What do you think of this wheel build?

Everything about building wheels, glueing tubs, etc.
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themidge
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by themidge

My shimano DA c24's are just about toast, so I'll need some new wheels for next spring. I was going to get some carbon tubs but on second thoughts, I think I'll be happy with alloy clinchers for practicality and cost reasons.
I've had a look at the stock options for lightweight clincher alloy wheels, and they're all super expensive, so I'm thinking about building my own.
This is what I came up with, going for a light, cheap build:
Image
What do my fellow weight weenies and wheel building experts think?
Some things to consider about me/my riding:
-I currently weigh about 53kg, but for peace of mind I'd like the wheels to be good for someone at least 60kg if not 65
-I, the rider, am not harsh on wheels, but the roads I ride are suitably British i.e. rough and full of bumps
-I don't want the wheels to be flexy, I only have the aforementioned c24's and some high spoke count retro wheels to compare anything with, but brake rub or a sluggish feel are not what I want to end up with.

Ought I go with a heavier rim? Stronger drive side spokes? Should I consider 16:8 rear lacing? Might I be alright using the lighter Kinlin XR200, or would that result in an aesthetically unpleasing high spoke count?
I'm new to this whole wheel building thing, so any advice would be most welcome!

Thanks, themidge

alcatraz
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by alcatraz

The largest aero gain comes from a very small weight cost by going 40-50mm rims. Maybe 2km/h free speed if you're not climbing.

This rear hub is using four 6802 bearings. I have a hub like that and it's fine (after skf bearing upgrade) except for one bearing, the inner wheel bearing. There is a new generation unbranded taiwanese hubs (ul190 is one of them) that instead of one 6802 uses a 15267 bearing on that sensitive position without adding weight.

Check for Dati R7 on alixpress for example.

I'm only recommending that hub because you are lightweight yourself. If you're 75kg it's not a long lasting choice. Certainly these noname taiwanese hubs aren't on the same level as dura-ace but ok if you're light like yourself.

16:8 lacing is better. 2x/2x 12+12 is a close second and for your weight makes no real difference. For weight saving you can build with thinner spokes if you go the 16:8 route than with 12:12.

If you plan to use alloy rims your wheels will be flexier. I wouldn't go with ultralight spokes on an alloy rim.

Narrower internal rim width will mean higher pressures, less comfort, less speed. For your weight I think the aero/width balance point is somewhere between 25-28mm external width (including tire which will be narrower than this number if you want a good aero profile, rim center is widest).

These hubs mentioned will have a notching issue because of the alloy freehub. I use sram red cassettes (cheap 10 speed) to save weight and freehubs. Never had an issue.

The good thing about your situation is that you are the perfect demographic for chinese/asian components. 55-65kg is often what their stronger riders are so their hubs/rims are designed for that.

/a

Edit:
Dati R6 SL (straightpull 16:8)
https://www.aliexpress.com/item/-/32830680453.html

Dati R7 (J-bend 12:12)
https://www.aliexpress.com/item/-/32832635611.html
Last edited by alcatraz on Sun Sep 30, 2018 5:12 am, edited 2 times in total.

by Weenie


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pdlpsher1
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by pdlpsher1

Light, cheap, and durable. Pick two :D

To me the hub is the heart and soul of a wheelset. Don't ever skimp on the hubs. If you are already on Dura Ace hubs it would be a downgrade to go with anything other than Dura Ace, Campy, or Chris King hubs.

bm0p700f
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by bm0p700f

Triplet on the triplet hubs you can buy is less stiff than 2x lacing both sides. Please do the maths before recommending something. If the triplet hub had the nds flange 46mm from centre then the rear wheel would as laterally stiff as 2x lacing. The bitex hub has a nds to centre spacing if 38mm. I keep on having to repeat this about triplet lacing which means there is a fundamental miss understanding by posters on this forum.

Even though the rider is light a 24spoke rear is still advisable. The rear proposed is so flexible in 20h drilling that it will be difficult to build as side loading (the final stress test) will always throw it out.

The rear wheel needs more spokes, it will be a better wheel even if a 20 spoke rear may be reliable in terms if lack of spoke failure.

The kinlin xr200 is fine with 28 spoke rear not with 24 spoke rear as it is so flexible. I personally if asked to build the specification asked for would refuse.

Also those laser spokes are coming out expensive.

