Fixed/Single Speed Commuting

itboffin

Having not ridden a bike with gears for 2 months and not even attempted a hill in that time I found myself both yesterday and today getting out of the saddle to attack hills

"Oh! yes I have gears" doh! - didn't stop me doing it on every hill

N0bodyOfTheGoat

If you FG/SS gurus had £350 to spend on a new steed, would you buy...

Tricross Singlecross
Mongoose Maurice

or something else?

I'm starting to feel a great urge to buy a new, different style of bike, to compliment my Felt F5C and Saracen Pylon8!

The 63 gear inch ratio on the Tricross looks doable, as my cruising gear is about 61" on the Saracen...

DevUK

I've test ridden a Maurice and I kinda liked it. It was very comfy to ride, but definately a sit-up riding style. It was a short reach, even though I was riding a size too big for me. I did like it, but I settled for a charge plug freestyler, which is very similar but higher quality IMHO (and £530!).

Anyhow, it depends what you want, town/city bike or something faster with drops If you just want something to play with, maybe look into buying a second hand half decent steel track frame and building a cheap fixie?

DevUK

Clever Pun wrote:

you'll need to change your FCN, it's just skyrocketed

Fixed! (A pun for Mr Pun )

biondino

Is it possible to tighten your fixie chain too much? I can't swear on it but I am sure my rear wheel isn't rotating as freely today, stopping more quickly when I turn it by hand. On the weekend I tightened the chain when it became loose on one side, and I also gave the chain a good wash which, weirdly, left it sounding like it had half of Bondi Beach stuck between the links, even after lubing it up. And it seemed (again, possibly imaginary) harder work cycling in this morning.

If i push the upper part of the chain upwards, I get maybe half an inch movement, possibly a touch more. If I push it down, maybe only 1/4 of an inch movement.

wgwarburton

biondino wrote:

Is it possible to tighten your fixie chain too much?

Yes, it's possible.

I can't swear on it but I am sure my rear wheel isn't rotating as freely today, stopping more quickly when I turn it by hand. On the weekend I tightened the chain when it became loose on one side, and I also gave the chain a good wash which, weirdly, left it sounding like it had half of Bondi Beach stuck between the links, even after lubing it up. And it seemed (again, possibly imaginary) harder work cycling in this morning.

Have you checked the "D'oh!" stuff? Brake dragging? Mudguard? Wheel off centre?

If i push the upper part of the chain upwards, I get maybe half an inch movement, possibly a touch more. If I push it down, maybe only 1/4 of an inch movement.

That's a bit odd... but half an inch of play is about right.
Best way to set it is to get it centred but slack, then see how long it takes to spin down, then get it as tight as you can without affecting the spin-down time. This ought to give you about half-an-inch of play.
If this process doesn't work, then there's something not quite right- worn bearings, something rubbing (or maybe something fundamental, like a duff chainline or chainring out-of-round).
I've got into the habit of checking for slackness by eye and by the amount of backlash in the drivetrain and for drag by lifting the rear wheel while walking the bike to check spin-down. If there's a problem then these checks will likely show it up.

Could it be that your chain has picked up muck with all the wet weather we've been having? Fine grit inside the links could be hard to remove?

Cheers,
W.

ride_whenever

what's the best way to sort chainline, mine isn't quite right given the new wheels. I really don't want to move the wheel over a touch and re-dish it, because i'm lazy and that's too much work tbh.

Are thin washers between the chainring and spider okay on a fixie? It is probably only a mil out.

wgwarburton

ride_whenever wrote:

what's the best way to sort chainline, mine isn't quite right given the new wheels. I really don't want to move the wheel over a touch and re-dish it, because i'm lazy and that's too much work tbh.

Are thin washers between the chainring and spider okay on a fixie? It is probably only a mil out.

You'll probably get better answers than mine, but...

I don't think I'd worry too much about 1mm.

