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BMX General => BMX Chat => Topic started by: BMX1973 on June 28, 2011, 03:30 PM
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How can you tell the width of a rim, where is the measurement taken from?
:daumenhoch:
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How can you tell the width of a rim, where is the measurement taken from?
:daumenhoch:
The 2 faces that your brake pads run on.
A
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Read what is says on the tire! :LolLolLolLol:
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Read what is says on the tire! :LolLolLolLol:
He said width......
Reading the tyre does'nt give you the width of the rim. ;D
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I'm a bit confused :-[
I've got two rims one has 1.5 on it and the second is definately wider but no size on it, so I guess this is 1.75.
However both the faces that the brake pads rub on are both just over half inch. :-\
But I still cant work out where to take the measurment from :-\
:D
[/quote]The 2 faces that your brake pads run on.
A
[/quote]
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please help :(
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If someone can answer, can they also say why 20 x 1.75 rims are a smaller diameter to 20 x 1 3/8 rims?
When they came up with the names of wheel sizes they were just making it up as they went along!!!
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Ah, someone knows where I'm coming from ;)
If someone can answer, can they also say why 20 x 1.75 rims are a smaller diameter to 20 x 1 3/8 rims?
When they came up with the names of wheel sizes they were just making it up as they went along!!!
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I think you will find that the sizes stamped into the rims are the recommended tyre size for that rim.
You may have a wide rim but it may also only be single walled for lightness thus enabling lighter riders to use 1 3/8 tyres. You could have the same size rim but double walled enabling the rider to be heavier but also having slightly wider tyres like 1.75.
:daumenhoch: :daumenhoch:
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You may have a wide rim but it may also only be single walled for lightness thus enabling lighter riders to use 1 3/8 tyres. You could have the same size rim but double walled enabling the rider to be heavier but also having slightly wider tyres like 1.75.
Na dude. (20 x 1 3/8) & (20 x 1 1/8) are a TOTALLY different wheel size to (20 x 1.75) & (20 x 1.5). "Skinnies" are much bigger diameter. You have to have a shorter reach brake and everything.
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True on the TYRE sizes but you wouldn't put a 20 X 1.75 tyre on race rim would you ???
Most of the first gen Peregrine rims were unstamped and the early Ukai's and Arayas only had Ukai and Araya stamped on the rim. The tyre sizes back in the day were really only 1.75.
As for the race rims, they also did not have sizes stamped on the rim, just the name.
If you look at a guide to tyres fitted to rims, it states what size tyre should be used in what weight catergory.
Check out this wheel/tyre/age/weight guide http://localbmxco.com/articles/buyers-guide-to-bmx-bikes-pg58.htm
Hope this helps
Tj
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True on the TYRE sizes but you wouldn't put a 20 X 1.75 tyre on race rim would you ???
You lost me now. Isn't a comp3 a race tire? What rim are you meant to put a 1.75 Comp3 on, if not a race rim?
You wouldnt put a 20 x 1.75 tire on a "Skinny" (1 1/8 or 1 3/8) rim cos it just wont fit, The rim's dia is way to big
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True on the TYRE sizes but you wouldn't put a 20 X 1.75 tyre on race rim would you ???
You lost me now. Isn't a comp3 a race tire? What rim are you meant to put a 1.75 Comp3 on, if not a race rim?
You wouldnt put a 20 x 1.75 tire on a "Skinny" (1 1/8 or 1 3/8) rim cos it just wont fit, The rim's dia is way to big
When racing first started, wheel size was 20 inch. You fitted 1.75 tyres on the rear, 2.125 on the front for grip on the corners. As it progressed, wheels got bigger i.e 22 inch and thinner for 'lighter' riders, KIDS etc etc......Tyres had to do the same, obviously. 1.75 tyres are for the 'heavier' racers and 1 1/8 are for 'lighter' racers. You wouldn't see my 14 stone body hacking it round a track with 1 1/8 rims and tyres would you ?? NO......They are for the lighter rider, KIDS.
As for the diameter, or RADIUS, you cannot fit a 20 X 1.75 tyre to a 21 or 22 inch rim can you ?? NO.... but you can fit a 20 X 1.75 tyre to a 20 inch 'skinny' rim. Likewise, you can fit a 20 X 1 1/8 tyre to standard size Ukai but it don't look right, the rim would ground on the corners and 'heavier' rider would rip it to shreds
Understand now ???
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Understand now ???
No, and TBH, i stopped caring soon after my own reply :LolLolLolLol:
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Is 20" roughly, give or take a fraction (not Faction) of an inch, not just the overall diameter of the complete wheel/tyre assembly?
clearly skinny rims for kids racing bike have a larger diameter (just the rim) than my big fokk off fat chrome Ody rims.
Therefore, the skinny racing tyres, with lower profile side walls, and a larger diameter hole, ie, between the beading won't fit on a wider bmx rim, not because of the rim width but because of the diameter?
The actual rims have different diameters but are all still 20" wheels.
22" wheels, as seen on Factions bikes, and so i'm told on some bikes from Toy R Us (though I can't confirm this, I thought Toy R Us only sold Lego, Action Figures and Top Trumps) don't have 22" diameter rims...the whole wheel/tyre assembly is 22"....give or take.
as the 2nd bestest front brake rider on Rad says, the skinny rims have a larger diameter.
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where's Ratty?
I'm certain he'd know for sure.
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How can you tell the width of a rim, where is the measurement taken from?
