# Bicycles **URL:** \ **Category:** Factual Questions\ **Created:** [July 13, 2000, 3:01pm UTC](https://boards.straightdope.com/t/bicycles/25439 "2000-07-13T15:01:42Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![zebbmx](https://avatars.discourse-cdn.com/v4/letter/z/958977/32.png) [@zebbmx](https://boards.straightdope.com/u/zebbmx)\ **Post date:** [July 13, 2000, 3:01pm UTC](https://boards.straightdope.com/t/bicycles/25439/1 "2000-07-13T15:01:42Z")
i was lying in bed earlier and got to thinkin…why on bicycles is the crank on the right side?ive studied the bike over and over but why cant we just switch sides then switch the freeweheel(on the back rim) to the other side? i think id like it better over there anyway ---
**Author:** ![Coldfire](https://avatars.discourse-cdn.com/v4/letter/c/a587f6/32.png) [@Coldfire](https://boards.straightdope.com/u/Coldfire)\ **Post date:** [July 13, 2000, 3:07pm UTC](https://boards.straightdope.com/t/bicycles/25439/2 "2000-07-13T15:07:44Z")
So you basically want to switch the entire drive mechanism to the left side of the bicycle? What good would that do? Why is it better to have it on either side? ---
**Author:** ![zebbmx](https://avatars.discourse-cdn.com/v4/letter/z/958977/32.png) [@zebbmx](https://boards.straightdope.com/u/zebbmx)\ **Post date:** [July 13, 2000, 3:16pm UTC](https://boards.straightdope.com/t/bicycles/25439/3 "2000-07-13T15:16:47Z")
i dunno i would like it better…everytime i ride my pant leg gets caught in the chain so i figure maybe its the left pant leg’s turn ---
**Author:** ![DVous\_Means](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@DVous\_Means](https://boards.straightdope.com/u/DVous_Means)\ **Post date:** [July 13, 2000, 3:20pm UTC](https://boards.straightdope.com/t/bicycles/25439/4 "2000-07-13T15:20:17Z")
While you’re redesigning the bicycle, why not make it a shaft drive? That way your pants leg will never get caught again…🙂 ---
**Author:** ![Coldfire](https://avatars.discourse-cdn.com/v4/letter/c/a587f6/32.png) [@Coldfire](https://boards.straightdope.com/u/Coldfire)\ **Post date:** [July 13, 2000, 3:20pm UTC](https://boards.straightdope.com/t/bicycles/25439/5 "2000-07-13T15:20:37Z")
How about one of the following, less dramatic measures and/or solutions: a) Wear short pants like any real cyclist; b) Wear an elastic band around your right trouser leg; c) Fix wider pedals; d) Install a chain cover. Howzat? ---
**Author:** ![zebbmx](https://avatars.discourse-cdn.com/v4/letter/z/958977/32.png) [@zebbmx](https://boards.straightdope.com/u/zebbmx)\ **Post date:** [July 13, 2000, 3:47pm UTC](https://boards.straightdope.com/t/bicycles/25439/6 "2000-07-13T15:47:42Z")
OK here it is coldfire A) I dont wanna be A REAL f\*cking cyclist B)I’LL tell you wear to put this “elastic band” C)i have small FEET and WIDE PEDALS would look GAY! D)hey…that ones not so bad Thanks for the input! maybe ill try the chain gaurd one ---
**Author:** ![zebbmx](https://avatars.discourse-cdn.com/v4/letter/z/958977/32.png) [@zebbmx](https://boards.straightdope.com/u/zebbmx)\ **Post date:** [July 13, 2000, 3:49pm UTC](https://boards.straightdope.com/t/bicycles/25439/7 "2000-07-13T15:49:27Z")
Oh and also im gonna look into starting a left sided shaft drive for bicycles its a long-shot but im only gonna look into it for now… ---
**Author:** ![cornflakes](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@cornflakes](https://boards.straightdope.com/u/cornflakes)\ **Post date:** [July 13, 2000, 3:50pm UTC](https://boards.straightdope.com/t/bicycles/25439/8 "2000-07-13T15:50:43Z")
Probably for the same reason road bikes use 700mm tires when nothing on the tire measures 700mm across. I couldn’t find a tape measure; someone correct me if I’m wrong, but this was the outside diameter of tires that fit that rim back a century ago. Bicylists are really nutty about tradition with some things. ---
**Author:** ![cornflakes](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@cornflakes](https://boards.straightdope.com/u/cornflakes)\ **Post date:** [July 13, 2000, 3:55pm UTC](https://boards.straightdope.com/t/bicycles/25439/9 "2000-07-13T15:55:55Z")
Oh yeah, shaft drives are more complicated and use up more power than chain drives and derailers (I’m sure of this, not like the wheel thing.) I know a guy with a drag bike who shaved a few tenths off his time when he replaced the shaft drive with a chain. ---
**Author:** ![zebbmx](https://avatars.discourse-cdn.com/v4/letter/z/958977/32.png) [@zebbmx](https://boards.straightdope.com/u/zebbmx)\ **Post date:** [July 13, 2000, 4:03pm UTC](https://boards.straightdope.com/t/bicycles/25439/10 "2000-07-13T16:03:46Z")
well im not to worried about time im worried about my pant leg gettin caught in the chain 😃 ---
