Recommend me a singlespeed gear ratio...
Discussion
Right, the bike is an On-One Inbred singlespeed, running 26x1.25" road tyres. I tend to ride on road, canal towpaths, that kind of thing, and for proper off road work take the one with gears, or for proper road rides take my roadie!
According to my iPhone app, with those tyres, 175mm cranks and a 32/16 setup the numbers are as follows:
Gear ratio 2.00/2:1
Gain ratio 3.78
Gear Inches 52.1
Rollout 4.154m/163.5m
Problem is, where I ride is pretty flat and it's not quite fast enough. I tracked fairly flat 19 mile ride which I tend to do on it using Endomondo and I'm averaging 11.27mph. I'd like to gear it up just a smidge.
A 15 on the back will give me 55.5", a 14 will give 59.5", and a 13 will give 64.1". Any recommendations? I'm not particularly fit (although here comes summer!) and ideally I'd like to be able to swap back without taking links out the chain if that is at all possible.
Cheers in advance!
According to my iPhone app, with those tyres, 175mm cranks and a 32/16 setup the numbers are as follows:
Gear ratio 2.00/2:1
Gain ratio 3.78
Gear Inches 52.1
Rollout 4.154m/163.5m
Problem is, where I ride is pretty flat and it's not quite fast enough. I tracked fairly flat 19 mile ride which I tend to do on it using Endomondo and I'm averaging 11.27mph. I'd like to gear it up just a smidge.
A 15 on the back will give me 55.5", a 14 will give 59.5", and a 13 will give 64.1". Any recommendations? I'm not particularly fit (although here comes summer!) and ideally I'd like to be able to swap back without taking links out the chain if that is at all possible.
Cheers in advance!
This calculator disagrees with your figures:
http://software.bareknucklebrigade.com/rabbit.appl...
If you want to switch ratios without splitting the chain you'll probably need a tensioner of some sort as most frames won't give you two teeth's adjustment just by moving the wheel backwards or forwards.
<edit> actually maybe it doesn't disagree by much, I changed the calculator to '26" nominal' and it comes out about the same. </edit>
http://software.bareknucklebrigade.com/rabbit.appl...
If you want to switch ratios without splitting the chain you'll probably need a tensioner of some sort as most frames won't give you two teeth's adjustment just by moving the wheel backwards or forwards.
<edit> actually maybe it doesn't disagree by much, I changed the calculator to '26" nominal' and it comes out about the same. </edit>
Edited by HardWorkers on Wednesday 28th March 10:00
Hard-Drive said:
Problem is, where I ride is pretty flat and it's not quite fast enough. I tracked fairly flat 19 mile ride which I tend to do on it using Endomondo and I'm averaging 11.27mph. I'd like to gear it up just a smidge.
A 15 on the back will give me 55.5", a 14 will give 59.5", and a 13 will give 64.1". Any recommendations? I'm not particularly fit (although here comes summer!) and ideally I'd like to be able to swap back without taking links out the chain if that is at all possible.
On flat roads and 700-25 tyres I run 79in (48/16). This is way too high if there are any significant hills.A 15 on the back will give me 55.5", a 14 will give 59.5", and a 13 will give 64.1". Any recommendations? I'm not particularly fit (although here comes summer!) and ideally I'd like to be able to swap back without taking links out the chain if that is at all possible.
A stock Langster runs 69in (42/16).
Those are both road-oriented though of course.
However, if you really don't want to buy a new front chainring, and you want to go singlespeed rather than fixie, you are going to be somewhat limited by the availability of rear freewheel sprockets.
I am not sure anyone makes a 13T!
As you get fitter you are just going to want to continue to gear up and since you are so low anyway I would simply buy the smallest possible and go for it.
As for the chain - only you can tell us. It completely depends on how much room there is in the drop outs (the part of the frame that holds the back wheel).
If you are currently near the front on 16T then you should be able to swap to 14T and just shift the wheel back a bit.
But as the chain stretches you may need to drop a link.
Lastly, to swap out the freewheel sprocket you will need a tool like this:
http://www.tredz.co.uk/.Park-Tool-FR6C-Freewheel-R...
Great advice, thanks all. On One do a 13 so that's what I'll order...mid 60s should be about right then taking into account the weight/aeros of the bike versus a road ss.
Next question...can I just split and rejoin a single speed chain, or do I need a powerlink / powerlock equivalent?
Next question...can I just split and rejoin a single speed chain, or do I need a powerlink / powerlock equivalent?
mchammer89 said:
Around 70GI, it's what all of the stock road SS bikes come with and for a good reason.
because it looks trendy? personally i think the vast majority of stock ss/fixie bikes are massively overgeared, quite often i see riders struggling to push that sort of gearing. there is just no point running a big gear if you are spinning <70rpm, they might as well run something far shorter and get the cadence up but that just doesnt look cool....Ive got an inbred set up as a single speed. I played around with the ratios a little when I first got it last year, Im now running a 32/13, and I sit quite happily at around 17mph. Finding it a little easy going at the mo tho, so Ive got a 34 tooth front ring on order. (Mostly riding on flat cycle paths and canal tow paths)
I found that changing just one tooth on the back made quite a noticeable difference, Im hoping two on the front is a smaller step -up.
