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Singlespeed & Fixed Gear "I still feel that variable gears are only for people over forty-five. Isn't it better to triumph by the strength of your muscles than by the artifice of a derailer? We are getting soft...As for me, give me a fixed gear!"-- Henri Desgrange (31 January 1865 - 16 August 1940)

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Old 04-26-14, 09:14 PM   #1
overbyte
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Exploring Portland and Eugene, Oregon, on a single-speed. How many gear-inches?

I'm hoping someone with experience riding in Portland and Eugene can help me on this.

I'm planning to take a trip by bus and Amtrak train to Portland and Eugene, Oregon, in July this year. I want to explore these 2 cities, have some fun, and photograph their bike infrastructure to make a video to educate my home city and county about the things Portand especially has done to make it a safe, convenient place to ride a bike for fun and transportation. I'm going to take a side trip from Eugene out to the Oregon Country Fair, too. I want to take one of my folding bikes along, since it's easier to take a small folder than a full-size bike on Amtrak, for reasons explained in other threads.

My question is about the smallest bike I could take, which has 46 gear inches, single speed, freewheel, not a fixie. I'm not familiar with the topography of these 2 cities and the route from Eugene westward to Veneta where the Fair will be located. I know I can sit on the little bike going up a grade of 3% or less. At a cadence of 60 rpm, I travel 8 mph; at 90 rpm, 12 mph. Will I have trouble getting around on 2 wheels with this little bike? Should I bring my 16-speed folding bike which has great gear range?

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Old 04-26-14, 11:08 PM   #2
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46 gi for the road sounds very unpleasant. I ride fixed on 48x19 ( 68gi ) and 48x 17 (76gi) around Portland without any major issues, unless you plan on going up vista drive, there aren't any noticeable hills with any length to them. Hawthorne has a small steady 3-4% grade going up most of it, Alberta is flat, mississipi is another 3% grade, downtown is either up or down but very small grades.

I have a video of my commute in the today I thread and if you want to go look at that, should be on the last page or two. I also go down one of the bigger eastside hills around the 7 minute mark if I remember right.

Enjoy your trip to Portland, make sure to enjoy all of our cheap beer and food while here.
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Old 04-26-14, 11:51 PM   #3
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My question is about the smallest bike I could take, which has 46 gear inches, single speed, freewheel, not a fixie.
What do you use this bike for now? That's very low gearing, are you sure you've calculated it properly? Can you fit a smaller freewheel or larger chainring (to increase the gearing)?

From what Huffandstuff says though, if you enjoy that bike around town now, take it.
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Old 04-27-14, 02:12 AM   #4
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Enjoy your trip to Portland, make sure to enjoy all of our cheap beer and food while here.
And strippers.

I'm just saying...
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Old 04-27-14, 09:35 AM   #5
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What do you use this bike for now? That's very low gearing, are you sure you've calculated it properly? Can you fit a smaller freewheel or larger chainring (to increase the gearing)?

From what Huffandstuff says though, if you enjoy that bike around town now, take it.
I've only had this bike for about a month now. I've been testing it out around Santa Cruz, California, where I live. I've ridden it about 25 miles so far. Riding it along the coastal multi-use trail (Westcliff Drive) among pedestrians and roller bladers and dog walkers, and through downtown, the speed is perfect. It's a good speed for casual, looking-around, tourist riding. If I were a commuter, I'd be crazy to rely on this bike for a long distance, but I've gone 5 miles around town without feeling I'm too slow for riding in the class 2 bike lanes along city streets. It's ok for getting to the bus and getting to destination after getting off the bus.

The main attraction of this bike is that it can fold up very small, smaller than a Brompton 16" folding bike, smaller than a Dahon Jifo 16. Here's a video showing the folded size and unfolding action:
and casually riding at low cadence it in China:
[video]http://s1095.photobucket.com/user/gydha88/media/001-1.mp4.html[/ame]

Here's a picture of the bike plus my helmet and gloves inside of a 25"x12"x13" rolling duffle bag, folded, with no disassembly required:
So, you can see that it's an easy-to-take-along bike, meeting the size requirements for Amtrak carry-on luggage and airline checked-in luggage. Amtrak only allows 2 carry-ons, including a folding bike if you bring one, but they're allowed on any train even when there's no checked-baggage service. I can also take it inside a bus even when the front bike carriers are fully occupied. I was more concerned about getting up hills than riding fast enough on Flatlandia.

I've gone over my calculations in several ways. The wheels are 12" diameter nominally, but Sheldon Brown's gear calculator doesn't go that small, so I did the calculations with his "slide rule" method and using a different online calculator. If I use the actual loaded diameter of 11.5", I get about 46". Using the online calculator with 12" wheel selected, I get 48". The chainring is 40T; the jackshaft sprocket for the chain is 10T; the belt drive from jackshaft to rear hub is a 1:1 (equal size belt sprockets) so it can be ignored. The chainring is a 1-piece with the crank arm, not bolted on. The jackshaft sprocket is welded to a nut that screws on, so it's non-standard. The belt-drive sprockets are custom for this bike, all made in China. I've been trying to find a way to change the gearing or install an IGH, but the unique size of the bike parts makes that a difficult modification, so I'm probably going to live with it as-is other than adding a taller seatpost and perhaps changing the handlebar. Here's a thread with extensive discussion and photos: Who else wants one of these?
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Old 04-27-14, 10:57 PM   #6
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A few thoughts. I took my Vaya to Portland this past February for the Worst Day of the Year Ride (cancelled, ironically, due to weather). When I went back earlier this month, I just rented for the ride days.