**Author:** ![vandal](https://avatars.discourse-cdn.com/v4/letter/v/858c86/32.png) [@vandal](https://boards.straightdope.com/u/vandal)\ **Post date:** [July 13, 2000, 6:11pm UTC](https://boards.straightdope.com/t/bicycles/25439/11 "2000-07-13T18:11:22Z")
Why don’t you just switch the sprocket over to the left side and flip your rear wheel around? You’re drivetrain would be on the left side then. ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [July 13, 2000, 6:54pm UTC](https://boards.straightdope.com/t/bicycles/25439/12 "2000-07-13T18:54:06Z")
> [@](#): > > \*Originally posted by vandal \* > \*\*Why don’t you just switch the sprocket over to the left side and flip your rear wheel around? You’re drivetrain would be on the left side then. \*\* There’d be a little more to it than that. If you sit down by the back hub and look at the sprocket, the chain is pulling the wheel clockwise. If you pull it counter-clockwise (pedalling backwards), it just freewheels. If you just turned the wheel and crank around, you’d be able to pedal the bike backwards, but not forewards. Also, I think the frame and brake are aligned to allow for the extra width on the right side. And the teeth on the rear cogs have an asymetric profile, but that might not be severe enough to keep them working in reverse. ---
**Author:** ![casdave](https://avatars.discourse-cdn.com/v4/letter/c/c6cbf5/32.png) [@casdave](https://boards.straightdope.com/u/casdave)\ **Post date:** [July 13, 2000, 7:07pm UTC](https://boards.straightdope.com/t/bicycles/25439/13 "2000-07-13T19:07:53Z")
Most of the basic arrangements of the bicycle were made early on from the shape of the frame, the chain pitch, and the side of chain drive. Shimano tried to use a differant chain pitch in the early 80’s which had the advantage of having smaller sprockets and chainrings, hence less weight,(much much faster wear). Shimano is the largest manufacturer of bicycle components and had previously managed to force the market to its own ideas so it must have felt some confidence in trying this. They failed dismally. Why come up with that you might ask, well to start a manufacturing run to change for no benefit whatsoever the side of chain drive would be a hopeless failure. Cyclists are a conservative bunch in the main despite what you see them wearing. To change the drivetrain side would involve reworking the bottom bracket The way the frame splays out at the back to take the back wheel and sprockets(known as dishing) the threads on the pedals would have to be reversed to prevent them winding themselves out, the thread upon which the sprockets are mounted would have to be reversed for the same reason, the freewheel threads and the freewheel pawl mechanism would have to be reversed, the gear levers would have to be designed differantly as would the gear changers, all the cable runs to those gear changers would have to be revised. Accesories such as chaingaurds, stands etc would not fit. Remember that much of the tooling used to produce current equipment is standardised engineering plant that might be capable of being used to produce other threaded items, so all your tooling would have to be custom made to manufacture bicycle components. I’m sure that if I looked harder I could find lots of other expensive reasons why no-one is likely to attempt production of such bicycles but those are plenty enough. Question for you do you prefer oil on the other leg of your pants? If so then the explanation for it would be fascinating 😉 Chains are the most efficient drive mechanism and the gear arrangment is fairly light. Shaft drive is heavier, not as efficient and puting gears on would add to the complications enormously, perhaps hub gears might be possible. Shaft drive has been tried and, like many ‘innovations’, died the Darwinian death. As for wheel sizes - there used to be common in the UK 26" rims usually quite wide. Originally they were designed to be used with rod operated brakes and the friction surface was on the flat of the rim rather than the edge(Westwood type rim).As cable brakes were used they were adopted to have a deeper section so that the friction surface was on the rim edge. Club riders would use 27" wheels for serious riding. On the Continent, where cycling is way more popular, they were using 700c rims and lots of technology was put into the rims and the tyres, result was an improvement in performance. Eventually the UK market in 27" wheels was not enough to sustain itself as UK riders slowly changed to the better 700c wheels.The reason that it took so long to change was that to do so involved buying a new frame and cyclists get sentimental about throwing them away.(or tightfisted) ---
**Author:** ![zebbmx](https://avatars.discourse-cdn.com/v4/letter/z/958977/32.png) [@zebbmx](https://boards.straightdope.com/u/zebbmx)\ **Post date:** [July 14, 2000, 2:43am UTC](https://boards.straightdope.com/t/bicycles/25439/14 "2000-07-14T02:43:08Z")
ok ok took crank out tried replacing on left side…WONT fit something in the bearing or bearing pre load is not fitting im guessing because it was made for the right side…oh well another wild try at something failed… ---
