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#11
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Wheels for 700lb guy?
Pete Biggs wrote:
wrote: Presumably I had uneven spoke tension that I should have kept an eye on, and I got cracks from that, causing the wheel to go out of true. Does that sound right? Cracks around the spoke holes sounds like excessive spoke tension. --which is only a chronic issue with Mavic rims from the last ~20 years. "Excessive" spoke tension therefore can be evaluated alternatively as "substandard" rim structure. I can say that recent Mavic rims have failed for me at spoke tensions where lighter rims from other makers have held up fine. Chalo |
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#12
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Wheels for 700lb guy?
On Nov 16, 10:49*pm, landotter wrote:
On Nov 16, 9:56*pm, wrote: Alex DM18s are a good choice for a clyde. It's got even more meat than the Mavic. Less than $20. ERD is close enough to the 604 I found for the Mavics for you do tape 'em up and do a direct swap. You'll need to emery paper the joints as they aren't welded, if you want smooth braking. Well that sounds like maybe a good combo of cheap solution and an intro to wheel building. *If I mess it up, not such a big deal for $20. *It does look like a pretty hefty cross section too. You'll have to double check the ERD for sure, but if it's within a couple mms--indeed, just tape the rims together, making sure that the "handedness" of the spoke holes is correct, and swap the spokes one by one. Use an electric driver from the inside to do this. A flat head will do, or a philips bit with most of two fins ground off works as well. If you don't have a truing stand, like most of us, do remember to set your brake pads very carefully and closely before you do this-- and you can use your bike as a truing stand. The Alex is a good strong rim--it's not machined and it's not welded, so it will take emery paper for a minute or three on the joint. It should solve your problem if built right and tensioned well. My last rerimming I did with some has a couple thousand miles on 'em with no touch ups needed. I've hauled groceries, ice biked--you name it, DM18s is strong stuff. Don't let the non-Eurosnob price tag fool you. I'll cast another vote for Alex, but I say spring for another 5 bucks and get the Adventurer, which has eyeleted spoke holes. |
#13
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Wheels for 700lb guy?
wrote:
landotter wrote: Alex DM18s are a good choice for a clyde. It's got even more meat than the Mavic. Less than $20. ERD is close enough to the 604 I found for the Mavics for you do tape 'em up and do a direct swap. You'll need to emery paper the joints as they aren't welded, if you want smooth braking. Well that sounds like maybe a good combo of cheap solution and an intro to wheel building. If I mess it up, not such a big deal for $20. It does look like a pretty hefty cross section too. After trying a variety of spoke types and gauges we switched to a 48 spoke rim and haven't had any more problems. That sounds like the correct long term solution for me. I'm going to take a hard look at tandem wheels. Rebuilding with a cheap rim is probably better given my grad school budget at the moment, but more spokes sound like a good idea as soon as I can. I second landotter's recommendation of the Alex DM18. It's a sane cross-section, heavy enough for the job, made of good strong 6061-T6 alloy, and cheap to buy. It's what most people should have on their road bikes if they don't like to repair their wheels and don't want to spend a lot of money on them. If you intend to run tires at least 30mm wide (and you should do so), the Sun Rhyno Lite 700c is another good candidate. It weighs in the same range as the DM18, but it has a larger cross-section (therefore more stiffness and better load sharing among spokes). Both of the above rims are made from much more ductile and less crack- prone than anything Mavic has made in a long time. If you want to use narrow tires of less than 28mm width, the Velocity Deep-V is a more expensive but very strong rim, especially when laced with 36 or more spokes. It's pretty lightweight, too-- just 520g claimed, though all rims vary from one specimen to the next. Most of my bikes have 48 spoke wheels. (I weigh about 350 lbs. at the moment, but I have weighed as much as 400 lbs. I am 6'8" tall.) But most of my bikes have rims that are no longer available. To complicate matters, most of today's strongest rims come only in 32 and 36 hole versions. So it's no longer the undisputed best idea to use 48 spokes if you want the strongest possible wheel. You have to weigh your priorities against the available options. Where 48 spokes may still offer the best weight bearing and the greatest future serviceability, some 36 spoke wheels may offer better stiffness and less frequent maintenance simply because the choice of rims is better. For the ultimate in strength, but a width that makes it incompatible with most road bikes, the Kris Holm 29" (700c) mountain unicycle rim is currently without peer in its rim diameter. It's 38mm wide and weighs in the neighborhood of 900g. It comes only in 32 and 36 hole variants. http://www.unicycle.com/shopping/shopexd.asp?id=805 I don't think that will be necessary for you. I think that a good wheel build with 36 14ga. or 14/15ga. spokes and Alex DM18 rims should do the trick. If your riding habits or road conditions are particularly harsh and that does not solve your problems, it is at least the cheapest and most effective next step along your way. 300 pounds is really not all that much in the grand scheme of things. 700 pounds, well... that's another matter. Check back in with me in that case. I have some ideas. I encourage you to read _The Bicycle Wheel_ by Jobst Brandt, or http://www.sheldonbrown.com/wheelbuild.html, or b oth, and try your hand at building your own wheels. If your above average mass, like mine, is a permanent condition rather than a weight fluctuation, you will do yourself a service in the long term by building and maintaining your own wheels. Chalo |
#14
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Wheels for 700lb guy?
