2strokepoke
Member
it's a rotten shame things arent made to last anymore, jus like our HT engines haha
Thoughts on Potholes... Reinforced -vs- Double-Wall Rims
- Thread starter sparky
- Start date
I don't believe that a stronger rim is going to prevent damage if you're hitting pavement edges hard enough for them to do damage directly to the rim's edges.
The main advantage of a stronger rim is that they distribute bump-caused shock loads better around the whole wheel and so prevent individual spokes from breaking.
Not to be a smart-alek or anything, but you're not supposed to hit anything so hard that it compresses the tires enough to contact the rims.... Not in a truck, in a car, in any motorcycle, not any bicycle or anything else I can think of.
It sounds like OP should be using fatter tires, or preferably, suspension.
The main advantage of a stronger rim is that they distribute bump-caused shock loads better around the whole wheel and so prevent individual spokes from breaking.
Not to be a smart-alek or anything, but you're not supposed to hit anything so hard that it compresses the tires enough to contact the rims.... Not in a truck, in a car, in any motorcycle, not any bicycle or anything else I can think of.
It sounds like OP should be using fatter tires, or preferably, suspension.
retromike3
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strong rim VS. strong wheel
A bicycle wheel is a amazing thing. It is a very strong structure and it holds up hundreds of times its own weight under load. You can have a very light rim and a very strong wheel if it is built correctly. On the other hand you can have a very strong rim and a weak wheel if the wrong person built it. I have been in bike crashes where both wheels were perfectly straight and true, and yet the frame got bent. The case that I was referring to actually had the front wheel in perfect shape and yet the frame collapsed right where the down tube and the head tube met.
Building wheels is still in some cases is more art than science. I know that they can make a very strong machine built wheel, however there are some things that I really think are done best by hand.
Wheels like many mechanical objects generally fail at the weakest point. Where that point is can vary depending on the mechanical structure of the object. Modern bicycle rims are very strong and the number of spokes on these new wheels has been dropping precipitously. Lately the modern mountain bike has dropped from 36 to 32 spokes. When I started building wheels at my shop 36 was the number that most people used. I did set up a number of mountain bicycles with 48 spoke wheels. These were generally used for tandem wheels but, they seem to work quite well for mountain bikes. I never had any of my 48 spoke wheels come back "potato chipped"
I think there's nothing wrong with over building wheel. Currently I have been building a lot of 32 spoke wheels in my current motor bicycle is running that set up. With the Wieman double wall rim with spoke eyelets. I also try not to go wider than 135 mm with no more then an eight speed spacing on my motor bicycle because, when you over dish the wheel it seems to be way too much tension on the pedal drive side.
I just recently built a set of wheels with velocity aero rims. These rims are 36 spoke and I'm planning on using them on a get around bike I'll let you guys know about it after they find there way on something I put together.
mike
A bicycle wheel is a amazing thing. It is a very strong structure and it holds up hundreds of times its own weight under load. You can have a very light rim and a very strong wheel if it is built correctly. On the other hand you can have a very strong rim and a weak wheel if the wrong person built it. I have been in bike crashes where both wheels were perfectly straight and true, and yet the frame got bent. The case that I was referring to actually had the front wheel in perfect shape and yet the frame collapsed right where the down tube and the head tube met.
Building wheels is still in some cases is more art than science. I know that they can make a very strong machine built wheel, however there are some things that I really think are done best by hand.
Wheels like many mechanical objects generally fail at the weakest point. Where that point is can vary depending on the mechanical structure of the object. Modern bicycle rims are very strong and the number of spokes on these new wheels has been dropping precipitously. Lately the modern mountain bike has dropped from 36 to 32 spokes. When I started building wheels at my shop 36 was the number that most people used. I did set up a number of mountain bicycles with 48 spoke wheels. These were generally used for tandem wheels but, they seem to work quite well for mountain bikes. I never had any of my 48 spoke wheels come back "potato chipped"
I think there's nothing wrong with over building wheel. Currently I have been building a lot of 32 spoke wheels in my current motor bicycle is running that set up. With the Wieman double wall rim with spoke eyelets. I also try not to go wider than 135 mm with no more then an eight speed spacing on my motor bicycle because, when you over dish the wheel it seems to be way too much tension on the pedal drive side.
I just recently built a set of wheels with velocity aero rims. These rims are 36 spoke and I'm planning on using them on a get around bike I'll let you guys know about it after they find there way on something I put together.
mike
motorpsycho
Active Member
yeah but the tires these days are manufactrued to withstand more shock. the sidewalls are extremely tough.
most "aluminum" rims on cars these days have a steel hoop with an aluminum insert for the center, which makes the rims a lot stronger than you think.
sparky
Active Member
I'll take a 15" steelie over a 22" aluminum rim all day long...
