Right, I need to get a new rear wheel. I'm skint but thinking that it might be worth paying for DT double butted spokes to save a bit of weight without sacrificing strength (I ride a HT and weigh ~90kg). But then I read somewhere that plain gauge on the drive side is a good idea...I'm confused...help.
Bike Forum
Spokes: plain gauge -v- double butted
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Posted 7 months ago #
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Having studied the strength of spokes for a mechanical engineering paper, you probably won't notice a difference. In fact the butted spokes in my testing (although only having 90%of the strength) actually stretch less which provides a more solid drive in the rear wheel. The fact a wheel is built correctly has more bearing on the overall strength.
Posted 7 months ago # -
Thanks - sounds like db are worth the extra £9...
Posted 7 months ago # -
The fact a wheel is built correctly has more bearing on the overall strength.
This.
Posted 7 months ago # -
I'm getting it from Merlin and hopefully they know what they're doing...
Posted 7 months ago # -
build it yourself.
useful,cheaper.
Posted 7 months ago # -
MarkyG82 in "self proclaimed engineer misses various relevant points" shocker!
OP either will be fine.
Posted 7 months ago # -
Having studied the strength of spokes for a mechanical engineering paper
I presume given your other comments you only studied them in isolation (though I'm very confused by your comments about butted spokes stretching less - basic physics shows that can't be so).Don't get butted spokes to save weight. They do however build stronger wheels (all else being equal - as mentioned, build is more important). There is an argument for PG on drive side, as it will help to reduce the difference in stretch of the spokes on either side due to dishing, but it's outweighed by the advantages of butting (I have normal butted drive side and DT Revs NDS for that reason on one of my wheels, but the difference it makes is marginal).
Posted 7 months ago # -
Thing is aracer, using the "more butted" spokes on ghe DS gives a stiffer wheel...
My conclusion....mosf of this guff does not matter a great deal.
Posted 7 months ago # -
I'm getting it from Merlin and hopefully they know what they're doing...
I bought some wheels from merlin a few years ago, didn't last long 'til they went out of true. LBS (Jackie at Nirvana) straightened them and they never went out of true again.
Posted 7 months ago # -
I bought some wheels off of merlin 5 and a half years ago and have been abusing them every week since and they haven't needed truing ever.
Posted 7 months ago # -
using the "more butted" spokes on ghe DS gives a stiffer wheel...
Laterally stiffer initially, yes. Under heavy impacts they'll become less laterally stiff than if you'd laced them the other way round though...Posted 7 months ago # -
build it yourself.
useful,cheaper.
+1
Just built mine, can't comment on longjevity yet but it's strangely satisfying and addictive turning a pile of spokes, hubs and rims into wheels.
Going to build some for the road bike next (they were origainly meant to be practice before the MTB ones, but the pitch ate it's rear wheel).
Posted 7 months ago # -
build it yourself.
useful,cheaper.
Are you sure about the cheaper? Last time I priced it up, buying the individual bits cost more than a cheap pre-build wheel.Posted 7 months ago # -
What do you need to build a wheel? Do you need a jig or can you improvise?
Ta
Posted 7 months ago # -
I weigh 70kg and have run double butted spokes for the last three years with no problems other than the alloy nipples I originally used going brittle. All nipples now changed for brass ones.
Posted 7 months ago # -
cheaper
hahahaha
Posted 7 months ago # -
An upside down bike and a piece of chalk make a good substitute for a proper jig.
Posted 7 months ago # -
Are you sure about the cheaper? Last time I priced it up, buying the individual bits cost more than a cheap pre-build wheel.
LBS wanted £85 to build a rear wheel onto an existing hub, the parts for 2 wheels form rose bikes cost £85 excluding hubs.
I reckon you could build a pair of hope hoops with any of the options other than Stans for the £310 they sell for in most shops.
Depends on the shop/wheel though, apparently CRC build them on machines now which may/may not be better than handbuilt.
Posted 7 months ago # -
http://pardo.net/bike/pic/howto-001/component-details.html
As long as you have a good spoke key, then you can just use the bike as the wheel jig. Depending on the hub / dropout type you can just reverse the wheel to check the wheel-dishing.
Posted 7 months ago # -
ok.cheaper in the long run.
maybe not cheaper like for like.but if you buy when something's on offer,and aren't set on something too specific.it's cheaper.
no truing costs, ever.factor that in..a nice ghetto stand is(are?)some forks mounted in a vice.
