Cycling UK Forum

i don't really mind 'weird' spoke configurations and find some of the science behind them interesting but i wouldn't fancy finding a spare spoke for one of the above DA or Mavic wheels this many years down the line.

do wheels with fewer spoke counts tend to have heavier rims anyway?

mig wrote: ↑7 Nov 2023, 1:31pm i don't really mind 'weird' spoke configurations and find some of the science behind them interesting but i wouldn't fancy finding a spare spoke for one of the above DA or Mavic wheels this many years down the line.
Do wheels with fewer spoke counts tend to have heavier rims anyway?

I don't know about actual rim weight but weights of three "front" wheels including tyres. :-
Kysysium = 40 ozs. (25 size tyre)
Scirocco = 44 ozs (23 size tyre)
Open Pro = 42 ozs (23 size tyre - 32 spokes)

Ksyrium spokes are readily available but are expensive. (never needed any - touch wood. )
The one unexpected drawback I found with the Ksyriums is they are affected by side winds.
I've no idea how any of the above wheels compare with todays carbon offerings ?

it isn't at all difficult to build a better front wheel than a Ksyrium; just use DB aero spokes, aluminium nipples and a Ti axle. Also, I have quite recently figured out how to save even more weight in most hubs whilst retaining a steel axle.
BTW using Al for the spokes themselves is pretty dumb really; they are both fatter than they need to be and susceptible to fatigue.

cycleruk wrote: ↑7 Nov 2023, 2:37pm I've no idea how any of the above wheels compare with todays carbon offerings ?

The main development over the last 10 years with wheels has been aero. Weights are largely unchanged, it's difficult to get much below about 1200g for a wheelset (not impossible but it rapidly becomes ridiculously expensive to do so).

Disc brakes have been a total game changer for rims too - the fact that you no longer need a parallel brake track on there means rims can be wider (therefore stiffer/stronger) and shaped for strength/aero. Plus you're no longer wearing out an expensive carbon rim!

I'm still a fan of factory built wheelsets where the working of the whole wheel has been considered although I'm less a fan of proprietary spokes and spoking patterns.

rareposter wrote: ↑7 Nov 2023, 3:22pm .....Disc brakes have been a total game changer for rims too.....

not as much as most people think; the 'extra' material in the brake track only weighs about 40g or so; far less weight than is hidden elsewhere on a disc braked bike, and rim brakes could easily be made to work with most aero rim sections. The main thing that is 'wrong' with rim brakes is that the cycle industry no longer wants to make them.

Don't get me wrong, I liked my hydro discs well enough, but I have no love for what these brakes have done to the rest of the bike.

Brucey wrote: ↑7 Nov 2023, 4:02pm not as much as most people think; the 'extra' material in the brake track only weighs about 40g or so; far less weight than is hidden elsewhere on a disc braked bike,

Wasn't really talking about weight to be honest, more the complete freedom it's given to the rest of the wheel profile.

Overall weight - there's mere grams in it now between disc and rim brake road bikes.

Thankfully, the 90's and early 00's obsession with weight has largely died off in favour of having actual reliable components (and in the world of performance road bikes, everything has tended to aero).

rareposter wrote: ↑7 Nov 2023, 4:13pm .....Wasn't really talking about weight to be honest, more the complete freedom it's given to the rest of the wheel profile.

Overall weight - there's mere grams in it now between disc and rim brake road bikes....

weight is only because they deliberately don't really bother any more with the rim brake designs. As my earlier post mentioned the 'complete freedom' is very frequently overstated.

Thank you all for your replies - I am most grateful. For the record, I am familiar with the Batavus brand and my spelling in my OP (Bativus) was a careless error .

I do feel more informed now. When I first saw the wheel, my concern was strength of the wheel and whether it would be more susceptible to going out of true. I have to admit that they don't "look right" to me (an emotional response) and with CJ saying that they are built that way for appearance, it puts me off them even more.

rareposter wrote: ↑7 Nov 2023, 3:22pm Disc brakes have been a total game changer for rims too - the fact that you no longer need a parallel brake track on there means rims can be wider (therefore stiffer/stronger) and shaped for strength/aero.

