The wheelbuilding thread

Everything about building wheels, glueing tubs, etc.
85L
Posts: 8
Joined: Mon Sep 30, 2019 3:05 pm

by 85L

bm0p700f wrote:
Tue Oct 15, 2019 11:30 am
85L my own hubs are lighter than hope or chrisking as reliable as both and a bit cheaper than hope.

Yes your wheelbuilder is right to suggest hope but there are other hub too. dt swiss 350 are pretty good disc brake hubs too.
Thanx

To be honest I suggested him DT350 and he replyed that RS4 was à better option.

To resume, I'm lost

by Weenie


bm0p700f
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by bm0p700f

They are equivalent options as I my BORG DX hub.

If buying wheels from.me I am obviously going to suggest my hub not just because I have dropped.money on them but because I have spares for them in stock.

So how easy is it to get hope or dt swiss spares. With 350 hubs does your dealer have the ring nut tool that allows the rear hub DS bearing to be changed its these details that decide which hub.

pier11
Posts: 3
Joined: Thu Oct 17, 2019 2:38 pm
Location: USA

by pier11

Hi wheel builders,
Please help me identify my stock wheel hub.
I think it's unbranded Novatec F162SB.

Wheel is stock on Schwinn Fastback 1 with 105 groupset. Rim used - Alex R500. 28h.
RearHub
RearHub
Having ongoing issues with the wheel, but that's for separate post.

bushido55
Posts: 20
Joined: Sun Jan 27, 2008 5:10 am
Location: USA

by bushido55

re-tensioning after tubeless tire install??? My thought is that even if the tire went flat it would still be lowering spoke tension and keep the tension in check. Does this make sense?

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Alexbn921
Posts: 650
Joined: Wed Apr 10, 2019 6:39 pm

by Alexbn921

bushido55 wrote:
Fri Oct 25, 2019 12:14 pm
re-tensioning after tubeless tire install??? My thought is that even if the tire went flat it would still be lowering spoke tension and keep the tension in check. Does this make sense?
No.
You get a lowing of spoke tention from the air pressure in the tire only.

Edit
getting the tire seated on the bear lock can impart some pressure into the rim depending on the combo, but should be a very very small percentage of the force 70-90psi will impart.
Last edited by Alexbn921 on Fri Oct 25, 2019 9:51 pm, edited 1 time in total.

bushido55
Posts: 20
Joined: Sun Jan 27, 2008 5:10 am
Location: USA

by bushido55

I have read in several places that the lower tension is due to the tire bead and simply mounting the tire will lower presure. I also read, possibly a theory, that air expands in all directions and puts outward force as well as inward. I dont know enough about real world wheel building dybamics but I am trying to learn.

bm0p700f
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by bm0p700f

Air pressure on almost all the setups I have done barely changes the spoke tension. It seating the tyre that does it.

bm0p700f
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by bm0p700f

Air pressure does act in all directions and that why pressure barely has any affect on spoke tension. I have a good tension gauge and measure these things. 250N DS tension drop is what you see on most tu eless installs. If you dont get your stress relieving right then girting tyre and seating knocks it out of true. Also for dishes wheels seating the turn changes the dish by about 1/4 turn of the NDS nipples.

bushido55
Posts: 20
Joined: Sun Jan 27, 2008 5:10 am
Location: USA

by bushido55

That's more in line with what I have read. Do you think it safe to tension during the wheel build prior to installing the tire but then adjusting the tension if needed to get the NDS high enough. On one wheel that I was having some trouble with in this respect, after installing the tire, I bumped the tension up a little to a DS of about 95 and NDS of about 60-65