But I can't find steel rims for bicycles. That's why I started this thread... for thoughts on potholes!!!
I have a 4-stroke motor and pedals... I can apply all the torque in the world needed to get this puppy up to speed for pennies or less. Once you get the forward inertia of a rolling wheel, it doesn't matter how much it weighs... and, in fact, the larger & heavier (i.e. - more inert) one should roll farther!!
Anyway... I think that the Sun BFR rim is actually what I was looking for, since I see no steel bicycle rims. Even tho it's aluminum, those sidewalls look incredibly tought.
And yes, my Shadow Conspiracy Undertaker tires hold plenty of PSI... 110 psi, actually. But I tend to run over a good number of pebble patches in the middle of intersections, so I usually keep it around 60 psi. Much better for the road, but the inevitability is that sometimes it falls down to 50 psi. And the eventuality of riding on sidewalks is that you won't see the damage in the concrete until it's too late, and a sliver of a concrete teaches you all about calculating psi... specifically, dividing with a denominator as a fraction of a fraction of a sq. inch.
But I can't find steel rims for bicycles. That's why I started this thread... for thoughts on potholes!!!
I have a 4-stroke motor and pedals... I can apply all the torque in the world needed to get this puppy up to speed for pennies or less. Once you get the forward inertia of a rolling wheel, it doesn't matter how much it weighs... and, in fact, the larger & heavier (i.e. - more inert) one should roll farther!!
Anyway... I think that the Sun BFR rim is actually what I was looking for, since I see no steel bicycle rims. Even tho it's aluminum, those sidewalls look incredibly tought.
And yes, my Shadow Conspiracy Undertaker tires hold plenty of PSI... 110 psi, actually. But I tend to run over a good number of pebble patches in the middle of intersections, so I usually keep it around 60 psi. Much better for the road, but the inevitability is that sometimes it falls down to 50 psi. And the eventuality of riding on sidewalks is that you won't see the damage in the concrete until it's too late, and a sliver of a concrete teaches you all about calculating psi... specifically, dividing with a denominator as a fraction of a fraction of a sq. inch.
Last edited:
retromike3
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I beg to differ a bit
The question of forward inertia is really not much of a factor, But the "spin up" energy can make a big difference. I was told that if you take one pound off of the rotating weight it compares to taking seven pounds off the frame. The current set of wheels I am running right now are pretty heavy, mainly because I found some torn proof tubes that weigh a bit more than standard.
The main reason I am not found of steel rims is not necessarily all about the weight but the fact that they don't brake worth a darn. if you are running steel rimes its going to take you a lot longer to stop than if you use aluminum rims. i have been told that if you set up a six bolt hub and a Kings adapter than you can use a disk brake and those will stop regardless of the rim material.
Something that I also read about in BikeTec magazine a few years ago was that when you do decrease the height of the wheel then the rolling resistance is increased exponentially. So I tall wheel requires much less energy to spin than a small one.( I guess bigger is better)
If you look at most racing bicycles and even the new 29er mountain bikes they go with a fairly tall wheel. The only reason that my motorized bicycle is running 26 x 1.5's is because I have no suspension on my bike and I like the dampening effects that these particular wheels have. Plus there is something to be said about not having to to fix flat tires, especially rear tires on these particular types of bikes.
mike
The question of forward inertia is really not much of a factor, But the "spin up" energy can make a big difference. I was told that if you take one pound off of the rotating weight it compares to taking seven pounds off the frame. The current set of wheels I am running right now are pretty heavy, mainly because I found some torn proof tubes that weigh a bit more than standard.
The main reason I am not found of steel rims is not necessarily all about the weight but the fact that they don't brake worth a darn. if you are running steel rimes its going to take you a lot longer to stop than if you use aluminum rims. i have been told that if you set up a six bolt hub and a Kings adapter than you can use a disk brake and those will stop regardless of the rim material.
Something that I also read about in BikeTec magazine a few years ago was that when you do decrease the height of the wheel then the rolling resistance is increased exponentially. So I tall wheel requires much less energy to spin than a small one.( I guess bigger is better)
If you look at most racing bicycles and even the new 29er mountain bikes they go with a fairly tall wheel. The only reason that my motorized bicycle is running 26 x 1.5's is because I have no suspension on my bike and I like the dampening effects that these particular wheels have. Plus there is something to be said about not having to to fix flat tires, especially rear tires on these particular types of bikes.
mike
HeadSmess
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come to australia were youll find the footpath is the better option, when there is one...
potholes? we consider ourselves lucky that theres some tarred gravel in the middle of all these mineshafts!