**Author:** ![casdave](https://avatars.discourse-cdn.com/v4/letter/c/c6cbf5/32.png) [@casdave](https://boards.straightdope.com/u/casdave)\ **Post date:** [July 14, 2000, 5:41am UTC](https://boards.straightdope.com/t/bicycles/25439/15 "2000-07-14T05:41:43Z")
I’ll tell you what happened. The axle through the frame is not symmetrical.The whole assembly (bottom bracket)where the bearings live isn’t either. The drive side is made so that the crank arm sits further away from the frame to allow the chainwheels enough space. I saw someone change the axle around and put the chainset on and it fitted but you will find that the chainring may well catch on the frame as many frames are designed to keep the axle as short as possible to reduce flex , you may well find a dint in the frame on the normal chainring side to accomodate it. Even if you do change the axle round you then have to align the chainring with the sprocket(s). Sorry but it won’t happen, frames too are assymetrical and you will find that the rear wheel would have to be rebuilt. The real killer is that the threads will all unscrew as you put pressure on them. Trust me on this. ---
**Author:** ![The\_Ryan](https://avatars.discourse-cdn.com/v4/letter/t/7feea3/32.png) [@The\_Ryan](https://boards.straightdope.com/u/The_Ryan)\ **Post date:** [July 14, 2000, 7:32am UTC](https://boards.straightdope.com/t/bicycles/25439/16 "2000-07-14T07:32:25Z")
It seems like you could put a generator on one wheel, and attach it with wires to a motor on the other wheel. It would have fewer moving parts. And changing gears would be much easier (just put in a transformer). Of course, there may certainly be engineering problems I am unaware of. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [July 14, 2000, 10:56am UTC](https://boards.straightdope.com/t/bicycles/25439/17 "2000-07-14T10:56:46Z")
> [@](#): > > \*\*It seems like you could put a generator on one wheel, and attach it with wires to a motor on the other wheel. It would have fewer moving parts. \*\* Hmm… It may be interesting to try, but I don’t think it will catch on. Motors and generators are heavy! I think adding a motor and generator would at least double the weight of a road bike. Motors and generators aren’t that efficient either. Even if each had 90% efficiency, you’d be throwing away 20% of the output of your legs. It may be better if you add a battery and regeneratvie braking to this combination. That would be an interesting project… There are already motor-assist bicycles, but I think they still use a chain/pedal system, and no regenerative braking. As for the OP, is it possible that there used to be a screw that held the chainwheel in place? If was on the left side, it would turn counter-clockwise and loosen the screw. ---
**Author:** ![Fiver](https://avatars.discourse-cdn.com/v4/letter/f/e274bd/32.png) [@Fiver](https://boards.straightdope.com/u/Fiver)\ **Post date:** [July 14, 2000, 1:44pm UTC](https://boards.straightdope.com/t/bicycles/25439/18 "2000-07-14T13:44:31Z")
**zebbmx** > [@](#): > > i dunno i would like it better…everytime i ride my pant leg gets caught in the chain so i figure maybe its the left pant leg’s turn That’s an easy one, and the answer has nothing to do with your bicycle chain: Wear your pants backwards. ---
**Author:** ![capybara](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/capybara/32/202_2.png) [@capybara](https://boards.straightdope.com/u/capybara)\ **Post date:** [July 14, 2000, 2:51pm UTC](https://boards.straightdope.com/t/bicycles/25439/19 "2000-07-14T14:51:28Z")
Casdave, hasn’t Shimano, et al done exactly that (thinning chain and cogs) with the nine-speed stuff? As far as sticking the drivetrain on the left I think it would take a lot of work and monkeying from the bottom bracket up (all that stuff is threaded in specific ways- not neccessarily “lefty-loosey”), unless you used something very simplified like a direct-drive fixed gear, with no freewheel (the same idea as flip-flop hubs). As far as pants legs, we take a chainring larger than the one we are using, grind the teeth off (so that it is just a circle a tad larger than the chainring carrying the chain), and mount it on the outside as if it were the next larger ring, and this seems to do fine as a small chainguard. ---
**Author:** ![vandal](https://avatars.discourse-cdn.com/v4/letter/v/858c86/32.png) [@vandal](https://boards.straightdope.com/u/vandal)\ **Post date:** [July 14, 2000, 4:21pm UTC](https://boards.straightdope.com/t/bicycles/25439/20 "2000-07-14T16:21:50Z")
> [@](#): > > **If you just turned the wheel and crank around, you’d be able to pedal the bike backwards, but not forewards.** Good point. But, I’ve thought of something to get around that. In addition to flipping the rear wheel around, flip the freewheel around too. That should take care of it. [Next page](https://boards.straightdope.com/t/bicycles/25439.md?page=2)