IGHs & temperature
09-09-21, 11:14 AM
#1
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Thread Starter
IGHs & temperature
How hot do IGHs get when used continuously?
Any differences between models?
Assume well lubricated.
Any differences between models?
Assume well lubricated.
09-09-21, 11:37 AM
#2
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I've never known any of my IGH's to be any temperature other than ambient.
Granted, all IGH's have some internal friction of some degree or another, but the difference in total system efficiency between an IGH & a conventional derailleur system is not that great, if there is one at all.
When you factor in chain angle & drivetrain lubrication, cleanliness, cog sizes, etc...between a broken-in Rohloff & conventional derailleur drivetrain, the Rohloff is actually more efficient in some ratios (direct, 1:1) & within a few percent in others. What's a 3% difference at 200 watts input? 6 watts? Certainly not enough to make a detectable difference in real world use.
Other IGH's aren't as efficient as a Rohloff, especially if neglected. But, certainly not enough to be concerned about from a thermal perspective.
All that being said, & being an owner of a N380, I'll tell you the Nuvinci is a wasteful friction box. Friction is actually it's method of operation. Though I never noted it to get warm, it is probably better suited to an ebike where drivetrain efficiency just doesn't matter. I had had high hopes for the N380 & was sorely disappointed. It has been removed from the non-ebike it was on & has been hanging in the garage for the last several years. Maybe someday...
Granted, all IGH's have some internal friction of some degree or another, but the difference in total system efficiency between an IGH & a conventional derailleur system is not that great, if there is one at all.
When you factor in chain angle & drivetrain lubrication, cleanliness, cog sizes, etc...between a broken-in Rohloff & conventional derailleur drivetrain, the Rohloff is actually more efficient in some ratios (direct, 1:1) & within a few percent in others. What's a 3% difference at 200 watts input? 6 watts? Certainly not enough to make a detectable difference in real world use.
Other IGH's aren't as efficient as a Rohloff, especially if neglected. But, certainly not enough to be concerned about from a thermal perspective.
All that being said, & being an owner of a N380, I'll tell you the Nuvinci is a wasteful friction box. Friction is actually it's method of operation. Though I never noted it to get warm, it is probably better suited to an ebike where drivetrain efficiency just doesn't matter. I had had high hopes for the N380 & was sorely disappointed. It has been removed from the non-ebike it was on & has been hanging in the garage for the last several years. Maybe someday...
Last edited by base2; 09-09-21 at 11:45 AM.
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09-09-21, 12:50 PM
#3
Really Old Senior Member
Ambient air temp is probably your greatest factor.
If it's WAAAAY below freezing, the hub probably won't get very warm.
Curious as to the why of the question.
If it's WAAAAY below freezing, the hub probably won't get very warm.
Curious as to the why of the question.
09-09-21, 01:40 PM
#4
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No noticeable rise in temperature. With the stock lubricating grease, my Alfine 8sp hub in extreme cold was very stiff feeling, and no amount of riding would improve it.
A fit cyclist might be able to output 300W of power over some time, but it would take a significant fraction (>10%) of that power to heat up the hub noticeably.
A fit cyclist might be able to output 300W of power over some time, but it would take a significant fraction (>10%) of that power to heat up the hub noticeably.
09-09-21, 11:29 PM
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It depends on whether your IGH contains a coaster brake. Without I do not know of any heat issues, while with you can toast one on long mountain descents without the addition of fins and lots of really high melting point grease.
09-10-21, 01:27 AM
#7
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Thread Starter
I've never known any of my IGH's to be any temperature other than ambient.
Granted, all IGH's have some internal friction of some degree or another, but the difference in total system efficiency between an IGH & a conventional derailleur system is not that great, if there is one at all.
When you factor in chain angle & drivetrain lubrication, cleanliness, cog sizes, etc...between a broken-in Rohloff & conventional derailleur drivetrain, the Rohloff is actually more efficient in some ratios (direct, 1:1) & within a few percent in others. What's a 3% difference at 200 watts input? 6 watts? Certainly not enough to make a detectable difference in real world use.
Other IGH's aren't as efficient as a Rohloff, especially if neglected. But, certainly not enough to be concerned about from a thermal perspective.
All that being said, & being an owner of a N380, I'll tell you the Nuvinci is a wasteful friction box. Friction is actually it's method of operation. Though I never noted it to get warm, it is probably better suited to an ebike where drivetrain efficiency just doesn't matter. I had had high hopes for the N380 & was sorely disappointed. It has been removed from the non-ebike it was on & has been hanging in the garage for the last several years. Maybe someday...
Granted, all IGH's have some internal friction of some degree or another, but the difference in total system efficiency between an IGH & a conventional derailleur system is not that great, if there is one at all.
When you factor in chain angle & drivetrain lubrication, cleanliness, cog sizes, etc...between a broken-in Rohloff & conventional derailleur drivetrain, the Rohloff is actually more efficient in some ratios (direct, 1:1) & within a few percent in others. What's a 3% difference at 200 watts input? 6 watts? Certainly not enough to make a detectable difference in real world use.
Other IGH's aren't as efficient as a Rohloff, especially if neglected. But, certainly not enough to be concerned about from a thermal perspective.
All that being said, & being an owner of a N380, I'll tell you the Nuvinci is a wasteful friction box. Friction is actually it's method of operation. Though I never noted it to get warm, it is probably better suited to an ebike where drivetrain efficiency just doesn't matter. I had had high hopes for the N380 & was sorely disappointed. It has been removed from the non-ebike it was on & has been hanging in the garage for the last several years. Maybe someday...
Suggested grease for internal lubrication is NLGI 00.
Probably need to adjust NLGI grade for higher ambient temperature, given that most of forum experience is in much colder locations.
No noticeable rise in temperature. With the stock lubricating grease, my Alfine 8sp hub in extreme cold was very stiff feeling, and no amount of riding would improve it.
A fit cyclist might be able to output 300W of power over some time, but it would take a significant fraction (>10%) of that power to heat up the hub noticeably.
A fit cyclist might be able to output 300W of power over some time, but it would take a significant fraction (>10%) of that power to heat up the hub noticeably.
Thanks. No coaster brake.
09-10-21, 08:52 AM
#8
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That’s the beauty of an IGH hub, never give it a 2nd thought, just ride it. Worked with my Schwinn growing up, works with my Schwinn now.
Tim
Tim
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09-10-21, 12:49 PM
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09-10-21, 03:02 PM
#10
Really Old Senior Member
How much power are YOU going to put out when it's 122F?
The only thing that would possibly concern me temperature wise, is if you had a motor assist to that hub and rode it for somewhat "extended" periods.
The only thing that would possibly concern me temperature wise, is if you had a motor assist to that hub and rode it for somewhat "extended" periods.
09-10-21, 08:10 PM
#11
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Do higher ambient temperatures require higher NLGI grades to minimize leaks?
Read in a non-bicycle forum that NLGI grade decreases by 1 or 2 going from Florida to Canada.
Any experiences from Arizona?
09-11-21, 05:38 PM
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09-12-21, 06:24 AM
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You didn't say what sort of hub you have. My experience with Shimano Nexus-8 and Alfine-11 is that they may leak if the bike is stored on its side, especially drive-side down. Otherwise, leakage is not an issue.
