Trailer Design Questions
04-04-11, 08:42 PM
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Trailer Design Questions
I plan to build a trailer for a typical load of 4 large bags of groceries, or two bags and a couple of 30 lb boxes of cat litter. Construction won't be a problem, as I'm a halfways decent framebuilder. But I haven't pulled a trailer since the very 1st Cannondale Bugger, so I have a couple of questions about the dynamics of towing.
1. Tongue length - Do I want the tongue to be as short as possible or will the trailer tow better if the tongue is longer? If so, how much longer. The hitch, probably a QR ball joint, will be just below the left rear axle.
2. Weight distribution – Structurally, my design works best with 2/3 of the box ahead of the trailer axles. Does this sound about right or do I want to minimize tongue weight? Or should I center the box on the axles and just load the heavier items towards the front?
3. Box – Being lazy I'd like to use a plastic tub. Seems like 26-30” x 18-20” by 13-15” tall would be ideal. Can anyone suggest something in that range? A cover would be nice but not essential.
We've been using 2 Sunlite Grocery Getter panniers on the rear of Jane's bike, and a 2nd pair on my front low riders, with the largest Wald 535 baskets on the rear. Works OK but it takes quite a while to load up outside the store, the bikes want to tip over while we're loading and we can't carry the kitty litter. We've always been Car-Lite but we want to get even Car Lite'er when Jane follows me into retirement in 6 weeks.
1. Tongue length - Do I want the tongue to be as short as possible or will the trailer tow better if the tongue is longer? If so, how much longer. The hitch, probably a QR ball joint, will be just below the left rear axle.
2. Weight distribution – Structurally, my design works best with 2/3 of the box ahead of the trailer axles. Does this sound about right or do I want to minimize tongue weight? Or should I center the box on the axles and just load the heavier items towards the front?
3. Box – Being lazy I'd like to use a plastic tub. Seems like 26-30” x 18-20” by 13-15” tall would be ideal. Can anyone suggest something in that range? A cover would be nice but not essential.
We've been using 2 Sunlite Grocery Getter panniers on the rear of Jane's bike, and a 2nd pair on my front low riders, with the largest Wald 535 baskets on the rear. Works OK but it takes quite a while to load up outside the store, the bikes want to tip over while we're loading and we can't carry the kitty litter. We've always been Car-Lite but we want to get even Car Lite'er when Jane follows me into retirement in 6 weeks.
04-04-11, 09:29 PM
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Humvee of bikes =Worksman
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I built this trailer using salvaged materials for about $25 in the 80's. Still use it today........
https://www.motherearthnews.com/Do-It...e-Trailer.aspx
https://www.motherearthnews.com/multi...id=67956&seq=1
https://www.motherearthnews.com/Do-It...e-Trailer.aspx
https://www.motherearthnews.com/multi...id=67956&seq=1
__________________
My preferred bicycle brand is.......WORKSMAN CYCLES
I dislike clipless pedals on any city bike since I feel they are unsafe.
Originally Posted by krazygluon
Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred, which one would you rather have under your butt at 30mph?
My preferred bicycle brand is.......WORKSMAN CYCLES
I dislike clipless pedals on any city bike since I feel they are unsafe.
Originally Posted by krazygluon
Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred, which one would you rather have under your butt at 30mph?
04-05-11, 09:29 PM
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Hi Mark,
I just bought a 90 qt. Sterilite #1865 from Walmart. Label states 35" x 16.75" x 12.875". My only gripe is the lack of hinged latches (has snap, interference lips instead). Weighs just short of 2200g. I bought this one for my RV solar batteries container - $13 and change.
(link shows 4, but my store sells individually):
https://www.walmart.com/ip/Sterilite-...-of-4/10401040
I prefer a tongue weight somewhere shy of 10% loaded trailer weight. Keeping the trailer's CoG just slightly forward of the trailer axle helps to prevent infamous 'tail wagging' at speed. However, equally important to me is load height. The lower the cargo, the less effect it seems to have on the bike, especially when braking.
Last summer, my 87 YO Father came home with an older Schwinn enclosed trailer he found at a yard sale. After close inspection of his $5 investment, I walked away not the least bit disappointed. After replacing the rotted tires, it towed well too. But what I discovered is the lack of a typical side-to-side solid axle permitted lowering the cargo, which vastly improved towing. Approximate numbers are:
Wheels 20"
Estimated empty weight 12-15 lbs. (guesstimate)
Cargo box length 33"
Width between wheels 23"
Tongue length 23"
(tongue has an 7" offset and is removable - ideally, I plan to make it telescoping). Looks similar to this one, but I suspect an older model.
https://www.amazon.com/gp/product/B00...SIN=B002482Q4O
I just bought a 90 qt. Sterilite #1865 from Walmart. Label states 35" x 16.75" x 12.875". My only gripe is the lack of hinged latches (has snap, interference lips instead). Weighs just short of 2200g. I bought this one for my RV solar batteries container - $13 and change.
(link shows 4, but my store sells individually):
https://www.walmart.com/ip/Sterilite-...-of-4/10401040
I prefer a tongue weight somewhere shy of 10% loaded trailer weight. Keeping the trailer's CoG just slightly forward of the trailer axle helps to prevent infamous 'tail wagging' at speed. However, equally important to me is load height. The lower the cargo, the less effect it seems to have on the bike, especially when braking.
Last summer, my 87 YO Father came home with an older Schwinn enclosed trailer he found at a yard sale. After close inspection of his $5 investment, I walked away not the least bit disappointed. After replacing the rotted tires, it towed well too. But what I discovered is the lack of a typical side-to-side solid axle permitted lowering the cargo, which vastly improved towing. Approximate numbers are:
Wheels 20"
Estimated empty weight 12-15 lbs. (guesstimate)
Cargo box length 33"
Width between wheels 23"
Tongue length 23"
(tongue has an 7" offset and is removable - ideally, I plan to make it telescoping). Looks similar to this one, but I suspect an older model.
https://www.amazon.com/gp/product/B00...SIN=B002482Q4O
04-06-11, 12:04 AM
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Mark,
Just discovered this one and is closer to the dimensions you mentioned:
32.13"L x 19.13"W x 13.75"H Availability reveals a few Wally stores in your area do stock it.
https://www.walmart.com/ip/Sterilite-...-of-4/15528561
(again, the price quoted is for a set of 4)
Just discovered this one and is closer to the dimensions you mentioned:
32.13"L x 19.13"W x 13.75"H Availability reveals a few Wally stores in your area do stock it.
https://www.walmart.com/ip/Sterilite-...-of-4/15528561
(again, the price quoted is for a set of 4)
04-06-11, 01:52 PM
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I make something that is exactly what you're asking for you can check it out at www.redbiketrailer.com. Now that i've plugged my product I'll give my two cents. I'm guessing by "tounge" length you mean the towing arm i.e. distance between the trailer and your bike. I try to keep it fairly close to the bike. I like to keep the footprint of whole rig a small as possible to i can get into tight spaces. Also as the trailer arm get longer you need to make it stronger/heavier or it develops more play in it. I agree with Papa about the tounge weight. The nice thing about two wheel trailers is they support the weight independent of the bike (mostly) the 2/3 idea you have will put a lot of strain on the connection to the bike.
