My wife has a Mini Cooper with the built in bike rack. The rack is great in how it mounts to the car, but horrible in how it clamps the bikes. The clamps are two ruber padded hunks of metal that get squished together with big screws with handles. They clamp the top tube in one spot and seems really bad for a carbon frame. You need a lot of force to keep the bike from rocking.
I want to modify this rack to a two-point frame support, and was thinking of using aluminum to keep it lightweight, but then it occured to me that I don't think I've seen any car bike racks made from aluminum. Is that just to keep cost down, or is it a bad idea from a work-hardening, stress, vibration point of view.
I would be keeping the part of the existing rack that mounts to the car bumper. That is steel. But I was thinking of changing the vertical post (which is bolted on) to aluminum and then having a two point support (al la Thule), also from aluminum. Is aluminum unwise for a rear-mounted car rack?
Dans le message de news:[email hidden], [email hidden] <[email hidden]> a réfléchi, et puis a déclaré :
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My wife has a Mini Cooper with the built in bike rack. The rack is great in how it mounts to the car, but horrible in how it clamps the bikes. The clamps are two ruber padded hunks of metal that get squished together with big screws with handles. They clamp the top tube in one spot and seems really bad for a carbon frame. You need a lot of force to keep the bike from rocking.
I want to modify this rack to a two-point frame support, and was thinking of using aluminum to keep it lightweight, but then it occured to me that I don't think I've seen any car bike racks made from aluminum. Is that just to keep cost down, or is it a bad idea from a work-hardening, stress, vibration point of view.
I would be keeping the part of the existing rack that mounts to the car bumper. That is steel. But I was thinking of changing the vertical post (which is bolted on) to aluminum and then having a two point support (al la Thule), also from aluminum. Is aluminum unwise for a rear-mounted car rack?
On 14 Mar 2006 00:24:45 -0800, [email hidden] wrote: [snip]
Quoted message said:
I would be keeping the part of the existing rack that mounts to the car bumper. That is steel. But I was thinking of changing the vertical post (which is bolted on) to aluminum and then having a two point support (al la Thule), also from aluminum. Is aluminum unwise for a rear-mounted car rack?
Before trying to reinvent that rear rack and make something, which isn't as simple as it looks, why not see what you can get in a ready-made solution? Personally, I find the Yakima and Rocky Mounts roof racks to be much more useful with my Escort Wagon, but if a roof rack isn't what you want, I'm betting that you'll discover that it's still easier to buy a prefab rear rack and use it. Working with aluminum is easy if you have all of the tools and skills that you'll need, such as an inert gas welding setup and proper cutting and milling equipment to make the joints...but a cobbled-together bolted-joint rack is probably a bad idea. The tech required to make a safely usable rear rack is not so different from what's needed to make a bike frame; are you up to it? -- Typoes are a feature, not a bug. Some gardening required to reply via email. Words processed in a facility that contains nuts.
I neglected mention that I have a milling machine and TIG welder, so I would not be cobbling it together. Also the car is a convertible so no roof option. The Mini Cooper bike rack is unlike any other rear-mount rack. There is no room for a hitch-mount. It has two round rods that slide into sockets in the bumper. I have not finished researching this, but I don't think this is a standard rack type and don't expect to find other racks that fit the car. We got this setup from the car dealer. I think my only option is to modify it. But your suggestion does lead to the idea of buying a rack with a better bike clamping method and then mounting the parts that I need to my rack. I have no problem buying what will work. I don't *have* to make it.
However still no answer to my original question: Are any rear-mount bike car rack made from aluminum?
BTW the links in Sandy's post did not work on my PC. Maybe they were pictures of an aluminum rack?
My wife has a Mini Cooper with the built in bike rack. The rack is great in how it mounts to the car, but horrible in how it clamps the bikes. The clamps are two ruber padded hunks of metal that get squished together with big screws with handles. They clamp the top tube in one spot and seems really bad for a carbon frame. You need a lot of force to keep the bike from rocking.
