The wheelbuilding thread
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The spirit of this board is to compile and organize wheels and tires related discussions.
If a new wheel tech is released, (say for example, TPU tubes, a brand new tire, or a new rim standard), feel free to start the discussion in the popular "Road". Your topic will eventually be moved here!
The spirit of this board is to compile and organize wheels and tires related discussions.
If a new wheel tech is released, (say for example, TPU tubes, a brand new tire, or a new rim standard), feel free to start the discussion in the popular "Road". Your topic will eventually be moved here!
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strobbekoen
- Posts: 4426
- Joined: Wed May 18, 2005 6:24 pm
- Location: BELGIUM
Not much.. but it does change the structure of the wheel.
I am just curious why historically wheels are built this way. Is it for structural reasons or not ? I can't imagine it not to be ?
I am just curious why historically wheels are built this way. Is it for structural reasons or not ? I can't imagine it not to be ?
A lot of things in cycling are done for no good reason at all.
Ok... I spent some time figuring. The easiest way is to assume that the spoke has zero lateral stiffness... ie they are strings. This would maximize the effect. Then calculate the change in spoke length going from the normal crossed configuration, to one where one of the spokes is removed... ie it's gone completely slack and no longer effects the other.
Starting with the following:
5 mm offset between spokes at the hub
60mm to the cross (centered distance)
220mm after that to the rim
The initial spoke length is 280.052mm. With one spoke removed the length drops to 280.011mm, for a .041mm reduction. A CX-Ray at 120kg stretches ~.90mm so the spoke tension change is 5kg... worst possible case. In normal use I doubt this would exceed 1kg very often, and then only during periods of high torque.
Ok... I spent some time figuring. The easiest way is to assume that the spoke has zero lateral stiffness... ie they are strings. This would maximize the effect. Then calculate the change in spoke length going from the normal crossed configuration, to one where one of the spokes is removed... ie it's gone completely slack and no longer effects the other.
Starting with the following:
5 mm offset between spokes at the hub
60mm to the cross (centered distance)
220mm after that to the rim
The initial spoke length is 280.052mm. With one spoke removed the length drops to 280.011mm, for a .041mm reduction. A CX-Ray at 120kg stretches ~.90mm so the spoke tension change is 5kg... worst possible case. In normal use I doubt this would exceed 1kg very often, and then only during periods of high torque.
petal666 wrote:My faith in these lightweight Chinese rims has been somewhat diminished from my already fairly low expectations.
I had just finished building a front wheel, very even 100kgf spoke tension, 24 spokes on a 20mm farsport 224g tubular rim and was giving the last spoke a tweak and thinking about glueing on a tire rather than what I was doing. The spoke key slipped and cracked the alloy nipple.
The wheel was straight and I could have left it but I thought I'd do it properly so decided to replace the nipple. Stupidly I unwound just that one spoke and removed it. I was about to put in the new nipple when the below happened.
Obviously the rim can't handle full tension on all spokes and then having one removed. It makes me wonder what would happen if you ever broke a spoke during a ride.
From what I can decipher from farsports replies, they suggest that the wheel should be built by one of their experienced wheel builders, not that would make a lick of difference if a spoke ever broke. Plus it's not as though I had uneven or super high spoke tension.
I also bought a set of 210 gr. farsport china rims. like I already wrote in another topic, these rims are complete crap (they cracked at the fist testride). I bought some 38mm tubulars (china also) and they hold very well. the 20 mm rims are just too light.
pino76 wrote:I also bought a set of 210 gr. farsport china rims. like I already wrote in another topic, these rims are complete crap (they cracked at the fist testride). I bought some 38mm tubulars (china also) and they hold very well. the 20 mm rims are just too light.
Correct me if I'm wrong, but aren't you the same guy who tensioned the RDS to 210kg?
I'm rebuilding this rear wheelset. 32h 3X with laser spokes on a Kinlin XR 200 rim.
It's centered, round and true now, but I didn't finish to put it to tension. I checked all spkes to make shure the tension is about even.
On the NDS, two spokes have almost zero tension on them.
Is it because they've streched (they were on a previous build)?
Or the rim bed is not even from the previous build ?
What should I do to correct this guys ?
Louis
It's centered, round and true now, but I didn't finish to put it to tension. I checked all spkes to make shure the tension is about even.
On the NDS, two spokes have almost zero tension on them.
Is it because they've streched (they were on a previous build)?
Or the rim bed is not even from the previous build ?
What should I do to correct this guys ?
Louis
I am getting to around 90 on the drive side.
When I say zero, they probably have a little tension, but not enough so the Park Tool TM-1 can measure it. With a Novatec F482SB as a rear hub, it's normal I get very little tension at the moment, but these two are really lower than the other ones.
I am building using the "usual steps":
1) Bring the spokes to the first threads at the nipples
2) Progressively tension evenly starting at the valve hole
3) Center the hub
4) Check and adjust roundness
5) True
Plus relieve the stress on spokes regularly.
It's the first time I use a very "soft rim", like the XR 200. It moves just by turning the nipples very little. Could it be that it can have "flat spots" ? The "roundness" guage gives it less than 1 mm difference now.
Louis
When I say zero, they probably have a little tension, but not enough so the Park Tool TM-1 can measure it. With a Novatec F482SB as a rear hub, it's normal I get very little tension at the moment, but these two are really lower than the other ones.
