Any way to do 12t 1/8" ingle speed?

[cdx]

Hi,

I'm trying to find a way to build a single speed bike with 12t (ideally) or 13t 1/8" cog out of a Langster. It currently has 16t/13t freewheel/fixed.

I'm assuming I'll need a new wheel with a cassette, and something like this:
http://www.chainreactioncycles.com/gusset-1-er-micro-single-speed-conversion-kit/rp-prod17777 ,
http://www.chainreactioncycles.com/gusset-1-er-single-speed-conversion-kit/rp-prod17776 or
http://www.chainreactioncycles.com/gusset-double-six-single-speed-conversion-kit/rp-prod17774?

From one of the reviews: "If you're using this kit with single-speed, half-link or 1/8" chains and having problems, it's your own fault, because you bought the wrong kit/chain."

Any way to put 1/8" cog/chain on a similar setup? I have a 1/8 chainring which I'd really like to keep.

I don't mind approaching it from a different way, maybe there is something else than freehub plus conversion kit? Just spacers? Different type of wheel?

I'd be grateful for any suggestions

 

[Tim Hall]

Isn't the Langster a single speed/fixed already? Those kits are for converting wheels on derailleur equipped bikes. Surely you just buy a 12t cog and screw it on, although actually finding a such a cog might be tricky. Try Hubjub.

 

[voyager]

What is fitted to the bike currently and what are you trying to achieve.
The question is a little too vague to give you a better answer ..

Rather than using such a small rear sprocket ( more friction ) most fixie users would go for a bigger chainwheel .

 

[Deleted member 1258]

Isn't the Langster a single speed/fixed already? Those kits are for converting wheels on derailleur equipped bikes. Surely you just buy a 12t cog and screw it on, although actually finding a such a cog might be tricky. Try Hubjub.

I believe the langster has a fixed hub on the back, I haven't seen a 1/8" freewheel in a 12, and I suspect you my struggle to find one.

 

[cdx]

Thanks for the replies!

Tim, I can get a 12t cog but it would fixed gear and I'm trying to avoid that. Right now I have 13t which is great, except for having to spin all the time.

Dave, I believe you're right about the 12t freewheel, I searched for something like this for a long time but I didn't find any smaller than 14t and I think it was for a different axle. 16t seem to be the smallest freewheels out there that I could use.

Some more details: right now it has a flip-flop hub. On one side is a 16t freewheel and on the other is a 13t fixed cog. It's a 120mm hub.

What I'm looking for is a 12t 1/8" that works like a freewheel - so it is not fixed and I don't have to spin all the time. Any configuration of axle/hub/wheel would be ok, within a sensible budget.

Actually I had that - a road bike on which I only used the highest gear. Unfortunately this seemed to wear out way too quickly. I'm hoping that a single speed with 1/8' components will wear out more slowly and I'm also skipping all the gearing/tensioner things that I don't use.

I'm not sure if it's doable on this frame and if at all. I don't mind getting another frame if I have to, as long as I know it would work with it.

I already increased the chainring, it's 56t. I don't think there's a way to get a chainring that's so big as to get the same result from going 16t to 12t at the back. I realise it seems a bit silly to go for a ratio like that but I prefer spinning slower/harder and I don't mind walking up hills every now and then. A 12t on the back would be great for my commute if not for any longer trips.

Any ideas how to do this, even on a different frame? Or would my only option be a geared bike (and the 3/32)?

 

[cdx]

Yes, I'm very happy with the 56/13 ratio right now but I don't like having to spin all the time.

On the road bike I was with 53/12 all the time until it wore out. Quickly. Got a new cassette and the 12 wore out quite quickly, too. I got a third, somebody nicked my rear wheel and I decided it was time for a single speed

56x12 is probably not a very good idea and would be useless in many cases but it would work great for my commute and I'd really enjoy it.

 

[Deleted member 1258]

Thanks for the replies!

Tim, I can get a 12t cog but it would fixed gear and I'm trying to avoid that. Right now I have 13t which is great, except for having to spin all the time.

Dave, I believe you're right about the 12t freewheel, I searched for something like this for a long time but I didn't find any smaller than 14t and I think it was for a different axle. 16t seem to be the smallest freewheels out there that I could use.

Some more details: right now it has a flip-flop hub. On one side is a 16t freewheel and on the other is a 13t fixed cog. It's a 120mm hub.

What I'm looking for is a 12t 1/8" that works like a freewheel - so it is not fixed and I don't have to spin all the time. Any configuration of axle/hub/wheel would be ok, within a sensible budget.

