Bike Sizing...

[Monsieur Remings]

Okay, am currently riding a Ribble New Sportive, a medium size which is 53cm from the centre of the BB to the top of the seat tube. However, it is a sloping geometry.

I'm looking to buy a Focus Izalco and seem to be slap bang in the middle of two sizes - I'm 5'10 with an inside leg of 82 cm and so between 54cm and 56cm. Which size should I go for and why - the techies at AllTerrain seem to think a 56cm...but I'm not so sure given that this will only give me a fraction of a clearance in terms of stand-over.

Is there anyone out there with any ideas?

 

[black'n'yellow]

Stand-over height is not really an issue - it's not a mountain bike. Providing you can actually stand over it, that's all that matters. You should be comparing the top tube length and possibly the head tube height - those are far more important in achieving a good bike fit.

 

[Monsieur Remings]

Thanks black and yellow, interesting...the Ribble has a top tube length of 55.4cm and the Focus Izalco 54.3cm length in the 54 size and a 55.5cm length in the 56.

I know the length on the top tube is long enough on the Ribble and wouldn't want it any longer or shorter, so unless I'm missing something, then that's very helpful, cheers. All seems to be edging back in favour of the 56cm. (I also have a + positive ape index!)

In regard to your reply on the compact vs standard, the supplier has provisionally offered to change the cassette ratio to one that suits me better (a 12-27 or 11-28 in place of the offered 12-25) so long as it incurs no extra cost to them. If it does then I'll buy a separate cassette and they'll fit and index it free of charge. So, thanks for that input too but if I can get the lower end ratios on a standard set-up, that's what I'm going to do.

 

[slowmotion]

Are you an ape, Monsieur Remmings?
Height and inside leg measurements come into a lot of frame size calculators. Another useful thing to consider is your Ape Index..... see here...
http://www.cycle.org.uk/bike-sizing-charts/
A rule of thumb, if you fall between two frame sizes, is to go for the larger if you are a positive Ape, and vice versa. Yes it's a crude generalisation, but it puts you somewhere close. BTW, changing the stem length is another way of fiddling things if you find your new steed isn't quite right.

Good luck, and have fun.

 

[Monsieur Remings]

Cheers Slow, I am indeed. It is mentioned briefly in the post before yours. I'm an ape by about half-an-inch!

I've changed the stem on the Ribble and I couldn't have it any longer what with the top tube length plus 110mm of stem. The guy at Allterrain did suggest a 56cm frame but a shorter stem too.

 

[slowmotion]

I'm an ape by about half-an-inch!

SNAP!