is this possible??? Or feasible?

[outskirtscustoms]

I have been toying with the idea of a new design for a cruiser, throw on a 3 speed crank set from a mountain bike, a 7 speed mountain bike gear cluster and somehow attach it to a 5 speed internally geared hub therefore making 105 speeds. Would this be possible? Feasible? What would be the benefits and downfalls? Like I said only an idea I've been toying with so far but interesting to say the least.

 

[user 135]

The biggest problem is fitting a freewheel on the hub. Though SRAM already makes a 3 speed hub designed to fit 8 or 9 speed cluster. SRAM DualDrive

Sheldon Brown did a 63 speed many years ago.
http://www.sheldonbrown.com/otb.html

 

[DougC]

Could you do it yes, but you'd need machine tools or to hire a shop.

Harris Cyclery still sells them. Looks like a 3x9 speed would hit up around $250-$300 or so when you're done.

I know a LOT of better folding/travel bikes used the Sachs 3x7s for many years, so it is possible a scrounger could run into one while rummaging on trash day.
~

 

[outskirtscustoms]

Cool, I also just saw on flea-bay they have a 10 speed cassette for mountain bikes, so I could very possibly make a 150 speed or even more! I'd need to machine a longer axle but I know a guy who owns a machine shop and could do some of the work cheap. Just an idea that has been bugging me.

 

[Wildcat]

You would have to calculate all the ratios, any that were the same would only be counted as one gear. You would probably wind up with only 139 gears.

 

[outskirtscustoms]

would there be any top speed advantage?

 

[Buck Masterson]

I'm happy with 1 speed!

 

[outskirtscustoms]

I'm happy with 1 speed!

Me too, I'm just tossing the idea around and wondering if I could make a bike insanely fast. Speed is my other obsession, trying to combine the two.

 

[user 135]

Looking for Speed? This is probably the best way

 

[deorman]

Off-road bikes use many gears to be able to keep going through tough terrain and still make speed over easy. Similarly, with the roadies, the purpose of many gears is not so much for top speed, as it is to be able to maintain a steady cadence during grade changes. I think 10 speeds, or even 5, is plenty to get up to as high a gear as you can push. If maximum speed is your thing, one thing that will help push a really tall gear is the connecting shoe/pedal dealies, or just some old fashioned toe clips. With them, you are no longer restricted by how much weight you can put on the pedal. Also works a whole other set of muscle mass, which improves your cardio performance over time.

 

[FunkyStickman]

You could do it, they have 3-speed rear hubs that take 9-speed cassettes (SRAM and Sturmey both make them) and with a triple chainring, you'd have 109 gears, but as was mentioned, you'd duplicate a LOT of gears....

I'll give you an example.

With a Sturmey CS-RF3 hub, an 11-34 cassette, and a 22-32-42 crank, you'd end up with the following gear inches (assuming a 26" wheel):
Duplicate gears (within a half inch) are in red, and don't count. Most people couldn't tell the difference between 1 gear inch... if you widen the duplicate range to 1 gear inch, it eliminates another 20 gears or so.

small ring, 1:1 hub gear
16.8, 19, 22, 24.8, 28.6, 33.6, 38.1, 44, 52
middle ring, 1:1 hub gear
24.5, 27.7, 32, 36.2, 41.6, 48.9, 55.5, 64, 75.6
big ring, 1:1 hub gear
32.1, 36.4, 42, 47.5, 54.6, 64.2, 72.8, 84, 99.3

You can see, there's already a few gears duplicated. Putting the rear hub in 1st drops all gear ratios 25%, so you get:
12.6, 14.3, 16.5, 18.6, 21.5, 25.2, 28.6, 33, 39
18.4, 20.8, 24, 27.2, 31.2, 36.7, 41.6, 48, 56.7
24, 27.3, 31.5, 35.6, 41, 48.1, 54.6, 63, 74.5

And the hub in 3rd would be everything +33%
22.3, 25.3, 29.3, 33, 38, 44.7, 50.6, 58.5, 69.1
32.6, 36.8, 42.5, 48.1, 55.3, 65, 73.8, 85.1, 100.5
42.7, 48.4, 55.9, 63.2, 72.6, 85.4, 96.8, 111.7, 132

Not only are there tons of overlap, by the time you get to either extreme, you get bigger and bigger gaps, which defeats the purpose of having lots of gears. It would be nuts having three shifters on the handlebars... I could see somebody modding an old Hurst shifter with three knobs for this

Would it be cool? Heck yeah! Would it be functional and efficient? Not really. You'd be better off with a Nuvinci hub and infinite gears.