Actually I had that - a road bike on which I only used the highest gear. Unfortunately this seemed to wear out way too quickly. I'm hoping that a single speed with 1/8' components will wear out more slowly and I'm also skipping all the gearing/tensioner things that I don't use.

I'm not sure if it's doable on this frame and if at all. I don't mind getting another frame if I have to, as long as I know it would work with it.

I already increased the chainring, it's 56t. I don't think there's a way to get a chainring that's so big as to get the same result from going 16t to 12t at the back. I realise it seems a bit silly to go for a ratio like that but I prefer spinning slower/harder and I don't mind walking up hills every now and then. A 12t on the back would be great for my commute if not for any longer trips.

Any ideas how to do this, even on a different frame? Or would my only option be a geared bike (and the 3/32)?

A 56x12 is a gear in excess of 110 inches, my gear calculator only goes to 54x13, what are you doing? Flat time trials? My fixed, a Genesis Flyer, runs a 46x18 to give me 67 inch gear and 20mph at a cadence of 100 rpm, thats a good gear for commuting and winter riding, and means I can get up most hills, I'm thinking a 44x18 on 165 cranks would improve the hills without compromising the flat. Makes me wonder why you want such a big gear.

 

[cdx]

... Makes me wonder why you want such a big gear.

I get tired very quickly spinning at high cadence. For me spinning slower at the same bike speed feels much more comfortable, thus the high gear. 56/13 is very enjoyable (except for the fixed gear part) for the same reason and I believe I'd like 56/12 even more. Also, no hills along my commute, which makes the thing usable.

Practicality aside, do you think it's a feasible build?

 

[Tim Hall]

123 inches. @cdx, in case you're wondering what we're banging on about, gear ratios are traditionally expressed in "gear inches", meaning the equivalent diameter wheel of an imaginary penny farthing. 123 inches is huge. If you manage to spin that at 100rpm, you'll be doing 36mph. 120 rpm and you'll (theoretically) be doing 44mph. Fitness and wind resistance may well put paid to that. I'd suggest learning how to pedal faster.

 

[Deleted member 1258]

I get tired very quickly spinning at high cadence. For me spinning slower at the same bike speed feels much more comfortable, thus the high gear. 56/13 is very enjoyable (except for the fixed gear part) for the same reason and I believe I'd like 56/12 even more. Also, no hills along my commute, which makes the thing usable.

Practicality aside, do you think it's a feasible build?

If you get tired spinning then you need to get fitter, no I don't think its a feasible build.

 

[voyager]

.

Practicality aside, do you think it's a feasible build?

No and soon you will be going in a couple of knee ops if you are NOT careful

track cyclist use about a 90" max ( front / rear ) x wheel dia in inches

 

[mickle]

What is fitted to the bike currently and what are you trying to achieve.
The question is a little too vague to give you a better answer ..

Rather than using such a small rear sprocket ( more friction ) most fixie users would go for a bigger chainwheel .

More friction? How.much more? And what is this figure expressed as a percentage of the total of all the drag factors on a bike?

 

[cdx]

No way to build a bike like this then? That's unfortunate. I was hoping that there was a way but I just couldn't see it.

About my level of fitness - I think I'm quite happy with it, just high cadence isn't my thing. Same as climbing stairs, I find it quite tiresome to make a lot of steps so I take them two at a time and I don't get tired. Takes the same time and feels more enjoyable for me.

I hadn't thought about the long-term effect on my knees though. Very good point. I don't have any issues with them at the moment but I guess high gear ratio does put unnecessary pressure on them. I'll have to think about that.

In the meantime I guess I'll have to stick with the fixed gear for a while. Or maybe get a rear wheel for the road bike.

... Darn, voyager, now you have me all worried about my knees!

Edit: typo

 

[cdx]

Just spent a couple of hours reading about high gears and knee issues. I feel a bit silly now. And lucky, I guess, for not injuring myself during the last few years.

I imagined there was stress but didn't think about it much. My knees seemed fine so I imagined the pressure can't be too bad. Thanks for for the wake-up call guys, especially voyager. Not quite sure what I'm going to ride but I'm not that excited about 12t single speed any more.

 

[jazzkat]

@cdx you are Sir Chris Hoy, can I claim my prize?

Seriously, glad you've seen sense about the gearing. Learning to spin is no bad thing, imagine driving your car around in top gear all the time, not so good.
Lot's of folk have time-trialled using a lower gearing, google medium gear timetrial.