Fixed gear with vertical dropouts help?

[Sharpy]

Hi all,
In light of recent events I've been restricted from riding a bike for six weeks (damn cast!). Therefore to keep me busy I've got a few projects I would like to start.. No.1 is a frame swap from aluminium to carbon on my road bike which will be pretty straight forward I think.
No.2 will be a result of no.1, I'll have an aluminium road frame spare... I've decided I would like to make it into a fixie but unfortunately there's several hurdles I need to jump. The first being the bike has vertical dropouts, I've looked at both eccentric hubs and bottom brackets but to be honest they are really expensive so does anybody have any other products/techniques they have used, any feedback would be appreciated.
Hurdle no.2 is I don't know how long the bottom bracket should be, is there a way of measuring this or is it trail and error?
Regards
Andrew

 

[HLaB]

I think you can buy chain tensioners to take out any slack.

 

[Sharpy]

I think you can buy chain tensioners to take out any slack.

I've been reading up on this and apparently they're are not ideal? But cheers for the thought though

 

[mcshroom]

Not much in the way of options with what you have. If you are lucky you may get a magic-ratio where the tension is right, or if you are happy with singlespeed then a tensioner would work. Sprung tensioners do not work on fixed.

 

[Canrider]

#1 with what you've said you'll just have to chase a magic ratio that keeps the chain sufficiently tight

#2, you should be able to measure the spindle length with a ruler/tape across the spindle even while it's installed on the bike. You'll get close enough to know what size you need, at least. If you mean chainline, again a solid ruler or tape measure across the chainrings should get you close enough to know where you need the cog/freewheel to sit at the back.

 

[Sharky]

You can get half links that may get you to that "magic ratio" .

On the bottom bracket question. I had a similar problem. Bought one, but had problems getting the old bearings off, so took it to the lbs. it turned out I'd bought the wrong length, so they fitted a new one. All for about £30. So might be worth going straight to the lbs and then they will put the right one in.

Cheers keith