I want to modify this rack to a two-point frame support, and was thinking of using aluminum to keep it lightweight, but then it occured to me that I don't think I've seen any car bike racks made from aluminum. Is that just to keep cost down, or is it a bad idea from a work-hardening, stress, vibration point of view.
Both, I would guess. Weight saving of a few pounds is not important when you have a 100bhp+ engine.
I make my own out of 2x3 alumimnium tubing. Just drill it for a front axle and usetoestraps to hold the rear wheel on. Mine work fine even with a tandem-the fork mounts on a vertical L about 7" high. Phil Brown
On 14 Mar 2006 11:27:47 -0800, "Chris M" <[email hidden]>
Quoted message said:
The first 2 lead to pages with problems (maybe the site needs some work) but the 3rd and 4th (at least) lead to aluminum roof racks.
Roof rack = no bueno for the OP. Te car's a ragtop.
I'm thinking that scavenging the clamping stuff and arms from a commercial product, and fabricating a post to mount that to his existing bracket, may be the hot ticket. -- Typoes are a feature, not a bug. Some gardening required to reply via email. Words processed in a facility that contains nuts.
However still no answer to my original question: Are any rear-mount bike car rack made from aluminum?
I haven't seen any whose vertical post was aluminum, but I haven't seen everything by a long shot.
Quoted message said:
BTW the links in Sandy's post did not work on my PC. Maybe they were pictures of an aluminum rack?
Maybe; at the very least, they might provide ideas or a source for components. From the other comments coming in, I think (in retrospect, of course) that it might have been a good idea to mention that the car was a convertible sooner; there's a lot of favor for rooftop racks in general, which, as you later noted, isn't a useful approach in your case. -- Typoes are a feature, not a bug. Some gardening required to reply via email. Words processed in a facility that contains nuts.
<[email hidden]> wrote: (clip) thinking of using aluminum to keep it lightweight, but then it occured to me that I don't think I've seen any car bike racks made from aluminum. Is that just to keep cost down, or is it a bad idea from a work-hardening, stress, vibration point of view. ^^^^^^^^^^^^^^^^^ If you really like welding aluminum, and are good at it, it certainly is feasible, but you won't gain much, weightwise. Since aluminum is not as strong as steel, you will have to make everything thicker. So, on a rack that weights about the same as a bicycle, and only redoing the clamps, you will be lucky to gain a couple of pounds. How significant is that when you add the weight of the car to the total?
My wife has a Mini Cooper with the built in bike rack. The rack is great in how it mounts to the car, but horrible in how it clamps the bikes. The clamps are two ruber padded hunks of metal that get squished together with big screws with handles. They clamp the top tube in one spot and seems really bad for a carbon frame. You need a lot of force to keep the bike from rocking.
I want to modify this rack to a two-point frame support, and was thinking of using aluminum to keep it lightweight, but then it occured to me that I don't think I've seen any car bike racks made from aluminum. Is that just to keep cost down, or is it a bad idea from a work-hardening, stress, vibration point of view.
I would be keeping the part of the existing rack that mounts to the car bumper. That is steel. But I was thinking of changing the vertical post (which is bolted on) to aluminum and then having a two point support (al la Thule), also from aluminum. Is aluminum unwise for a rear-mounted car rack?
Why couldn't you fabricate an arm that reaches from the vertical post to another point on the bike? You should be able to clamp the seat tube, down tube, or maybe the crank.
Go ahead, make it from aluminum. Wait -- it's a Cooper. We should be writing aluminium.
<[email hidden]> wrote: (clip) thinking of using aluminum to keep it lightweight, but then it occured to me that I don't think I've seen any car bike racks made from aluminum. Is that just to keep cost down, or is it a bad idea from a work-hardening, stress, vibration point of view. ^^^^^^^^^^^^^^^^^ If you really like welding aluminum, and are good at it, it certainly is feasible, but you won't gain much, weightwise. Since aluminum is not as strong as steel, you will have to make everything thicker. So, on a rack that weights about the same as a bicycle, and only redoing the clamps, you will be lucky to gain a couple of pounds. How significant is that when you add the weight of the car to the total?
