Fixed gear gear advice please

EKE_38BPM

I'm at the stage of buying parts to make a fixie and have come across a 56t chainset on fleabay. What size sprocket should I team it with for riding around a hilly part of London?

Using this site and using a Bowery (46x17) for comparison, I should be going for a 20 or 21t sprocket (around 73GI).

I'm going for a spin on my geared bike to compare the different gears for the hills I'll be riding, but is this a fair comparison as I've been told that fixies 'generate their own momentum' and 'help' you get over the hills.

Craggers

You do get a slight flywheel effect from the rotation of the rear wheel, but if you're a heavy rider (like me-16st) it probably wont make that much difference. I'd go with whatever ratio feels best on your geared bike... even if you end up not liking it it's not much cost or effort to change the rear sprocket.

56t is a huge chainring though, I'd be wary of not being able to get a decent chainline with it (you might not be able to get it inboard enough without fouling the frame)

wgwarburton

EKE_38BPM wrote:

I'm at the stage of buying parts to make a fixie and have come across a 56t chainset on fleabay. What size sprocket should I team it with for riding around a hilly part of London?

Using this site and using a Bowery (46x17) for comparison, I should be going for a 20 or 21t sprocket (around 73GI).

I'm going for a spin on my geared bike to compare the different gears for the hills I'll be riding, but is this a fair comparison as I've been told that fixies 'generate their own momentum' and 'help' you get over the hills.

73" is probably a pretty useful gear for London- I'd be inclined to start low and build up, personally, as I think it's likely to be easier on your knees. If you have many climbs and/or traffic lights you'll spend a lot of time straining to accelerate. Depends how strong & fit you are. I started on a 64" gear and moved up to around 70" after a year or two. Most people here seem to think that's too "spinny"... but that's just 'cos they lack technique :-)

56T is a big chainring. Should work well enough if it does fit OK (depends on the frame), will wear a little better and might be cheaper than a more popular size.

You can get sprockets up to about 22T. I've got a part-worn 22T (1/8") that I could probably spare for a small consideration, if you need it. I don't think I'll be likely to use it again ('cos i couldn't find a 56T chainring for my chainset!!!)

Using your geared bike as reference is pretty fair- you ought to find it just a little bit easier when you do go fixed, since you won't have the weight of the gear-system to contend with, won't be thinkiing quite so much about what gear you are in and wont need to work so hard to avoid freewheeling.

Cheers,
W.

EKE_38BPM

I had another look at the chainring and it was 52t. Don't ask me where I got 56t from.

Anyway, went for a spin (13 miles) and did the whole ride in 42x14(81"). Obviously, couldn't simulate being fixed in a gear for the downhills, andI can confirm that going up hill was a bit of a mission but the flats didn't feel that quick? No speedo to confirm speed or cadence though.

I guess I'll have to choose 52x19(73.9") or 52x20(70.2") and in either case, learn to spin faster.

BTW, the Langster uses 42x16(70.9")
and the Bowery usesn 46x17(73.1")

Craggers

Chances are, whatever gear feels right first off, won't feel as right after a couple of months of riding on it. Trial and error is pretty much the name of the game when first taking up SS/FG!

I started off with 42/16 on the langster, then after a while felt it too spinny so went to 42/14, which was much better but still not perfect so I tried 46/14 which was just a little too big. I'm back on 42/14 for now but I reckon 44/14 will be perfect for me. FWIW... If you're after outright speed then I wouldn't bother with SS/FG if I were you.

Alphabet

i'm using 52x16 at the moment, but i tend to ride fairly mashy. it really is personal preference. only got one hill on my commute and it;s right at the end on the way home, so i don't mind nearly killing myself getting up it. too much.

EKE_38BPM

I posted this status update of Facebook:
"EKE is about to start building a fixie but has to choose a gear which is fast on the flats but still allows me to climb the hills in Barnet. Decisions, decisions." and got called a geek. Fair enough, but then the person that called me a geek then goes on to post this to my wall:
"go for a 49/19 general all rounder for the novice like yourself..."
Who's geekier? The geek, or the person who knows what the geek is talking about and then offers advice!

Anyway, 49x19 does seem really spinny, but there are hills around here and as he pointed out, I'm a novice to FG, even though I do centuries and longer on my geared bike.

I think I'll have to start at around 52x18 and take it from there.

As far as the fixie build is going, I'm watching a frame (inc handlebars, brakes, mudguards, forks and headset) on fleabay which looks like it will be mine and I'll be buying the chainset from a different fleabay seller who has a few.
I have a saddle I can use (not 100% certain the seat post will fit, but I'm optimistic). same with a bottom bracket (needs bearings), pedals are an issue. I have some platforms I can use temporarily, but I'll be wanting SPDs sooner rather than later.

Now just to get some wheels and tyres (I have spare tubes), and once I put them all together, I'll be ready to roll. Hopefully coming in at around the £200 mark for the whole build.

