New disc brake wheelset build for Felt F3X cross bike

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savechief
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by savechief

I'm planning on using my CX bike far more throughout the upcoming years than just racing cross, so I'm planning on building up a new wheelset (was hoping for something that was 1,5XX grams total) to replace the stock DT Swiss wheels (898g front, 1,043g rear, 1,941g total). I'm 73kg and these wheels will mainly be used on the road with 28mm (Continental GP4000S II) to 32mm (Clement Strada LGG) tires.

I've pretty much settled on this:
1) Bitex BX106F/BX106R Centerlock disc hubs
2) 28H front and rear, 2-cross

What I'm still debating is this:
1) Rims - Currently torn between HED Belgium Plus Disc or Easton R90 SL Disc. The Eastons are a bit lighter and a bit less expensive, but I just love the aesthetics of the HEDs. Are there others I should consider...should I look at rims that measure 17-18mm internally rather than just those that are 19-20mm internally?
2) Spokes - Was initially thinking Sapim Race, but the way the discounts work, the price difference to jump to CX-Rays is not that big.
3) Nipples - Black brass for durability, though tempted by black alloy for the approximately 40g weight savings.
Last edited by savechief on Wed Nov 29, 2017 3:15 pm, edited 1 time in total.
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morganb
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by morganb

Pacenti Forza is another option in that weight/width category. I would do 19-20mm+ internal with those tires sizes for sure. You'll get a much better tire profile and be able to take advantage of low pressure better because the tire should be more stable.

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savechief
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by savechief

From what I can tell, the only advantage that the Forza offers is that it's asymmetric, unlike the Easton or HED.
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hmai18
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by hmai18

Personally, I'd stay away from Pacenti rims. They have a poor history of quality issues (cracking at nipples, rattling sleeves, etc).

savechief
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by savechief

That's exactly why I hadn't considered the Forza along with the Belgium Plus and R90 SL. I know the SL23 was updated, and the new Forza further allows for lessons learned to be incorporated, but I was still a bit uneasy with their perceived reputation.
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jeanjacques
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by jeanjacques

Dt Swiss RR421 rim ? Asymmetric, 20mm internal, 425g.

bm0p700f
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by bm0p700f

the new forza seems to have none of the issues that the older pacenti rims had. for reference the SL25 disc brake rim had no issues at all. It is a good a rim.

The hed rims are expensive and while they are good the velocity aileron is a lovely rim that is wide deep and very stiff.

The Kinlin XR31RTS has non of the athestic appeal but it is a fine rim. The Dt RR421 is 21mm deep will be less stiff than the rims you are considering.

For 28 spoke disc wheels lace 3x please.

A CX-ray spoke to me in the trade with the discounts I get is 3x the price of a black sapim race. so how you can get them without a big price hike I dont know.

savechief
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by savechief

There is a fixed percentage discount for all builds but there is also free shipping if you go above a certain value. If I use the cheaper spokes, I don't end up going over that value that gets me free shipping. But if I use the CX-rays, I do get about that value, and end up getting free shipping. So that closes the gap between the cheaper spokes and the cx-ray spokes.

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savechief
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by savechief

On a scale of 1 to 10, with 1 being barely noticeable difference, and 10 being game-changer, how much difference does it make to build a disc wheelset with an asymmetric rim versus a symmetric rim? I'm trying to figure out how much priority I should put on using an asymmetric rim in this build.

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joejack951
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by joejack951

In my experience, you'll gain 10-15% better tension balance by using an offset rim. For a front wheel, that means ~90% of disc side tension on the non-disc side versus ~80%. For the rear, ~75% of drive side tension on disc side with offset rim vs. ~65% without.

jeanjacques
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by jeanjacques

bm0p700f wrote:For 28 spoke disc wheels lace 3x please.


You are the first one I saw to said this, why 3x over 2x ?

savechief
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by savechief

jeanjacques wrote:
bm0p700f wrote:For 28 spoke disc wheels lace 3x please.


You are the first one I saw to said this, why 3x over 2x ?
You beat me to it, I was going to ask the same question. I looked at every wheel manufacturer I could think of that produces road disc wheels, and I couldn't find any that used 3X with 28H.

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CallumRD1
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by CallumRD1

I have a wheelset I built with Bitex BX106 hubs and LightBicycle 46mm hookless rims using CX-Ray spokes and I have nothing bad to say about any of the components. The hubs have been perfect and are very easy to service. I chose CX-Ray spokes because they're a little easier to build with, not for any marginal aerodynamic benefits. (They make it easy to see and control spoke windup.)

bm0p700f
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by bm0p700f

for the high spoke loads that disc brakes can and do apply spokes being tangential to the flange is beneficial. torsional stiffness is higher for 3x lacing than 2x lacing for 28 spoke wheels.

see fig 7 in this paper http://people.duke.edu/~hpgavin/papers/ ... -Paper.pdf
but it really is basic physics. the loss in lateral wheel stiffness is inconsequential, as it is small and with proper wheel design you can compensate for that.

The fact that wheel manufacturers don't do this means they have some fuzzy logic applied to there wheel. some manufacturers are doing triplet lacing for rear disc brake wheels but lateral stiffness is reduced compared to 1:1 lacing and if you use an asymmetric rim tension balance is pretty good anyway so the benefit is simply not there. Such wheels may pass testing but that does not mean they are an optimal design that properly balances all characteristics.

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bm0p700f
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by bm0p700f

Asymmetric rims lead to longer spoke life's an identical rim that is symmetric. The service life from spokes using symmetric rims is normally more than acceptable though. Asymmetric rims do help when tubeless tyres are used. I dont think asymmetric rims are essential but are nice to have.

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