:daumenhoch:
1st question^^^^^
answer = take off the tyre, now hold a tape measure from 1 side of the rim side to the other........measurement = rim width!
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How can you tell the width of a rim, where is the measurement taken from?
:daumenhoch:
1st question^^^^^
answer = take off the tyre, now hold a tape measure from 1 side of the rim side to the other........measurement = rim width!
fact!
but no where near as interesting as the rest of it! lol.
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Most 20 x 1.75 rims "measure" about 1.25" from brake surface to brake surface. 20 x 1.5 rims measure .... a bit less
The size of a bike rim (and tire) is more like a "name" rather than a measurement. The diameter and the width, are just reference names.
(Did you know that on normal bikes, a (26 x 1 3/8) wheel/tire is a different diameter to a (26 x 1 1/4)? Yeah .... stupid, aint it!)
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thanks S&MAlex that answears it.
Most 20 x 1.75 rims "measure" about 1.25" from brake surface to brake surface. 20 x 1.5 rims measure .... a bit less
The size of a bike rim (and tire) is more like a "name" rather than a measurement. The diameter and the width, are just reference names.
(Did you know that on normal bikes, a (26 x 1 3/8) wheel/tire is a different diameter to a (26 x 1 1/4)? Yeah .... stupid, aint it!)
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When racing first started, wheel size was 20 inch. You fitted 1.75 tyres on the rear, 2.125 on the front for grip on the corners. As it progressed, wheels got bigger i.e 22 inch and thinner for 'lighter' riders, KIDS etc etc......Tyres had to do the same, obviously. 1.75 tyres are for the 'heavier' racers and 1 1/8 are for 'lighter' racers. You wouldn't see my 14 stone body hacking it round a track with 1 1/8 rims and tyres would you ?? NO......They are for the lighter rider, KIDS.
As for the diameter, or RADIUS, you cannot fit a 20 X 1.75 tyre to a 21 or 22 inch rim can you ?? NO.... but you can fit a 20 X 1.75 tyre to a 20 inch 'skinny' rim. Likewise, you can fit a 20 X 1 1/8 tyre to standard size Ukai but it don't look right, the rim would ground on the corners and 'heavier' rider would rip it to shreds
Understand now ???
Actually 'skinny' rims are 17 3/4" (451mm ERD) in diameter, whereas 'normal' bmx rims are 16" (406mm ERD) in diameter, I cannot remember why they are different I think it is to do with one being measured 'fractional' (1.5, 1.75 etc) and one 'dicimel' (1 1/8, 1 3/8).
Oh good God am I really that sad ;D :'(
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Bet the poor bloke is wishing he'd never asked... ;D
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True on the TYRE sizes but you wouldn't put a 20 X 1.75 tyre on race rim would you ???
You lost me now. Isn't a comp3 a race tire? What rim are you meant to put a 1.75 Comp3 on, if not a race rim?
You wouldnt put a 20 x 1.75 tire on a "Skinny" (1 1/8 or 1 3/8) rim cos it just wont fit, The rim's dia is way to big
When racing first started, wheel size was 20 inch. You fitted 1.75 tyres on the rear, 2.125 on the front for grip on the corners. As it progressed, wheels got bigger i.e 22 inch and thinner for 'lighter' riders, KIDS etc etc......Tyres had to do the same, obviously. 1.75 tyres are for the 'heavier' racers and 1 1/8 are for 'lighter' racers. You wouldn't see my 14 stone body hacking it round a track with 1 1/8 rims and tyres would you ?? NO......They are for the lighter rider, KIDS.
As for the diameter, or RADIUS, you cannot fit a 20 X 1.75 tyre to a 21 or 22 inch rim can you ?? NO.... but you can fit a 20 X 1.75 tyre to a 20 inch 'skinny' rim. Likewise, you can fit a 20 X 1 1/8 tyre to standard size Ukai but it don't look right, the rim would ground on the corners and 'heavier' rider would rip it to shreds
Understand now ???
You clearly dont :LolLolLolLol:
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True on the TYRE sizes but you wouldn't put a 20 X 1.75 tyre on race rim would you ???
You lost me now. Isn't a comp3 a race tire? What rim are you meant to put a 1.75 Comp3 on, if not a race rim?
You wouldnt put a 20 x 1.75 tire on a "Skinny" (1 1/8 or 1 3/8) rim cos it just wont fit, The rim's dia is way to big
When racing first started, wheel size was 20 inch. You fitted 1.75 tyres on the rear, 2.125 on the front for grip on the corners. As it progressed, wheels got bigger i.e 22 inch and thinner for 'lighter' riders, KIDS etc etc......Tyres had to do the same, obviously. 1.75 tyres are for the 'heavier' racers and 1 1/8 are for 'lighter' racers. You wouldn't see my 14 stone body hacking it round a track with 1 1/8 rims and tyres would you ?? NO......They are for the lighter rider, KIDS.
As for the diameter, or RADIUS, you cannot fit a 20 X 1.75 tyre to a 21 or 22 inch rim can you ?? NO.... but you can fit a 20 X 1.75 tyre to a 20 inch 'skinny' rim. Likewise, you can fit a 20 X 1 1/8 tyre to standard size Ukai but it don't look right, the rim would ground on the corners and 'heavier' rider would rip it to shreds
Understand now ???
You clearly dont :LolLolLolLol:
Obviously :crazy2:
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S&MAlex answered it well - :daumenhoch: cheers mate
Bet the poor bloke is wishing he'd never asked... ;D