On Nov 17, 1:33*am, Hank wrote:
On Nov 16, 10:49*pm, landotter wrote: On Nov 16, 9:56*pm, wrote: Alex DM18s are a good choice for a clyde. It's got even more meat than the Mavic. Less than $20. ERD is close enough to the 604 I found for the Mavics for you do tape 'em up and do a direct swap. You'll need to emery paper the joints as they aren't welded, if you want smooth braking. Well that sounds like maybe a good combo of cheap solution and an intro to wheel building. *If I mess it up, not such a big deal for $20. *It does look like a pretty hefty cross section too. You'll have to double check the ERD for sure, but if it's within a couple mms--indeed, just tape the rims together, making sure that the "handedness" of the spoke holes is correct, and swap the spokes one by one. Use an electric driver from the inside to do this. A flat head will do, or a philips bit with most of two fins ground off works as well. If you don't have a truing stand, like most of us, do remember to set your brake pads very carefully and closely before you do this-- and you can use your bike as a truing stand. The Alex is a good strong rim--it's not machined and it's not welded, so it will take emery paper for a minute or three on the joint. It should solve your problem if built right and tensioned well. My last rerimming I did with some has a couple thousand miles on 'em with no touch ups needed. I've hauled groceries, ice biked--you name it, DM18s is strong stuff. Don't let the non-Eurosnob price tag fool you. I'll cast another vote for Alex, but I say spring for another 5 bucks and get the Adventurer, which has eyeleted spoke holes. DM18 in 700c *is* eyeleted.* The Adventurer is powder coated and has machined walls and handsomer for sure, but the ERD ain't right. |
#15
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Wheels for 700lb guy?
On Nov 17, 12:09*am, landotter wrote:
On Nov 17, 1:33*am, Hank wrote: On Nov 16, 10:49*pm, landotter wrote: On Nov 16, 9:56*pm, wrote: Alex DM18s are a good choice for a clyde. It's got even more meat than the Mavic. Less than $20. ERD is close enough to the 604 I found for the Mavics for you do tape 'em up and do a direct swap. You'll need to emery paper the joints as they aren't welded, if you want smooth braking. Well that sounds like maybe a good combo of cheap solution and an intro to wheel building. *If I mess it up, not such a big deal for $20. *It does look like a pretty hefty cross section too. You'll have to double check the ERD for sure, but if it's within a couple mms--indeed, just tape the rims together, making sure that the "handedness" of the spoke holes is correct, and swap the spokes one by one. Use an electric driver from the inside to do this. A flat head will do, or a philips bit with most of two fins ground off works as well. If you don't have a truing stand, like most of us, do remember to set your brake pads very carefully and closely before you do this-- and you can use your bike as a truing stand. The Alex is a good strong rim--it's not machined and it's not welded, so it will take emery paper for a minute or three on the joint. It should solve your problem if built right and tensioned well. My last rerimming I did with some has a couple thousand miles on 'em with no touch ups needed. I've hauled groceries, ice biked--you name it, DM18s is strong stuff. Don't let the non-Eurosnob price tag fool you. I'll cast another vote for Alex, but I say spring for another 5 bucks and get the Adventurer, which has eyeleted spoke holes. DM18 in 700c *is* eyeleted.* The Adventurer is powder coated and has machined walls and handsomer for sure, but the ERD ain't right. ERD for A719 is 600.5 (per Spocalc) Adventurer is 603.1 DM18 is 606.4 (per alexrims.com) I'd say you're much more likely to be able to do the swap with the Adventurer. |
#16
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Wheels for 700lb guy?
