I have a trusted old hybrid not shifting well. Rather than spending a few bucks on new grip shifters that repeatedly break I'm thinking of converting this one to a single speed. I have a new 17 tooth freewheel and chains, but I've got vertical drops. Don't really want to by a chain tensioner so the question is:

Can you accomodate the lack of travel with vertical drops simply by adjusting the chain length and/or using a half link?

Not real concerned about looks, this one is kind of a beater that stays on the porch and follows my kids to school each day.

Thanks for any advice.

You should be able to get a decent chain tension by adjusting the chain length. If it's still not enough i think adding or subtracting chain link moves the axle 1/2" either way. You could also go with a smaller tooth freewheel or bigger chain ring.

It's all trial and error with vertical drops.

since you mentioned the word beater, i assume you aren't interested in investing the money for an ENO hub, but that would be the most effective way for vertical drops.

You would probably be better off with a Singleator-type tensioner. But below is a calculator for the "magic gear" based on your chainstay length, and obviously a half-link gives you more usuable ratios to choose from.

https://www.eehouse.org/fixin/formfmu.php

If it is a "beater" a little creative filing could give you a little extra wiggle room for tensioning.

If it's not about looks, then why not a tensioner?

You basically have 4 choices.

1) You can buy a Horizontal Dropout and have a local metal shop cut and weld it into your frame. Prob cost you $30 (surly) plus labor.
2) You can buy an eccentric hub. (White industies makes them $130 plus labor and $$ of building a wheel)
3) Chain tensioner ($varies) Surly Singulator about $50. This is probably hte simplest install.
4) adjusting chain length (using half links to get closest) This is cheapest option but you'll have to get lucky to get an exact fit.
good luck.

go with one of these

I see you're in Santa Monica. If you need help in person then you should give the Bikerowave a visit.

https://www.bikerowave.org/

You'll be able to get your chain within 1/4" of the right length that way.
If your chainline is straight that should work fine.

If you have older style quick release skewers, you can cut down the axle to your dropout width, givign you a little wiggle room. Check it out on Sheldon Brown.

GHOOOOOST RIIIIIING o.O

You already have a derailleur, so why do you need a tensioner? Just adjust the derailleur to hold the chain where you want it. A chain tensioner is nothing more than a derailleur that doesn't shift gears.

I was thinking of buying This :https://www.amazon.com/Dimension-Chai...7138480&sr=8-2 but I think I might get lucky with a half-link so I'm waiting.

This is essentially what I was doing with my singulator. The singulator and all those simpler type tensioners will either allow too much chain slippage when power is really applied or downright snap at the spring.

I actually reversed mine to push the chain up and then have it held by bands, but they have to be replaced every few weeks as they stretch out. Very ghetto for the whole singulator + cog costs about 70 dollars.

Yes, I have rear derailleurs (Tiagra/105/Ultegra), but I've shamed the bike gods enough with converting a Caad9 so I'll let that go....

Anyways... I found that tensioner, (which seems extremely sturdy) via here: https://spicercycles.com/online-catal...oners-t806.htm Which has some interesting options I never knew about... just so happens Amazon sells it cheaper.

I also was thinking of the eccentric hub, but I like having the option of swapping out wheels on a whim.

half link baby.

I successfully converted my Caad9 to a single speed. I now run a 50/14 with the inclusion of a half-link, but it fits PERFECTLY!

that must be really fast in the given scenario

Well, a derailleur cage has 2 pulleys and an SS tensioner only has one. It will still work, but will require more chain and will create a little bit more drag. But, I agree that this is the cheapest way to go if you don't care about looks, and it doesn't require any cutting and grinding.

Seems a single speed on a Caad9 is a cardinal sin, but for my ride its fine... no real hills and its freewheel, but yeah, avg cadence is 90-100 and i go about 25-26, but when the energy is in and I don't have wind pushing against my body... a solid 30-31 for a few miles, but then my heart rate jumps to 180+

I did the conversion because I found out for 3 months I not once changed my gears. I figured if my drive-train was to go unused then I might as well protect them from the elements completely and retain their resale value.