The wheelbuilding thread

Everything about building wheels, glueing tubs, etc.
KLabs
Posts: 380
Joined: Wed Dec 01, 2010 4:29 am

by KLabs

Yes, it is all dependent on the wheelbuild...

So how much lower than a NDS ratio of 45% would you consider possible or ok?

thanks KL :)

by Weenie


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Calnago
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by Calnago

The thing is, there are so many factors that come into play. For example. If the overall tension is low, and the drive side is not tensioned enough, then 45% would probably result in the absolute tension of the NDS being low enough that the spokes could go slack. I once tensioned up a set of wheels like I described and used a Park TM-1 to check tension. But I discovered later that the Park gauge read high resulting in a lower than ideal tension all round. Eventually a non-drive spoke came loose so I retensioned everything by "feel"... tensioning to the point where it doesn't stay true after stress relieving to find the "max". Then I checked tension and it was then that I discovered that the park gauge was reading differently than my DT Swiss Digital Tensiometer. Hmmm, didn't know which one was right, or if either of them were. Curiosity got the best of me and I sent them both back to their respective manufacturers for a calibration check. According to DT Swiss, the Tensiometer was bang on. The Park needed a little recalibration. However, upon receiving them both back the same spoke (DT Comp) would still read a higher tension using the Park tension gauge versus the DT Swiss gauge. I decided to trust the DT Swiss gauge as far as absolute tension using their own spokes went. And the numbers just seemed more believable. Any gauge is fine but they are most valuable when using as a means of checking relative tension versus absolute tension.
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bm0p700f
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by bm0p700f

I am not sure how low a tension balance you can go as I have yet to find a hub that gives a lower tension balance than 45% (Miche, Power tap G3 e.t.c) All of these work if the DS is at 1100-1200N the closer to 1200N the better though.

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WMW
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by WMW

A lot of you seem to be forgetting that damn near anything will work great if you have sufficient margin. Plenty of people (though not everyone!) are having no issues at all with low NDS tension or lousy DS offset because the rim is stiff enough and the wheel has plenty of spokes for the load they are putting on them. Having a straight rim, even tension, and a good build are also very helpful.

The issues come in when you are trying to see how light you can go and how few spokes you can get away with on a light rim. It's worse if the rim isn't straight and the build is dodgy. And then you definitely don't want a hub with less than ideal geometry.
formerly rruff...

dmp
Posts: 328
Joined: Fri May 08, 2009 8:31 pm
Location: Denver

by dmp

I had a crash this autumn that left surprisingly minimal damage (to both me and the bike), but resulted in a small flat spot in the rim of the front wheel (Stan's 340 rim, C-xrays, Alchemy ELF hub). My mechanic recommended rebuilding the wheel with a new rim, as he is concerned about stability and braking at speed (we have lots of high speed descents here), and I am ok with that. However, I am thinking that I could re-purpose the damaged rim into a dedicated trainer rear wheel, where the hop in the wheel really won't matter.

Do the wheel gurus among you have any suggestions for a really cheap but serviceable hub, 24h, Campy compatible, that might serve the purpose for this? Also, can I reuse the spokes and nipples (I'll get new ones for the road wheel)? I don't want to spend much money on this, but I figured it might be worthwhile not just throwing the rim in the trash.

Thanks!

thprice
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Joined: Sun Jul 17, 2011 6:34 am

by thprice

dmp wrote:... suggestions for a really cheap but serviceable hub, 24h, Campy compatible...
Brandon should be able to look after you at http://www.bikehubstore.com/

pushstart
Posts: 414
Joined: Sat Jun 16, 2012 3:12 am

by pushstart

dmp wrote:Also, can I reuse the spokes and nipples (I'll get new ones for the road wheel)? I don't want to spend much money on this, but I figured it might be worthwhile not just throwing the rim in the trash.


You can reuse the spokes if the new hub has the same dimensions as the Alchemy hub. Most significantly the flange diameters.

I would just reuse your existing a spokes on the new 340 rim, since you know they are the right length and they are already slightly bent/conformed to hub, etc. And buy some cheap Sapim Race spokes for the new wheel.