Alphabet

excellent. if you build it, you have to use it on next year's dun run

wgwarburton

EKE_38BPM wrote:

..."go for a 49/19 general all rounder for the novice like yourself..."
Anyway, 49x19 does seem really spinny,
I think I'll have to start at around 52x18 and take it from there.
....

Big difference between the two! What size wheels/tyres are you using?

What's your "normal" cadence? The gear you want should map your preferred cadence onto your preferred roadspeed. So, if you usually cruise at, say, 18mph (be realistic..cruise, not sprint) and your comfortable cadence is around 90rpm your starting point should be around 68" (ie 49x19 on 700x25C wheels).

Running a 52x18 with 25Cs would have you turning under 60rpm whenever your speed drops below 14mph... that's pretty grindy, if you have any longish climbs or a nasty headwind to tackle, let alone both together....!

Cheers,
W.

EKE_38BPM

Alphabet, I did the Dun Run this year on my geared bike and that was hard enough. Oddjob regretted doing it fixed, says it nearly killed him. But who knows, maybe I'll get the fixie bug, join LFGSS and do it with them and all that jazz. Hmmm....

Buns, 49x19 was a friend's idea. I have no speedo so I can't say what my cruising speed and cadence are with any accuracy, but I think I'll be spinning out if I tried to get to whatever my usual cruising speed is if I rode 49x19. Climbing hills would be a breeze though.
I'm just going to have to ride around for a few days in a gear to test it out. I think I'll keep in 52x19 until I buy my wheels and have to make a decision. If its not right, I'll still be able to choose a different sprocket before I buy.

I see LiT rides 48x15 or 46x14. Thats some pretty big gearing. I'd hate to face a hill or headwind (or both) in either of those gears.

Alphabet

i know you did it geared - i arrived with you

i am Westernway's mate James - I've been sucked into this forum. we've been talking about making the DD more of an incentive next year as we now know we can do it. I'm contemplating my new SS and he's contemplating his brompton.

I've got a video of it with you in actually on FB

biondino

52/18 is too highly geared. Try and get something with low-mid 70s gear inches. If that's REALLY too spinny after a few hundred miles, replace the sprocket. High gearing is for men who need to prove themselves, if you know what I mean.

Alphabet

biondino wrote:

52/18 is too highly geared. Try and get something with low-mid 70s gear inches. If that's REALLY too spinny after a few hundred miles, replace the sprocket. High gearing is for men who need to prove themselves, if you know what I mean.

that's a bit harsh. i use 52/16 because my legs prefer a slower mashy cadence. I'm a skinny chap with no pretension of muscles - it's all personal preference.

Just go with what is good for you. there's no magic combination. All depends on your legs and your route. But with Highgate Hill, you might want something a touch more spinny of you're going to lose a lung

biondino

Alphabet wrote:

biondino wrote:

52/18 is too highly geared. Try and get something with low-mid 70s gear inches. If that's REALLY too spinny after a few hundred miles, replace the sprocket. High gearing is for men who need to prove themselves, if you know what I mean.

that's a bit harsh. i use 52/16 because my legs prefer a slower mashy cadence. I'm a skinny chap with no pretension of muscles - it's all personal preference.

Just go with what is good for you. there's no magic combination. All depends on your legs and your route. But with Highgate Hill, you might want something a touch more spinny of you're going to lose a lung

Fair enough I guess, there must be exceptions to the penis-substitute rule I find that when you have to keep stopping and starting - i.e. London - then it's simply too tiring to have to put all your energy into slowly slowly getting moving at every light and crossing. There are times when I wish I was slightly better geared when I'm cruising along happily on a good road surface - and even, occasionally, when I'm attacking a hill - but since most of what I do is slow, stuttering and flat, I don't think it's worth making the change.

(also, when you're on a slight incline or pushing into a headwind and you're slightly too highly geared for it and there's no sign of it abating then it's *miserable*, and a higher gear would be te final straw)

Alphabet

got a big hill at the end of my commute (uphill on the way home) and it's fairly nasty on my ratio, but it is right at the end and i figure i can put up with it as it's five minutes of my daily hour and a half and otherwise i'd be all spinny for the rest of it which would probably pop my kneecaps off

wgwarburton

Hi,
I think it's worth bearing in mind that while being undergeared is a little frustrating, being overgeared can be soul-destroying, as well as potentially harder on the knees (no hard evidence to back that up, BTW).

Personally, I think it wiser to lean towards undergearing, at least initially. Changing a sprocket is relatively inexpensive and straightforward... they wear out, anyway, so you'll probably need to change it in a year ot two.

Working towards smooth pedalling is one of the benefits of riding fixed. I reckon your technique and souplesse will develop better if you have to spin a bit.

If you find that you never spin out, then IMHO you are overgeared- on those rare occasions when you get a clear, fast run you should expect to have to work hard and/or feather the brakes to stay comfortable on a fixie.

