Vertical dropout single speed without tensioner

[cribbit]

Anyone here done it? Trying to muddle through the maths of chainring/cog size vs chain length to get something exact. Possible?

[unterhausen]

Might be possible. If you're a framebuilder

[Red Tornado]

A friend did it with two different bikes. Standard MTB frames. He called it "magic gearing" it. Gear combo, ratio, etc. you're looking for plus chain stay length all factor in. He found tried finding a gear combo that started out with the chain a tad tighter than you would normally run on a SS, then over time with wear it would stretch to close where he liked it.

[tigoat]

Originally Posted by cribbit

Anyone here done it? Trying to muddle through the maths of chainring/cog size vs chain length to get something exact. Possible?

You mean with a regular dropout for a derailleur? I have done this on many of my bikes. Below is one that I did a few years back. You need to do some calculations to determine a gear ratio/combo and chain length that work for you and your bike.

Here is a website that might help you find the gear and chain length that work:

http://eehouse.org/fixin/formfmu.php

[/URL]

[RFC]

With SS, the half link is your friend.

[mtechnica]

It doesn’t work in the long run because the chain stretches. I had to build a custom chain tensioner for my cross bike because of this.

[fmradio516]

Half link or Eno hub.

[ultraman6970]

When he says vertical he meant short or long ones?? Short ones are pita, it works but you need to get the gearing multiplication right or the chain will be off, you can move the wheel a little bit too, seen it hundreds of times in the track with guys that did not have a track bike. Again the problem is to find the right gearing because at least for racing if you dont get that right you can be in troubles really quick.

There was a guy in ebay that made a set of track drop outs that were bolted in the short road dropouts, great idea but no idea if he is still selling them. always you can make a set if you are handy and have everything on hand.

Another solution is the half link chain, never used one but sure will work.

[SoCalSteve]

Originally Posted by fmradio516

Half link or Eno hub.

ENO Eccentric hub. Solves all your chain length-tension issues. I have one for sale. Black, 130 spacing. Let me know if interested.

[fmradio516]

Originally Posted by SoCalSteve

ENO Eccentric hub. Solves all your chain length-tension issues. I have one for sale. Black, 130 spacing. Let me know if interested.

I have used one of these in the past and not only are they clever, they are AWESOME!

[harlond]

Originally Posted by fmradio516

I have used one of these in the past and not only are they clever, they are AWESOME!

Ditto.

[brewsmith]

I believe Phil and likely others also make an eccentric bb that can do the same

[smead]

No adjustment for chain w/o tensioner simply will not work for anything other than a few runs to the store ... Tensioner w/ vertical drops somewhat defeats the point of riding fixed. Adjustable BBs or rear hubs can work. But your best bet is a frame w/ horz dropouts.

[Jere]

Originally Posted by smead

No adjustment for chain w/o tensioner simply will not work for anything other than a few runs to the store ... Tensioner w/ vertical drops somewhat defeats the point of riding fixed. Adjustable BBs or rear hubs can work. But your best bet is a frame w/ horz dropouts.

That’s exactly what I would say , also nobody said anything about chain ring
Ailment ????
After 30 years of fix gear ridding every winter , hill repeats and indoor rollers.
Just one time having the chain derailed at 36 mph 180 RPM will want you to
everything put together right.
Just one Grumpy Old Man opinion
Jere B

[SoCalSteve]

Originally Posted by smead

No adjustment for chain w/o tensioner simply will not work for anything other than a few runs to the store ... Tensioner w/ vertical drops somewhat defeats the point of riding fixed. Adjustable BBs or rear hubs can work. But your best bet is a frame w/ horz dropouts.

Can and does work. I have ridden way past many stores ( and many thousands of miles ) on bikes that have vertical dropouts and the Eno eccentric hub. It’s a pretty ingenious device.