 

[udallcustombikes]

I remember seeing pics of a bike a while back where the builder had used 15-20 rear multi-speed hubs and derailluers to give him some astronomical number of gear combos. I will try to find the pics again.

 

[outskirtscustoms]

Thanks for the info, it would be kinda cool to have 3 suicide shifters, I think two would be plenty though. I already have the shift levers on my Bootlegger bike (2) and 10-21 gears would be great for towing my trailer, especially with a load of 10-15 bikes! but then I'd be tempted to build a bigger trailer to haul more bikes, then I'd be tempted to modify the gear system to have an even lower gear, then make the trailor the size of a semi truck, then a motor, then.......you get the idea.... :lol: It'd be overkill before you know it.

 

[B607]

You could do it, they have 3-speed rear hubs that take 9-speed cassettes (SRAM and Sturmey both make them) and with a triple chainring, you'd have 109 gears, but as was mentioned, you'd duplicate a LOT of gears....

I'll give you an example.

With a Sturmey CS-RF3 hub, an 11-34 cassette, and a 22-32-42 crank, you'd end up with the following gear inches (assuming a 26" wheel):
Duplicate gears (within a half inch) are in red, and don't count. Most people couldn't tell the difference between 1 gear inch... if you widen the duplicate range to 1 gear inch, it eliminates another 20 gears or so.

small ring, 1:1 hub gear
16.8, 19, 22, 24.8, 28.6, 33.6, 38.1, 44, 52
middle ring, 1:1 hub gear
24.5, 27.7, 32, 36.2, 41.6, 48.9, 55.5, 64, 75.6
big ring, 1:1 hub gear
32.1, 36.4, 42, 47.5, 54.6, 64.2, 72.8, 84, 99.3

You can see, there's already a few gears duplicated. Putting the rear hub in 1st drops all gear ratios 25%, so you get:
12.6, 14.3, 16.5, 18.6, 21.5, 25.2, 28.6, 33, 39
18.4, 20.8, 24, 27.2, 31.2, 36.7, 41.6, 48, 56.7
24, 27.3, 31.5, 35.6, 41, 48.1, 54.6, 63, 74.5

And the hub in 3rd would be everything +33%
22.3, 25.3, 29.3, 33, 38, 44.7, 50.6, 58.5, 69.1
32.6, 36.8, 42.5, 48.1, 55.3, 65, 73.8, 85.1, 100.5
42.7, 48.4, 55.9, 63.2, 72.6, 85.4, 96.8, 111.7, 132

Gee whiz, Funky. You must be the smartest man in LA. Gary

 

[frameteam2003]

Adding a derailer freewheel block to a sturmey/archer hub is a very old idea---been dome sence the late 30s.To do it you will need an "old" S/A theaded driver
that's the part the sprocket goes on.

 

[outskirtscustoms]

Adding a derailer freewheel block to a sturmey/archer hub is a very old idea---been dome sence the late 30s.To do it you will need an "old" S/A theaded driver
that's the part the sprocket goes on.

Cool, how well does it work? Would it hold up to the punishment of towing a trailer full of bikes?

 

[JoKeR63]

Another way to get insane gearing is to put in a mid-drive. Basically you put a cluster between your crank and rear wheel, need a long bike for this one. For an example,

http://www.google.com/imgres?imgurl=htt ... CCIQ9QEwAw

Add a road triple to that bad boy and you've got gearing aplenty! :wink:

 

[outskirtscustoms]

Another way to get insane gearing is to put in a mid-drive. Basically you put a cluster between your crank and rear wheel, need a long bike for this one. For an example,

http://www.google.com/imgres?imgurl=htt ... CCIQ9QEwAw

Add a road triple to that bad boy and you've got gearing aplenty! :wink:

Sweet, I've got a long bike to do that on too! It's long enough for 3 or 4 mid drives.....lol.