I second landotter's recommendation of the Alex DM18. It's a sane
cross-section, heavy enough for the job, made of good strong 6061-T6 alloy, and cheap to buy. It's what most people should have on their road bikes if they don't like to repair their wheels and don't want to spend a lot of money on them. Got some in my future then. *700 pounds, well... that's another matter. *Check back in with me in that case. *I have some ideas. Maybe someday with the full load of groceries and the dog ;-) I encourage you to read _The Bicycle Wheel_ by Jobst Brandt, orhttp://www..sheldonbrown.com/wheelbuild.html, or b oth, and try your hand at building your own wheels. *If your above average mass, like mine, is a permanent condition rather than a weight fluctuation, It is. I'm a big guy, dad was a big guy, I've been right around 300 for at least six years now, with practically no gain or loss. I was a little lower in college but *that* was the fluctuation ;-) you will do yourself a service in the long term by building and maintaining your own wheels. I'm a handy guy overall, so that appeals to me (as does some of your custom machined stuff, by the way ! ) I'm a little low on time at the moment, so the idea of the quick swap to the DM18 as people have described is pretty attractive, rather than lacing a new wheel from scratch, but I see the point to doing the work myself. I've spent way too much on broken wheels... Thanks for the advice, everyone, I think I'm going to go with the DM18's and do the taped swap with the existing spokes and hub; that sounds like the best and cheapest way to get me going again right now, and I'll learn to build from scratch by the next time. Thanks a lot, the existence of $20 decent rims makes me a lot more comfortable re-rimming my wheel somehow ;-) Dan |
#17
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Wheels for 700lb guy?
On Nov 16, 5:42*pm, wrote:
Ok, I don't weigh 700 pounds. *I weigh a solid 300. I don't care about the weight of my rims, I care only about strength and fatigue performance. * I have a short, flat, bike ride to work every day. I bought some Mavic A719 36 hole wheels for my bike and kept an eye (not good enough, apparently) on them to see if they were still running true. *They ran true for a long time but when did go out, I already had fatigue cracks around several spokes and I need a new rear wheel again. Presumably I had uneven spoke tension that I should have kept an eye on, and I got cracks from that, causing the wheel to go out of true. Does that sound right? There's nothing rough or hard about my ride...the big sin I'm committing, if any, is not paying enough attention to my spokes on a regular basis, but I'd really like to come up with a wheel configuration where I didn't have to ping each spoke every morning and sit right down there in the driveway with the spoke wrench if something's off. I used this subject line because I find plenty of "I'm 250lb and touring with 50lb of gear and my Mavic A719's are fine" kind of posts on the internet, but what I want to know is "I'm 300 pounds and want wheels I can ignore at least a little in the interest of just getting into work." *I'm not saying I'm not going to true the things, I'm just saying I want to do it on Saturday and I don't want eight miles of out- of-true ride to be an absolute death knell for my wheels Is that a ridiculous hope? *Is the 300-lb fat-guy wheel **with a margin of error** a pipe dream, at least in a price range under several hundred bucks? *Hopefully I'm not offending everyone by even asking ;-) I've gone through a couple decent sets of rims with fatigue cracks around the spoke holes (yes, both were eyeletted), and I suppose it's just my fault for being cavalier about maintenance *but it seems like cracking rims on an 8 mile round trip, flat, minimally bumpy ride means I'm right up at the capacity limit for the wheel, and I want something that will do more. *I probably can't have it, but I figured I'd ask. -Dan Zimmerman Set of these- http://www.velocityusa.com/default.asp?contentID=584 36 front, 48 rear. Good enough for a tandem, good enough for you. shimano tandem hubs modified for your frame or Phil Wood. |
#18
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Wheels for 700lb guy?
