Reach Dimensions – horizontal from BB centre to top of head tube.
16in – 395mm
18in – 408mm
20in – 430mm
Which to compare with a typical 73deg seat angle gives effective top tube lengths of:-
16in – 600mm (23.6in)
18in – 610mm (24in)
20in – 630mm (24.8in)
The actual “angle of the seat tube” is 70.5deg, and it’s offset forward about 35mm. This gives a 73.5deg seat angle at average saddle height. Interestingly, even with 6in of difference in saddle height, the seat position only varies by 3mm fore or aft of a “virtual seat angle”. So whilst yes, a taller saddle will have a slacker seat angle, the actual seat angle you’ll feel only varies by 0.5deg. So shorties will get a 74deg seat angle, and lanky sods end up at 73deg. Which is why the larger size gets a greater top tube length difference to allow people that want to move forward a bit to move forward without getting things too short.
Oh yes – I guess you can see that the seat tube is straight – it’s a key point – as I wanted people to be able to drop a full length 400mm post right down, so those of us that can’t afford (or don’t want) a dropper post aren’t hampered by the saddle in the way. I see quite a few bikes out there that don’t have this, and it’s just a bit rubbish I think. Post diameter is 31.6mm. Our Neil runs a 30.9mm post with a shim – they are out there. The seat tube is externally butted at the top to guard against the odd cracking you can get on frames where you don’t have some seatstays supporting the seat tube.
Chainstay length came in at 440mm, 17.3in. Which gives 6mm clearance between the corner of a Smorgasbord the edge of the chain stay, at the narrowest point. Proper tyres. Proper clearance.
The suspension is optimised for a 32t chainring. 34t will work. 30t would as well I think (we’ll check), but 32t offers absolutely perfect performance in terms of anti-squat. The bike climbs incredibly well with a fully open shock, without any requirement for lockout or propedal.
Might seem like a daft question, but why is it being specced with a 30T if it’s optimised for a 32T?