I said the spokes deform to allow the wheel to deform radialy. And I never said it was stiffer axialy than radialy, I said you could imporve the radial stiffness and reduce it axialy.
You’ve clearly forgotten, let me remind you:
You can’t crush a wheel radialy, that’s why arches are arch shaped! So A very siff rim lets you get huge side to side stiffness, but low enough spoke tension to allow it to deflect radialy.
Their logic is that the spokes only need to be tight enough that the unloaded spoke at any point is still in tension. The stiffer the rim, the easier this is to achieve as the rim doesn’t deflect, hence why they were using really low tesnions with the Enve rims. So in theory when Peaty/Minnar/Bryceland lands a big jump/hits a rock the load is taken evenly through the spokes in the top half and the wheel and the bottom half unloads more evenly. Whereas a softer rim would deform localy causing those spokes closes to the impact to come loose, meaning they have to be tighter to start with.
Apart from still having the bit about the wheel hanging off the top spokes that’s not a bad explanation of why they can have lower spoke tension. However it that doesn’t explain what advantage there is to lower spoke tension. The spokes will unload in just the same way no matter how much initial tension they have.
Laterally stiff, yet vertically compliant? Er, no. Spoke tension makes just as much difference to radial stiffness as it does to lateral stiffness. How on earth could it be otherwise – does the spoke know which direction the force is coming from?
Because the two sets of forces happen on different sides of the triangle, those having substantially different lengths and angles. A simple fag packet calculation will show that increasing the tension gains a lot more across the small side than the long side. High school maths.
£750 for about a tenners worth of material does seem like a bit of a joke though. No amount of development time, manufacturing and order processing could possibly justify that mark-up!
So do the people making this argument also believe that the same applies to £2500 carbon frames? What about the material costs for an aluminium frame which might only cost about 20% less?
My colleagues are horrified how much I’ve spent on bikes. I always get asked at the office how much my road bike cost. When I tell them it’s around 2k euros they look shocked; I don’t have the heart to tell them the MTB was far more expensive.
Enve rims are this experience just between cyclists. Either you want them, can afford them and buy them or you don’t. If you don’t want them or can’t afford them, don’t get them.
Because the two sets of forces happen on different sides of the triangle, those having substantially different lengths and angles. A simple fag packet calculation will show that increasing the tension gains a lot more across the small side than the long side. High school maths.
Have you actually done the maths you say is so simple? Let me help you with it, I’ll use some real numbers for an Ultegra hub and Open Pro rim:
horizontal spoke distance: 36.3
vertical spoke distance: 283
change in lateral stiffness due to change in spoke tension (from Mavic research): 0
change in radial stiffness = 283 / 36.3 * 0
I’ll leave you to put those numbers into a calculator to see what difference it makes.
If you don’t want them or can’t afford them, don’t get them.
What would we do without genius advice like this? Honestly, I was on the point of buying a set of Enve wheels that I didn’t want and couldn’t afford when I read this and was saved. Thank you and happy Friday 🙂
Geetee as I’m the quoted person, I do indeed think the same applies to £2500 carbon frames. I feel that many bike parts are over-priced in all fairness. In the past I used to buy expensive frames and components (before having 3 dependants!) so I would never ridicule anyone for doing the same, as I said before, if it makes you feel good and you enjoy riding them then that’s all that matters 🙂
So do the people making this argument also believe the same applies to £2500 carbon frames
Ere we go…. someone just bought a cf frame for 2500 and getting worried they might have been silly? Well anyway to answer that question for you yes. Same applies. Except there is more r&d and that the weight is almost a kg. So about 35 quids worth of material in it. Plus the quid for tooling and then there is the labour and overheads. Taiwanese labour being really quite cheap and certainly no more than 4 hours work. So work it outfor yourself. Carbon frame comes out at 200 smakers finished. That leavs 2300 of your cash to split between the remaining hand rubbers.
Oh, and all those quoting cost of raw materials, presumably none of you have ever bought an app or downloaded music from itunes? Or do you think those electrons are really expensive.
the point being all this talk of marginal gains and optmized performance is 99% bollokth and the only reason to spend thousands on bikes is cos you want to, trying to justify it in terms of the performance that is absolutley ‘critical’ to 40in waisted biffers circling carparks is nonsense. Just admit it you want it cos it’s shiny. And if you’re daft enough to pay for it someone will happily sell it to you. If you can’t afford it just be happy that someone can sell you something just as good (as far as you’ll ever be able to tell) for a fraction of the price. As long as you’re not selling your or anyone elses kidneys to fund it it’s fair game.
That said even if i had the money I wouldn’t buy them, cos i’m tight.
aracer – The change in stiffness is very small, not zero. You also seemed to miss the bit about Pythagoras at school, not sure what you’re formula are, show your working.
The “vertically compliant by laterally stiff” thing is the butt of many jokes in the bicycle industry, but that’s pretty much what a double-diamond frame is.
You see, descends into insult throwing again. Why be rude? Why be so insulting? Is your cock that small?
Besides the inference the having a 40″ waist in some way relegates you to being a ‘biffer’, whatever that is but I pressume it means someone who is slow and unfit, has been show as not neccessarily true. You can be fit and fat. I should know. 😀
You also seemed to miss the bit about Pythagoras at school, not sure what you’re formula are, show your working.
Pythagoras has nothing to do with it – maybe you’d like to explain why you think it does? I gave the radial and lateral components of the spoke’s length – I thought that was fairly straightforward and obvious. Also whilst it’s not normally the done thing to claim to be an engineer on here, in the circumstances it seems reasonable to point out I’ve studied forces, structures and materials at university (oh and I’ve also read Jobst Brandt’s wheel book – have you?)
The “vertically compliant by laterally stiff” thing is the butt of many jokes in the bicycle industry, but that’s pretty much what a double-diamond frame is.
Northwind,
Do I think tooling for a carbon bike is a quid? Well I never said that. Since I was talking about the cost of one part. I thought it would be obvious that the quid for tooling would be the proportion of the total cost of tooling amortised to that part. I thought it would be obvious that tooling did not cost a quid in total. I mean come on man get with the programme….
I’m genuinely impressed that this thread has devolved into two separate rows, both of which are quite unpleasant.
Can’t the wheel tension arguers meet up face-to-face for some kind of maths “burn” to settle things?
ive said this quite a bit recently ,it wouldnt matter if you designed the product theres always someone who will know more than you about your own product
well if i designed a product i’d expect there to be quite a few people in the world who’d be able to tell me something i don’t know about it. is that what you mean? 😀
Northwind,
I think I have made my point clear. If I was talking about material cost and labour for one item why would I then talk about total tooling cost rather than the proportion allocated to one item. Do you really think that someone would think a “complete tool” (haha) would cost a quid??? I think you misinterpreted a little but Im sorry for not making it compltely clear for you.
If I was talking about material cost and labour for one item why would I then talk about total tooling cost rather than the proportion allocated to one item.
OK then, do you actually believe that the tooling of a carbon frame distributed across every one sold is a quid?
OK then, do you actually believe that the tooling of a carbon frame distributed across every one sold is a quid?
Only an imbecile would think that.
Part of the price of Enve rims, up to now any way, is attributable to the lack of alternatives. When viable alternatives start to become available the price will come down.