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Interested to understand opinions on bike sizing. Does the old formula of Reach = 2.5 x height still apply? At 171.5 cm, my reach is 429mm using the formula.
Does anybody use RAD or is this to old now!
I recently bought a second hand Scott Genius in size small with a reach of 430mm (Which was also recommended by Scott website for a 'sportive' ride). It feels a little small when seated (Even with the seat pushed all the way back) and also in the air but it is absolutely amazing around berms and blue and red flow trails! Interestingly, the main measurements top tube and RAD are within 1cm of an S3 Specialized Levo SL and that feels completely different..... The official reach is 445mm for that.
you're a medium on a mountain bike at my height (which you are)
but if the manufacturer says small.. who am i to argue.. but on road bikes I'm probably a small
Well, neither reach or RAD will tell you how a bike "fits" when seated, but can help you understand how a bike fits and handles when stood up. I personally wouldn't use RAD for choosing a bike/frame, as it's so easily adjusted with bars, stems, grips etc. Top tube measurements are also generally useless these days when it comes to mountain bikes, IHMO, due to offset and kinked seattubes. When in doubt, talk to the manufacturer (or retailer) about sizing. If there's no one to help you... move on to another brand/retailer.
Reach = 2.5 x height
Outdated by the look of it, but is that for an XC bike with a long stem or a DH bike with a 35mm stem? A lot to be said for fitting to the bar not a frame measurement point. Also may not account for the bike's front-rear centre balance and your own CoM which are what create balance on the bike for the riding you prioritise. I don't know a lot about RAD but I'm generally sceptical of fitting formulas (apart from for saddle height, bc that's not about weight balance on the bike or handling)
According to this formula which I've never heard of I should be on a bike with a 467mm reach. Sod that.
That's 43mm shorter than my most comfortable bike and about 20mm shorter than my 'too small' bike.
According to this formula which I've never heard of I should be on a bike with a 467mm reach. Sod that.
Same. 2.5 x my height (187cm) gives a reach of 467.5mm... my MTBs are 512mm, 517mm and 533mm 🤣
It's not a formula I've used or was even aware of. I initially went roughly on manufacturer suggestion for height which used to put me between L and XL frame - even 9 years I was riding a 2014 Spesh Enduro 29, size large with 445mm reach (only reason I didn't choose XL was due to silly long seat-tube length).
Nowadays recommendations almost always put me on XL frames but I just go on what feels right to me: XXL, XXL and XL respectively for the above reaches.
I'm about the same height and my current bike feels about right. It's 428mm reach which on a hardtail probably becomes around 440ish mm at sag. My previous bike was a 460mm reach FS and it felt like too much bike for me, too long, stable and planted! It only came alive on big steep fast and rough DH stuff for me, whereas I mostly ride less steep and more jump/flow trails. So I think around 440-450 with an ETT of about 600mm is my sweet spot but I guess the rest of the geometry and travel plays a part too.
Drop bars are different. My road bike's a small and still feels too long on the hoods tbh, even with a 70mm stem. I think I must have weird body proportions or something. Short legs and short arms I think!
g, stable and planted! It only came alive on big steep fast and rough DH stuff for me, whereas I mostly ride less steep and more jump/flow trails. So I think around 440-450 with an ETT of about 600mm is my sweet spot but I guess the rest of the geometry and travel plays a part too.
I tried a Yeti SB160 in medium with a reach of 465mm. Hated it! Don't know if it was the bike or the geometry though - assume it was a geometry as a slightly shorter Torque on wasn't as much of a handful despite being 10kg heavier!