Why are top caps tapered?
05-03-21, 09:58 AM
#1
Newbie
Thread Starter
Why are top caps tapered?
I was looking in my small parts bin and noticed that a lot of headset top caps have that conical shape on the bottom side.
I find it kind of annoying as you have to leave extra gap between the top of the steerer and the last spacer, otherwise the cap ends up bottoming out on the steerer plug and doesn't actually put any preload on the headset. Sometimes that gap is as much as 5 mm, so you have to use a 10mm spacer (unless you have a 7.5 laying around) as your last spacer.
Can't they just make them flat?
Rant over
I find it kind of annoying as you have to leave extra gap between the top of the steerer and the last spacer, otherwise the cap ends up bottoming out on the steerer plug and doesn't actually put any preload on the headset. Sometimes that gap is as much as 5 mm, so you have to use a 10mm spacer (unless you have a 7.5 laying around) as your last spacer.
Can't they just make them flat?
Rant over
05-03-21, 11:33 AM
#2
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I was looking in my small parts bin and noticed that a lot of headset top caps have that conical shape on the bottom side.
I find it kind of annoying as you have to leave extra gap between the top of the steerer and the last spacer, otherwise the cap ends up bottoming out on the steerer plug and doesn't actually put any preload on the headset. Sometimes that gap is as much as 5 mm, so you have to use a 10mm spacer (unless you have a 7.5 laying around) as your last spacer.
Can't they just make them flat?
Rant over
I find it kind of annoying as you have to leave extra gap between the top of the steerer and the last spacer, otherwise the cap ends up bottoming out on the steerer plug and doesn't actually put any preload on the headset. Sometimes that gap is as much as 5 mm, so you have to use a 10mm spacer (unless you have a 7.5 laying around) as your last spacer.
Can't they just make them flat?
Rant over
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05-03-21, 09:31 PM
#3
Senior Member
Wolftooth makes some pretty neat ones. You can even do away with the spacer.https://www.wolftoothcomponents.com/...ted-5mm-spacer
05-04-21, 06:26 AM
#4
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I was looking in my small parts bin and noticed that a lot of headset top caps have that conical shape on the bottom side.
I find it kind of annoying as you have to leave extra gap between the top of the steerer and the last spacer, otherwise the cap ends up bottoming out on the steerer plug and doesn't actually put any preload on the headset. Sometimes that gap is as much as 5 mm, so you have to use a 10mm spacer (unless you have a 7.5 laying around) as your last spacer.
Can't they just make them flat?
Rant over
I find it kind of annoying as you have to leave extra gap between the top of the steerer and the last spacer, otherwise the cap ends up bottoming out on the steerer plug and doesn't actually put any preload on the headset. Sometimes that gap is as much as 5 mm, so you have to use a 10mm spacer (unless you have a 7.5 laying around) as your last spacer.
Can't they just make them flat?
Rant over
As for spacers, they come in tons of different sizes and are relatively cheap. Just get some extra thin ones to have on hand.
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Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
05-04-21, 09:14 AM
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The taper was never a problem for metal steerer tubes with star nuts and actually made the cap stronger, while reducing weight. They do pose problem with trying to use them on a carbon steerer with a compression plug, which sits flush (or nearly flush) with the top of the steerer. Most compression plugs come with a top cap that doesn't have the taper and work fine with a 5mm spacer on top of the stem.
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