I think he may be looking at the fact that the rack is going to be attached to a fairly light socketing arrangement on the rear bumper, and therefore he is regarding every ounce removed as a little more insurance against the attachment points being overstressed. They're used with the factory accessory bike rack now, but that rack uses an unsatisfactory hold-down.
-- Typoes are a feature, not a bug. Some gardening required to reply via email. Words processed in a facility that contains nuts.
From what people are saying, aluminum may not be worth the trouble. The
only reason I was trying to lighten the rack up is to make it easier for my wife to put it on the car, but a few pounds won't matter much. I think I will take a close look at the Yakima racks and see if I can make use of one of those. I like their clamp design - how it stabilizes the down tube and keeps the bike from swinging without straps or bars underneath the bike. If I make this work I'll be back to link some pics. There may be other Mini owners out there.
Dans le message de news:[email hidden], Werehatrack <[email hidden]> a réfléchi, et puis a déclaré :
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On 14 Mar 2006 11:27:47 -0800, "Chris M" <[email hidden]>
Quoted message said:
The first 2 lead to pages with problems (maybe the site needs some work) but the 3rd and 4th (at least) lead to aluminum roof racks.
Roof rack = no bueno for the OP. Te car's a ragtop.
Aha ! The new Mini. I only know about the non-German ones...
Even the old ones do exist in convertible style, these days. Not factory, possibly, but people have been converting regular cars to open-top since a roof became standard equipment. Hell, [censored] rode around in an open top Beetle every chance he could, and that was before Beetles even entered serious mass production.
Dans le message de news:[email hidden], Jasper Janssen <[email hidden]> a réfléchi, et puis a déclaré :
Quoted message said:
Sandy said:
Dans le message de news:[email hidden], Werehatrack <[email hidden]> a réfléchi, et puis a déclaré :
Quoted message said:
On 14 Mar 2006 11:27:47 -0800, "Chris M" <[email hidden]> wrote:
> The first 2 lead to pages with problems (maybe the site needs some > work) but the 3rd and 4th (at least) lead to aluminum roof racks.
Roof rack = no bueno for the OP. Te car's a ragtop.
Aha ! The new Mini. I only know about the non-German ones...
Even the old ones do exist in convertible style, these days. Not factory, possibly, but people have been converting regular cars to open-top since a roof became standard equipment. Hell, [censored] rode around in an open top Beetle every chance he could, and that was before Beetles even entered serious mass production.
Jasper
The convertible Minis I have seen were like sardine tin convertibles, having the roof rails still intact. Fully cut off Minis are entirely a different matter. Like Mini Mokes.
Dans le message de news:[email hidden], Jasper Janssen <[email hidden]> a réfléchi, et puis a déclaré :
Quoted message said:
Sandy said:
Dans le message de news:[email hidden], Werehatrack <[email hidden]> a réfléchi, et puis a déclaré : > On 14 Mar 2006 11:27:47 -0800, "Chris M" > <[email hidden]> wrote: > >> The first 2 lead to pages with problems (maybe the site needs some >> work) but the 3rd and 4th (at least) lead to aluminum roof racks. > > Roof rack = no bueno for the OP. Te car's a ragtop.
Aha ! The new Mini. I only know about the non-German ones...
Even the old ones do exist in convertible style, these days. Not factory, possibly, but people have been converting regular cars to open-top since a roof became standard equipment. Hell, [censored] rode around in an open top Beetle every chance he could, and that was before Beetles even entered serious mass production.
Jasper
The convertible Minis I have seen were like sardine tin convertibles, having the roof rails still intact. Fully cut off Minis are entirely a different matter. Like Mini Mokes.