Even at the op low weight a 28 spoke rear with shallow narrow rims is advisable. Use a rim like the xr22t and a 24 spoke rear is viable.

alcatraz
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by alcatraz

bm0p700f wrote:
Sun Sep 30, 2018 7:36 am
Triplet on the triplet hubs you can buy is less stiff than 2x lacing both sides. Please do the maths before recommending something. If the triplet hub had the nds flange 46mm from centre then the rear wheel would as laterally stiff as 2x lacing. The bitex hub has a nds to centre spacing if 38mm. I keep on having to repeat this about triplet lacing which means there is a fundamental miss understanding by posters on this forum.

Even though the rider is light a 24spoke rear is still advisable. The rear proposed is so flexible in 20h drilling that it will be difficult to build as side loading (the final stress test) will always throw it out.

The rear wheel needs more spokes, it will be a better wheel even if a 20 spoke rear may be reliable in terms if lack of spoke failure.

The kinlin xr200 is fine with 28 spoke rear not with 24 spoke rear as it is so flexible. I personally if asked to build the specification asked for would refuse.

Also those laser spokes are coming out expensive.

Even at the op low weight a 28 spoke rear with shallow narrow rims is advisable. Use a rim like the xr22t and a 24 spoke rear is viable.
I have a question about 12/12 vs 16/8. Thanks for helping me figure this out.

If two hubs have same flange spacing and diameters, in 16/8 all 24 spokes are tensioned @ around 120kgf = 24x120 = total tension 2880kgf.

Compared to a 12/12 hub with 12 spokes at 120kgf and 12 at 60kgf = total tension 2160kgf.

How can the triplet be less stiff?

I can understand that because of the different lacing patterns different portions of the tension goes into lateral and torsional stiffness but I still don't understand how it results in less.

Torsional stiffness is maybe slightly sacrificed on triplet compared to 2x/2x 12/12 but not lateral stiffness, right? 16 spokes @ 120kgf provide torsional stiffness on triplet (~1920kgf). 24 spokes provide torsional stiffness on 2x/2x 12/12 (~2160kgf). (Assuming 2x on both)

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themidge
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by themidge

bm0p700f wrote:
Sun Sep 30, 2018 7:36 am

Even though the rider is light a 24spoke rear is still advisable. The rear proposed is so flexible in 20h drilling that it will be difficult to build as side loading (the final stress test) will always throw it out.

The rear wheel needs more spokes, it will be a better wheel even if a 20 spoke rear may be reliable in terms if lack of spoke failure.

The kinlin xr200 is fine with 28 spoke rear not with 24 spoke rear as it is so flexible. I personally if asked to build the specification asked for would refuse.

Also those laser spokes are coming out expensive.

Even at the op low weight a 28 spoke rear with shallow narrow rims is advisable. Use a rim like the xr22t and a 24 spoke rear is viable.
I'm not sure I understand, I chose the Kinlin XR19W (406g) with 24 spokes for the rear, will that not be stiff enough,?
pdlpsher1 wrote: Light, cheap, and durable. Pick two :D

To me the hub is the heart and soul of a wheelset. Don't ever skimp on the hubs. If you are already on Dura Ace hubs it would be a downgrade to go with anything other than Dura Ace, Campy, or Chris King hubs.
Hmmm, you might be right on that. I'm hoping my light weight will mean I can get away with something less durable than most people would ride, while still keeping the price and weight down, might that be a bit optimistic of me?
I see what you mean about hubs, but I don't mind having cheaper ones, so long as they roll reasonably well. I'm perfectly happy riding my winter wheels with mavic Aksium hubs, for example. If I could afford it I'd get Extralite's, but alas, these seem to be the best I can get for the weight and price.

Re: rim width and aerodynamics. I don't mind riding 23 or 25mm tyres on narrow rims, in fact I rather like narrow tyres. I also don't really care about the aerodynamics of my wheel beyond it not having loads and loads of thick spokes churning through the air, I either ride by myself or in a group that isn't racing, so I'll stick to saving weight. If I were to get aero wheels, I think I'd save up for some deep carbon tubs to keep the weight down anyway.


My ultimate question is; will the wheels I specified in my OP work? Os there something about them that should definitely be changed, beyond personal preference?

Multebear
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by Multebear

I had almost that exact wheelset a couple years ago. XR19 rim, Bitex ultralight hubs and Sapim CX ray spokes. 24/28 spokeconfig. I guess I was 85-90 kg at the time. Wheels performed well enough. And if you don't need aero, durability or width, then I think they're rather perfect.

My experience was, that the rims wore fast, because of the thin braketrack and the bearings didn't last long because of the poor sealing in the bitex hubs. If those things aren't issues to you, then go ahead. If they are climbing wheels for good weather, then they are perfect.

But as bm0p700f mentioned, even if you are considerably lighter than me, 20/24 might be to risky. At least 28 rear I'd say.

