Yet Another Cycling Forum
General Category => Freewheeling => Velo Fixe => Topic started by: TPMB12 on 22 August, 2017, 10:25:24 am
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I'm considering a singlespeed (cheap as chips one) for a winter commuter. Probably use it in summer too if I like it. The question I have is what gearing would be best?
How long is a piece of string? Well terrain is a mix of very easy undulating road followed by a gradual incline over a mile with a bit of a steep rise halfway (rise, flat then another rise to the high point of 180m). Then a downhill that I can freewheel to reach just over 23mph without pedalling. Then a flat and a rise over a bridge passing over a main road. Freewheel to about 20mph. Then it's downhill or flat to work. It's slightly different going home because tyre mid point hill is in one rise not two but once passed it is a long fast downhill until the final undulations.
I tend to run my chain on the 50t chainring mostly mid cassette 12-32t. Sometimes I don't change gear much other than a cog each way.
So what's your view? 44-17? What's your recommendation?
BTW I think I'll not run it as a fixie. Any cheap bikes you'd recommend? I'm based near Lancaster and would prefer to be able to try one out if you know any bike shops with singlespeeds in store.
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Ride it on your normal geared bike in one gear but don't stop pedalling. that will tell you what gear you can use.
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single free is different from single fixed. If considering the former just ride the usual route using one gear and see what suits you best.
BTW I would choose a 16T freewheel (with a chainring to suit) for a purely pragmatic reason; they are commonly available and relatively inexpensive. 17T freewheels are less easy to come by and cost a little more IME.
FWIW I prefer single fixed than single free on the road in the wintertime; gets (and keeps) your legs moving.
cheers
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If you're buying a complete bike (as opposed to building one), why not just try the gear it comes with for a while, then decide whether it's too high/low or just right?
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i'd start from 48x18
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If you're buying a complete bike (as opposed to building one), why not just try the gear it comes with for a while, then decide whether it's too high/low or just right?
That's what I did.
In the end I geared down a little and now run 46:16. For me it's a good compromise between having a reasonable cruising speed on teh flat and not having to walk up too many hills.
At the end of the day it will depend on your level of fitness and the "lumpiness" of your route
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For a winter bike I'd go for 42/18, fixed.
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I was looking at genesis bikes, flyer or day one 10. Both use 42/17.
I'm not sure of the relevance but the suggestions above and the genesis options seem to run at 2.33 to 2.67 ratio between chainring and rear cog. The Genesis option is about 2.47, in the middle.
What is the effect of more teeth with the same ratio? What I mean if the ratio of two setups come out at 2.67 but one had more teeth on the chainring (plus cog) - if that's possible - or m then would you feel the difference? Or more realistically would you notice much difference between a 42/17 and a 48/18? Or 48/18 & 40/15 if that's possible?
I'm guessing if one revolution of two different chainring options turns the corresponding cog options by the same multiple the effort to turn it would be the same.
One more thing, chain length and changing cogs/chainring, what do I need to know I assume you need to adjust the full-length and make sure the wheel is positioned right in the rear dropout. Do such bikes have an adjustment / limit screw to keep the wheel located and chain tight? If you get a puncture is it easy to take the wheel off and.back on once the puncture has been fixed?
I'm really new to the singlespeed thing.
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If you have the same ratio but a greater number of teeth, for example 20:10 vs. 40:20 to take an extreme example the theory says the one with more teeth will be "better" but at the ranges that you're talking about it won't make an difference.
Don't know about the specific bikes that you mention but they will generally have horizontal drop outs so that you can tension the chain and remove the wheel. Some may have an eccentric bottom bracket to tension the chain instead
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Bigger rings and cogs should last longer as you'll spread the load over more teeth and have lower chain tension when pedalling. It'll feel the same when you're riding it.
Some bikes have adjustment screws or you can fit a chain tug. Use a decent hub with track nuts or good sized hex head screws to secure the rear wheel and you'll probably not need tugs or adjusters. If you use track ends (rear facing slots) then wheel removal can be a bit of a faff, particularly with mudguards, but it's not much harder than mucking about with a derailleur. The Flyer (and Condor Tempo, IIRC) uses forward facing dropouts that are easier if you do have mudguards.
Also consider the On One Pompino, as long as you don't know any Italian(s).
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I favour a gear around 70". I mostly ride on roads. I live in Devon, it's lumpy
My current single speed is an On-One Inbred 29er
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This really is one of those 'it depends' questions.
It depends on...
- your overall fitness
- your strength and endurance
- the terrain
- the load you will/won't be carrying
- the bike/tyre size/crank length etc.