Either way, as cools as I think folding bikes are, Portland might be the one place where they aren't really needed. The MAX (light rail) and streetcars allow bikes on board -- with dedicated bike spaces -- and the buses have bike racks on front. The Amtrak Cascades between PDX and Eugene (and Seattle in the other direction) have dedicated bike baggage cars (that don't require breaking the bike down) for an extra $5 per bike.

Speaking of MAX and the streetcars, I don't think gear inches will be the problem (unless you ride up into the West Hills), but I'd be a bit concerned about the recessed train tracks in the close-in areas (SW and parts of SE) on a bike with 12" diameter wheels. They seem to have invented their own streetsign to warn bicyclists, if you haven't seen it:

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Old 04-27-14, 11:51 PM   #7
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... Either way, as cools as I think folding bikes are, Portland might be the one place where they aren't really needed. The MAX (light rail) and streetcars allow bikes on board -- with dedicated bike spaces -- and the buses have bike racks on front. The Amtrak Cascades between PDX and Eugene (and Seattle in the other direction) have dedicated bike baggage cars (that don't require breaking the bike down) for an extra $5 per bike.

Speaking of MAX and the streetcars, I don't think gear inches will be the problem (unless you ride up into the West Hills), but I'd be a bit concerned about the recessed train tracks in the close-in areas (SW and parts of SE) on a bike with 12" diameter wheels.
John,

I'd like to take the bike along more as a proof of utility than as a necessity, not just for this trip but for trips I may take to areas that are not so accommodating to bikes. But, on the point about bike racks on buses, I've often wondered, what happens if the 2 or 3 slots on the bike rack are full and you are waiting to board the bus with your bike? I don't suppose the driver will allow a full-size bike into the bus, so you'd have to wait for the next bus. As a tourist, that's not usually a problem (unless maybe it's raining, and you're standing at an uncovered bus stop, and the bus is running on a weekend/holiday schedule where they come only once per hour, and you're trying to get to a theater before the performance starts, or something like that). But if someone is trying to get to work or to a class on time, that would be inconvenient unless the buses are coming every 10 minutes or less at that time of day. Here's another example: Looking at the "Wave" bus from Portland to Tillamook, I see that it runs westbound only twice a day, and it has a capacity of 2 bikes on the rack, so if you're the 3rd bike trying to leave Portland's Greyhound station at 10:40am, you'd have to wait until 3:20pm; but if you have a small folding bike that can fit in the bus's luggage compartment, no problem; you board and get to the coast on time.

But many bus systems now do allow a folded bike on board. Some require that the bike be covered so no one gets greasy. This little bike is small enough and light enough that you could put it on your lap if you had to for a short bus ride (i.e, not for hours but for more than a few minutes). Amtrak does not have baggage service at all stations, so some people with bikes may have to go beyond their destination just to get off with the bike. Planning ahead is important. But Amtrak allows folding bikes on all trains, if the bike meets the size limits for folding bikes, as one of the 2 allowed carry-ons which you can take on and off with you at any station. I know that's not an issue at PDX nor at EUG stations, but on other trips it may be. Here's the Amtrak bicycle policy and fees: Amtrak - Plan - Onboard - Bring Your Bicycle Onboard. It says that on trains where there are bicycle racks onboard, there's a $5 fee to walk your bike on if there is an available slot in the rack. If the racks are full, you can't board with the bike, but you may be able to check it as baggage. At stations where there is baggage service, the fee is $10 to check the bike but it must be in a bike box, which Amtrak can sell you for $15. On the other hand, there's no charge for a folding bike:
Quote:
  • Folding bicycles under the dimensions of 34" x 15" x 48"/860 x 380 x 1120 mm will be allowed onboard all trains in lieu of a piece of baggage.
Thanks for the info that grade % and gear inches will not be a problem, except for the western hills, where I don't intend to go on this trip nor with this bike. And I'm familiar with the hazards of train rails embedded in street pavements -- we have some where I live. I always do the necessary wiggle to cross the tracks as close to perpendicularly as I can. Even though the wheels are small diameter, they're 1.75" wide, so they don't necessarily get stuck in narrow grooves more easily than a large narrow tire like a 700c in common widths. Some 12" wheels (nominally 12-1/2") come as wide as 2.25".

That's a great warning sign. I'm going to show it to our city bike coordinator (if I can find such a person). There are places where a sign like that would be a good idea. There was one place where a cyclist fell due to front wheel getting stuck in a rail, and the city was sued, so the public works department re-striped the bike lane to make an S-curve so the cyclists are guided to cross at right angles, and they put arrows on the pavement and a "Bike Lane" sign next to it. However, other crossings have no warnings even where the tracks are not perpendicular to the direction of travel on the road. That sign might help prevent an accidental fall or at least get the city off the hook if someone does fall and sues.

I was pretty confident that the gear-inches would not be a problem for the grades in metropolitan Portland since so many single-speed and fixies are in use there and they usually have about 70 to 80 gear inches, but I just wanted to check before I got there and found that I had to push and walk too many places.

Last edited by overbyte; 04-28-14 at 08:20 AM.
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Old 04-28-14, 12:11 AM   #8
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I've always wanted one of those street signs but I've been too lazy to "acquire" one. I've only crashed once from them but that was all due to negligence on my end.
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