As the rear cogs aren't hugely expensive I bought three sizes and just tried all of them until I found the one that suited me best.
As for the chain - I would deffo get a power link - there soo much qucker and easier than splitting and rejoining with a conventional pin.
It might also be worth getting a half-link for fine-tuning the chain length
I found that changing just one tooth on the back made quite a noticeable difference, Im hoping two on the front is a smaller step -up.
As the rear cogs aren't hugely expensive I bought three sizes and just tried all of them until I found the one that suited me best.
As for the chain - I would deffo get a power link - there soo much qucker and easier than splitting and rejoining with a conventional pin.
It might also be worth getting a half-link for fine-tuning the chain length
Are you sure you need to split the chain?
If you do - powerlink FTW.
I always carry one anyway just in case the chain snaps, they are only a quid for three or something.
Personally, it isn't a fashion thing but on any sort of hill, you can hit say 30mph which is a 130 rpm cadence.
I am no good at spinning more than that.
Obviously less of a problem on a SS.
If you do - powerlink FTW.
I always carry one anyway just in case the chain snaps, they are only a quid for three or something.
Personally, it isn't a fashion thing but on any sort of hill, you can hit say 30mph which is a 130 rpm cadence.
I am no good at spinning more than that.
Obviously less of a problem on a SS.
mchammer89 said:
Around 70GI, it's what all of the stock road SS bikes come with and for a good reason.
Based on what exactly? My Spesh Langster is 42/16 and I spin out on the flat easily, I must look like a mentalist on my commute with the legs going at 5000rpm and don't like to change it to fixed for that reason. Think I'm going to go for a 48t on the front when I get a new chain in a few weeks!AyBee said:
Based on what exactly? My Spesh Langster is 42/16 and I spin out on the flat easily, I must look like a mentalist on my commute with the legs going at 5000rpm and don't like to change it to fixed for that reason. Think I'm going to go for a 48t on the front when I get a new chain in a few weeks!
Ah! If you do can I buy your chainset off you (if it's a sugino messenger)?I have totally mashed my left hand crank arm by way over-tightening it and it keeps falling off.
Since it is a 172.5mm literally NO ONE has a replacement so I am going to have to buy new arms which aren't cheap.
walm said:
AyBee said:
Based on what exactly? My Spesh Langster is 42/16 and I spin out on the flat easily, I must look like a mentalist on my commute with the legs going at 5000rpm and don't like to change it to fixed for that reason. Think I'm going to go for a 48t on the front when I get a new chain in a few weeks!
Ah! If you do can I buy your chainset off you (if it's a sugino messenger)?I have totally mashed my left hand crank arm by way over-tightening it and it keeps falling off.
Since it is a 172.5mm literally NO ONE has a replacement so I am going to have to buy new arms which aren't cheap.
pablo said:
because it looks trendy? personally i think the vast majority of stock ss/fixie bikes are massively overgeared, quite often i see riders struggling to push that sort of gearing. there is just no point running a big gear if you are spinning <70rpm, they might as well run something far shorter and get the cadence up but that just doesnt look cool....
...70GI looks trendy? How exactly can a gear ratio look trendy? I had my SS running 69GI when I first got it. After a while I upped it to 77GI as I felt undergeared. Yes some people may find that 70GI is overgeared. The OP asked for a suggestion, I gave him a valid suggestion for an average level rider. Less than average riders may want a lower gear, higher than average level riders may want a higher gear.For what it's worth I agree that someone shouldn't be riding around with gearing that almost limits their cadence to below 70rpm. And if that were the case then the gearing should be reduced, that's just common sense.
P.S. The bike I was referring to was my poo brown Langster, trendy? I don't think so...
AyBee said:
Based on what exactly? My Spesh Langster is 42/16 and I spin out on the flat easily, I must look like a mentalist on my commute with the legs going at 5000rpm and don't like to change it to fixed for that reason. Think I'm going to go for a 48t on the front when I get a new chain in a few weeks!
Great to get both sides of the coin here. I had the same gearing and changed so I was running 44/15, which I felt much more comfortable with. Like I said above, 42/16 is a nice all-rounder that allows people of a wide range of abilities to ride. Then if people wish they can adjust the gearing to suit them and their riding. They can't possibly cover everyone so having an average gearing is the best possible option.AyBee said:
I'd say yes, but I'm only planning on changing the cog on the front, not the cranks, unless you can see an issue with that? Is it not possible to repair the cranks you have?
Doh! Of course, you don't need to change the whole chainset!(The only issue might be that it's far cheaper to change the cog/freewheel on the back!!)
Unfortunately my crank is beyond repair. Once you have bent the square shape that pops onto the taper - it will just need continual tightening.
pablo said:
its far too sunny to be arguing.
Maybe its just a Bristol thing but the "look" is very much a huge front chainring, tiny rear sprocket, all part of the "yeah, just back from the velodrome dude..."
...42t is a huge chainring? Even with a 15t sprocket that gives around 75GI. Who rides track at 75GI? I can't see anything less than 46t being used, even that is at the lower end of the scale.Maybe its just a Bristol thing but the "look" is very much a huge front chainring, tiny rear sprocket, all part of the "yeah, just back from the velodrome dude..."
I don't think it's a Bristol thing, I think it's a cynical thing assuming anyone who rides SS/fixed is a wannabe hipster.
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