700x45c too big, 700x35c ok, wheel problem
07-26-18, 11:18 PM
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700x45c too big, 700x35c ok, wheel problem
I changed rear wheel and tried to put 700x45c (kenda 28x1.75 or 47-622) tire, but it is to big in a way that I can put it on the wheel using hands without extra tools and applying no force (and when inflating inner tube brakes or pops out). When I put old 700x35c tire on the new wheel it is still to big but I can drive without any problem. When I put kenda 1.75 tire on my front old wheel (supposed to be 700C) I need to use extra tools and it drives fine.
Could this be cause the new wheel is in fact 27.5'' instead of 28'' (700C) as advertized, would 27.5''x2.10 tire work with this new wheel ? Also I would like to know is tire 28x1.75 bigger than 27.5x2.1 in diameter (is this correct one is 29.75'' and the other is 29.6'' ) ?
Could this be cause the new wheel is in fact 27.5'' instead of 28'' (700C) as advertized, would 27.5''x2.10 tire work with this new wheel ? Also I would like to know is tire 28x1.75 bigger than 27.5x2.1 in diameter (is this correct one is 29.75'' and the other is 29.6'' ) ?
Last edited by dave25; 07-26-18 at 11:28 PM.
07-27-18, 03:58 AM
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Not sure what's going on but one thing I can say is that the 28x1.5 sizing (for example) refers to a diameter of 28 and a width of 1.5. You don't add those two numbers to get 29.5. Make sure the first number is compatible with what your wheel requires.
07-27-18, 08:24 AM
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Can 700x35c tire go on a 27.5'' rim (as common knowledge) ?
07-27-18, 09:27 AM
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Look at your tires for a number like: 35-622, in that format. The 35 is the width of the tire. 622 is the bead seat diameter (BSD). BSD is what is measured on automotive and motorcycle rims; an 18" rim has a BSD of 18". Somehow bicycle nomenclature got really messed up.
On many rims, you will also find a series of numbers like 18-622 or 23-559; the first number is the inner width of the rim (just like automotive) and the second number is BSD; both in millimeters.
Study: Tire Sizing Systems there will be a quizzes each and every time you purchase new bike tires.
On many rims, you will also find a series of numbers like 18-622 or 23-559; the first number is the inner width of the rim (just like automotive) and the second number is BSD; both in millimeters.
Study: Tire Sizing Systems there will be a quizzes each and every time you purchase new bike tires.
07-27-18, 10:08 AM
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This is why rims and tires are safer discussed in Millimeter sizes than inches.
700C tires and rims have a Bead Seat Diameter - where rim and tire overlap - of 622 mm. This size is sometimes called 28” for road bikes, hybrids and Townies. And 29” for MTB use. All 622 mm tires will pretty much mount to all 622 mm rims, unless there’s a huge difference in width.
Then there is a 27” rim and tire with a BSD of 630 mm.
Then there is a 28-and-something at 635 mm
The reborn 27.5” has a BSD of 584 mm.
there is some variety in how tires and rims fit together. There are some combinations that are known to be looser or tighter than average.
Loose tires will generally settle nicely if you inflate only a bit first, then work your way around, pulling the tire even against the rim.
700C tires and rims have a Bead Seat Diameter - where rim and tire overlap - of 622 mm. This size is sometimes called 28” for road bikes, hybrids and Townies. And 29” for MTB use. All 622 mm tires will pretty much mount to all 622 mm rims, unless there’s a huge difference in width.
Then there is a 27” rim and tire with a BSD of 630 mm.
Then there is a 28-and-something at 635 mm
The reborn 27.5” has a BSD of 584 mm.
there is some variety in how tires and rims fit together. There are some combinations that are known to be looser or tighter than average.
Loose tires will generally settle nicely if you inflate only a bit first, then work your way around, pulling the tire even against the rim.
07-28-18, 12:38 AM
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I got wheel without tire as a part of ebike conversion kit. There are no numbers on the rim. When I measure wheel diameter there is maybe less than 2cm difference between old (outer 64cm) and new rim (outer 62-63cm). When I deflate tire, and pull it upward, there is 1-2cm space between rim and tire.
Thanks now I'm sure that 622mm is all right.
Is it safe (same) to drive ?
Thanks now I'm sure that 622mm is all right.
Is it safe (same) to drive ?
Last edited by dave25; 07-28-18 at 12:50 AM.
07-28-18, 09:58 AM
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I got wheel without tire as a part of ebike conversion kit. There are no numbers on the rim. When I measure wheel diameter there is maybe less than 2cm difference between old (outer 64cm) and new rim (outer 62-63cm). When I deflate tire, and pull it upward, there is 1-2cm space between rim and tire.
Measure the Bead Seat Diameter - you can do this by measuring the outer diameter of the rim, then measuring down to the bead seat surface, subtract twice what you measure down to the bead seat surface from the outer diameter to get the BSD.
07-28-18, 04:08 PM
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go to where you got the ebike conversion and have them tell you or check their posted specs.
if you changed wheel size you may have other issues, like brakes and clearance. Best the the conversion wheel is same size as you original
if you changed wheel size you may have other issues, like brakes and clearance. Best the the conversion wheel is same size as you original
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Life is too short not to ride the best bike you have, as much as you can
(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)