Rim brakes did not and do not limit how wide a rim can be. I can show you some bikes with really wide rims that have rim brakes. Ryde Sputnik rims for example, are 26mm wide overall and work just fine with the cantilever brakes on my touring bike.

What previously limited the width of tyres and rims on racing bikes was a blinkered adherence of the racing fraternity to a particular configuration of rim brake, attached by a bolt above the tyre, that could not accept anything bigger without becoming larger in all dimensions and heavier, or else wobbly and ineffective. Once the fashion for close-clearance rim brakes had been broken by an altogther different method of braking, the path was literally opened to safer clearances, wider tyres and wider rims to suit those tyres.

At about same time someone realised that making the external dimensions of a rim similar to those of the tyre significantly reduced aerodynamic drag from air pumped out over the rim by the centrifugal fan effect of a spinning wheel. Had this light-bulb moment occurred sooner, we might have seen wider short-reach dual-pivot brakes. That design tweak wouldn't have been any problem at all, but by then disks were the way to go: end of story for rim brake development.

What disks allow is thinner sidewalls and that makes a rim LESS stiff laterally. But since rims have at the same time become wider, that loss is easily regained, for whilst the bending stiffness of a hollow shape is proportional to wall thickness, it is also proportional to width CUBED! So if a rim's sidewalls are half as thick, it need only be 26% wider to end up just as stiff - whilst still saving 37% in weight. In practice the potential weight saving of thinner sidewalls will already have been spent elsewhere, in making the rim a much deeper aerodynamic shape, incidentally boosting both its torsional and radial bending stiffnesses - and hugely so!

That XTR wheel (page 1) gets a lot of lateral rigidity because spokes from the left hub flange go to the right side of the rim, giving a better bracing angle. Some BMW motorcycle wheels do the same thing.
I think just about any modern hub with a wide alloy barrel will transfer torque from the cassette to the left spoke flange; certainly much more that (say) the old Airlite hubs with a narrow steel barrel and alloy flanges.
The Ksyriums are definitely radial on the right; I wonder why they didn't put the spokes the other side of the flange to get a better bracing angle.

IIRC they only stopped making wheels like this because they were worried that they would be sued by morons who couldn't keep their rim brakes correctly adjusted......

CJ wrote: ↑8 Nov 2023, 1:09pm At about same time someone realised that making the external dimensions of a rim similar to those of the tyre significantly reduced aerodynamic drag from air pumped out over the rim by the centrifugal fan effect of a spinning wheel. Had this light-bulb moment occurred sooner, we might have seen wider short-reach dual-pivot brakes. That design tweak wouldn't have been any problem at all, but by then disks were the way to go: end of story for rim brake development.

Can we 3D print workable (safe) dual-pivot calipers?!?

(I don't care about the cost - it's bound to be cheaper than buying a disc-brake bike )

Problem is that it's not just about brake calipers.
Frames have been redesigned (caliper mounting points, hose routing, thru-axle...), wheels are disc only, levers have hydraulic chambers rather than cable routing...

It's not one part in isolation.

Trying to fit a wider dual pivot caliper into an existing frame would just result in it fouling the inside of the forks and seatstays plus there's the issues of fitting a wider rim and tyre in there.

mattheus wrote: ↑9 Nov 2023, 12:12pm (I don't care about the cost - it's bound to be cheaper than buying a disc-brake bike )

Its getting to the point where it isn't, there's some phenomenal deals on all sorts of bikes at the moment!

I may well be getting a steel f+F made up over the winter, so I can sort all the other stuff.

p.s. I shan't be buying any wheels with non-standard spoke-spacing for it

IIRC Magura showed some time ago that hydraulic rim brakes could work well; so please don't make the mistake of confusing the niceties of engineering with the niceties of salesmanship.