Can a half link chain help find a magic gear vertical drop out bike

Yeah... cheers... That's so new, not like it's been posted in here before and we weren't talking about it...

That eehouse.org tells you what else should work doesn't it??

If 52X17 works then so will 48X13, 50X15, 37X13, 39X15, 41X17, 43X19.

Maybe ph1 reposted as you didn't seem to see it the first time :-)

I don't think you understand. 52x17 doesn't work, it's slack as fuck. However, I don't understand how to use the calculator to work out what ratio I should try to eliminate the slack.

Whoops, sorry. You're right, I didn't understand but that's maybe because you went from a bit of slack 1 day ago to slack as fuck today. The main problem with magic gears, those chains stretch overnight :-)

Just leave all the numbers as there are apart from the chainstay length where you put in you bb - axle measurement.
Or just leave all numbers as they are and any to the left of 52X17 would make the chain tighter. Closest being 40X14 with a slightly lower gearing.

Hey, does anyone know if you can have multiple "magic gears"? I know that 32-19 works (with a half link) but i can't get hold of a 19t freewheel.
Is it likely that there is another ratio that will work?
(Oh also i cant get the calculator to work, so i can't check)

if your using a freewheel, why not use a tensioner?

it's for polo and i just thought a tensioner might get broken in polo?

try a trials tensioner, they are tough as shit (with a low fibre content)

bodge it?

Jeez, I'm coming to the same conclusion too, going to go get an OTP with a cyclescheme voucher. Then fit on all the bits I bought. Then put gear back on to my conversion frame, because I have spent money on it already and I really like, even though its a teeny bit big for me. I have decided I don't like tensioners at all.

Yup magic gear is definitely a gamble. I had a Roberts lo pro on which the MG was perfect first time - using a 'pre stretched' chain (sram pc1) that I'd used for 6 months previous on another bike. My experience with this bike encouraged me to buy an Orbea road frame, again with vert drops and nice oversize tubes that I'd liked the look of for a while. And dammit, I tried 3 or 4 different chainring and sprocket combinations and switched out 2 or 3 chains including a beefy bmx half link all to no avail - always the dreaded slack chain. You can always make the MG work, but you've got to want it. The Roberts was worth it for sure, the Orbea was a piece of shit that I sold for about half the price I spent on it after buying so many bits to experiment with the drivetrain!

Definitely agree, if after all the shouting, swearing, stamping your feet, arguing on the forum, and crying, you can get it to work, then it makes you very happy. I wrecked a set of 7400 Dura Ace road cranks and I fucked the paint on my BB shell in the process of getting my magic gear setup but I'm loving my bike so much since I sorted it.

http://www.bikeforums.net/showthread.php?395581

?

I realise this thread is pretty old, been covered a million times etc etc but I've just got a proper nice simoncini lo pro with the dreaded vertical dropouts. I've read all the threads, seen the calculator etc etc, just wondered, anyone who has used the calculator, how did you measure your chain stays? Did you measure the actual stays c-c or of you measure along where the chain line would be?

Centre to centre BB to axel.

Cheers mate

If you want to get really accurate, measure from the inside contact points of each then add half the diameter of the axel and half the diameter of the BB shell. (Instead of estimating the centre of each)

Oh so measure from the front end of the dropout to the back end off the bb shell, then add the radius of the bb and dropout. That makes sense.

You got it.

I forgot there was a word for half of the diameter.