Who is Hambini?
10-30-19, 09:23 AM
#51
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I don't have any direct experience of this crankset. However the BB30 units I have seen are using wavy spring washers to control axial clearance (preload) at the non-drive side of the axle. In this case you should use DGBB (6806) as replacements and not ACBB. Generally with the wavy washers you don't need to adjust; you just tighten the cranks up which partially compresses the wavy spring washer which preloads the bearings.
10-30-19, 02:24 PM
#52
Senior Member
I have not read the book. Only seen some snippets/debates online.
Don’t mean to turn this into a debate but:
“Other than its tension the bicycle wheel is the same as any other wheel such as a wooden wagon wheel. The spoke under the hub is shortened in compression by a load on the axle, while the upper spokes remain unaffected by the load.”
Maybe I’m just dumb but I don’t see a lack of tension as the same thing as compression. We don’t have to discuss this any further, but I think this could be fairly easily resolved if someone heavily loaded a wheel and then cut the spoke at the bottom, and nothing happened. If that spoke were truly a load bearing structure, then something would happen. Regardless, you’re right that this has been debated endlessly and there’s no resolving it.
Don’t mean to turn this into a debate but:
“Other than its tension the bicycle wheel is the same as any other wheel such as a wooden wagon wheel. The spoke under the hub is shortened in compression by a load on the axle, while the upper spokes remain unaffected by the load.”
Maybe I’m just dumb but I don’t see a lack of tension as the same thing as compression. We don’t have to discuss this any further, but I think this could be fairly easily resolved if someone heavily loaded a wheel and then cut the spoke at the bottom, and nothing happened. If that spoke were truly a load bearing structure, then something would happen. Regardless, you’re right that this has been debated endlessly and there’s no resolving it.
10-30-19, 02:40 PM
#53
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thank you for these interesting information and precisions.For the preload of the bearings of the caad7, I caught the wave washer thing.Thanks everybody
10-30-19, 03:08 PM
#54
Senior Member
I don't have any direct experience of this crankset. However the BB30 units I have seen are using wavy spring washers to control axial clearance (preload) at the non-drive side of the axle. In this case you should use DGBB (6806) as replacements and not ACBB. Generally with the wavy washers you don't need to adjust; you just tighten the cranks up which partially compresses the wavy spring washer which preloads the bearings.
Some SRAM cranks also use the wavy washer with BB30 but my Red cranks do not. I have an adjustment collar like the one pictured. As you turn the adjuster the internal bit threads outward, eliminating play and preloading the bearing. A set screw locks it in place once set. Seems like this be sufficient to sustain a consistent contact angle.
10-30-19, 03:42 PM
#56
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Think of the spoke as a brake cable - works in tension but not in compression. The lowering of tension does not create compression only relaxation into the untensioned state. The change in the level of spoke tension is the result of elastic deformation of the component parts under load (rim and spokes).
10-30-19, 03:47 PM
#57
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I have a GXP BB and Hambini just said they were "bollocks" and "a bag of wank". I think that's bad.
10-30-19, 10:38 PM
#58
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Well, the discussion so far has centered on tension on the spokes. To that end, deformation of the local part of the rim is the cause of local lowered spoke tension.
When tensioned, spokes stretch. When the rim deforms under load the small portion of the rim, near where the tire touches the road, is deflected and the hub closer together. This reduces the length between spoke hole and nipple, and the spoke tension for those spokes is lowered. They're still in tension, but less so.
The key failure mode for a spoke in compression would be buckling. It would take about a quarter kilogram to buckle a spoke. So no, no compression.
Put another way: less tension, but zero compression.
When tensioned, spokes stretch. When the rim deforms under load the small portion of the rim, near where the tire touches the road, is deflected and the hub closer together. This reduces the length between spoke hole and nipple, and the spoke tension for those spokes is lowered. They're still in tension, but less so.
The key failure mode for a spoke in compression would be buckling. It would take about a quarter kilogram to buckle a spoke. So no, no compression.
Put another way: less tension, but zero compression.
Last edited by WizardOfBoz; 10-31-19 at 08:28 AM.