On Sun, 16 Nov 2008 23:02:41 -0800, Chalo wrote:
Pete Biggs wrote: wrote: Presumably I had uneven spoke tension that I should have kept an eye on, and I got cracks from that, causing the wheel to go out of true. Does that sound right? Cracks around the spoke holes sounds like excessive spoke tension. --which is only a chronic issue with Mavic rims from the last ~20 years. "Excessive" spoke tension therefore can be evaluated alternatively as "substandard" rim structure. not if the spoke tension is to spec. spoke tension "as high as the rim can bear" is not only wrong, it's borne of a fundamental misunderstanding of the rim's function in a wheel. I can say that recent Mavic rims have failed for me at spoke tensions where lighter rims from other makers have held up fine. but that is not the same as the manufacturers spec. applying the cylinder head bolt spec from a '57 chevy to a 2007 honda civic isn't a useful comparison. with rims, it's not overall weight, but where the material is distributed that matters. |
#19
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Wheels for 700lb guy?
On Mon, 17 Nov 2008 01:43:12 +0100, Pete Biggs wrote:
wrote: Ok, I don't weigh 700 pounds. I weigh a solid 300. I don't care about the weight of my rims, I care only about strength and fatigue performance. I have a short, flat, bike ride to work every day. I bought some Mavic A719 36 hole wheels for my bike and kept an eye (not good enough, apparently) on them to see if they were still running true. They ran true for a long time but when did go out, I already had fatigue cracks around several spokes and I need a new rear wheel again. Presumably I had uneven spoke tension that I should have kept an eye on, and I got cracks from that, causing the wheel to go out of true. Does that sound right? Cracks around the spoke holes sounds like excessive spoke tension. ~PB indeed - that's why manufacturers have spoke tension specifications for their rims. |
#20
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Wheels for 700lb guy?
On Sun, 16 Nov 2008 16:42:33 -0800, n3ox.dan wrote:
Ok, I don't weigh 700 pounds. I weigh a solid 300. I don't care about the weight of my rims, I care only about strength and fatigue performance. I have a short, flat, bike ride to work every day. I bought some Mavic A719 36 hole wheels for my bike and kept an eye (not good enough, apparently) on them to see if they were still running true. They ran true for a long time but when did go out, I already had fatigue cracks around several spokes and I need a new rear wheel again. Presumably I had uneven spoke tension that I should have kept an eye on, and I got cracks from that, causing the wheel to go out of true. Does that sound right? There's nothing rough or hard about my ride...the big sin I'm committing, if any, is not paying enough attention to my spokes on a regular basis, but I'd really like to come up with a wheel configuration where I didn't have to ping each spoke every morning and sit right down there in the driveway with the spoke wrench if something's off. I used this subject line because I find plenty of "I'm 250lb and touring with 50lb of gear and my Mavic A719's are fine" kind of posts on the internet, but what I want to know is "I'm 300 pounds and want wheels I can ignore at least a little in the interest of just getting into work." I'm not saying I'm not going to true the things, I'm just saying I want to do it on Saturday and I don't want eight miles of out- of-true ride to be an absolute death knell for my wheels Is that a ridiculous hope? Is the 300-lb fat-guy wheel **with a margin of error** a pipe dream, at least in a price range under several hundred bucks? Hopefully I'm not offending everyone by even asking ;-) I've gone through a couple decent sets of rims with fatigue cracks around the spoke holes (yes, both were eyeletted), excess spoke tension - pure and simple. use a tensiometer and build to the manufacturer's spoke tension spec. and I suppose it's just my fault for being cavalier about maintenance but it seems like cracking rims on an 8 mile round trip, flat, minimally bumpy ride means I'm right up at the capacity limit for the wheel, and I want something that will do more. I probably can't have it, but I figured I'd ask. use tandem wheels. and deep section rims distort less at the loading zone and thus do not lose as much spoke tension. thus there is less fatigue cycling and less spoke loosening. again, observe the rim manufacturer's spoke tension spec. |
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