How crucial is valvestem hole clearance?
10-06-21, 11:50 PM
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How crucial is valvestem hole clearance?
I've got a double-walled Rhyno-Lite rim that came with a Presta size hole, I'm drilling it out to Schrader size and finishing with a tapered round file that I'm spinning lightly in the hole. If a valvestem goes through and isn't being gouged by the sides of the hole and doesn't have burrs on the tube side is that good enough? It doesn't seem like it needs to be a precision job but thought I'd ask. Anything that's a good idea to do to the hole that might not be obvious?
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10-07-21, 12:32 AM
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i'd take some fine grit paper wrapped around something of the same diameter as the valve (a pencil?) and make it very very smooth. otherwise, yeah...so long as you can fit the valve through. even a hair bigger won't hurt.
10-07-21, 08:15 AM
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I've got a double-walled Rhyno-Lite rim that came with a Presta size hole, I'm drilling it out to Schrader size and finishing with a tapered round file that I'm spinning lightly in the hole. If a valvestem goes through and isn't being gouged by the sides of the hole and doesn't have burrs on the tube side is that good enough? It doesn't seem like it needs to be a precision job but thought I'd ask. Anything that's a good idea to do to the hole that might not be obvious?
Thanks
Thanks
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AndrewRStewart
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10-07-21, 08:32 AM
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What's the internal width of your rim? You might be making your tire changing a little harder if your have a narrow internal width rim. Also increase the chances you might damage the tube around the valve stem while getting the tire on.
But with enough room, it's no issue and many have drilled them out and cleaned up the hole with file or sandpaper, de-burring tool or other such. If you have another rim that is Schrader, then measure that hole.
Don't let your Schrader valve tubes get crooked in the rim and still ride the bike. I use to always make fun of those people when I was younger. My Schrader valves were always perfectly straight pointing to the center of my hub just like my presta's.
But with enough room, it's no issue and many have drilled them out and cleaned up the hole with file or sandpaper, de-burring tool or other such. If you have another rim that is Schrader, then measure that hole.
Don't let your Schrader valve tubes get crooked in the rim and still ride the bike. I use to always make fun of those people when I was younger. My Schrader valves were always perfectly straight pointing to the center of my hub just like my presta's.
10-07-21, 09:00 AM
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You want to make the hole ever so slightly larger than the stem. The valve should be able to move at an angle slightly as a safety device. This tells you if the valve is aligned properly and will keep it from tearing if for instance the valve was a tight fit but the tube was pulling on it the valve would still appear straight.
10-07-21, 10:31 AM
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What's the internal width of your rim? You might be making your tire changing a little harder if your have a narrow internal width rim. Also increase the chances you might damage the tube around the valve stem while getting the tire on.
But with enough room, it's no issue and many have drilled them out and cleaned up the hole with file or sandpaper, de-burring tool or other such. If you have another rim that is Schrader, then measure that hole.
Don't let your Schrader valve tubes get crooked in the rim and still ride the bike. I use to always make fun of those people when I was younger. My Schrader valves were always perfectly straight pointing to the center of my hub just like my presta's.
But with enough room, it's no issue and many have drilled them out and cleaned up the hole with file or sandpaper, de-burring tool or other such. If you have another rim that is Schrader, then measure that hole.
Don't let your Schrader valve tubes get crooked in the rim and still ride the bike. I use to always make fun of those people when I was younger. My Schrader valves were always perfectly straight pointing to the center of my hub just like my presta's.
10-07-21, 11:46 AM
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Close enough should be close enough. Just make sure the edge of the hole is de-burred.
SLIGHTLY OFF TOPIC COMMENT
If you are using a Presta valve in a Schrader hole, the allowed movement can increase wear on the rubber around the valve and cause a failure down the line. My solution to this is to use a convex washer from the back of a V-brake pad on the base of the valve (it's a close fit like it was meant to be used for this), convex side facing the rim so it holds the valve in the centre of the hole, and thread a Presta valve nut on to hold the whole thing together.
SLIGHTLY OFF TOPIC COMMENT
If you are using a Presta valve in a Schrader hole, the allowed movement can increase wear on the rubber around the valve and cause a failure down the line. My solution to this is to use a convex washer from the back of a V-brake pad on the base of the valve (it's a close fit like it was meant to be used for this), convex side facing the rim so it holds the valve in the centre of the hole, and thread a Presta valve nut on to hold the whole thing together.
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