- your tolerance for having to get off and push (I have no tolerance, I HATE pushing)
People will recommend what they use as it works for them, but you need to work out what works for you.
Go ride your geared bike over some of your normal loops, and do them in one gear only, but try a few different gears over different days to get a feel for what you like and more importantly, what you can handle.
Don't forget fatigue and headwinds can mean a gear that you're OK with 99% of the time can become arduous torture very quickly on a bad day, so in some regards it's better to gear for a bad day than a good one, you can always coast or work on your spinning if you're undergeared, but if you're overgeared there's not much you can do!
FWIW, I live in hilly Devon, and have run 46x17 on a nice light racey SS with 23mm tyres, and 44x17 on a slightly bigger 28/32mm tyred Audax SS bike.
Both are fine on moderately hilly (up to 1000ft/10mile) rides up to 100k, but for hillier or longer rides I sometimes gear down a bit, the extent of which depends more on how much hillier rather than distance as it's the hills that take it out of your more.
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My summer Single-speed is classic 48x18 - 72". It's a light bike and a blast to ride.
My heavier (Genesis Day One) is re-geared to 66" (I think, possibly 64") for winter use. I tend to carry more, mudguards, heavier tyres, skoggy roads, night riding..etc....
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Most riders on fixed/as tend to go for a gear of about 70 inches and for the riding you have described that sounds about right. If you go for a freewheel it will be a bit easier downhill. However 23 mph downhill wouldn't give you to much of a problem anyway on fixed. Try to keep the chain as tight as possible,it's not to critical on freewheel but fixed can be a bit scary if it de-rails going fast downhill.
My advice is to try fixed for a couple of weeks and if you don't like it turn the wheel around. It took me 200 miles to get used to fixed. Headwinds were a eastward and so was trying to keep up with my mates with a tailwind.Enjoy!
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There's also the question of odd or even numbers of teeth regarding wear. I've seen arguments in favour of both so I'm none the wiser.
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I was looking at genesis bikes, flyer or day one 10. Both use 42/17.
.....I'm really new to the singlespeed thing.
even though both those bikes have the same chainrings and sprockets, the gear size is different. This is because the tyres are different sizes and the wheel rolling diameter is different as a consequence.
There are many ways of expressing gear ratios but the traditional thing (in the UK and the USA and some other places) is to use gear inches. This gives an equivalent wheel diameter (as if you were riding an 'ordinary' bicycle).
Wheel dia (inches) x (chainring T/sprocket T) = gear (inches)
So comparing the flyer (28mm tyre) and the day one ten (35mm tyre)
http://www.gear-calculator.com/?GR=SGLS&KB=42&RZ=17&UF=2185&TF=90&SL=3.5&UN=MPH&GR2=SGLS&KB2=42&RZ2=17&UF2=2150 (http://www.gear-calculator.com/?GR=SGLS&KB=42&RZ=17&UF=2185&TF=90&SL=3.5&UN=MPH&GR2=SGLS&KB2=42&RZ2=17&UF2=2150)
you can see that the gear size is slightly under 67" for the flyer and slightly under 68" for the day one ten. [NB the wheel size is listed on the calculator as 28" but that is because the guy that programmed the calculator is German. For their own peculiar reasons they refer to 700C wheels as 28" wheels (*)... but the diameter and rollout are at least accurate.... ;) ]
* -which has a whiff of logic to it, more than you would think; the rim size was first used in the 1900s in the UK when it was known as a 28 x 1-3/4" size or something like that. The French later pinched the rim size and called it '700C' and today 700C wheels (622mm rims) vary in rolling diameter from around 26-1/2" (~20mm tyres) to about 29" (fat MTB tyres).
To this day most folk use gear inches when describing gear size.
cheers
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There's also the question of odd or even numbers of teeth regarding wear. I've seen arguments in favour of both so I'm none the wiser.
I like to have a combination of primes. 43/17 is a really nice gear. 8)
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There's also the question of odd or even numbers of teeth regarding wear. I've seen arguments in favour of both so I'm none the wiser.
I like to have a combination of primes. 43/17 is a really nice gear. 8)
My winter S/S is such a setup.
My own argument in favour of odd/prime numbers is that your chain and sprocket wear totally evenly. Even numbers mean that your chain and sprocket wear in an odd and even links pattern. I've found that this can result in an annoyingly "rumbly" drivetrain if you repair a puncture and refit the chain 1 tooth out. (it's 50/50).
It does take a hell of a lot of miles to wear this way and the fix is simple, move the chain left or right one link, so it's no real big deal.
