Biking Speed Machine?

Question

The ones where it's sort of like a rowing machine, but replace the bar with set handles and put foot pedals in the sides.

Answer 1

Are you asking about an automatic transmission for a bicycle? We need more information.

Answer 2

Sure, but I'm not sure what you question is.

There are single speed bikes, bikes with internal 3,5,7 or more speed hubs, bikes with derailleurs at front and rear that give anywhere from 10-30 gears (the number is the number of sprockets on the rear wheel x the number of chainwheels (front sprockets)).

More gears are not necessarily faster, they are primarily an advantage in that the intervals between gears are smaller. Top speed and hill climbing ability are determined by the extremes of the gears available, not the number.

Gearing is usually calculated to allow comparisons by dividing the number of teeth on the front chainwheel by the number of teeth on the rear sprocket and multiplying by the wheel diameter (in inches). A range of 30-40 gear-inches to 100-110 gear-inches is fairly common, but can be larger. Lower gear-inch numbers are associated with hill climbing ability while higher numbers relate to top speed (all dependent on the ability of the rider to turn the cranks).

Hope that helps.

Answer 3

What is a "Biking Machine"?

Anyway, to clarify, the 10 speeds of today are not like the 10 speeds of the 1970's.

In the 1970's, a ten speed had 5 gears on the rear wheel, and two gears on the cranks (chainwheel). Which gave the bike ten possible combinations of gear ratio,

The rear wheel was a five speed, because it had five gears.

Over the years, companies such as Shimano, Suntour, Campagnolo, etc. added another gear. So there were 6 speeds, 7 speeds, 8 speeds, and 9 speeds. (counting the number of gears on the rear wheel).

But the bike companies also added a third chainwheel to the cranks.

5 gears rear and three front gives you fifteen speeds. 6 gears rear and two in front gives you 12 speeds.

6 on the rear and three in front gives you eighteen speeds.

7 gears on the rear wheel and 3 gears on the front gives you 21 speeds.

8 gears rear and 3 on front gives 24 gear ratios.

9 gears rear and three in front gives you 27 speeds.

10 gears rear and three on the cranks give you THIRTY speeds, but it's also called a ten speed, for just the number of gears on the REAR wheel.

Your question was a little vague, but the mechanism that shifts the gears is called a "Deraileur". The rear deraileur has two little idler gears and a spring, to hold the slack in the chain. There needs to be slack in the chain because some gears are bigger than others, and need more chain to fit around them. Shift to a smaller gear and the rear deraileur takes up the slack.

Answer 4

I honestly don't know what your referring to. Bikes have muti-speed gears now - how would this differ?