your gonna have a lot of post exposed and feel far to cramped. Remember the best riding position on a mtb differs from that of a road bike.

http://anc.fotopic.net/p6507627.html
http://anc.fotopic.net/p6507626.html

Franx2

Another nice few bikes there

No, I'll not part with the Endorphin. I'd like a road bike as a second one; for training and that sort of thing, perhaps with a view to racing it....

I'd post a pic of mine, but it's in quite a few bits at the moment just whilst I do a few upgrades and a full stripdown & service It's already taken me 6 weeks on and off, although I was away for 5, having started before I left....