alanyu
Posts: 646
Joined: Thu Jun 06, 2019 1:10 pm

by alanyu

bm0p700f wrote:
Sat Oct 26, 2019 7:05 pm
Air pressure does act in all directions and that why pressure barely has any affect on spoke tension. I have a good tension gauge and measure these things. 250N DS tension drop is what you see on most tu eless installs. If you dont get your stress relieving right then girting tyre and seating knocks it out of true. Also for dishes wheels seating the turn changes the dish by about 1/4 turn of the NDS nipples.
Let the easy pressure test talk first.
The tension meter reading dropped from 27, ~ 85 kgf to 25, ~73 kgf, when the old pro one inflated from 15 psi to 65 psi.
IMG_20191101_171931.jpg
IMG_20191101_172109.jpg
IMG_20191101_172139.jpg
IMG_20191101_172202.jpg
Then the physics.
Air pressure does act in all directions, correct; thus pressure barely has any affect on tension, not correct.
F=P*S. The bold font means vector. The pressure does act on the rim and the tyre respectively. What forces are doing act on the rim iteself? Let's make it simple by only considering the force inward and outward. Those are the air pressure force inward and, the pushing force outward on the hook due to the tyre or the friction outward between the tyre and the rim if hookless. The former is easy, simply Fin = P*S1. Then the latter. If the tyre was ideally rigid, there would be no pushing force or fiction outward, only the air force inward. In this impossible situation, the tension would drop linearly due to the pressure. That's not reality. The tyre will be pushed and stretched by air in fact, but it is still a solid, and thus the force outward Fout < P*S2. I've said only considering the force inward and outward, so the area S1 and S2, is the projection, which means S1 = S2. Now we can easily get Fin > Fout.

bm0p700f
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by bm0p700f

Well when I have measured tensions before and after inflation I have not seen that big a difference. The difference I have seen is much smaller. then again I am not using a Park TM-1. The measurements I made are with a calibrated Sapim Guague.

RivetRider
Posts: 25
Joined: Mon Aug 13, 2018 12:17 pm

by RivetRider

Hello everybody,

I am looking to plunge into making my first wheelset :shock: and wanted to ask if somebody could check my spoke calculation numbers. Looking to build Kinlin XR31T (BORG) rims (Rim brake, 20H front, 24H asymmetric rear) onto Bitex RAF10/RAR9 Hubs in a 2 cross lacing pattern at the read and radial at the front (not decided on spokes yet, any advice would be appreciated).
Spoke Calculations Kinlin XR31T - Bitex RAF10 (Front).PNG
Bitex RAF10 (Front).PNG
Spoke Calculations Kinlin XR31T - Bitex RAR9 (Rear).PNG
Bitex RAR9 (Rear).PNG
Bitex RAR9 (Rear).PNG (7.46 KiB) Viewed 3340 times
Thanks in advance!
have you tried riding your bike harder?

bm0p700f
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by bm0p700f

Erd is 580mm. Download spokecalc from sheldon brown website and enter the numbers.

All spoke length queries start with downloading this spreadsheet and entering numbers. It's more versatile than other calculators as it does fractional crossings.

RivetRider
Posts: 25
Joined: Mon Aug 13, 2018 12:17 pm

by RivetRider

bm0p700f wrote:
Thu Nov 07, 2019 11:03 am
Erd is 580mm. Download spokecalc from sheldon brown website and enter the numbers.

All spoke length queries start with downloading this spreadsheet and entering numbers. It's more versatile than other calculators as it does fractional crossings.
Hey again,

Punched in the numbers on Spocalc and got he same result. I assume that with this Hub/Rim combo that fractional crossings is not applicable to me?
have you tried riding your bike harder?

by Weenie


pier11
Posts: 3
Joined: Thu Oct 17, 2019 2:38 pm
Location: USA

by pier11

9 broken spokes. Heads lost. 8 from DS.
6 "pushing" DS spokes (heads in). Then 2 pulling spokes DS. Then 1 NDS.
1 or 2 spokes per long ride, not every ride.
Broken spoke makes wheel out of true every time. Requires to disengage rear (rim) brake completely to be able to continue ride.

Wheel (rear): 28h, 2x, 2500km
Rim: Alex R500 (20x20mm approx.; I guess R450 rim is the same thing.)
Hub: Novatec F162SB (I think)
Spokes: no name 14g straight guage (7 gram per 285mm spoke - much lighter than DT Champion, only 0.5 gram havier than DT Comp).

Rider: 72kg/160lbs, recreational rides 100km+. No races, no spints. Not often out of saddle.

I replaced broken spokes each time with DT Comp (Ritche branded). It never broke yet.

On 9 count I replaced all remaining 19 spokes with DT Comp. 250 km after - good so far.

Shall I attribute such failure to low quality spokes? Anything else is going on?
9 broken spokes
9 broken spokes
No name vs DT Comp*
No name vs DT Comp*

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