Single Speed questions!

lvquestpaddler

Hi folks- I have a 2004 GT Avalanche framed experiment which is to be a fitness/trainer bike. It's a mish-mash of bits and I'm planning to SS it.
I found a website to see how to calculate a "magic gear" and if it was suitable for this as a seller of a frame I'd monitored on ebay said it would run 32/16(cos his hanger was bust).
The website is:
http://www.eehouse.org/fixin/formfmu.php
I manually measured the chainstays then googled it and found that the stays are 420mm.
Entering sprocket/chainring sizes around the 18/14:36/32 it comes out with the optimum being a 36/15 (2.25:1?) I can't see the bike being used properly off road so this may be ok given my level of fitness. But the 32/16 comes in at 418mm on chainstay length- would this still fit if all parts were new?
I don't want a tensioner setup, but with vertical dropouts don't want a chain that lasts no time and can't be readjusted.
What if I got a Haro 15T cog(Velosolo site says it's 3/32" but works fine with 1/8"), a spacer kit and lockring plus a 36T in 1/8 and a 1/8th chain? They do a good heavy duty one that comes in half link lengths too looks weird but probably robust.
Oh- are 1/8th chains those for 7/8speed?

nicklouse

36/15 is a bit big.

as to if what will fit etc I will not comment as i have not measure the bikes and i dont know if the info you have provided is correct.

new parts are tighter not slacker.



1/8 is SS

I run 32/15 on my SS MTB witha half link chain.

redvee

I had a GT with 420mm stays and ran 46/16 but stayed on road with it.

lvquestpaddler

Cheers Nick- the site gives a vertical line after inputing dimensions etc- the 32/16 comes in tight so presumably there would be no slack in the chain whatsoever from new(not good for any of the drivetrain or bearings?). The 32/15 you use comes in at the other side so would hopefully allow some slack in the chain.
The Velosolo site is curious in that you can get chain/chainrings dedicated to 1/8" but I can't seem to see any cogs/sprockets that are 1/8" specific- all seem to say 3/32" but will be ok with 1/8"?

nicklouse

yep they will be fine. you can always use a narrower cog.

lvquestpaddler

Redvee's post is pretty helpful- going by that data the 32/15 is definirely ok it's slightly less than the 46/16 length. More importantly the 32/15 seems to be the same size as the 34/17 to stay on a 2:1 ratio.
If I opted for this and got a heavy duty chain such as the Onza(KMC) K710 in 1/8" with a 1300kg load capacity and a 1/8" steel chainring(can't seem to find any in stainless?) would it be ok? Is it a case with SS of monitoring chain wear and replacing before sprocket/chainring wear occurs.
My other option is to stick with 3/32" chain, 32T chainring and add a simple tensioner? If I did this could I have enough slack on the chain to alternate with a 16/18 and could the tensioner safely take up the slack on the 16T?

Sorry for sounding a bit flummoxed, just don't want a costly mistake!
The second option could probably be done cheaper so maybe the best route into SS just in case I hate it!!!

lvquestpaddler

Easily came to a decision after going out on my steel rigid leaving it in 32/16. Hate it. Just seems like something that would have been braw in the 19th Century.
So just bought an 11-28t 7 speed cassette(£11 plus spacer £3, delivered), Acera rear derailleur(£8 CRC delivered, Revoshift(yuck but it's a trainer bike) 7 spd shifter £7.30 delivered. Combining it all with a 36t front ring to give better gears for the road where a lot of the time will be spent anyway....
Thanks for all the advice but I doubt SS will ever be for me :P