Redishing will move the rim, not the sprocket. To move the sprocket you'll need to muck about with spacers on the axle (or possibly on the sprocket thread itself). If you can move 1mm of washers from driveside to nearside (or vice-versa) then the sprocket will line up with your chainring. The rim will now be 1mm further over, too, but unless your frame has very tight clearance you can probably just adjust your brakes to suit.

If the clearances are all too tight, or you want to get it spot-on, then I think you'll have to put in the time to do it right.

Cheers,
W.

ride_whenever

Right, i have officially no clearance with cx tyres on, i had to shave off the stubble on the tyres to stop them rubbing in places. Hence to screw the wheel over on the cup and cones even a mill i'd end up having to re-dish the wheel.

Not to mention having a non-centered wheel giving odd cornering.

In the past, even without washers i've made the holes in crank spiders elliptical through my hench quad-power, would the washers exacerbate this issue?

wgwarburton

ride_whenever wrote:

Right, i have officially no clearance with cx tyres on, i had to shave off the stubble on the tyres to stop them rubbing in places. Hence to screw the wheel over on the cup and cones even a mill i'd end up having to re-dish the wheel.

Hmm, I see your problem.

Not to mention having a non-centered wheel giving odd cornering.

TBH, I've never noticed this in practice. Maybe I just adapt to it subconciously.

In the past, even without washers i've made the holes in crank spiders elliptical through my hench quad-power, would the washers exacerbate this issue?

IMHO, yes, it would, as the pressure on the stack-bolts would be further off-line.

I'm still not clear which direction you need to move- is the chainring too far out or too far in?

I'm guessing you're using a single 'ring crank or the outer chainring position on a double, so you need to move the ring outboard. Can you move the crank or BB, rather than the chainring? If you have a square taper BB, then a spacer between the fixed cup and the BB shell would push the whole chainset across. I don't know how this would be achieved with the new-style BBs as I've never played with one.

Try these: http://www.billys.co.uk/english/group.php?prod=fwbr-spacer

Cheers,
W.

ride_whenever

I was worried that might happen :?

Sorry need to move the chainring towards bike center, it's currently on the middle position of a mtb triple as the old stronglight cranks i killed as detailed above :oops:

Or move the sprocket out a smidge!

It's an external BB setup, so I might have a spacer I can move over to shift the cranks in, chainstay clearance permitting. Or just order some thinner spacers so i can move it over a smidge as opposed to the whol lot.

It definitely isn't straight, but i cannot tell if the chain is deflecting or if it is just running with the chainring touching the inside plate and the sprocket touching the outside plate. Probably is deflecting slightly as i'm getting slight clicking from the rear.

wgwarburton

ride_whenever wrote:

I was worried that might happen :?

Sorry need to move the chainring towards bike center, it's currently on the middle position of a mtb triple as the old stronglight cranks i killed as detailed above :oops:

Or move the sprocket out a smidge!

The same spacer will work for sprocket or BB shell, so if you have enough thread depth on the hub you should be able to space out the rear cog & be done. I'd go with this option if it's available as it'll be easier and more elegant than mucking about with the BB.

I've done this with a BB lockring (which was maybe 1.5mm thick) in the past, when the sprocket stripped the thread on the inner few mm of the hub. Spacing it out engaged new threads and kept the hub useable for another couple of years until the inner cups wore out and the bearings collapsed....

Cheers,
W.

ride_whenever

I'm a little warey of spacing out the sprocket for some unfathomable reason, probably because at the weekend i managed to undo the lockring skid stopping, which i shouldn't have been able to. Haven't taken it off to assess the damage yet either :?

The BB side is much easier for me, i have all the tools to hand and i don't need to worry about getting the lockring back on again.

PS any ideas how i managed to undo the sprocket skid stopping when i had a lockring on?

biondino

Thanks Buns.

WGWarburton wrote:

Have you checked the "D'oh!" stuff? Brake dragging? Mudguard? Wheel off centre?

Definitely not the brake, as there isn't one, and definitely not the wheel off centre, because it was off centre (rubbing against the stay!) before I put it back in place. The mudguard is the new Crud road jobby and while it uses the brushes-on-the-rim to keep it in place, I don't think that adds more than negligible drag.

