Fixed/Single Speed Commuting

Oddjob62

itboffin wrote:

nice one however I suspect a 39/16 on anything but the hilliest or off road riding is going to be too spinny, still only you will know.

Agreed.

lardboy

If you're running 26"*1.5, then you'll have a GI of 60.6. Waaay too spinny to maintain 18mph, unless you really want to work on your cardio fitness.

pastryboy

My crank remover tool thingy arrived so if it is too spinny I can do something about it now - I have a 50t chainring and an 18t cog that I can try out. I will probably get a proper SS chainring but I wanted to try it out first and avoid spending too much.

I have no idea about any of that gear inches business. My tyres are 700x32. With gears I rarely came off the middle ring and had an 11-23 cassette - I could get to 30 with that. 18 is my cruising speed on gravelly towpath - I'm usually 21-22 on the road.

I see some single speed bikes are sold with 42/18 so I thought 39/16 would be close to that

I'll report back on Monday and see how the journey time/top speed goes. I

wgwarburton

pastryboy wrote:

My crank remover tool thingy arrived so if it is too spinny I can do something about it now - I have a 50t chainring and an 18t cog that I can try out. I will probably get a proper SS chainring but I wanted to try it out first and avoid spending too much.

I have no idea about any of that gear inches business. My tyres are 700x32. With gears I rarely came off the middle ring and had an 11-23 cassette - I could get to 30 with that. 18 is my cruising speed on gravelly towpath - I'm usually 21-22 on the road.

I see some single speed bikes are sold with 42/18 so I thought 39/16 would be close to that

I'll report back on Monday and see how the journey time/top speed goes. I

Couple of things leap out at me:

Firstly, I ran 38x16 (~64") and 52x22 (also ~64") on my "summer fixie" & the winter hack for the first couple of years riding fixed. Worked fine for me.
I currently use 48x19 (68") and feel overgeared (grinding on hills & headwinds) more often than undergeared. I would have gone back to a mid-60s gear through the winter, if I'd found the time to swap. I've been averaging 19mph on flat roads a couple of times recently without feeling undergeared and that may be close to your 22mph "cruise"?
This is all on 700x25 or 28cs, so smaller wheels than you, too.

Secondly- without wishing to be preachy, and not knowing your route, I'd question whether it's responsible to ride on a shared use path at 18mph+, especially a narrow, gravelly one with water on one side and an expectation of travel at walking pace.

Cheers,
W.

pastryboy

Fortunatley for the most part there's plenty of width and it's so straight that visibility is excellent - I've been as high as 30 on occasions. I woudln't dream of hurtling round corners or doing anything that would potentially injure someone though and keep the speed sensible where I need to.

Back on the single speed subject though.

I went for a quick test ride and it wasn't good. When I pushed hard at the bottom of each pedal stroke there was a loud clunk. Since everything at the back of the bike (including the wheel) is brand new it hard to be the chain ring.

Whilst I was riding I got to 15 and wanted to change gear - I think I would have spun out too soon on the roads.

I swapped over to the 50t ring and stuck the 18 on the back and went for another test ride which seemed to run smoothly.

This gearing felt pretty much spot on - acceleration from standing is a little laboured but it gave a nice cruising speed and I feel like hitting the mid twenties should be no trouble. I do have a few inclines on my route which I'm not looking forward to but I'd rather suffer than fork out for another chainring at the moment.

Harveytile

Hey Pastryboy,

Good to see another dipping their toes into the decidedly murky SS world.

I have converted my Jake to SS and this morning was my first crack at it. Two jumped chains, one adjusted STS and all good. I averaged 18mph once into London but the hills were surprisingly easy. Looking at the strengthening headwind, the evening commute may be a touch harder. 20 miles into a 19mph headwind is not enticing.

I'm running 39:15 due to a slight "technical issue" with the chain tool - measure once, cut twice does not work :roll: .

Hopefully will be sitting pretty at 42:16 come Saturday when the SS chainring arrives.

I feel this is the future.

wgwarburton

Harveytile wrote:

...I'm running 39:15 ...Hopefully will be sitting pretty at 42:16 come Saturday ....

I'd be surprised if you could tell the difference. Very nearly the same ratio...

Cheers,
W.

pastryboy

First day (28 miles) done.

Had to make a pit stop as the bolt holding the little cage and jockey wheel came loose causing the cage to flick back and forth catching on the chain.

Apart from that no problems, chain was good and never skipped - gearing caused me no problems at all although I wouldn't fancy anything higher on the inclines. I may struggle a little on windy days. Journey time seemed no different, just had to push a little harder to maintain usual speeds.

Managed to hit 27 on the towpath and 29.1 on the road.

Saw a roadie over my shoulder but scalp still intact.

Assuming the drivetrain lasts don't see me going back to geared for commuting.

