Timeline for Why is 53/39 known as "standard" for road bikes?
Current License: CC BY-SA 3.0
15 events
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| Jun 10, 2016 at 9:18 | history | tweeted | twitter.com/StackBicycles/status/741197913871798272 | ||
| Jun 9, 2016 at 14:50 | history | edited | Ealhmund | CC BY-SA 3.0 |
Clarified title
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| Jun 9, 2016 at 14:14 | history | edited | Ealhmund | CC BY-SA 3.0 |
Edited for clarity
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| Jun 9, 2016 at 13:47 | comment | added | Ealhmund | @gaurwraith - In common cycling parlance, "standard" gearing refers to 53/39, regardless of the fact that most bikes ship with compact cranksets nowadays. It's not an ISO standard nor is it indicative of the majority of new bikes (which usually ship with compact cranks). | |
| Jun 9, 2016 at 8:21 | comment | added | gaurwraith | But does your bike shop stock mostly 53/39? Because I see mostly 50/34 and 52/36, and some, not the majority, 53/39 ... maybe it is because I live surrounded by hills ? | |
| Jun 9, 2016 at 4:31 | answer | added | R. Chung | timeline score: 6 | |
| Jun 9, 2016 at 0:47 | comment | added | mattnz | I put it the standard (if there is one, which I doubt) is mostly commercial. If very road bike is delivered with the same size gears it makes the supply chain logistics a load easier cheaper. Most people buying bikes don't care, the LBS can "sell" an upgrade to people who do. Ego and Testosterone Dictates Bigger chain rings sell better than smaller ones - "mines bigger that yours.....", so 53 is chosen (54 and 55 are not noticeably bigger and very few people can push gears that tall for more than a few minutes), and 39, as already pointed out, is the smallest that fits a 130BCD. | |
| Jun 8, 2016 at 23:52 | comment | added | gaurwraith | I think it was me who asked in a comment, and still, I don't think there is a standard "these days". I mean at some point it sure was 52/42, but now? 53/39 ? Is that what the majority of road bikes carry? No way, it must be the compact or the semicompact. Of course it would be a de facto standard, since I don't think there are ISO regulations (someone care to check ?). And a de facto standard should be taken from the most widespread combination, which I seriously doubt is 53/39 as of today | |
| Jun 8, 2016 at 19:15 | comment | added | ojs | The next question would be, why 130 (or 135) mm BCD is the standard? It is already a step down from older 144mm standard. And why 53/39? It gives one spot per rotation where the teeth are aligned, where 52/39 would give four. | |
| Jun 8, 2016 at 18:09 | comment | added | Kibbee | Technically you can get a 38 tooth 130 BCD chainring although the amount of metal between the edge of the chainring and the mounting holes gets really small. | |
| Jun 8, 2016 at 16:20 | comment | added | Rider_X | @R.Chung +1 you should post that as an answer. I would add that smaller BCDs weren't used to to keep chain ring flex down, while keeping things light. Now that newer processes (e.g., hollow chain rings) give a super stiff platform, we are seeing smaller BCDs again (e.g., semi-compact). As a historical note some 1940's randonneur setups had very small BCD (e.g., 70 mm) so they could have a large difference in the chain rings (e.g., 28/48) as the cassettes had fewer gears and cassettes didn't have ramping to facilitate shifts between large tooth jumps. | |
| Jun 8, 2016 at 16:04 | comment | added | Ealhmund | True, the standard crankset (until recently) used 130 BCD...do you know who/what company first adopted that? | |
| Jun 8, 2016 at 15:24 | comment | added | R. Chung | One common standard for cranksets is 130mm BCD. The smallest inner chainring you can use with 130 BCD is a 39. I believe (but this part is a guess, which is why it's not given as an answer) that the 52 or 53 was chosen so that with the common cogs on a cassette back when 130 BCD was established as a standard, there would be relatively little overlap and a reasonable range of gearing. | |
| Jun 8, 2016 at 15:18 | comment | added | Kibbee | I would say it mostly has to do with tradition. You could get basically the exact same gear range using 54-40 or 52-38. Now that we have things like 11 tooth cogs, it makes little sense for non-pro riders to have a 53 tooth chainring since most people can't push it at a reasonable cadence. This is why compact (50-34) is becoming more popular. Gets rid of the hard gears you don't have the power to push and gives you easier gears for getting up the hills, since again, you don't have as much power as the pros. | |
| Jun 8, 2016 at 14:43 | history | asked | Ealhmund | CC BY-SA 3.0 |