Singlespeed & Fixed Gear - Horiz. road dropouts: Min. safe insertion?

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caloso
02-24-06, 11:56 AM
Brand new fixer here and I hope this hasn't been covered a million times. (The search function didn't pull up any threads on this.)

I've converted an old Trek 660 into a fixed gear commuter/run-around bike. I chose 42/15 because that's the gear I found myself riding around town in most often, and it made things really simple by using the existing inner chainring.

I got really lucky with chain line. It was absolutely dead straight.

But chain tension was another issue. Pulled all the way to the back of the dropouts, I had a good 3/4 in of droop. Maybe not enough to throw a chain, but enough that there was a noticeable jerk when starting or stopping. After all that I've read here, on FGG.com, and on Sheldon's site, it seems that a nice tight chain is very important.

So I took out a link, and it just barely fits in the dropout: See the pics below.


http://i2.photobucket.com/albums/y18/CalOso/Picture037.jpg
http://i2.photobucket.com/albums/y18/CalOso/Picture035.jpg
http://i2.photobucket.com/albums/y18/CalOso/Picture034.jpg

These seem like good quality steel nuts on a steel dropout so I've cranked them down pretty hard. So the question is:

Does this look unsafe?


onetwentyeight
02-24-06, 12:04 PM
Try adding a halflink.

ponchotempest
02-24-06, 12:05 PM
Get a half-link for your chain

Edit: too slow


dolface
02-24-06, 12:07 PM
did you back the dropout adjusters all the way out? in the pictures it looks like you still have about 1/2" left in the dropout.

onetwentyeight
02-24-06, 12:10 PM
I think the problem is his chain is too short and wont go back any further, but when he added a whole link he couldnt pull it back far enough to give it the right tension... correct me if im wrong.

Offhoff
02-24-06, 12:10 PM
I own exactly the same bike, you need a halflink for a perfect chain at 42/15, but the frame is lugged and you can get a framebuilder to put track ends on if you want.

caloso
02-24-06, 12:12 PM
did you back the dropout adjusters all the way out? in the pictures it looks like you still have about 1/2" left in the dropout.

Yep. In fact, I took them all the way out. It's funny, I measured it and found that I had just about 1/2". Which should equal 1 link, which should fit perfectly, but it didn't.

Well, I'm off to the LBS to get a half-link. I don't know why I didn't think of that sooner.

caloso
02-24-06, 12:17 PM
I own exactly the same bike, you need a halflink for a perfect chain at 42/15, but the frame is lugged and you can get a framebuilder to put track ends on if you want.

Offhoff, have you tried any other combinations? I suppose I could go with a 14-tooth cog instead of the half-link. I think I read somewhere (Sheldon Brown?) that even-even is more efficient.

Cynikal
02-24-06, 12:19 PM
Welcome to the world of fixed. I faily sure that College Cycles has half links. If not check with Bike Chef on J. They are a few of us in Sac who are doing a fixed group ride. PM me if you want to come out and play.

Offhoff
02-24-06, 12:19 PM
Nah I used it at 42/15 for the summer when i first got it and put it together and then got trackends put on it over the winter, you can see the trackends in the wicked cool dropouts thread I made. If your serious about fixed I'd really sugget putting longer horizontal drops or true track ends on it will make it a whole lot easier to find a comfortable combo.

caloso
02-24-06, 12:23 PM
Welcome to the world of fixed. I faily sure that College Cycles has half links. If not check with Bike Chef on J. They are a few of us in Sac who are doing a fixed group ride. PM me if you want to come out and play.

Thanks. I'm going to head over to Bicycle Chef or City at lunch.

Sheldon Brown
02-24-06, 02:28 PM
I've converted an old Trek 660 into a fixed gear commuter/run-around bike. I chose 42/15 because that's the gear I found myself riding around town in most often, and it made things really simple by using the existing inner chainring.

But chain tension was another issue. Pulled all the way to the back of the dropouts, I had a good 3/4 in of droop. Maybe not enough to throw a chain, but enough that there was a noticeable jerk when starting or stopping. After all that I've read here, on FGG.com, and on Sheldon's site, it seems that a nice tight chain is very important.

Did you remove the adjuster screws? If you didn't do so. This will give you more room to move the axle back. Those adjusters are a useless hindrance for a fixed-gear or singlespeed. They're only of use with derailer gears.

The advice to use a half link is also good advice, but you may not need that once you remove the adjuster screws.


So I took out a link, and it just barely fits in the dropout: See the pics...

These seem like good quality steel nuts on a steel dropout so I've cranked them down pretty hard. So the question is:

Does this look unsafe?

Borderline. Fortunately, it will get better as the chain wears in.

Those are not "good quality" nuts, they're dog poop! Get proper track nuts with captive washers. Failing that, at least use separate washers, or, better yet, install a hollow axle and a good quick release skewer.

Those serrated nuts suck big time. You should never have a nut tighen up by turning directly against a stationary part without some sort of washer in between.

The advice to use a half link is also good advice, but you may not need that once you remove the adjuster screws.

Sheldon "Track Nuts" Brown
+-------------------------------------+
| Natural laws have no pity. |
| --Robert A. Heinlein |
+-------------------------------------+

Matthew A Brown
02-24-06, 02:47 PM
Those are not "good quality" nuts, they're dog poop!



BWAHAHAHA

caloso
02-24-06, 02:58 PM
Well, I can't be seen riding around town with dog poop nuts, I've got my pride. I'll get some decent track nuts and a half-link at College Cyclery on the way home then.

(Strangely enough, the two midtown shops told me there was no such thing as a half-link. But the Harris Cyclery website begs to differ.)

Cynikal
02-24-06, 03:11 PM
You also might stop by Rex's shop. I know he has good track nuts cuz thats where I got mine.

lemurhouse
02-24-06, 03:13 PM
I've got the exact same 660 frame, am running the exact same 42 X 15 gearing, and have (had) the exact same problem. The dropouts aren't long enough to provide enough fore/aft adjustment w/certain gear combos. I went with the half-link, and its been fine. Seems a little noisy tho.

edit: ps. I removed the adjusters.

Cynikal
02-24-06, 03:15 PM
Also keep in mind that a half link may be only available in 1/8th. You may want to think about getting a new gearing combo.

caloso
02-24-06, 03:21 PM
Where did I get this bizarre idea that fixed gear was going to simplify my cycling experience?

Cynikal
02-24-06, 03:24 PM
Cmon...don't you enjoy puzzles? ;) If you need to experiment with various chain rings I have a bunch. I'm in the Land Park area.

caloso
02-26-06, 10:31 PM
Well, I just decided to go with a 16 tooth cog and the tension is perfect.

jacobpriest
02-26-06, 10:42 PM
someone was talking about getting someone to put trackends on it. how much would that run, minus the trackends?

kludge
02-26-06, 11:01 PM
im on a trek 760 conversion(old treks have the sickest seat clusters!) and i had the SAME EXACT issue. i just ended up moving up to 1/8th chain and the problem went away instantly. now i have tight chain and a nicer chain line. 44/17(imma weenie)

humancongereel
02-27-06, 02:12 AM
someone was talking about getting someone to put trackends on it. how much would that run, minus the trackends?

ummmm...the way you phrased it....free, i guess?

jacobpriest
02-27-06, 02:24 AM
i mean to get them installed. meaning not the price of trackends themselves...but getting them brazed on

humancongereel
02-27-06, 02:47 AM
ah. okay. so labor cost alone?

jacobpriest
02-27-06, 03:03 AM
yes