Buns wrote:

Best way to set it is to get it centred but slack, then see how long it takes to spin down, then get it as tight as you can without affecting the spin-down time. This ought to give you about half-an-inch of play.
If this process doesn't work, then there's something not quite right- worn bearings, something rubbing (or maybe something fundamental, like a duff chainline or chainring out-of-round).
I've got into the habit of checking for slackness by eye and by the amount of backlash in the drivetrain and for drag by lifting the rear wheel while walking the bike to check spin-down. If there's a problem then these checks will likely show it up.

Could it be that your chain has picked up muck with all the wet weather we've been having? Fine grit inside the links could be hard to remove?

I think everything is fine with the chainline, chainring and bearings. The chain itself is, I think, suffering from the fine grit you mention. Ah well.

I might try re-tensioning the chain tonight as you suggest, and see if it makes a difference. Of course, I could decide on the ride home that actually all I needed to do was MTFU. It's happened before...

wgwarburton

ride_whenever wrote:

I'm a little warey of spacing out the sprocket for some unfathomable reason, probably because at the weekend i managed to undo the lockring skid stopping, which i shouldn't have been able to. Haven't taken it off to assess the damage yet either :?
The BB side is much easier for me, i have all the tools to hand and i don't need to worry about getting the lockring back on again.

Well, either should work. As I wrote above, I would probably opt for spacing the sprocket, it seems more elegant to me and I'm not sure how you would move the BB cup inwards- If this is an easy option on an external BB then it's probably the way to go!

PS any ideas how i managed to undo the sprocket skid stopping when i had a lockring on?

No- that doesn't sound right, though I suppose that the lockring could work loose- even if it were snug when fitted: The sprocket could bed in, leaving the lockring behind (even unscrewing it a little as it tightens itself). A bit of vibration would let the lockring unscrew further and then a skid-stop might break the sprocket loose as you describe.
It seems unlikely but that doesn't mean it wouldn't happen. I'm sure it's advised to check a lockring after riding for a bit on a newly fitted sprocket, and I guess this would be why.

Cheers,
W.

biondino

So I adjusted my chain and think I've got the tension about right. It was definitely dragging before - the wheel would rotate maybe once when I gave the pedal a push, versus half a dozen times with the chain slack.

Now, hopefully, it's a) aligned properly, b) secure and c) tight but not too tight - the 15 second ride around my work garage seemed to indicate all was good. Thanks again, everyone.

N0bodyOfTheGoat

Just been to Hargroves and they are building up a 56cm Specialized Tricross Singlecross for me to test ride later this week. Looked lovely and lightweight in the flesh, plus I was shocked in a good way at how upright the 56cm frames put me, when compared to my 54cm Felt F5C (which should help my back injury).

I asked them about fitting a bigger sproket on the fixed side (eg. 20 or 21T) to give me some leaway on my homeward hilly leg of the commute, but was told it would cause lots of agro, if I was going to keep the freewheel 18T sprocket on the other side. Never realized that freewheel and fixed sprockets should be the same size... Is it really a big no-no?

wgwarburton

NitrousOxide wrote:

Just been to Hargroves and they are building up a 56cm Specialized Tricross Singlecross for me to test ride later this week. Looked lovely and lightweight in the flesh, plus I was shocked in a good way at how upright the 56cm frames put me, when compared to my 54cm Felt F5C (which should help my back injury).

I asked them about fitting a bigger sproket on the fixed side (eg. 20 or 21T) to give me some leaway on my homeward hilly leg of the commute, but was told it would cause lots of agro, if I was going to keep the freewheel 18T sprocket on the other side. Never realized that freewheel and fixed sprockets should be the same size... Is it really a big no-no?

The chain length needs to accommodate both alternatives within the range of adjustment available on the dropouts/trackends. Too big a difference and you will need to take links in & out to be able to tension it.

