5

For an ordinary bicycle (neither fixed gear nor capable of changing any gears).

Is it possible to modify it to have a reverse gear on it?

(i.e. reverse pedaling causes the bicycle to go backward)

(By modifying or attaching components to the rear wheel)

Thank you in advance

  • 6
    Your definition of an ordinary bike is an interesting one. You're down to just single speed bikes which are in a minority. – Chris H Mar 14 '16 at 17:59
  • 3
    Not really - fixies would fit the question, as would ordinaries and big wheel kids trikes. Do note that motorbikes don't have reverse gears, unless they're trikes built on a car transmission. Even aeroplanes don't have a reverse gear, hence "pushback" at the gate. It'd be very hard to pedal in reverse for far, cyclists don't want to carry extra weight, and just use your feet on the ground to push backwards. – Criggie Mar 14 '16 at 19:18
  • 7
    Simply get yourself a unicycle. – Daniel R Hicks Mar 15 '16 at 1:20
  • 2
    @Criggie Interestingly (or not) the closest to a reverse gear on a motorbike is on the biggest Goldwings - they can use the starter motor to gentle push the bike backwards. This is just intended as an aid to paddling the hideously heavy (as well as just plain hideous) bike back out of a parking space rather than actually riding around. – Grimm The Opiner Sep 27 '16 at 11:04
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    @Criggie your point is a good one, but airplanes can push back from the gate under their own power, it's just a tremendous waste of fuel aviation.stackexchange.com/questions/8084/… – Paul H Sep 12 '19 at 19:14
14

Such a hub exists for trike and quads . Pedal forward with 3 or 5 gears then having a coaster brake to stop . At full stop with the brake engaged continued backward pedal pressure will cause the cycle will move in reverse in a reduced gear . Sturmey-Archer has made these hubs for the niche market (velomobiles ) for some years now . The hubs have a sprocket bolted to the right spoke flange to drive the rear axle , some clever types have removed this and laced it into a wheel for a single rear wheel trike . Maybe this could work for a bike , still a question of balance in reverse ?!

model QS-RC5 with reverse+coaster brake
model TS-RC5 only coaster brake and no reverse

SA Specification Sheet PDF

enter image description here

  • 5 Speed internal gear hub with coaster brake
  • Special use hub, includes a reverse gear on QS-RC5 model

There's also a 3 speed version with reverse, model QS-RC3.

Specs

  • Hub Shell Material - 6061 Aluminium
  • Axle Diameter - 13/32” Slotted
  • Axle Length - 185mm
  • Over Locknut Dimension - 139mm
  • Right Axle Protrusion Length - 24mm
  • Left Axle Protrusion Length - 22mm
  • Flange Width - 65mm
  • Flange Sprocket Teeth - 22T
  • Flange Sprocket C.L. - 39.4mm
  • Sprocket Teeth - 21T through 22T
  • Sprocket Chain Line: 53.9mm
  • Indicator Chain - HSA585 Mark Yellow

  • Weight - 2010g

Gear Ratio

• Overall Range - 256%
• Gear 1 - 62.5% (-)37.5%
• Gear 2 - 75% (-)25% (Gear 1 + 20%)
• Gear 3 - 100% Direct Drive (Gear 2 + 33%)
• Gear 4 - 133.3% (+)33.3% (Gear 3 + 33%)
• Gear 5 - 160% (+)60% (Gear 4 + 20%)

  • Chain sprockets mounting: 3 notch mounting
  • Colour: silver
  • Flange distance (right): 39 mm
  • Flange PCD (right): 67 mm
  • Flange distance (left): 32 mm
  • Flange PCD (left): 67 mm
  • Over Locknut Distance (O.L.D.): 139 [EN] mm

There's an operation manual available at https://hfchristiansen.zendesk.com/hc/da/article_attachments/115010677845/Manual_-_QS-RC5.pdf

To operate reverse, you stop the bike, then start pedalling backwards.

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  • 1
    Do you have a link? bolting to the spoke flange sounds bizarre, so I'd like more details. – Móż Sep 26 '16 at 22:01
10

While it may be possible, by creating a mechanism that shifts the chain from one freewheel to another, or disconnecting one temporarily through mechanical actuators, the hassle and engineering it would take to make happen would be outweighed by the fact that it is almost entirely pointless. A fixed gear would be your best bet as it already does that.

Although pedalling and going backwards on a bicycle is not an easy task for any distance, and to keep momentum and balance for BMX applications, there are clutch coaster brakes that allow forward pedalling while rolling backwards. You may be able to devise a clutch system hub that allows freewheeling while rolling forward and engages while pedalling backwards but again the engineering behind it would outweigh its purpose most likely.

