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Very Important Question!!!!!!!!

PB Forum :: BMX (20")
Very Important Question!!!!!!!!
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flag THEMANGLER
Posted: Mar 18, 2008 at 11:50 Quote
AaronZuffa wrote:
If you flop your hub, it will be turning the wrong way. Pedalling forward would get you no where but pedalling backwards will get you going backwards. I had one of these hubs once (on my specialized fuse). The point of it is so you can run LHD or RHD on the same hub, assuming you have the proper setup up front (cranks and sprocket). Get what I mean?

You are thinking (and I like that) but, never-the-less; you are still wrong. Sorry.
This should clear all questions:
[edit] Fixed gear/track bicycles
Usually, one side has a fixed type stepped threading, and the other side is threaded for a standard freewheel. Occasionally you may find double sided fixed hubs with stepped threading on both sides, but these are rare, only a few companies offer them (Phil Wood in the US and Goldtec in the UK are two examples). The fixed side has a stepped down diameter thread to accept a lockring. The larger diameter thread on the fixed side accepts a standard threaded cog, and uses the same size threads as the freewheel side of the hub. The most common standard I.S.O. thread size is 1.375" x 24 tpi (threads per inch), but there are other less common older sizes (British 1.370" x 24 tpi, French 34.7 x 1 mm, Italian 35 mm x 24 tpi).

The smaller diameter thread on the fixed side has reverse/left hand threads to accept a lockring. The lock ring is reverse threaded to prevent the cog from coming loose when applying reverse/braking power to the pedals. There are also different sized threads for the left hand lockring (English/ISO 1.29" x 24 TPI) Campagnolo/Phil Wood 1.32" x 24 TPI Old French 33 mm x 1.0 mm). The first two are the most common, the french threading is older, and a little less common. Always check with the manufacturer of the hub for lock ring compatibility. Often, the wrong thread type lockring will easily thread onto the wrong hub, but with use over time, the poorly mating thread interface will cause the threads on the hub to become damaged or destroyed.

This allows the installation of a cog (or freewheel) on one side of the hub, and another (cog or freewheel) on the other side of the same hub. Flip-Flopping the rear wheel allows switching between Fixed/Free drivetrain, between two different size gears, or both. Generally, the freewheel is selected to be the same size, or slightly larger (more teeth) than the fixed cog. Same size allows the same gearing, but with coasting option, while a slightly larger freewheel gear allows coasting and easier pedaling for longer or hilly rides. Both could also be freewheels for two different coasting gear selections. Any two different size cogs/freewheels can be used as long as they are within the limits of adjustibility allowed by the length of the frame's dropout slots and chain length. Large differences in the number of teeth may require adding or subtracting chain links to achieve proper fit. Also, if rear brakes are used (recommended for fixed/free, or free/free setups) brake pad reach to the rear rim may need to be adjusted.

The ISO threading for freewheels (Single or Multiple Speed) is the same as for track/fixed cogs. You CAN mount a standard single speed BMX style freewheel to the track threaded side of the hub. This is perfectly acceptable, but because of the stepped down lock ring threads, not as many threads of the freewheel engage the hub threads as they would if it were threaded to an actual freewheel threaded hub. This, however, is not a problem since the same number of threads are sufficient to secure a track cog. The force applied to a freewheel is the same as that applied to a fixed cog of the same size, so the missing threads cause no durability issue. Also, there is never any reverse torque on the threads with a freewheel, so a freewheel actually puts less strain on the thr[eads then a fixed cog does.

If a track hub is not available, or if a beginner wishes to try a fixed gear bicycle without buying a new hub or rear wheel, track cogs can be installed on a standard Freewheel hub using a right hand threaded ISO English bottom bracket lockring as the lockring for the cog (the threads are exactly the same). This may work for some lighter, or delicate riders, but any repeated reverse or braking pressure on the pedals will eventually cause the cog and lockring to come loose. It is recommended that anyone using a freewheel hub with a track cog in this manner do so with caution and with both front and rear brakes mounted to the bicycle.

Track cogs are generally available in a range of sizes from 12T to 23T (number of teeth) and two different widths - 3/32" and 1/8" (thickness of teeth). The 3/32" size is made to accommodate narrower 3/32" racing chains, but is also compatible with 1/8" and wider bmx/single speed chains. The thicker 1/8" cogs are ONLY compatible with 1/8" or wider single speed chains. There may be larger (number of teeth) sizes available as well, either custom manufactured or adapted from chainwheels or front sprockets using a number of methods or devices. There are some heavy duty 3/16" chains designed for BMX use which are compatible with most cogs. However, because these chains usually have taller thicker side plates, they may not work properly with some cogs smaller than 11T or freewheels smaller than 16T.

Freewheels are available in sizes 16T to 23T and in the same two different widths as the cogs (3/32" and 1/8"). ACS makes a special "FAT" heavy duty BMX freewheel in 14T and 16T with 3/16" teeth compatible only with 3/16" Chains.


[edit] BMX/Single Speed Bicycles
A different type of flip flop hub is made for use with BMX bicycles. There are actually a few variations of the BMX type. The most common type of BMX flip flop hub has standard ISO freewheel threads on one side and smaller metric BMX threads (30 mm x 1 mm) on the other side that are designed to work with smaller 14T to 15T BMX freewheels. In recent years a few companies have started making 13T freewheels compatible with this thread as well, allowing more gearing options.