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Wouldn't the solution be to have a wide/narrow chainring that ensured a fixed or singlespeed chain always engaged with the 'right' teeth?
I imagine that this sort of chainring would also make it more difficult to unship a loose chain, given the claims for such MTB chainrings.
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Wouldn't the solution be to have a wide/narrow chainring that ensured a fixed or singlespeed chain always engaged with the 'right' teeth?
I imagine that this sort of chainring would also make it more difficult to unship a loose chain, given the claims for such MTB chainrings.
I don't think that would work terribly well with my 43T rings.
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So you are willing to put up with chainrings that comparatively easily unship chains?
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There's also the question of odd or even numbers of teeth regarding wear. I've seen arguments in favour of both so I'm none the wiser.
I like to have a combination of primes. 43/17 is a really nice gear. 8)
My winter S/S is such a setup.
My own argument in favour of odd/prime numbers is that your chain and sprocket wear totally evenly. Even numbers mean that your chain and sprocket wear in an odd and even links pattern. I've found that this can result in an annoyingly "rumbly" drivetrain if you repair a puncture and refit the chain 1 tooth out. (it's 50/50).
It does take a hell of a lot of miles to wear this way and the fix is simple, move the chain left or right one link, so it's no real big deal.
I'm not convinced it makes much difference. Change the chain every couple of thousand miles, change the cog every other chain, change the ring every other cog.
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So you are willing to put up with chainrings that comparatively easily unship chains?
Never lost a chain yet, and I usually use rings for geared setups, with ramps and cutouts and such.
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Others don't replace chains or adjust chain tension as often as you.
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I have a 47T chainring on my fixed bike and have usually 18T or 19T sprocket.
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Wouldn't the solution be to have a wide/narrow chainring that ensured a fixed or singlespeed chain always engaged with the 'right' teeth?
I imagine that this sort of chainring would also make it more difficult to unship a loose chain, given the claims for such MTB chainrings.
They have a greater benefit with a geared set up with a single ring up front than for singlespeed. Even with an elliptical chainring I rarely lose the chain when single speeding but net a chain guide when I put gears on. Narrow wide stopped the chain dropping when I put gears on
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It depends on your preferred cadence. I'm doing about 100rpm at 18mph so I have a gear of about 60" (41 x 18). On a fixie it's different because you have to gear for the downhills to avoud spinning out.
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So you are willing to put up with chainrings that comparatively easily unship chains?
I have the scars. But I do try to check chain tension, etc., regularly. 1/8" chain as well.
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It's a commuter bike so same route each day. Undulating but a free rolling undulation that doesn't benefit much.from a gear change at first. One natural hill and a man-made.hill over a main link road bridge. Then it's practically flat into work.
Thinking of the gearing I use most it's a 50 chainring and the third biggest chainring on a tiagra 12-32 chainring I'm not sure what the teeth count on the cassette cog in use most often. On a very tired day or strong headwinds I use 50-32 (cross chain be damned!). Or I drop into the small chainring.
So if my guess on cassette teeth is right I'm on 50/21 or 26 mostly anyway when I want an easy ride. At 50/21 I would think 42/18 is closest but 44/18 is also close. Indeed the genesis ss would be ok at 42/17.
Mind you that's my relaxing gear on my commute. I can n grind out high gears closer to 50/15 I think tyre third highest gearing is and that's up my commuting hill. I do tend to mash it. For example I had a quite high gearing range on my old 7 speed road bike 400 exage groupset IIRC. I used.to do 1 in 4 hills every time I went out (the easiest hill to my house was 1 in 5!j. I would just take my time and almost trackstand to get my breath back.
I also used to leg press 525lb IIRC for fun at the time. Used to find it funny to share the leg press between reps with the muscle Mary's and watch their faces as they reduce the weights after me.
Knee op since then and I've lost that strength but mashing it uphill is something I can still manage. I don't walk even if I'm towing a loaded trailer stuck in my.big chainring. 50/25 with a heavy adventure cx1 luggage trailer plus panniers plus tent on rack top up Scottish hills. No walking there.
I reckon singlespeed is a good fit for me. My only.concern is spinning. I don't do that very well.
So gearing looks like 42/17 to start with (or whatever the bike comes with) then adjust with experience. What do you think?
What do I need to spend to get a reasonable SS? I've seen £499-799 for PX/On One or genesis SS bikes. Can you get disc braked ss for cheaper? I didnt want to spend that much. Was hoping they were a lot cheaper. Any cheaoer ones worth it? Prefer disc brakes as they're lower maintenance I reckon.
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The best s/s and fixies are built, not bought :)
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The best s/s and fixies are built, not bought :)
Yebbut: that applies to all bikes (except possibly Bromptons).