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  • 3
    The hub you described also sounds dangerous. If the clutch malfunctioned you could get thrown unexpectedly. – ebrohman Mar 15 '16 at 0:53
3

Have a look at the system Berg toys use for their go-karts. Its called a BFR hub (for brake, forward and reverse). This hub lets you go forward or backward, while always pedalling in forward direction. It also has a freewheel.

The system needs two chains, with this being in the middle of your drive sprocket and axle sprocket.

Hub: BFR Hub stands for brake, forward and reverse; this hub allows the rider to pedal forward, coast with the pedals remaining static, pedal back slightly to engage the coaster brake or use the hand brake to stop, once stopped pedal backwards to go in reverse!

Source: Product page for Berg John Deere BFR go-kart

Of course, it is not sold (or even meant) for bicycles, so you'd need to either adapt it for a bicycle, or build your own. However, it shows how much technical effort is necessary to combine reverse gear and freewheel.

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  • 3
    Welcome to Bicycles. This sounds like an ad. If you are connected to this product in some way, the rules say you must declare it. OTOH I don't see how it would work on a bike. – andy256 May 25 '16 at 5:35
  • I don't see the use - a bike is damn-near impossible to ride backwards while balancing. Plus if you were doing this on the road, you'd utterly confound motorists, as well as having a very poor weight distribution and limited visibility. – Criggie May 25 '16 at 8:42
  • Looks like they don't sell the hub separately. Vote to close. – Criggie May 25 '16 at 8:47
  • 2
    @andy256: I don't see this as advertising. It is actually a good answer, as it shows how it could be done in principle. As there is probably no "reverse freewhell" available for bicycles, this is the closest you can get. – sleske May 25 '16 at 9:39
  • 1
    except there's no actual answer, just a suggested search term. The poster can't even be bothered doing the search and embedding an image or summarising the results. – Móż May 25 '16 at 9:45
2

I have repaired a pedal powered toy that had an arrangement like this. It was an Italian ride-on toy tractor that had a modified coaster brake set up so that instead of back pedalling applying a brake, the "brake" mechanism inside the hub locked against the hub body so that you could pedal the toy backwards. The modification didn't seem particularly difficult, but from memory I think a lathe would be required unless you really like filing small amounts off a round part until it fits.

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  • That sounds like a system similar to the Berg toys BFR mentioned in user26203's answer. – sleske May 25 '16 at 9:49
  • maybe, they didn't give enough information to even guess how it works so I can't tell. It did remind me of the toy I worked on. But the one I serviced only needed one chain and looked outwardly exactly like a standard coaster brake. Only when you rode it did it become apparent that pedalling backwards made the toy go backwards rather than applying the brake. – Móż May 25 '16 at 9:54
0

Cut then weld the bottom cranks and rear hub of two bikes to mirror the drive side. You will have gears and chains on both sides of your bike. -]---[- To make one ride backwards full time, just swap the parts right to left.

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  • 3
    You'll also have a bicycle that can't freewheel in either direction, since one of the freewheels stops the rear wheel going faster than the cranks and the other stops it going slower. So this is just a complicated way of creating a fixed-gear bicycle with two chains. – David Richerby Jul 22 '18 at 11:00
  • 1
    What parts would you swap - the whole chain? – Criggie Sep 13 '19 at 4:56
-2

Yes. Some type of freewheel or freehub manual lockup should do the trick. It would also be cool if you could pedal backwards to apply power forwards, thus using muscles in a different way.

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  • 1
    en.wikipedia.org/wiki/Retro-direct – ojs Mar 15 '16 at 19:44
  • 1
    We normally take questions that have simple yes-no answers as being "how do I..." and answer that question. Could you do that, please. – Móż Mar 15 '16 at 20:05
  • As it stands, this answers sounds a bit speculative. Please consider expanding the answer to explain how one could do something like this. Specifically, you could describe the locking mechanism you have in mind in more detail. If you do not expand this answer, it is likely to be downvoted, flagged for moderator intervention, and possibly deleted. – jimchristie Mar 16 '16 at 1:23
  • The O.P. asked if it IS possible, but didn't ask how. I am not a Mechanical Engineer and am not applying for a patent so divuging details is not required here. My answer is implying all you need is some way to stop the ratcheting mechanism manually. This would actually be desirable in some cases while going forward. For example, imagine going down a hill but not wanting to gain too much speed. You could lock the freewheel but not pedal but leave your feet on the pedals, thus forcing the bike to lift your legs. Might be a good way to "engine brake". If the speed gets too fast disengage it. – David Mar 16 '16 at 7:58
  • 2
    Well, you didn't prove that such freewheel would be possible, just postulated existence of one. And descending on a fixie doesn't work like that, ask anyone who has done it. – ojs Mar 16 '16 at 17:56

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