#31
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Tim |
#32
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Soapy water or other lubricating agents help on tubeless setups. Maybe try it here? |
#33
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THIS!!! Carbon Clincher is a such an industry driven idea. So many variables when you toss in clincher tires getting stretched out over wide carbon clinchers, tubes heating up, etc.
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#34
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For that last section of tire bead to move up into position just under the bead hook (or, more correctly, on top of the "BSD ledge" at the base of the rim's outer wall), the tire bead needs to SLIP LENGTHWISE along the rim, so that full tension along a greater length of the bead can yield enough stretch to relax the increasing tension in the bead as it lifts up in response to tension in the tire sidewall.
So in addition to the diameter difference between the bead and the bead-seating ledge of the rim, and the casing tension resulting from increased air pressure, some degree of slip must occur along the length of the tire bead. Using a little soapy water (per Jaybee recommendation) or rubbing alcohol usually improves the slip by reducing the grip o the surfaces, so a tire-endangering pressure need not be used to fully seat the beads up onto the bead-seating ledges at the inside corners of the rim cavity. It also often helps to deflate and then re-inflate after perhaps jostling the deflated tire and supporting the bike's weight off of the deflated tire before re-inflating. This is often required to get tires seated onto Schwinn's old steel rims, which can be most difficult to get seated after roadside puncture repairs. Of course it's also necessary to prevent any portion of the tube (or the rim strip, where applicable) from getting between the tire bead and the bead-seating ledges! I ALWAYS plump the tube with air before fitting it in the tire, so that it resists getting pinched and stuck between either bead seating ledge and either tire bead, and I also flex the installed tire to each side along it's entire circumference, AND push the valve stem into the tire to free the thicker reinforced (thicker) portion of the tube surrounding the valve stem from getting stuck under either bead. Only then is it safe to inflate the tire, and preferably without the bike's weight squashing down on the deflated tire(!). Lastly, while veering even further away from the OP's question, using a wide tire on a much narrower rim also often causes tube failure as the tube 1) first fills the circular tire volume, 2) then somewhat pins the pressurized tube against the round inside volume of the tire, 3) and finally forces the tube to stretch locally along it's innermost major diameter to fill the rim cavity as 5psi or so is exceeded. Very often such a tube will end up with it's reinforced area around the valve resisting dropping down between the closely-spaced rim sidewalls and tire beads, so the surrounding thinner rubber to each side of the reinforced pad can get torn open as the tube finally gets pressed down against the rim strip. I have seen many, many such ruptures (and near-ruptures, evidenced by overstretched areas adjacent to the thicker reinforcement). It is thus imperative to tug on the valve stem after the first couple of psi are introduced into the tire, so as to seat the reinforcement inside of the rim. Note that while this rubber reinforcement around the valve stem is the last to get pushed down to meet the rim, the rest of the tube's length also gets stressed by having to stretch locally as the tube resists (by friction) being pulled past the inside corner created by the wide tire's sidewalls flexing sharply outward above the narrow rim's sidewalls. So, especially when the tire is much wider than the rim, it's important to use a tube of generous width that does not have to stretch and pressurize as much while it initially fills the round inside of the inflating tire. Tubes are labeled for their width, but the accuracy or this published measurement varies wildly relative to the actual deflated-and-pressed-flat width dimension of various manufacturer's tubes, which should always nearly equal (or slightly exceed) the inflated width of the tire (especially when the tire is much wider than a narrow rim)!!! Last edited by dddd; 10-20-2017 at 01:51 PM. Reason: clarity, punctuation, etc. |
#35
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And for a general reply to other comments; I now how to mount tires. I have been at this for over 30 years and never had this much trouble. But, this was my first set of carbon rims as well as the first that were made to accept tubeless. I looked at the channel when I took the tire back off and the interior walls looked a bit too steep to me. I could easily see how the tire bead could hang up in the trench and not pop in place. If all else was great, I would have tried some talc to make things slide a bit more. Tim Last edited by mcteague; 10-20-2017 at 04:19 PM. |
#36
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I've built different wheels that had very stiff rims yet still rubbed at the pads under sprinting-type loading even at my modest weight. The spoke system (spoke guage, ends, attachments, count and bracing angles) plays huge into whether or not a wheel ends up flexy, and a stiffer rim may exacerbate any such weakness as the flex down at the road side of the wheel is more strongly transmitted through the rigid rim, effectively pivoting about the central hub! I couldn't believe that I was getting brake rub the first time that I encountered this with a known-stiff rim tensioned highly and with what I thought was generous spoke count. Straight-pull spokes help, as does an offset rim and stiffer hub "flange" structure. |
#37
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Might be a good option for the OP to try out |
#38
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#39
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Campagnolo makes it even easier now. The only graphic on the new Shamal Mille is a small removable rim sticker. The hubs don't even say Campagnolo, just a small sticker that says Ultra Smooth Bearings.
__________________
BIXXIS Prima Cyfac Fignon Proxidium Legend TX6.5 |
#40
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Shamals are killer.
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#41
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I agree with above post stating carbon can be an advantage on tubular rims, but because of the design on a clincher rim, not much advantage on clinchers. Get steel spoked Campagnolo Zonda's if you don't like fat aluminum spokes. My wheel builder friend says she can fix a Zonda with off the shelf steel spokes.
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#42
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Pure BS. Carbon clinchers work fine. Take the time to seat the bead correctly, and it's all good.
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#43
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Well it's all coming together as far as tire maker's products working with rim-maker's products.
There have been some real duds among products that were released even by reputable makers, everything from carbon clinchers to tubeless clinchers, and a lot of customers got burned. Some even crashed due to the various issues. While there are a lot of good products that are rapidly getting even better, it is still up to the buyer to check reviews of popular, proven products. I am liking the newer carbon rims that eschew delicate bead hooks for precisely manufactured rims with thicker, straight-walled sidewalls, and rims with durable braking surfaces that allow good braking in all conditions. Carbon rims still make the most sense on disc-braked wheels though, they are nearly a no-brainer if you have the cash or can build good wheels yourself. What is established in the mtb world is slowly coming to the road bike world, whether we like it or not. |
#44
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For the original poster: The best wheelset I have ever ridden is the HED wheelset. Amazing, light, super fast, reasonable affordable, comfortable, better cornering to boot. It's not hype, it's real-world physics.
Yes, wider is better. All of the manufacturers are pretty much going that way. The wider internal rim width of these clinchers allow for a larger contact patch. They have lower rolling resistance. Of course, if funds are unlimited you can go to the carbon clincher wheel sets made by Zipp and Bontrager. There are now some amazing options out there with wider carbon clincher rims. My aluminum HED clinchers are faster than my Enve carbon tubulars. Yup. |
#45
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To go from custom made Joe Young wheels to anything else might be a disappointment (except for custom made old potatoe's or custom built ergott's). I have three pairs of DT Swiss hubs / DT Swiss rims / Joe Young built wheels all made just for me, my weight and my riding style, and could not be happier.
If you have a new wheel itch, why not see what Mr Chisholm or Mr Ergott have to offer (especially if the shop will take them back within 30 days)? Or give Joe a call. There is no substitute for getting advice from people who have been there and done that. Last edited by George_H; 10-21-2017 at 08:12 PM. |
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