10-31-19, 11:20 AM
#59
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10-31-19, 11:31 AM
#60
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Here's a small clue that is consistently ignored by the ostriches who attempt to debate the spoke question: bike spokes have been replaced with strings and the wheel functioned as normal.
For anyone who really wants to understand rather than cling to a known false premiss for comfort sake, just do what Brandt refused to do: construct a free body diagram of a bicycle spoke.
For anyone who really wants to understand rather than cling to a known false premiss for comfort sake, just do what Brandt refused to do: construct a free body diagram of a bicycle spoke.
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10-31-19, 11:53 AM
#61
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Do we need to rehash the spoke argument here? Neither analogy (hub hangs from spokes, hub stands on spokes) is completely accurate, so it's dumb to keep arguing as if one is.
10-31-19, 11:38 PM
#62
Senior Member
I love Hambini, the debunker of Zipp, Flo, CeramicSpeed, etc...
Hambini and Leusher are favorite cycling related youtube channels
Hambini and Leusher are favorite cycling related youtube channels
03-28-20, 01:58 PM
#63
Senior Member
What data did he falsify? You have proof?
03-28-20, 02:00 PM
#64
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03-29-20, 02:57 PM
#65
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03-30-20, 12:35 AM
#66
Senior Member
+1 Having been involved in a long drawn out discussion on wheel dynamics, this is the key to my problem with Brandt's point. He (and others) look on a decrease in tension as an increase in compression as if they are directly opposite forces. They aren't. For compression to occur, especially in a tensioned bicycle wheel, tension has to be zero and vice versa.
Additionally, there is also nothing to "compress" when it comes to a spoke. Put a single spoke in a rim (or piece of rim) and hang a hub from it. Hold on to the rim and turn it upside down. The hub will fall through the rim along the spoke until the hub hits the rim. The end of the spoke doesn't "stand" on anything so it can't be compressed.
Additionally, there is also nothing to "compress" when it comes to a spoke. Put a single spoke in a rim (or piece of rim) and hang a hub from it. Hold on to the rim and turn it upside down. The hub will fall through the rim along the spoke until the hub hits the rim. The end of the spoke doesn't "stand" on anything so it can't be compressed.
03-30-20, 07:06 AM
#67
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03-31-20, 03:07 PM
#68
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03-31-20, 03:21 PM
#69
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[QUOTE=seb1466;21187328]Think of the spoke as a brake cable - works in tension but not in compression. The lowering of tension does not create compression only relaxation into the untensioned state. The change in the level of spoke tension is the result of elastic deformation of the component parts under load (rim and spokes).
Can't compare brake or shift cables because they don't work in tensions as high as a spoke.
Can't compare brake or shift cables because they don't work in tensions as high as a spoke.
03-31-20, 03:25 PM
#70
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Follow the links in the Flo statement. https://flocycling.com/blogs/blog/fl...ni-accusations
04-02-20, 12:19 PM
#71
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04-03-20, 07:30 AM
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Uh.... wasn’t Jobst Brandt the one who thought spokes act like pillars in compression when under load? And wrote a book saying that? He said that the wheel load was carried by the bottom few spokes. I’m 99.9% sure that’s a load of bull because there exist spokes that are literally string..
I didn't agree with everything he said by any means but just to be clear he was a great guy and knew what he was talking about, and his book about wheels is rightly considered a classic.
04-03-20, 10:40 AM
#73
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The time for politeness is over. If you think the only reason why Hambini’s “rudeness” is appealing is that we are a bunch of immature children, you are quite mistaken.
Last edited by smashndash; 04-03-20 at 05:55 PM.
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04-03-20, 03:44 PM
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04-05-20, 01:17 PM
#75
Senior Member
Here's a small clue that is consistently ignored by the ostriches who attempt to debate the spoke question: bike spokes have been replaced with strings and the wheel functioned as normal.
For anyone who really wants to understand rather than cling to a known false premiss for comfort sake, just do what Brandt refused to do: construct a free body diagram of a bicycle spoke.
For anyone who really wants to understand rather than cling to a known false premiss for comfort sake, just do what Brandt refused to do: construct a free body diagram of a bicycle spoke.