All The Six Fifty Bees Thread! (650b, 27.5 etc.).

Imo it's not really worth putting 47-584 on a bike that takes 40-622 already. Might be if you want to go all monstercross and put something bigger than 50-584 on

Edited post cause I wrote it when still sleepy

True. The rational was to have plusher tyres without a massively big wheel. This and the 650b cool factor, obviously!

A Ti coffee mug dangling from your luggage is bound to make you almost as cool as a set of 650b wheels :D

Got these bad boys for sale if anyone is looking for a six fifty bee wheelset

https://www.lfgss.com/conversations/311698

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Imo it's not really worth putting 47-584 on a bike that takes 40-622 already.

The difference is much bigger than you'd think, especially in term of weight.

When I went from 38mm 650b to 42mm 650b, the difference was nigh and day.

Yo Ed! Sorry to be a complete stalker but did you see my DM re. the Vigorelli?

When I went from 38mm 650b to 42mm 650b

Do you mean 38mm 700c to 42mm 650b?

First commute on Horizons, living the dream

The area of the cross section is pi times radius squared, so the difference between 40mm and 47mm alone is 49mm^2
Then multiply that with the circumference of the wheel

Volume of a 700Cx40mm is 2454mm^3
Volume of a 65oBx47mm is 3318mm^3

TL;DR It makes a huge difference.

Yes I did, sorry lots of shit at work (suddenly now the only mechanic for the time being).

Nope, both 650b.

The difference was that obvious to me.

So I bought the wheels above from @Dick
Going to slap them into my Genesis Equilibrium Disc. I'd like the girthiest tyre I can fit in. What do you think my options are with/without mudguards?

In a good or bad way? Didn't you settle on 38c on your oak?

I don't think you'll get any bigger than 38c in there

38mm on Oaks due to clearance of mudguard.

TBF it is very tight as I requested it to have a really short wheelbase of a gnat over 1 metres for a 57cm bike.

That's what I thought...

Imo it's not really worth putting 47-584 on a bike that takes 40-622 already.

Just realised that if we can feel the difference of 2mm from 23mm to 25mm, then what you mentioned is a massive difference.

Re @edscoble and @MisterMikkel sure you are right about volume and ride quality but going from 40-622 to 47-584 will equal a bb drop of 31 mm which is less than desirable depending on what's the 'optimal' (ie the tyre size the producer had in mind) size for the frame

Possibly even more, given that the wider tire can be run at lower pressure.
I'd be quite interested in experiencing just how that would affect a bike.

Ah another good question.

The right question is why B.B. is so high already?

They were at that height so the clip and strap pedals is less likely to scrap the grounds.

With clipless, you can go lower, and still be fine, moreso, you can go extremely low and still be fine.

It’s only when you go off road you might want it s little high but I didn’t have any problem with a bike that have barely 250mm from centre of B.B. to ground (normal is 270mm).

They were at that height so the clip and strap pedals is less likely to scrap the grounds.

I doubt bikes are designed around pedal convenience dude...
Saying that...did forget about lower BB when converted to 650 and did strike a couple times.

IRL it would be less than 31mm (it's rim dependent but the tyre nominal width does not equal tyre height).
Plus, as Ed said, a lot of OTP bikes have a way too high BB to start with. I much preferred the handling on my Straggler with 650B wheels, although it was designed for the same sort of volume on 700c.

for bb height difference wouldn't (rim diameter / 2) + tire height be how you'd work it out?

It's a very near estimate and if anything like @MisterMikkel said tyre sag will probably take it to that 31 mm even if the tyre isn't as high as it is wide. OTP bikes' bottom bracket are high so you don't get pedal strike while cornering or while you're out in the woods with squishy capable tyres. Moreover lowering the BB by altering the geometry would slack the frame and alter the ride even more for you'll have to lengthen chainstays & DT. You may personally like how your straggler rides with smaller wheels (I call placebo but I'd be interested to try). All this makes me think going from 622-40 to 584-47 definitely makes less sense than putting 584-38 or 42 mm on a bike that wouldn't take anything larger than 622-28s, for you more or less keep the same ride. ✌️

Pedal strike was never an issue with the Straggler (while I often scrap my flats on my daily). You could argue it's all in my head, or a confidence thing, but ultimately I corner better on lower BB bikes (and yes I have tried old school geo CX race bikes on the same sort of terrain too). I'm not saying the Straggler on 650B was perfect, and I found its front end a bit vague, but it was super stable and it could corner faster than everything else I've ridden before or since.