What sort of chain life can I expect and what chains are people using - seem some KMC brown chains for £4 but not sure if they'd be crap - currently using a KMC Z510

itboffin

Miche 1/8th track chain, doesn't rust or attract dirt and no stretching after more than 2 years of all year round usage.... simples!

http://www.italian-solutions.co.uk/prod ... tid=161661

Skippy2309

Arghhh.... whipped the bike out today to give it a good once over, had a tinker fitted the MKS tugs to the rear which make getting everything in place a lot easier.

well when cleaning i decided to check what the actual tooth count was - the print said 48t I counted 44 teeth..... bare in mind I just ordered a 50t chain ring. I am going to get myself a 15t sproket for the rear so i can have something a little less harsh than just the 13t on the rear...

I must say I was surprised but not totally shocked by it, I was disappointed that I was spinning stupidly fast and just breaking 35mph. I am sure I am strong enough to push the 50/13 gearing but 50/15 will be a bit nicer to start out :roll:


Will be starting to commute again soon, got more good news from work should be getting an extra £300 a month which means I can upgrade the parts I want sooner rather than later

itboffin

Couldn't help but notice that super slack chains seem to be all the rage these days

flamite

yes having to keep on tightening my chain every few weeks at the moment!?!?

flipped over to fixed from ss a few weeks ago, took a few days to get used to but now loving it!!

Clever Pun

itboffin wrote:

Couldn't help but notice that super slack chains seem to be all the rage these days

I know it's like wizards sleeves provide pootle power

il_principe

Skippy2309 wrote:

Arghhh.... whipped the bike out today to give it a good once over, had a tinker fitted the MKS tugs to the rear which make getting everything in place a lot easier.

well when cleaning i decided to check what the actual tooth count was - the print said 48t I counted 44 teeth..... bare in mind I just ordered a 50t chain ring. I am going to get myself a 15t sproket for the rear so i can have something a little less harsh than just the 13t on the rear...

I must say I was surprised but not totally shocked by it, I was disappointed that I was spinning stupidly fast and just breaking 35mph. I am sure I am strong enough to push the 50/13 gearing but 50/15 will be a bit nicer to start out :roll:


Will be starting to commute again soon, got more good news from work should be getting an extra £300 a month which means I can upgrade the parts I want sooner rather than later

50/15 is a pretty heavy gear. I run a 50/16 on 700 rims and that's about perfect for a flat commute, I would want much lower at the back though or pulling away from lights would become a bit of a bore!

lost_in_thought

Il Principe wrote:

Skippy2309 wrote:

Arghhh.... whipped the bike out today to give it a good once over, had a tinker fitted the MKS tugs to the rear which make getting everything in place a lot easier.

well when cleaning i decided to check what the actual tooth count was - the print said 48t I counted 44 teeth..... bare in mind I just ordered a 50t chain ring. I am going to get myself a 15t sproket for the rear so i can have something a little less harsh than just the 13t on the rear...

I must say I was surprised but not totally shocked by it, I was disappointed that I was spinning stupidly fast and just breaking 35mph. I am sure I am strong enough to push the 50/13 gearing but 50/15 will be a bit nicer to start out :roll:


Will be starting to commute again soon, got more good news from work should be getting an extra £300 a month which means I can upgrade the parts I want sooner rather than later

50/15 is a pretty heavy gear. I run a 50/16 on 700 rims and that's about perfect for a flat commute, I would want much lower at the back though or pulling away from lights would become a bit of a bore!

Skippy, maybe you should count the teeth on your sprocket as well just to make sure...

44/13 = 91.4"
50/15 = 90.0"
50/13 = 99.7"

I would also purchase a 14t sprocket - they're not expensive - then you've got an interim gear rather than going for a 10% hike in one hit.

You might find, like I did, that one step up is a step too far - I was on 48/14 (92.6") and tried 46/13 (95.5") and it was just a bit too much, my back started hurting and my acceleration became completely pants. I'm in London, though, home of the traffic light, so good acceleration is needed.

spasypaddy

how quickly do you go through chains?

wgwarburton

lost_in_thought wrote:

Skippy2309 wrote:

... I was spinning stupidly fast and just breaking 35mph. ...

Skippy, maybe you should count the teeth on your sprocket as well just to make sure...

44/13 = 91.4"
50/15 = 90.0"
50/13 = 99.7"

+1

A 91" gear at 35mph is only 130rpm. That's not stupidly fast.
It may (or may not) be sustainable for longer periods but for short sprints or downhills you want to be spinning fast, so that you can get a reasonable cadence at cruising speed.

If you are cruising at 30mph, then fair enough, you may need a higher gear. Don't risk hurting yourself by trying to be macho, though!!

Maybe you should work on your technique, rather than strength?

