StyrbjornSterki said:
I think 150# with no mechanical advantage and just a skinny rope would be a bit dodgy. Even the single bike hoists sold commercially generally are rigged with pulleys that create a 2:1 MA. I have never used one but I always have had my doubts as to their ability to lift the load in a level fashion, but with that much weight, I see few other choices.
Agree - you absolutely need some mechanical advantage, even for one or two bikes it wouldn't hurt.
I also agree having an additional pulley at the ceiling/wall junction is required if what you're lifting is longer than the spacing between your pulleys (i.e. the pulleys on the ceiling would need to be spaced further apart than the total length of your bikes or your lifting frame, otherwise the haul rope will interfere)
Level lifting isn't a big issue with the cheapo commercial system I use, and IMO greater weight actually works in favour of overcoming differences in friction between the pulleys at each end (since the friction component is proportionally a smaller contributor to the overall lifting work). One boat is a bit tail-heavy so that end lifts slower, but as soon as the pulley at the nose end reaches the ceiling, the tail end comes up. I am however only lifting one kayak at a time, the OP's proposed design would have serious issues with uneven loading side to side.
StyrbjornSterki said:
Or you could forget the B&T, use just single pulleys mounted to the ceiling, and wind up your rope with a winch mounted to the wall.
Here's my idea, quick and dirty:
In the side view, I've used an extra pulley than your design to keep the rope(s) running closer to the ceiling and wall. YMMV.
The most unsettled part is what to do with four individual ropes. <snip>
I want to like your proposed solution because you've explained everything so well, but I think in reality it's over-engineered and will suffer from usability issues. I forget how high the OP said his ceiling is, but say the total lift required is 2m. Estimating the circumference of the winch drum at 6cm, with a mechanical advantage of 3x that gives 2cm lift per crank revolution. That gives a total of 100 cranks of the handle to go up, and 100 cranks to come down. Sounds tedious to me, even if you drop the mechanical advantage by eliminating the gear drive or increasing the size of the winch drum.
I don't think passing knots or splices through pulleys would necessarily be required, but the pulleys at each corner would need to be on swivels as the direction of the load would change significantly.
Elapid, how often do you want to get down all the bikes at once? Unless the answer to that is "most of the time", I think you'll be better off hoisting each bike separately.
Pros:
- only lift the bike you want, instead of lifting all the bikes every time. A true cyclist has no use for bigger heavier arms

- lower mechanical advantage required = faster lifting/lowering
- no headaches trying to keep the load level
- load distributed across your ceiling instead of concentrated at one point
- lower load & complexity = reduced risk (and consequences) of failure (at worst you only drop one bike)
- you can can buy kits really cheaply on ebay (although mine didn't include the pulley to go in the corner between the ceiling at wall)
Cons:
- Maybe slower on those times you do want multiple bikes (except you can reduce the mechanical advantage to lift more with each pull)
- Won't be able to pack the bikes quite as close together (but you could easily stagger them end to end, or at the four corners of your garage as the lifting systems will be completely independent). Getting the middle bike in your diagram out would be a nuisance anyway.
- More individual parts required to purchase (but you can use cheaper parts, such as the kits linked in my previous post)
- More individual parts to install (but no construction of a frame required)
Final word of advice: when drilling or screwing, particularly overhead, ALWAYS WEAR SAFETY GLASSES. I got a small metal shaving stuck in my eyeball when fixing my system to the ceiling, carved off a galvanised bracket by a screw head. Luckily one of my riding buddies is an eye surgeon, who opened up his rooms on a Sunday morning to get it out for me (thanks Andy).
