Chainring Bolt Patterns
09-18-01 | 04:51 AM
#1
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From: Churton Park, Wellington, NZ
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Chainring Bolt Patterns
Hi Guys,
How should I measure my chainrings to find out the bolt pattern?
I've been given two lenghts to check
58/94 and 74/110.
I'm not too sure which one I have.
Many thanks
Rich
How should I measure my chainrings to find out the bolt pattern?
I've been given two lenghts to check
58/94 and 74/110.
I'm not too sure which one I have.
Many thanks
Rich
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09-18-01 | 05:10 AM
#2
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Joined: Feb 2001
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From: England
The Nashbar (USA mail order) catalogue used to have a nifty pattern guide.
You can make your own with a compass. Draw some concentric circle of suitable diamter (58, 74,94 110 mm). Place the chainrings over, and see which circles hit the centre of the bolt holes.
You can make your own with a compass. Draw some concentric circle of suitable diamter (58, 74,94 110 mm). Place the chainrings over, and see which circles hit the centre of the bolt holes.
09-18-01 | 05:23 AM
#3
Thread Starter
It's the fight in the man
Joined: Oct 2000
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From: Churton Park, Wellington, NZ
Bikes: Pace RC200 F2 (British Built!)
Thanks Michael,
As always you are the fix it guru!!!
I honour you!!!!
Rich
As always you are the fix it guru!!!
I honour you!!!!
Rich
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Making New Zealand a safer place :)
Making New Zealand a safer place :)
09-18-01 | 05:36 AM
#4
You can also try geometry to find the diameter. Divide 360 by the # of bolts, then divide that # by 2. This will give you the half angle of the triangle. The bolt diameter is
(dist between holes)/{cos(90- 'half angle')}
(in degrees, of course.)
(dist between holes)/{cos(90- 'half angle')}
(in degrees, of course.)
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09-18-01 | 05:41 AM
#5
Thread Starter
It's the fight in the man
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From: Churton Park, Wellington, NZ
Bikes: Pace RC200 F2 (British Built!)
Thanks D*Alex,
Maths was never my fortay..... :confused:
Rich :blush:
Maths was never my fortay..... :confused:
Rich :blush:
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