In recent years, an innovation in BMX freestyle riding spawned "Left Side Drive." This component option switches the drivetrain to the left side of the bike in order to move the sprocket and chain out of harms way for riders who prefer to do grinding tricks using the pegs or pedal on the right side of the bike. Moving the drivetrain to the left side required modification to the design of three components. 1. A freewheel with left hand threads which threads on and ratchets in the opposite direction for use on the left side. 2. A rear hub with left hand threads to accept the LH freewheel. 3. A left side drive crank arm. * Although you could simply reverse a normal set of crank arms, the left side and right side specific pedal bosses would be reversed, causing them to tend to come loose and spin out with normal riding. Also, directional pedals would look backwards unless the pedal spindles were also reversed. Many companies now provide cranksets in which both arms are designed to be drive arms with the appropriate sprocket drive bosses. While this application to BMX is new, this is not a new idea. For decades, tandem bicycles have used left side drive cranks to drive the timing chain.

Left side drive introduced a different type of flip flop hub for BMX. This hub is a Right Hand/Left Hand flip flop hub. One side of the hub allows the use of normal right hand freewheels, while the other side is threaded with left hand threads (1.375" x 24L tpi) and accepts the new left hand drive freewheels. The first/most common was the ACS South Paw Claw model, available in 16T. Later, a version of this hub was made with small metric BMX (30 mm x 1 mm) threads, left hand on one side and right hand on the other side. These hubs accepted either Left or right side drive freewheels in the smaller 13T-15T sizes.

DK bicycles introduced the dual drive hub which is a BMX Left/Right drive flip flop hub with the smaller sized metric (30 mm x 1 mm) BMX threads for 13T-15T freewheels, but also includes two threaded adapters, one left and one right, threaded inside to match the smaller metric threads and threaded on the outside with standard ISO threads. This allows the hub to use any size or combination of left and right drive freewheels available.
flag BMX8000
Posted: Mar 18, 2008 at 12:07 Quote
My question is... Is my hub a flip flop hub so u can use standard freewheels or is it a lhd flip flop hub because they can be either or. Is there anyway of finding if it is one or the other.
flag BMX8000
Posted: Mar 18, 2008 at 12:07 Quote
Good Job on copying that of wikipedia. lol
flag DMerritt
Posted: Mar 18, 2008 at 12:12 Quote
BMX8000 wrote:
Good Job on copying that of wikipedia. lol

ohh, thats disapointing. i thought he actually typed all that (I didnt read it, cause i have a life)
flag curlxupxandxdle
Posted: Mar 18, 2008 at 12:15 Quote
wee-man1on1 wrote:
no such thing as left hand drive haro hub freewheel flip flop thingie majigger so ya if my random worded frase helpsed you at all...

yeah there is i got one on my piece of crap haro lol
flag bradyc
Posted: Mar 18, 2008 at 19:49 Quote
Standard flip flop as far as Im concerned has to different thread size's (or maybe diameter) whatever point being ones for metric freewheels ones for standard size. However there are LHD flip flops ( i beleive eastern makes em) So this could be it msot likely though since haro is a lower cost company, one side of the hub is for metric one side is for standard. I have never seen a freewheel that said metric or standard, but I jsut remember reading that here on the forums one day.
flag DavidMakalaster
Posted: Mar 18, 2008 at 19:54 Quote
Flip flop hubs are not made to run LHD. They are exactly what they say A DAMN FLIP FLOP HUB. Take a clue from the name.
flag totalbikerdude
Posted: Mar 18, 2008 at 20:40 Quote
flip flop hub,. my bmx has that same thing, i heard there good for the exact same uses
flag totalbikerdude
Posted: Mar 18, 2008 at 20:42 Quote
Mountian bike chain on a signle speed. versus bmx chain on a single speed
flag THEMANGLER
Posted: Mar 18, 2008 at 21:58 Quote
I think it is hilarious that the person who posted this can not figure such a simple issue out. I use a "FLIP FLOP" on my single speed XC bike and I've had them on my BMX race bikes. They are just as I've said, just as Wikipedia said, and just as anyone who has been around for more than a week has said. It really does not get much more simplistic.

Also; I do find it greatly amusing that you "hated" on me for the Wikipedia thing. After asking such a question, I assumed that the Wikipedia answer would be all that you Rhodes scholars would understand. After all, it was extremely accurate.Beer
flag AaronZuffa
Posted: Mar 19, 2008 at 0:09 Quote
Left side drive introduced a different type of flip flop hub for BMX. This hub is a Right Hand/Left Hand flip flop hub. One side of the hub allows the use of normal right hand freewheels, while the other side is threaded with left hand threads (1.375" x 24L tpi) and accepts the new left hand drive freewheels. The first/most common was the ACS South Paw Claw model, available in 16T. Later, a version of this hub was made with small metric BMX (30 mm x 1 mm) threads, left hand on one side and right hand on the other side. These hubs accepted either Left or right side drive freewheels in the smaller 13T-15T sizes.


This is what I'm talking about though. I know what I'm trying to get across, but I just cant seem to explain it over the forum. I'm tempted to make a video >_. I totally agree with Mangler though, and I also learned that there is a different type of flip flop hub than the one on my old specialised. (or so it seems)
flag BMX8000
Posted: Mar 19, 2008 at 12:32 Quote
If the left side has a reverse thread its a lhb hub right?
flag bradyc
Posted: Mar 19, 2008 at 15:37 Quote
You can't be cereal...... Blank Stare
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