The wheelbuilding thread

Everything about building wheels, glueing tubs, etc.
Timmy269
Posts: 184
Joined: Tue Nov 25, 2014 2:34 pm

by Timmy269

Oké thanks, I will use copper grease. Thanks

Nixster
Posts: 76
Joined: Wed Oct 04, 2017 3:30 pm

by Nixster

After a bit of help please.

I'm building Far Sports 30x23mm tubular rims onto Carbon Ti road hubs. Far Sports have the ERD at 585mm but taking on board what I read here I measured it at 588/589mm. Using this and Roger Mussons spoke calc got me 280 NDS/290DS spokes, I'm using CX Rays. Lacing them up the DS was obviously too long, couldn't even get the slack out let alone tension and dish.

Thinking FS might well be right and me wrong i plugged 585 into the calc and bought some 288mm spokes for the DS. Now I can get them to build a wheel and dish BUT DS tension is about 12-13 on a Park TM1 and NDS does not register a value! A couple of DS spokes are bottoming out, so I can't just add DS tension. If I dish about 1-2mm to NDS I can get 2-3 on the NDS spokes with the TM1 but I was expecting 44% of the DS so 5-6 and correctly dished.

So, what am I doing wrong? Is it as simple as shorter spokes DS? Or is 2-3 on the TM1 enough and I should stop worrying? I'm thinking not though as I have very limited adjustability with DS spokes running out of threads. If the answer is shorter spokes, how short? Trial and error is getting expensive!

Help greatly appreciated!

Nixster

by Weenie


Jengaback
Posts: 86
Joined: Thu Jan 29, 2015 9:17 pm

by Jengaback

Nixster wrote:After a bit of help please.

I'm building Far Sports 30x23mm tubular rims onto Carbon Ti road hubs. Far Sports have the ERD at 585mm but taking on board what I read here I measured it at 588/589mm. Using this and Roger Mussons spoke calc got me 280 NDS/290DS spokes, I'm using CX Rays. Lacing them up the DS was obviously too long, couldn't even get the slack out let alone tension and dish.

Thinking FS might well be right and me wrong i plugged 585 into the calc and bought some 288mm spokes for the DS. Now I can get them to build a wheel and dish BUT DS tension is about 12-13 on a Park TM1 and NDS does not register a value! A couple of DS spokes are bottoming out, so I can't just add DS tension. If I dish about 1-2mm to NDS I can get 2-3 on the NDS spokes with the TM1 but I was expecting 44% of the DS so 5-6 and correctly dished.

So, what am I doing wrong? Is it as simple as shorter spokes DS? Or is 2-3 on the TM1 enough and I should stop worrying? I'm thinking not though as I have very limited adjustability with DS spokes running out of threads. If the answer is shorter spokes, how short? Trial and error is getting expensive!

Help greatly appreciated!

Nixster
My advice would always be to measure the erd yourself. Get a pair of spokes of a known length and thread on the nipples you plan to use until they're flush with the bottom of the cut section of the nipple. Pull them through opposite holes of the rim. Make sure they're co-linear and measure the gap between them. Add this to the length of the spokes and voilà you have the actual erd of the rim with the spokes you plan to use

Sent from my SM-G950F using Tapatalk


Nixster
Posts: 76
Joined: Wed Oct 04, 2017 3:30 pm

by Nixster

Nixster[/quote]My advice would always be to measure the erd yourself. Get a pair of spokes of a known length and thread on the nipples you plan to use until they're flush with the bottom of the cut section of the nipple. Pull them through opposite holes of the rim. Make sure they're co-linear and measure the gap between them. Add this to the length of the spokes and voilà you have the actual erd of the rim with the spokes you plan to use

Sent from my SM-G950F using Tapatalk
[/quote]

Yes, I did that with the results described.
The spoke calc may be wrong, but putting in either ERD (my measured or Far Sports spec) gives a result that one of the spoke lengths should 'work' but experience suggests neither does. So, something is awry, possibly my technique, possibly the spoke calc, possibly something else.

seve88
Posts: 62
Joined: Tue Mar 18, 2008 7:06 pm

by seve88

Just converted to disc brakes on road bikes and looking to build a spare set of wheels. Built about 100 rim wheels but never a disc set and don't pretend to be an expert in physics.

I have a pair of 24h Pacenti SL25 rims. I would build on Bitex hubs, 2 cross with Sapim Race or DT Competition. Is 24 enough?

Logic says it should be. My new bike has 24 front and rear and is a Hed Ardenne rim, so similar to the SL25. I'm 150 lbs and ride plenty if hills in northern England.

The conservative person in me would go 28 front and rear but the cheap rims in 24h and so far no issues with 24h wheels is swaying me to give them a go.

