Building a Single Speed
 

I'm building up a single speed with a steel colnago master light.
I have never ridden a single speed or a fixie and would like some gearing advice.
I have a campy crankset 53/39 and was either going to:

A) use the 39 in the front or
B) go to a 42 in the front.

My concern is gearing in the back. What would be recommended for rolling to hilly roads of upstate NY.
I was thinking 39/17. It would be hard on steep climbs but manageable on the long sustained climbs of 5-7%. I climb OK and want to use it to make me stronger. 5'9'' 155lbs.

I have a set of Mavic OP that I would like to convert to a singlespeed. Any recommendations or suggestions would be appreciated.

Thanks.

I'm thinking 39/15. Maybe a 16 on the flip.

39/17 is a pretty light gearing - but I also live in a flat country ;-)
If you go lighter, I think you'll get sick of going slow pretty soon.
Good luck with the build - I don't see a problem with the Mavic OP set, but I'm no guru...

I run a 42x16 on a couple of mine but Sacramento is very flat. I would say it's a good place to start. Lukily BMX freewheels are cheap. Most folks here (including myself) will tell you to experiment and find what works best for your riding style. Then again, most of us enjoy tinkering almost as much as riding.

any minute now...

Do you have a geared bike? Try not shifting it for a couple of rides. When you find a gear you like, use it.

39/17 may be too easy, if you are a decent climber - also you are not heavy. Also you will spin your legs off down-hill. I started out with 40/16, which still is very easy, and went to 44/16 or and recently to 44/15.

I'd second 39/16 or even 15

This may not be the best measure because of the added resistance of the derailers. I tried this years ago and wound up with a gear that was too easy.

I see this sort of question asked a lot, around here. Most of the time, the one who asks, isn't aware of one of the most important factors in deciding the gear ratio for their FG/SS: their cadence. So, what is your cadence on flat road, no wind?

Another factor often forgotten is wheelsize. Obviously, with a smaller wheel+tire, the gear inch number will be lesser, than with a larger wheel+tire. So if a gearing is OK for 26" with thin tires, it's not going to work quite the same for 29ers.

That's why gear inches, which take into consideration the wheel diameter as well, is a more useful figure.

For the record, I am a wuss and hence ride around 60 gear inches (it's slightly less, even). But, if I need to go fast, I can rely on a cadence of about 110 rpm.

When I first went fixed I started with 39/15. That was fine for a while, but eventually I went to 42/15. Mechanically its only a slight difference, but very noticeable if you ride the same hills over and over.

One other suggestion...if and when you plan on getting a singlespeed/fixed specific hub (rather than using a converted road hub, which is also fine for a singlespeed), I would suggest going with one that is threaded for a fixed gear (one that has the usual threads, plus reverse threads for the lockring). You can use a freewheel with that type of hub, but if you decide to go fixed, you will have that option without having to change hubs.

The guy is building a singlespeed, not a fixie.

any minute now what?

To the OP - I had a hard time finding a good street SS gear after bringing my SS MTB to Chicago many moons ago. On the street, I have ridden 48x16, 42x16, and 36x16.

so far, the 42x16 SS gearing is fine on the street. the 36x16 is a bit light for being so flat out here.

Thanks, all good things to consider.
Tires will be 700 X 23 because I have lots floating around.
I'll be building it up in the future so I'll monitor cadence. I used to be a masher but I am trying to find a medium between spinning fast and mashing...locating the sweet spot.

Thanks again for all the responses.

Yup...I tried this too (riding a geared bike and not shifting) and wound up picking a gear ratio that is too easy..fortunately I realized this before I actually got my first singlespeed. The trouble is with trying this is that you tend to think about what gear is best for climbing, forgetting that most of the time you will be spinning on a nearly level surface. The temptation to shift throws your judgement off you end up picking a gear thats lower than you'd really want if you were actually stuck with one gear.

good call - I, too, am trying to rebalance mashing and spinning. There is nothing like a good spin...nothing.

i found out that if i can't feel fast, at least i can feel smooth. i fairly flew down lexington avenue on my commute this morning, quicker than ever before, for some reason.

I'm building up my old Litespeed Classic frame with semi-horizontal dropouts as a singlespeed. I'll probably be running a 42 up front. My wheelset is an old set of Campy freehub bodied Spinergy Rev-X's. I'm thinking of using 2 or 3 cogs on the freehub body for quick gear ratio changes. Hopefully the dropouts can handle maybe up to a 6 tooth difference.....we'll see....
I'm going with with moustache or drops, and both front and rear brakes. This bike should weigh almost next to nothing....:D

i am happy to see that many people are posting helpful responses - i thought for sure there would be some forum members who would immediately jump on the op for converting a colnago - hasn't that been a hot topic in some previous threads?

