upgrading crank (metric conversions)
10-14-12, 11:59 AM
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upgrading crank (metric conversions)
My 1984 crank measures 6 3/4". that converts to 171.45 mm.
I guess I want a 175mm crank. That's only 1/8th inch longer.
I'm going with a Deore XT silver crank for the touring bike.
https://www.ebay.com/itm/NEW-Shimano-...item2a175e4d0c
Have I got this figured right?
I guess I want a 175mm crank. That's only 1/8th inch longer.
I'm going with a Deore XT silver crank for the touring bike.
https://www.ebay.com/itm/NEW-Shimano-...item2a175e4d0c
Have I got this figured right?
10-14-12, 12:10 PM
#2
Really Old Senior Member
Maybe look inside the crank arm and read the length?
Did you measure center to center of the "holes".
Did you measure center to center of the "holes".
10-14-12, 12:19 PM
#3
Banned
Get the appropriate BB to go with the Crankset .. Crank designs have different relationships to
what spindle they need ..
though the newer External BB setups eliminate/simplify the choice ,
by fitting the spindle tube permanantly to the right crank arm
things made using the metric system will usually use whole MM.
the Decimal point Metric sizes are equivalents for Fractional sized things
frame tubes , Quill stems , and other international standard components,
now that the ,( metaphoric) , break away French exclusivity has been brought back,
into the 'peloton', by the overwhelming numbers of bikes
and component parts, made in the far east.
what spindle they need ..
though the newer External BB setups eliminate/simplify the choice ,
by fitting the spindle tube permanantly to the right crank arm
things made using the metric system will usually use whole MM.
the Decimal point Metric sizes are equivalents for Fractional sized things
frame tubes , Quill stems , and other international standard components,
now that the ,( metaphoric) , break away French exclusivity has been brought back,
into the 'peloton', by the overwhelming numbers of bikes
and component parts, made in the far east.
Last edited by fietsbob; 10-14-12 at 12:25 PM.
10-14-12, 12:21 PM
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Yes, if you want a longer crank, 175 is the next size up. Otherwise the standard crank corresponding to the 6-3/4" size is 170mm.
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10-14-12, 12:32 PM
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the 1000 was metric and the 610 had American sizes.
Maybe that was thier way to convert to inches.
Last edited by Pinkelephant64; 10-14-12 at 12:40 PM.
10-14-12, 05:14 PM
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For a crank of that era, it is almost certainly 170 mm. These days the next longer size available on higher-line cranks is 172.5 mm and 175 mm is commonly available on the entire range of crank models.
10-14-12, 06:45 PM
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I just went back to the basement and looked for markings. it's a 170.
5mm equals a fifth of an inch. (0.19685"). I think I will still go with the 175
5mm equals a fifth of an inch. (0.19685"). I think I will still go with the 175
10-15-12, 10:19 AM
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10-16-12, 07:12 AM
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I assumed it wasn't metric.
I have no need or desire for a metric measuring tape and if I wanted one, it would have been an hour round trip to get one.
I later found the markings on the crank that showed the size. We got it all figured out without driving to town.
10-16-12, 11:25 AM
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10-16-12, 11:33 AM
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You don't even need arithmetic.
You obviously have a computer connected to the internet.
Enter "6-3/4 inches in millimeters" or a similar phrase into your search engine and you'll have answer faster than you can dig up a meter stick.
You obviously have a computer connected to the internet.
Enter "6-3/4 inches in millimeters" or a similar phrase into your search engine and you'll have answer faster than you can dig up a meter stick.
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An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
10-16-12, 11:36 AM
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Miyata 610s did not have metric measurements like the Miyata 1000.
I assumed it wasn't metric.
I have no need or desire for a metric measuring tape and if I wanted one, it would have been an hour round trip to get one.
I later found the markings on the crank that showed the size. We got it all figured out without driving to town.
I assumed it wasn't metric.
I have no need or desire for a metric measuring tape and if I wanted one, it would have been an hour round trip to get one.
I later found the markings on the crank that showed the size. We got it all figured out without driving to town.
Whether it was an Eighty, One Hundred, Nine Twelve, Ridge Runner or AlumiCross... they were built METRIC.
How do I know? I've been to the FACTORY. NO yard sticks, inch rulers, or fractional calipers there.
10-16-12, 11:41 AM
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Plus all the tubing is inch sized 1", 1-1/8" 1-1/4" or larger, but all inch diameters.
Maybe they didn't have inch measurement tools, but their suppliers sure did.
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An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
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An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
10-16-12, 07:27 PM
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the frame sizes, the wheel sizes on the 610 was not sold in metric sizes, but the 1000 sizes were all sold in metric.
I assume they converted those measurments to metric at the plant. that would probably be the reason there is a 171 crank out there.
I have needed a metric measuring tape exactly one time now in 48 years. I will most likely be dead before I need one again.
But the missed point was that I THOUGHT it wasn't metric. I was wrong.
If I knew everything, I wouldn't be here asking for help. I haven't tightened a bolt on a bicycle in 25 years. I'm trying to catch up on new tech.
I assume they converted those measurments to metric at the plant. that would probably be the reason there is a 171 crank out there.
I have needed a metric measuring tape exactly one time now in 48 years. I will most likely be dead before I need one again.
But the missed point was that I THOUGHT it wasn't metric. I was wrong.
If I knew everything, I wouldn't be here asking for help. I haven't tightened a bolt on a bicycle in 25 years. I'm trying to catch up on new tech.