Timmy269
Posts: 184
Joined: Tue Nov 25, 2014 2:34 pm

by Timmy269

I have changed all the nipples, the most of them are corroded. Now my wheel is out of trueness.
What's the first step, adjust lateral trueness or radial trueness

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Lightweenie
Posts: 166
Joined: Sun Aug 03, 2014 1:00 pm

by Lightweenie

Do small iterative adjustments in both lateral and radial trueness. Just find the point of maximum untrueness and reduce that. Rinse and repeat.

bm0p700f
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by bm0p700f

Nixter. The park tm1 tells you relative tension not absolute meaning you need to calibrate it with a Spoke hooked to a load cell under tension. The nds spokes won't show a reading on the tm1.

Tommy269 even out tensions that should sort the radial trueness out.

At your low weight 24spoke SL25's should be o.k.
Last edited by bm0p700f on Fri Feb 09, 2018 12:42 am, edited 1 time in total.

Timmy269
Posts: 184
Joined: Tue Nov 25, 2014 2:34 pm

by Timmy269

Thanks, tis evening a little bit fine tuning and the are oké. Before I switched the nipples the tension was 10 ont the park tooltm1, now i tighI tightened the nippels to 11, that makes the wheel a little bit stiffer I think.

Nixster
Posts: 76
Joined: Wed Oct 04, 2017 3:30 pm

by Nixster

bm0p700f wrote:
Thu Feb 08, 2018 12:21 am
Nixter. The park tm1 tells you relative tension not absolute ensuing as you need to calibrate it with. Spoke hooked to a load cell under tension. The nds spokes won't show a reading on the tm1.

Tommy269 even out tensions that should sort the radial trueness out.

At your low weight 24spoke SL25's should be o.k.
@bm0p700 - thanks for the response, I read that you have CF wheels with the same hubs.

Yep, I understood that on the TM1, so I was comparing tension values to other wheels I have with the same spokes, which show higher DS tension (15-16) and NDS tension at 5-6, even on hubs with worse geometry than the C-Ti hubs. Basically I'm about 1-1.5 turns away from those values but the spokes are bottoming out before I can get there on the DS.
I need to thank Sandy at Far Sports here, he has kindly told me what spoke lengths they use for the same build and to summarise I need 286mm on the DS. This makes sense given what I'm experiencing but it is frustrating after I went to the trouble of measuring the ERD and still got the wrong spoke length! Looking to get my 290mm spokes trimmed and rolled to 286mm now.

Worth saying that the Musson calc wouldn't have given 286mm DS even with the smaller ERD value so I suggest people apply caution when using it on straight pull hubs. Or I did something wrong but I struggle to see what.

bm0p700f
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by bm0p700f

DS crossing is 2.5 for the carbon ti hubs. With an ERD of 556mm on a new 45mm carbon clincher I was building with today DS rear length was 272mm and NDS length was 266mm. I used nipple washers and the lengths were prefect.

With straight pull hub getting the right lentgh is tricky you have to know the fractional crossing to calculate. spocalc allows the use of fractional crossings.

Nixster
Posts: 76
Joined: Wed Oct 04, 2017 3:30 pm

by Nixster

bm0p700f wrote:
Fri Feb 09, 2018 12:40 am
DS crossing is 2.5 for the carbon ti hubs. With an ERD of 556mm on a new 45mm carbon clincher I was building with today DS rear length was 272mm and NDS length was 266mm. I used nipple washers and the lengths were prefect.

With straight pull hub getting the right lentgh is tricky you have to know the fractional crossing to calculate. spocalc allows the use of fractional crossings.
That's a new one on me. The Musson calc doesn't do fractional crossings anyway. Can I ask how you get to know whether a hub has fractional crossings or the usual 1x, 2x, 3x?

Found somewhere to trim and roll my spokes, Custom Cut Cycle Spokes AKA Bournemouth Cycles. I rang them in the morning and by lunchtime they were offering it as an option on their website! Much cheaper than a new set :D

Timmy269
Posts: 184
Joined: Tue Nov 25, 2014 2:34 pm

by Timmy269

Timmy269 wrote:
Thu Feb 08, 2018 8:34 am
Thanks, tis evening a little bit fine tuning and the are oké. Before I switched the nipples the tension was 10 ont the park tooltm1, now i tighI tightened the nippels to 11, that makes the wheel a little bit stiffer I think.
I have put the tire on the front wheel en inflate it to 8.1 bar. Is it normal that the tesnion is dropped to 8,5 on the Parktool TM1?
What is the correct weight limit, the tension measured with tire or without tire?

bm0p700f
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by bm0p700f

All straight pull hubs have fractional crossing for 1x 2x or 3x lacing for calculation purposes. Spocalc allows fractional crossing. As the guy who imports carbon Ti into the u.k I kind of need to know how to works out spoke lengths for builds with them.

So give me your measured ERD and I can let you know the spoke length you need.

by Weenie


bm0p700f
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by bm0p700f

the TM-1 for the 15th million times does not give you your tension it only tells you relative tension (I am not annoyed but this is a cheap and frankly useless tension meter that should not be bought by anyone). yes you do get a tension drop with an inflated tyre bigger with tubeless tyres. this should be accounted for when tensioning the wheel.

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