If you're fitting a freewheel on each side you could use a tensioner, I guess, but again, the hassle and complexity starts to interfere with the simplicity of a FG/SS drivetrain.

Cheers,
W.

N0bodyOfTheGoat

WGWarburton wrote:

NitrousOxide wrote:

Just been to Hargroves and they are building up a 56cm Specialized Tricross Singlecross for me to test ride later this week. Looked lovely and lightweight in the flesh, plus I was shocked in a good way at how upright the 56cm frames put me, when compared to my 54cm Felt F5C (which should help my back injury).

I asked them about fitting a bigger sproket on the fixed side (eg. 20 or 21T) to give me some leaway on my homeward hilly leg of the commute, but was told it would cause lots of agro, if I was going to keep the freewheel 18T sprocket on the other side. Never realized that freewheel and fixed sprockets should be the same size... Is it really a big no-no?

The chain length needs to accommodate both alternatives within the range of adjustment available on the dropouts/trackends. Too big a difference and you will need to take links in & out to be able to tension it.

If you're fitting a freewheel on each side you could use a tensioner, I guess, but again, the hassle and complexity starts to interfere with the simplicity of a FG/SS drivetrain.

Cheers,
W.

Cheers for the input...

What sort of ballpark would we be talking about in terms of number of chain links for each tooth difference?

I must remember to check the dropout length on the test ride, as I might be able to lose some slack by shifting the axle nuts back further?

wgwarburton

NitrousOxide wrote:

What sort of ballpark would we be talking about in terms of number of chain links for each tooth difference?

From Sheldon Brown (RIP)'s site:

Sheldon Brown wrote:

Adding or subtracting a link in the chain will move the axle 1/2". Changing either sprocket size by one tooth is the equivalent of moving the axle 1/8"

Cheers,
W.

Oddjob62

NitrousOxide wrote:

What sort of ballpark would we be talking about in terms of number of chain links for each tooth difference?

My bike is fixed fixed, with 18t one side and 15t the other.

ride_whenever

Are alloy lockrings okay?

Turns out that i'd damaged the threads a little when i pushed the lockring off.

I've tightened it up with the proper tool now it's arrived, fixed the chainline (cheers for the BB idea, worked a treat) and fitted a new chain so the thing is totally silent 8) but slightly worried about this lockring fiasco.

N0bodyOfTheGoat

Has anybody converted their FG/SS into a Sturmey S3X (3 speed fixed, available in 120 and 130 OLD I believe) yet?

blakef111

NitrousOxide wrote:

Has anybody converted their FG/SS into a Sturmey S3X (3 speed fixed, available in 120 and 130 OLD I believe) yet?

i work in stratford upon avon for a company that has daily dealings with pashley, as soon as i can get my hands on it i'll be building one up

ride_whenever

we have one in the shop, just the hub that is, but we can't get a staff discount on it because the manager is a gimp sometimes. :?

wgwarburton

ride_whenever wrote:

we have one in the shop, just the hub that is, but we can't get a staff discount on it because the manager is a gimp sometimes. :?

I want one of these- I even have the bike in the shed waiting for it- but I don't have the budget... I posted a few weeks ago about this- I'm pretty hacked off with the price SA are asking. Even if I re-use a rim we're talking over £200 on a bike that cost me less than £100 to acquire & use for two years. The current hub's stuffed, too, so it's not like I am even using the bike.. it's just sitting there waiting for me to get over myself.

Maybe Santa will be kind...

Cheers,
W.

N0bodyOfTheGoat

Still waiting for my 56cm Tricross Singlecross test ride, looks like at least Monday now.

At some point I might be tempted by a S3X, but I want to explore single gear (both fixed and freewheel) for the first time since a BMX I had around '82!

lost_in_thought

Mutter mutter hipsters mutter mutter...

http://photo.mpora.com/other/collections/london-fixies/

_Brun_

You surely didn't expect to see photos of them actually riding the things?

Oddjob62

no spoks
Hipsters are getting hit by the recession :P