Posted 7 months ago # -
^ only works for front wheels though
If you are wanting a high end set of wheels with all new bits then just get them built somewhere like Merlin etc.
If you are knocking yourself up some wheels on the cheap with bits you already have then sure have a go at DIY. you can get spokes pretty cheaply if you look hard enough.
Posted 7 months ago # -
Aracer:
You are right that they were isolated from real world use. The principle is correct though. I discussed it with a materials science lecturer and we came to the conclusion that the process of butting the spokes 'compresses' the structure if the metal causing it to be less elastic. So for a given force it will stretch less but ultimately hold less load due to smaller CSA of the material overall.
This is what I found. Whether its correct or not is another matter al together
Posted 7 months ago # -
I discussed it with a materials science lecturer and we came to the conclusion that the process of butting the spokes 'compresses' the structure if the metal causing it to be less elastic. So for a given force it will stretch less
Well I'd love to see your results. Maybe you don't realise what you've got there, as it appears to contradict all known scientific theory. It could be as big a thing as the latest "faster than light" discovery at CERN in terms of a new understanding of the way the world works. You need to get your findings in a major peer reviewed journal, so that other scientists can comment on them (it sounds like your materials science lecturer also didn't realise how existing laws of physics don't adequately explain your work).I'm impressed at such a major new discovery first coming to light on the STW forum.
Posted 7 months ago # -
aracer - don't be such a c0ck. Marky is right.
As I understand it, butting the spokes plastically deforms them (they're rolled thinner). Yes, it will be weaker, but will have a different stress-strain curve, so the spoke will perform differently to a non-deformed spoke of the same diameter and material.Posted 7 months ago # -
I reckon you could build a pair of hope hoops with any of the options other than Stans for the £310 they sell for in most shops.
So if you compare apples with oranges you mean?
You can get the Stan's ones for £250ish from many online sources. You could probably buy all the component parts, albeit with cheaper rims, for £60 more... ergo, pre-built is cheaper!
Getting a shop to build on your existing hubs/rims may not be cheaper, but going to the 'usual culprits' who have online wheelbuild facilities will almost certainly be cheaper than building your own, depends on what you're trying to achieve.
Posted 7 months ago # -
Studied materials science, ir_bandito? Understand Hooke's Law and Young's Modulus? Checked the results of studies into the effects of cold working on elastic modulus of stainless steel?
Ironically, if you check the data provided by Sapim, the PG spokes are actually weaker than the butted ones (and the more butted the better), as the cold working does significantly increase the strength, so you're wrong on both counts!
http://www.sapim.be/index.php?st=products&sub=spokes&category=3961&id=3389&detail=basic
http://www.sapim.be/index.php?st=products&sub=spokes&category=3960&id=3385&detail=butted
http://www.sapim.be/index.php?st=products&sub=spokes&category=3960&id=3386&detail=buttedPosted 7 months ago # -
andyl
just mount the rear on one dropout.
and zipties.for indicators.
edit.doesn't work for 20mm axles.
edit2.nor do 20mm forks work for this.Posted 7 months ago # -
Aracer is right.
You don't make steel stiffer by cold working it.
Posted 7 months ago # -
schraner says the 'hammering of the spokes compresses the metal'.
not an exact quote,but roundabouts.besides,the question isn't that.spokes break at the head.not in the middle.
as my nan always says-always use spoke washers.
Posted 7 months ago # -
if you get stans in the sales then they're cheaper.
got some 819s at half price.granted they have machined sidewalls.but I saved 30eu per rim.Posted 7 months ago # -
The rim brake ones? The bigger issue is that they weigh a **** ton!
Posted 7 months ago # -
aracer is correct - if he isnt then the op is heading for nobel prize territory. I'm a materials scientist.
Posted 7 months ago # -
schraner says the 'hammering of the spokes compresses the metal'.
Is Schraner a materials scientist (or any form of scientist)? If Brandt had said it, it might have been worth bearing in mind, however he actually says "The diameter reduction increases spoke elasticity". Of course if you check in the back of Brandt you'll find he's done some testing which directly contradicts Marky's findings.Oh, and thanks toys - you trump me as I only studied materials science at undergrad level.
Posted 7 months ago # -
Oh, and thanks toys - you trump me as I only studied materials science at undergrad level.
well that was my degree, and my masters and my unfinished phd, and I've spent that last 17 years working as a materials scientist. Don't ask me about nursing though.Posted 7 months ago #
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