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Cycled home in 50/21. Started off at 50/19 but forgot what I was doing so changed down out of habit when lights went red just before me (only 2 sets of lights on my commute). I was over the hills before I realIsed. D'oh!
I changed back to 50/19 and reckon that's a good gear for me except on those really.tired winter days, in the dark with.strong wind and rain. Those days tire me out anyway so with a singlespeed will not leave me much in the tank I reckon.
BTW the 50/21 was nothing. I didn't slow down going uphill. TBH on a good day I'm probably running a higher gear anyway going up that hardest section.
The thing I didn't like with the 50/21 was how I had to spin a lot higher cadence than I like on the flat. Forget about downhill sections. On the flat it felt like I was bouncing on the saddle. Poor pedalling technique no.doubt. I.once got told singlespeed is good.for pedalling technique (smoother circles) and power.
So based on this do you think 50/19 is too highly geared? Running 37-622 tyres gives 72.5" if I understand.that gear calculator someone posted earlier. That's the gear I found easy. I could manage 50/17 too but at 81" it's too much. I could do it but would not enjoy it as much.as the 72.5".
So what bike options that are cheaper than the excellent genesis SS bikes? Anything worth getting that's cheaper but with disc brakes?
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I've picked up a couple of Specialized Langsters off ebay for around £200. I use mine for a 24km each way commute with a couple of short sharp hills. Gearing is 42/16.
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So based on this do you think 50/19 is too highly geared?
Only you can say ;-)
Do it for a few more days and see how you get on on different days and weather etc. And don't over think it, even if you do get your gearing 'wrong' you can change it later for the cost of a chainring or freewheel so not the end of the world.
As for spinning, you WILL get better at this if you go SS/fixed, you'll also realise that for a lot of downhills you'll get more benefit out of a good tuck and coast than frantic spinning.
The cheapest way to do it is normally a home build out of spare bits and an old frame, or accumulated/borrowed parts from friends. But this can result in a bit of a bodge job or actually end up more work than you expect if you're not sued to all the idiosyncrasies of what will fit and what won't so sometimes it's better to either bite the bullet and buy something new and 'done for you' or at least look at 2nd hand options.
Be aware that a lot of SS and fixies are more track-esque than road-esque, so have very racey geometry and lack provisions for guards and big tyres, so be careful if you spot a bargain that it's not actually totally inappropriate!
I've had Langsters in the past, they are nippy, tough and ride well, and available very cheap 2nd hand, but you'll only get a 25mm (maybe 28) tyre in there and they are a pig to get guards on.
The Genesis Flyer is a decent all rounder to look out for, takes 25/28mm with guards and is sensibly built, but not often easy to find second hand.
My current SS is a 1980's Mercian* 531ST frame, with some home-built wheels, and it cost me under £200 all in, but I did already have the wheels... but decent old frames are easy to come by and as long as you pay attention to things like making sure it has horizontal dropouts, the right clearances and braze-ons etc. you can put together an excellent bike for very little cash.
*less well known builders or mainstream brands can be found even cheaper and at equal quality.
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Could you make something out of this bike? I have one in mint condition.
http://www.ebay.co.uk/itm/like/152343970303?chn=ps&dispItem=1&adgroupid=46395905027&rlsatarget=pla-326110881982&abcId=1129006&adtype=pla&merchantid=114942517&poi=&googleloc=1007098&device=m&campaignid=862328541&crdt=0&ul_ref=http%253A%252F%252Frover.ebay.com%252Frover%252F1%252F710-134428-41853-0%252F2%253Fmpre%253Dhttp%25253A%25252F%25252Fwww.ebay.co.uk%25252Fitm%25252Flike%25252F152343970303%25253Fchn%25253Dps%252526dispItem%25253D1%2526itemid%253D152343970303%2526targetid%253D326110881982%2526device%253Dm%2526adtype%253Dpla%2526googleloc%253D1007098%2526poi%253D%2526campaignid%253D862328541%2526adgroupid%253D46395905027%2526rlsatarget%253Dpla-326110881982%2526abcId%253D1129006%2526merchantid%253D114942517%2526gclid%253DCj0KCQjwz_TMBRD0ARIsADfk7hT1cg0EciKOwnnz7RZe3FGKKyh4hTGNDzEZeNIIPNGeDcjA4GMePGoaAn7UEALw_wcB%2526srcrot%253D710-134428-41853-0%2526rvr_id%253D1291689005359 (http://www.ebay.co.uk/itm/like/152343970303?chn=ps&dispItem=1&adgroupid=46395905027&rlsatarget=pla-326110881982&abcId=1129006&adtype=pla&merchantid=114942517&poi=&googleloc=1007098&device=m&campaignid=862328541&crdt=0&ul_ref=http%253A%252F%252Frover.ebay.com%252Frover%252F1%252F710-134428-41853-0%252F2%253Fmpre%253Dhttp%25253A%25252F%25252Fwww.ebay.co.uk%25252Fitm%25252Flike%25252F152343970303%25253Fchn%25253Dps%252526dispItem%25253D1%2526itemid%253D152343970303%2526targetid%253D326110881982%2526device%253Dm%2526adtype%253Dpla%2526googleloc%253D1007098%2526poi%253D%2526campaignid%253D862328541%2526adgroupid%253D46395905027%2526rlsatarget%253Dpla-326110881982%2526abcId%253D1129006%2526merchantid%253D114942517%2526gclid%253DCj0KCQjwz_TMBRD0ARIsADfk7hT1cg0EciKOwnnz7RZe3FGKKyh4hTGNDzEZeNIIPNGeDcjA4GMePGoaAn7UEALw_wcB%2526srcrot%253D710-134428-41853-0%2526rvr_id%253D1291689005359)
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that is the longest link to an e-bay ad I have ever seen. They say a picture is worth a thousand words....