This program helped me a lot in determining which gears to use. I highly recommend it.
http://www.machinehead-software.co.u...alculator.html

This place is slowly getting back to the great fixed/ss sub-forum it once used to be......:D

Very slowly http://www.bikeforums.net/showthread.php?t=256582

I'm mostly a road cyclist and have been riding a converted road ss for about ten years for commuting, errands, etc. First, I'm glad to see others doing this - although I just got a fixie too, It seems like no one rides road ss bikes around here:(

I'd say stick your 39 on the front and buy a range of BMX cogs (15, 16, 17 or something like that - this would probably necessitate a shimano freehub body, but it might be worth converting if you have campy because cogs from a cassette make loosing your chain very easy even with good tension) - they are cheap - and a spacer kit or conversion kit form some place like Rennen Design (they have a really nice two piece spacer that telescopes to allow an exact chainline adjustment) to convert your freehub body - and try your best guess first and just change sprockets as you get a better idea - did this about ten years ago and it worked itself out pretty fast. (seems like lots of people end up around 70 inches in a wide range of terrain, which would put you at about 39 x 15). Some will say that BMX cogs damage your freehub body, but I have been beating the hell out of mine for years with no problems.

True, but it will give you a good starting point. It can't be any less useful than asking a bunch of strangers on the internet. Maybe a better idea is to figure out a ratio that works on a geared bike, then add a tooth or 2 in the front, or lose a tooth in the back.

I'm running 42x17 in hilly Seattle. Works great. 39x16 is pretty much identical gear inch-wise.

Haha

go fixie!
oh yeah and 39/17 should be about right- if you are a singlespeed you can run pretty light gearing and get around fine, as you are able to coast downhill.

+1...I had been riding 42/18 on 700c's for awhile and tend to run out of gear too easily on the flats. Just switched today back to a 16t and it felt like too much gear at first but once up to cruising speed it was good. Hills were'nt too tough as well. Just buy some cogs as mentioned, they're cheap

Since my question is very similar to the OP's I'll just add to the thread instead of starting a new one;

My mother is a huge estate sale fanatic, and one saturday came home with a late '80s (I'm guessing here) Motobecane Mirage. Other than the obvious lack of maintenance the bike is in perfect condition and I'd like to turn it into a SS commuter. I'll start grad school in August and the campus is less than 3 miles from my house so I'm going to try commuting to and from school and I'd rather not ride my race bike.

My goal here is to build a bike that is simple, rock-solid reliable, tough, and easy to work on (i.e. say I wanted to change the rear cog, it'd have to be something a "shade-tree" bike mechanic could do) that I can commute with, run errands on, and ride some local Rails-to-Trails trails (I'm near the Katy Trail).

Now onto my questions:

1. Can I just simply pop off whatever chain-ring I don't want on the crank? Is there anything else that I'll need to do? Also, I've never ridden this bike and I have no idea what condition the BB is in. Is replacing the BB generally something you do when converting an old roadie to a single-speed?

2. What needs to be done to the cassette to complete the conversion? I'm assuming that I can't simply pop off the cogs I don't want and just leave the gear I do want. Am I going to be looking at purchasing a new hub?

3. While this bike will primarily see road action, I'd like to be able to comfortably ride on the crushed-limestone trails in my area (Katy Trail) with my girlfriend, so I'm thinking I'd need something bigger than the 700x23 tires on my Lemond. Suggestions?

4. And finally the quintessential question: While I am mechanically inclined, I lack the tools and experience working on bikes to feel comfortable riding on a conversion I do in my own garage with the help of my friends (who say they do know what they are doing, but aren't exactly bike mechanics). Should I trust this job to my LBS?

I'd like to stay within a budget of $150, but don't have a problem spending money where it needs to be spent to ensure the longevity of the finished product.

I'm anxiously awaiting replies because I can't wait to get this conversion completed so I can sport my SS with pride!!

1. you'll need shorter bolts probably
2. It's probably a freewheel not a cassette hub
-take off the freewheel
-put on appropriate ss freewheel
-respace the the axle to get correct chainline
-redish the wheel
3. not really you don't want cx tread for riding around town but you probably want 32s at least for the trail
4. You can probably do it all yourself especially if you just buy a new ss wheelset($130) If you do take it to a shop ask around and find out what shops do conversions frequently.

I hadn't thought of that.