Cheers,
W.

Canny Jock

So - built up a single speed bike over the weekend, my brother in law kindly gave me his old winter frame, fork and wheels as he's got some new stuff on the way. Not ideal for single speed due to the vertical dropouts, I was hoping to get away without a chain tensioner but in the end had to use one - here's the result:



Just need to tape the handlebars - got some nice black and blue fizik tape to go on.

Running with 48 front and 15 rear, which is 84.4 gear inches according to Sheldon, this seems about right for London - it's pretty light so easy to get going, and gets up to a decent speed on the flat.

I was a little worried I wouldn't like it, as I was riding the Tricross in one gear for a couple days to work out what ratio to go for, but kept wanting to change up. Not sure if it's more efficient running single, or because the bike is lighter, or cos I've got normal tyres instead of Marathon Plus, but really happy with it so far.

asprilla

And here's me happy with myself for moving down to 48/17 from 48/18.

Got to admit I much prefer it though, couple of weeks on this and then I'll move to 48/15. I'm also going to take my WI freehub off this weekend to sell. I've never used it and I can't really see myself doing so so why keep it.

Canny Jock

Asprilla, do you mean a White Industries rear hub, which is eccentric and can be used to tension the chain? If so I may be interested...

Oddjob62

Canny Jock wrote:

Asprilla, do you mean a White Industries rear hub, which is eccentric and can be used to tension the chain? If so I may be interested...

I'm pretty sure from his previous posts that it's just a freewheel.

asprilla

Yeah, it's just a freewheel, not the eccentric one I'm afraid.

biondino

Guys, can you remind me of the cheap, sealed track pedals mentioned a few months ago? That came in many colours?

Also, my chain seems to need re-tighening every couple of weeks, and that's with a (apparently non-slipping) Surly tuggnut on board. Can the chain really be stretching that much?

Which leads to question no. 3. I have a lovely Phil Wood 18t fixed cog, and I've done about 3000 miles on the bike. If I replace the chain, is the cog likely to be hardy enough, or will I have to shell out for a new one of them too?

lost_in_thought

biondino wrote:

Also, my chain seems to need re-tighening every couple of weeks, and that's with a (apparently non-slipping) Surly tuggnut on board. Can the chain really be stretching that much?

No! I would imagine the tuggnut is not as non-slip as it claims...

biondino wrote:

Which leads to question no. 3. I have a lovely Phil Wood 18t fixed cog, and I've done about 3000 miles on the bike. If I replace the chain, is the cog likely to be hardy enough, or will I have to shell out for a new one of them too?

No! It should be fine, unless it's all spiky and bad-looking. Buy a chain checker for £4 and check your chain for stretched-ness... or borrow mine! I still have your knog light...

biondino

Yeah, I checked the chain and it says it's stretched, but as I checked it I had both fingers in my ears and was shouting LA LA LA so it doesn't count. Maybe the chain checker itself has stretched...

I can tell the tuggnut hasn't slipped because the adjuster screw is in the same position. Unless *this* has stretched too. Bloody metal and its inherent malleability.

wgwarburton

biondino wrote:

Yeah, I checked the chain and it says it's stretched, but as I checked it I had both fingers in my ears and was shouting LA LA LA so it doesn't count. Maybe the chain checker itself has stretched...

I can tell the tuggnut hasn't slipped because the adjuster screw is in the same position. Unless *this* has stretched too. Bloody metal and its inherent malleability.

This probably isn't what you are experiencing, but...

When I had this problem last year, it turned out that the root cause was the hub bearings wearing out. The chain would work loose, the bearings would be slack so I'd adjust everything up and all would be fine for a while. I carried on adjusting and re-adjusting whilst racking my brains to try and work out why they kept going slack. Then, one fine morning (actually, that's just a turn of phrase- it was p****** it down) on my way to catch a train to my first day at a new job the bearing shell inside the hub gave way and I ground to a halt. Cue one major "A-ha!" moment coupled with substantial lumps of panic....

Cheers,
W.

_Brun_

My dropouts have grub screws built in and I still have to adjust them every few weeks. My conclusion was stretching chain, although I haven't checked it to make sure.

biondino

Thanks guys. My hubs are also Phil Woods (aren't I posh) so I would hope they're a bit sturdier than that.

Having said that, there is a new level of grindiness somewhere in my drivetrain right now, and I suspect something will have to be replaced. I would have expected the non-sealed track pedals, but it's a very symmetrical grinding and, unless Buns' hub-death is the cause, I think it has to be the BB. Bloody bikes.

Clever Pun

just bought myself a 1/2 link chain is there any recommendations as to which way round it goes or is it just a choice of aesthetics?

Zachariah

If you want to go forwards, it should go clockwise as seen from the right side of the bike. The other way to go backwards.