Cheers,
W.

EKE_38BPM

As I said, I'm new to this fixed gear malarky, so all advice is greatfully received and I have nothing to compare it to.

Learning to spin a bit more is probably better for my cycling, so I will try 52x19 on my geared bike as Biondino suggested. Buns' "soul destroying" comment was the persuader there.

The frame I'm watching on fleabay is still looking good, so now I have to get the drive side BB cup out of the Banana frame that it is stuck in and then I'll be able to re-use that (it only had about 500 miles on it when the bike was abandoned for a car). Time to have a word with my neighbour, the mechanic. He has waaaay more tools than me and has got me out of a spot a few times. From what I can see, the Banana frame only has surface rust, so my next project will be to clean it up and build another bike out of that.

Alphabet, I forgot that was you on here. I'll PM you my FB details so that you can send me that video of us at Dunwich. I haven't seen WesternWay on here for a while. Still riding, I hope.

Its my birthday today as always, the heavens are celebrating the day of my birth with a meteor shower.

If you've never seen a shooting star, look to the north and away from light pollution tonight. If you're lucky, you should see more than one a minute.

Oddjob62

Just so you can compare, i've been on 51/18 the times you've riden with me.

And with regards to the DD it was 50miles longer (and at a lot tougher pace) than my longest ride ever (one of last year's slowcials which included a long pub lunch). Chances are i'll end up doing it fixed again

Alphabet

yeah, WesternWay has been on holiday cycling on the Dutch flatland with his kids - leaving me at work with noone to have a sneaky lunchtime pint with. Send me your details - the video isn't very long as the camera doesn't work spectacularly well in the dark - bit of a problem with the DD.

Good luck on the build. My advice would be to ride around in a gear that you feel comfortable in on the flat and downhill and then test it out on the biggest hill of your commute - if you can make it, you're all set. Might not be the best way to do it, but that's how i decided. I'm seriously out of breath at the top, but sod it - it's all good exercise.

Oddjob62

Also try to get a hub that's fixed/fixed, then you can have a choice. I have 18 on one side and 15 on the other.

biondino

EKE_38BPM wrote:

Learning to spin a bit more is probably better for my cycling, so I will try 52x19 on my geared bike as Biondino suggested. Buns' "soul destroying" comment was the persuader there.

I was thinking about this on the way in today. I've never found myself not wanting to take the fixie out for a commute or a short ride around town, even when it's been windy or I've had hills to contend with. But I reckon if it was even 5% higher geared I would have thought twice on some occasions, and I never want to feel like that about a bike!

biondino

Another observation: When I ride the roadie after having used the fixed for a few days/weeks, I find that the perceived effort is the same in 50/16 on the roadie as 48/18 on the fixie. That's 82 gear inches vs 72! I guess that's the difference between a steel track bike and a lighter, stiffer carbon bike with longer cranks.

EKE_38BPM

The frame I was watching on fleabay started at £70 and there were no bids until 45 mins before the auction ended. It eventually went for £132. Who wants a 1970s brown frame, anyway?

emotionless_softcore

I picked up a second hand Tricross single recently, been bowling around on 42/15 (73.9 GI) fixed for a few weeks now and although it's a very usable ratio, I've found that in certain cadences, e.g. descending hills, or caning along the flat, the inexorable spinning has been having a worrying tendency to bounce me up and down and generally be unsettling.
(lrn2souplesse fail).
stuck a 51 tooth ring on there today (now 89.7 GI), went out for a ride.
Perfect, apart from certain hills. (I had to get off and walk.)
I can't find my lockring tool to change the cog for a bigger one, christ knows how I'll make it to Luton and back for work tomorrow (going from near Watford.)
I'll just allow extra time for the getting off and walking I guess.

In any case, I'm liking the visual aspect of the larger chainring.

EKE_38BPM

HOW MANY TEETH ON THAT CHAINRING!!!!!!!!!!!

I went for a 36 mile ride today and did it all in 52x19 (73.9") on my geared bike. The return leg of ride was into a headwind and I was dreading Archway Hill all the way from the Thames (Blackfriars Bridge). The hills on the way were a struggle but in the back of my mind was Archway Hill, but when I got there, I MTFU'd and it was surprisingly easy (well, it wasn't that bad).

I think 52x19 is the way to go.

Taking OddJob's advice though, I'm buying a fixed/fixed wheelset. The one I'm looking at comes with 15t and 16t sprockets, so I'll have to buy the 19t seperately, but I still getting a bargain.

£110 for front wheel + fixed/fixed rear wheel + 15t sprocket + 16t sprocket + 2 lockrings
£14 for a 19t sprocket
Throw in the two tyres (Gator Skins) and two Continental inner tubes for £45 and that is £169 all in.

Sweet!

EKE_38BPM

After a bit of research, I found out that chain ring has 77 teeth.

I'm bored!