I am building using the "usual steps":
1) Bring the spokes to the first threads at the nipples
2) Progressively tension evenly starting at the valve hole
3) Center the hub
4) Check and adjust roundness
5) True
Plus relieve the stress on spokes regularly.
rruff wrote:Rim could be bent...
It's the first time I use a very "soft rim", like the XR 200. It moves just by turning the nipples very little. Could it be that it can have "flat spots" ? The "roundness" guage gives it less than 1 mm difference now.
Louis
I'm looking at putting together a tubeless wheelset for my wife's road bike. She currently has some Zipp team clinchers and while the simplest way would be to convert them to tubeless via a Stan's road kit, I thought a lighter alternative (about 200g less) would be to relace the Zipp hubs/CX-Rays to Stan's Alpha 340 rims.
Zipp Team Clincher = Zipp 108/208 hubs / Sapim CX-Ray / DT Swiss R450 rims
---Spoke lengths
Front wheel (2x) = 284.1mm
Rear wheel (3x) = NDS 290.8mm / DS 291.6mm
Zipp/Stan's Alpha 340 = Zipp 108/208 hubs / Sapim CX-Ray / Stan's Alpha 340 rims
---Spoke lengths -
Front wheel (2x) = 282.6mm
Rear wheel (3x) = NDS 289.3mm / DS 290.1mm
So my question is:
-----Are these spoke lengths close enough that I can reuse the spokes?
Zipp Team Clincher = Zipp 108/208 hubs / Sapim CX-Ray / DT Swiss R450 rims
---Spoke lengths
Front wheel (2x) = 284.1mm
Rear wheel (3x) = NDS 290.8mm / DS 291.6mm
Zipp/Stan's Alpha 340 = Zipp 108/208 hubs / Sapim CX-Ray / Stan's Alpha 340 rims
---Spoke lengths -
Front wheel (2x) = 282.6mm
Rear wheel (3x) = NDS 289.3mm / DS 290.1mm
So my question is:
-----Are these spoke lengths close enough that I can reuse the spokes?
Garth, be careful with using the spokes again on a different rim if they're a little too short?
If you're using an alloy nipple a spoke that's 2-3mm too short can lead to problems a bit further down the line?
The spoke thread needs to thread into the bulbous head of the nipple, if it's a bit short and doesn't do that, alloy nipples are very prone to fatigue cracking and shearing the nipple head off?
Take a look and check to see how far the threads come up in the nipple on the current rim?
If they're slightly too long and protrude from the nipple head you may be able to re-use them.
If it looks a bit touch and go, you may be better off changing to a brass nipple instead as they're way stronger.
Although not ideal, you could also go for a longer nipple?
You get an extra 1mm of thread on a 14mm nipple and an extra 2mm on a 16mm.
If you're using an alloy nipple a spoke that's 2-3mm too short can lead to problems a bit further down the line?
The spoke thread needs to thread into the bulbous head of the nipple, if it's a bit short and doesn't do that, alloy nipples are very prone to fatigue cracking and shearing the nipple head off?
Take a look and check to see how far the threads come up in the nipple on the current rim?
If they're slightly too long and protrude from the nipple head you may be able to re-use them.
If it looks a bit touch and go, you may be better off changing to a brass nipple instead as they're way stronger.
Although not ideal, you could also go for a longer nipple?
You get an extra 1mm of thread on a 14mm nipple and an extra 2mm on a 16mm.
Pedalling Law Student.
Mackers wrote:pino76 wrote:I also bought a set of 210 gr. farsport china rims. like I already wrote in another topic, these rims are complete crap (they cracked at the fist testride). I bought some 38mm tubulars (china also) and they hold very well. the 20 mm rims are just too light.
Correct me if I'm wrong, but aren't you the same guy who tensioned the RDS to 210kg?
yes
, but I changed the lacing pattern and after that the tension was 150 (DS)I did a radial lacing in the front, even then it was more like a fishing rod.....
note: in my opinion it make a huge different if you use different spoke thicknes for the tension. when you use DT comp for the ds, and revo's for the NDS, then you can't compare the spoke tension of both sides because a thinner spoke bends more easy, what results in a lower tension on your tensionmeter...
thats why I came on the 210 kgf on the ds.
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Hi guys, If all goes to plan I'll be building up a nice retro wheelset in the next couple of weeks. I already have hubs and rims sourced and on their way (Sachs New Success cassette hubs (130mm OLN) and Mavic Mach 2 CD 2 tub rims, 32 hole) but I need some recommendations for spokes and lacing. I was thinking 2 cross on the front and 3 cross on the rear. I guess that's feasible?
Not sure about spokes, probably something non-aero from sapim or DT. What's my best bet? Any suggestions? I haven't got the hubs and rims yet, so need to measure them and decide on the lacing pattern before calculating spoke lengths, but I don't imagine having any weird lengths to find. I'm not too worried about weight (the hubs and rims aren't exactly lightweight so I don't see the point using really light spokes) so something double butted at a reasonable price would be great.
Thanks!
Not sure about spokes, probably something non-aero from sapim or DT. What's my best bet? Any suggestions? I haven't got the hubs and rims yet, so need to measure them and decide on the lacing pattern before calculating spoke lengths, but I don't imagine having any weird lengths to find. I'm not too worried about weight (the hubs and rims aren't exactly lightweight so I don't see the point using really light spokes) so something double butted at a reasonable price would be great.
Thanks!