Personally, I wouldn't bother reusing nipples, but you probably could -- esp if they are brass.

bm0p700f
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by bm0p700f

WSM like you probbaly do I only use rims that are 1) round and 2) build to +/- 5% tension variance or better, so yes almost anything can be made to work and stiff rims helps. 11 speed hub geometry is not ideal so the NDS flange has to be further out so the NDS bracing angle is kept up, this means a poor tension balance. If you have a hubs with a 16-17mm DS flange spacing then the NDS flange has to be 36-38mm from the centre or you end up having to use stiff rims only with the hub like the case is with DT Swiss 240 hubs.

Lateral wheel stiffness is a non linear function of bracing angle so the NDS bracing angle is more important than the DS bracing angle for lateral stiffness. On balance for 11 speed hubs a NDS flange sitting at 38mm from centre may give a low NDS tension but as it improves the wheel stiffness it works.

It is all a comprimise if we did not want a comprimise when we would all ride fixed gear.

jooo
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Joined: Wed Feb 02, 2011 3:48 am

by jooo

bm0p700f wrote:so while the build done is interesting it does not make the wheel "better" just different.

errr right... If a wheel has a better bracing angle and more balanced spoke tension, how is it not better?

Asymptotic
Posts: 267
Joined: Mon Jul 11, 2011 11:06 am
Location: North Adelaide, South Australia

by Asymptotic

Exploring doing a new build for a one-wheel-for-everything. On a tight budget so was aiming for bikehubstore hubs (20/24) / sapim lazers / Stans Alphs 400's.

Curious to hear opinions on the Alpha 400's, few seem to be using them but the rim seems to be a good balance in weight between the 340 and wider rims like the Pacenti/Hed etc
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bm0p700f
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by bm0p700f

If the flange on his 36 spoke wheel crack due to radial lacing down the line then the better bracing angle and better tension balance (by about 60N so not much) will not count for much. Also adding a 1mm to the flange spacing on the drive side make less of improvement in stiffness then adding a 1mm of spacing on the NDS. So given the improvement in tension balance is with the noise of measurement or at least with the normal tension variation you get with a wheel I am not sure the "improvements" will even be noticed.

bm0p700f
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by bm0p700f

Asymtomatic, because there are better rims out there. DT Swiss RR440 is a good all round rim as is the archetype, these maybe heavier but are more of a do everything rim. Read the stan 340 tyre blow off thread. That kind of worries me unless you plan to run tubeless.

dogg
Posts: 291
Joined: Fri Jan 03, 2014 7:37 am

by dogg

hello I'm currently looking into building up a tubular wheelset for my new bike - i fluctuate between 60-65kg, ride mostly rolling terrain, with the occasionally excursion to the mountains for a few weeks.

with that out of the way ill cut to the chase

rims: chinese carbons, 30-50mm in depth. I'm thinking ill go staggered 30f 50r.

i was planning on going 20/24 as this seems a popular choice, and i already have a set of bonti hubs laying around with this drilling

spokes: probably going double butted, but is there a big difference between a wheel with double vs triple butted? obviously less weight with the triples, but how do they ride? i pedal some fairly rough roads, the occasional gravel track. obviously being only ~63kg I'm no powerhouse but i like my wheels to be relatively solid and not require constant truing. not too bothered by a bit of extra weight either

lacing: the only wheels I've owned have been 32 3x/32 3x and 20 radial/24 3x so i will probably go with the same lacing on the 20/24s i had.

building: i will be building them myself, as i do with all my wheels now. but I've never built carbon wheels before. spoke washers seem like a wise idea, anything special i need to do or keep in mind?

looking forward to your feedback, seems like theres a lot of knowledge on here

pushstart
Posts: 414
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by pushstart

I just built my first set of carbon wheels (I have built probably a dozen other wheelsets). I used polyax nipple washers since I typically do -- more for providing a consistent nipple-rim interface; I have found it makes the builds easier. Some rims may require larger washers; you should probably see if the rims you are looking at recommend washer use.

For 24h you want 2x, not 3x. 3x can usually work for 28h, but not 24. Radial and 2x sounds good. I have a set of 50mm clinchers that are radial and 2x with CX-Ray spokes and they are plenty stiff (I weigh around 75kg). So lightweight 2.0/1.5/2.0 double butted or similar triple butted should be fine, if you are doing 38mm+.

Good luck. Sounds fun.

by Weenie


bm0p700f
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by bm0p700f

If you are not going to use aero spokes then Lasers would be fine, washers in the rim are not needed. If the rim needs these the manufacturer will say so if they don't they don't. Also finding washers that will fit may prove hard.

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