I didn't rebuild the wheelset with new rims, because a) I wanted better hubs, and b) I wanted more aero rims. So I just took them a part and trashed the rims, kept the spokes and hubs. But haven't used them since.

alcatraz
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by alcatraz

I don't know why bm0p700f is talking about a 20h rear. That was never mentioned.

Yes you can get away with a simpler hub but don't use a 6802 inner wheel bearing hub like the ul190. You can have 6802---xxx---6802---6802 where xxx is something larger than 6802 seen from the rear.

Extralite/carbon-ti use 6903 there which is huge compared to a 6802. You don't need a 6903, because that's for riders heavier than you. But you will enjoy a good longevity like 5 years maybe if you choose it. Swapping a 15267 every 2 years is also not too bad I think.

robertbb
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by robertbb

Easton R90SL's 24 (radial) and 28 (2x). With CXRays or aerolites. Pick a hub that, for you, represents the best balance of weight, price and longevity.

You'll get ~1450g with DT 240's, and it will be a reliable and zippy wheelset for mixed terrain.

bm0p700f
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by bm0p700f

Alcatraz,

Wheel Stiffness has nothing to do with spoke tension. Spoke guage, spoke count, spoke Young's modulus (fixed) and bracing angles are the only variables. The nds flange has to at 45 or 46mm for an 11 speed hub to have the same lateral stiffness to give a big enough bracing angle to compensate for the lack of nds spokes. Wheels are a structure, apply physics not pusudo nonsense.

Campagnolo hubs have an nds flange 45mm from centre. Now you know why.

Spoke tension has nothing to do with wheel stiffness. Triplet has an advantage when done with a proper triplet hub because the higher nds tension means higher side loads can be applied before a spoke goes slack.

Torsional stiffness has nothing to do with spoke tension. For triplet you get tangential spokes to the flange. Given there are 16 of them Ds you might not have any loss in torsional stiffness.

Smidge as I have tried to explain the wheel you asked about would be light but a poor performer. It would be tricky to build because it is not very stiff raidally or laterally and because of that spoke failure for you is quite possible.that rim need 28 spokes, it would be a better wheel to ride with that spoke count, easier to build and more reliable. The price an extra 40g.

bm0p700f
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by bm0p700f

Smidge the number of nippldin you spreadsheet snap for the rear is 20. 24 if going with the hub is still quite low for that rim.

Stiff wheels build well. Your suggestion won't be stiff and won't be easy to build.

Why recommend the 240 hub. The nds bracing angle is poor leading to lower lateral stiffness.

DT swiss when you look at there design don't make good wheels. There hubs also need a propriety ring nut tool to get the ring nut out to replace the Ds rear bearing. I can't think of another hub that has such a daft design making them shop serviceable only, if the shop has the tool. It also is very tight and sometimes does not come out.

Marin
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by Marin

I've been riding a 16:8 190g Bitex ("Farsports Edhub") and 50mm carbon rim since 2013, and I've been 75-80kg all this time. I had to change the rear main bearing so often (1-2x/year) that the bearing seat is worn out and I need to use Loctite so the bearing doesn't fall out :D

However, stiffness is ok I an I never had to replace a spoke or even turn a nipple, so I'd expect a 2:1 build for a rider 20kg lighter than me to last forever.
Last edited by Marin on Tue Oct 02, 2018 8:03 am, edited 1 time in total.

bm0p700f
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by bm0p700f

That's also why the bearing fails so often. If it falls out it a dead hub.

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themidge
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by themidge

Thanks for the advice dudes, I have much to learn about all this :D.

Yeah I meant 24h rear, didn't notice the inconsistency in the spreadsheet there, sorry for the confusion.

If the 190g hub is inadvisable, how about BHS/bitex's 210 gram hub? 2x 6802 bearings and 2x 6902 bearings. It has the same dimensions as the 190g one though, so would 28h rear still be the best option?
Even if I go with the 210g rear hub, 24/28, It'll still be light at ~1338g, which is good, but I'd like to get under 1300 if I can!

alcatraz
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by alcatraz

I think 24/28h is a bit much but it's not unwise. It would be a tour around the world safe build for you. But yes that hub is much much better for bearing life.

Most of your weight is resting on that inner wheel bearing. The outer wheel bearing, being a 6902 too, is larger than it needs to be so when you pop these out later, chances are your outer will have plenty of km left in it.

If you have the dough maybe spring for some carbon-ti hubs. Hubs can be reused in future wheelsets so it's not a crazy idea. Straighpull spokes are a bit more durable but their hubs are designed for a certain lacing pattern so before buying maybe just give the pattern a green light.

by Weenie


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