cheers
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There's also the question of odd or even numbers of teeth regarding wear. I've seen arguments in favour of both so I'm none the wiser.
I like to have a combination of primes. 43/17 is a really nice gear. 8)
I thought it was less an issue of primes but rather how many times round your cog divides into your chainring, and that only if you do skids and need to worry about even wear on the tyre.
I have never heard of a reason to use even cog:chain.
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I have never heard of a reason to use even cog:chain.
the chain wears unevenly (given a chance) in that the way the pin bushings wear means that unless the roller bushings wear in sympathy, the chain wears such that the pitch is different on every other link. If you use uneven tooth counts every tooth sees both types of chain link and the chain wears more evenly. If you use even tooth counts and run it long enough, the chain runs properly only when it is installed one way on the teeth, because the teeth wear to match the uneven chain. I think this might become important if you intend to run the chain to death.
Also note that chains, once worn, need to be able to ride up on the teeth slightly. This means it is a bad idea to run a tight chain, once it is even slightly worn; it will be noisy and will wear everything at about x10 the rate.
IME full height teeth on chainset and sprocket, and a (pref 1/8") chain that uses cambered inner side plates makes for an IGH/SS drive that will tolerate being run fairly slack without unshipping. I have intentionally run such an IGH drive with up to 3-1/2" of slack and the chain will not unship more than once every few thousand miles, or once a year. Fixed is a different matter.
cheers
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that is the longest link to an e-bay ad I have ever seen. They say a picture is worth a thousand words....
cheers
I couldn't get the link thing working properly. It's a Raleigh m-trax 6000R road bike. Reynolds steel, 7 speed and a nice old bike IMHO. I was wondering if it could be made a single speed and whether it could make a reasonable singlespeed bike at that?
BTW it's a classic, old style, steel bike with skinny seat stays and indeed all tubing is skinny.
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Have a read: http://www.sheldonbrown.com/singlespeed.html and http://www.sheldonbrown.com/no-derailers.html
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There's also the question of odd or even numbers of teeth regarding wear. I've seen arguments in favour of both so I'm none the wiser.
I like to have a combination of primes. 43/17 is a really nice gear. 8)
I thought it was less an issue of primes but rather how many times round your cog divides into your chainring, and that only if you do skids and need to worry about even wear on the tyre.
I have never heard of a reason to use even cog:chain.
A prime chainring can never divide by a cog so no matter what cog you can't get uneven tyre wear. I suspect if you had something like 32/16 you'd have uneven tyre wear because of where the power is applied unevenly in the pedal stroke always being in just a few places on the wheel.
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Sure, but if you had a prime mix that worked out at 1.5x:x it would mean that you get back to your starting position after two pedal strokes. If, however, your setup were 2x+1:x then you would need 2x+1 rotations to get back to your starting point (that is as long as they don't have a common divisor).
Or at least something like that.
Brucey, are you suggesting that beyond this there is a further advantage to uneven:uneven (vs even:uneven). And I still have yet to hear anyone supporting even:even, or did I misunderstand your post?
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http://www.sheldonbrown.com/chain-life.html is the best explanation I've read for choosing even-numbered sprockets and chainrings.
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Havimg now ridden the Bob Griffin, 42 x 18 is just right for me. But I'm a 100rpm spinner.