Stack and reach question

Tom Butcher

Wasn't sure if this should be in buying advice or here but here goes. Stack and reach - good way to size a frame and if yes am I getting it wrong ?

Looking at getting a new bike to replace my 6 year old Look 585 - most modern geometry charts give stack and reach figures - can't find them for the Look but from this: http://i961.photobucket.com/albums/ae91 ... 852007.jpg
- am I right thinking the reach is horizontal top tube (B) minus E ?

Just that gives my XL a reach of 408 mm - which would be longer than a 60cm CAAD 10, a 61cm Cervelo R3, and basically some very big frame sizes given I'm 187cm (just under 6'2 in old money). Have I got the figures for the Look wrong or do I need to be looking at frames a size bigger than I have been ?

kwozzymodo

Your formula is correct for Reach.

Are there any differences in the seat tube angles between existing and new frames?

Some other things to consider - stem length and seat setback.

Mccaria

Tom.

I am 6'2 with pretty standard limb length. I have a Supersix in a 58cm and a Cervelo R5 in a 58cm and run both with 13cm stems. I could probably ride a 60 in the Supersix, but wouldn't go for a 61 in the Cervelo (the Cervelo's have long head tubes, the R5 in a 58cm is set up with no spacers). Wouldn't go any bigger than 60 cm in the Cannondale and 58 cm in the Cervelo.

Head tube wise the Cannondale and the Cervelo come at it from very different perspectives. The Cannondale in a 58cm is 17.5 cm and the Cervelo is 19.9 cm. So back flexibility, saddle to bar drop, attitude to spacers, stem angles all come in to play !

Rgds

Tom Butcher

Thanks, interesting as I'd always kind of discounted Cannondales as being too low but maybe I could ride a 60, Whereas I'd always thought some Cervelos might suit with longer head tubes than my Look when in fact to get the same reach on one I'd be riding a sit up and beg.