singlespeed conversion virgin, noob questions !

AdrianStreet1973":3lhha13m said:
Ooo! Good thread.

I think I've just decided that I'll convert my Axis TT to a SS. I stripped it last week and was considering selling the frame. But I can hardly bear to get rid of it.

+1.
I'm in the same boat with my '97 stumpy. This thread is answering all my questions. :D
 
This
http://eehouse.org/fixin/formfmu.php has been posted, but in my experience it gives you a good indication at best where to start finding a Magic Gear. If you don't have the published chain stay length from the bike manufactuer, then trying to measure it accuratly with a ruler will give you a starting ball park figure. When you've plugged in the info, then try these practicle tips to finalise your Magic Gear:

- put your wanted chain-ring on.
- get your wanted chain ready.
- set up the spacers closest to the hub to give you a reasonable chain line.
- play with old sprockets from a cassette first by simply seeing
if the chain will more or less join. Old 6/7 speed Uniglide road corn-cob cassettes are perfet for trying and perfectly rideable in SS mode.
- if it looks alright, put the remaining spacers on, tighten it all up.
- break the chain to right length and fit it.
- Pop the wheel back in.

If the chain is a fraction too slack, a new SS cog of the same teeth will tighten it up nicely. They have a slightly larger diameter, along with taller teeth.

If the chain is too tight - the wheel won't even engage or marked locking points when you turn the cranks, file a bit from the hub axel - and I mean a bit - so the rear wheel can move forward slightly. See Saint Sheldon: http://www.sheldonbrown.com/singlespeed.html

OR if you are not keen on filling, get your chain back on a normal bike, do a few 100 miles, then try again with the added chain stretch. Riding with no oil will speed up the process :!:

DON'T file the frame unless you are really settled on that Magic Gear on that bike.

Bear in mind that what is seemingly a very tight chain will actually loosen very quick after a few rides in SS mode. Putting new chains on first that seem perfect with a magic gear can quickly lead to a disappointing sloppy chain after a few rides.

If the above doesn't work, then try a chain tensioner. I've had no success really faffing with half-links - but that's just me.

This procedure is not recommended if you planning a visit to the velodrome, but it get's you going on the cheap and plenty good enough for getting a retro conversion started. ;)

I've even heard people having custom chain stay lengths with vertical drop-outs using the above principals since there's no faffing with EBB or fiddling with sliding drop-outs when using disk brakes.
 
Whack your normal chain on and run it through an old mech. Tensions the chain and costs nothing.

I do fancy a half link chain for mine but other than looks it's not worth the money when the bodge works fine.
 
I have used a BB mounted tensioner for years with no isses. Every few moneth I had to adjust it but there was nothing at the back to rip off.

On my next SS build I will be using a singulator though.
 
Job done.... well nearly, but we have some hitches.

OK, I posted on this thread a week or so ago about converting my DBR Axis TT to a single speed, and now I've finished it. Well it looks complete but I have a glitch to solve I think. I only jumped on it quickly tonight to see what it felt like and though I could only fit in few pedal strokes around the garden I immediately felt a 'jumping chain'. Like when you put a new chain on an old sprocket. It's all new of course. I've posted a few pics to show what it looks like. Some new stuff on there, so its not all retro I'm afraid. I like the look of it, I just need to sort the jumping chain issue. The drive chain is.
Chainset: Raceface Ride XC SS - 32T
Sprocket and spacer: Gusset Double Six 16T
Chain: SRAM PC1 SS Chain
Tensioner: Superstar Sprung Tensioner - Gold anodised Jockey Wheel

Any clues what's up?
 

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I have the same problem with my single speed build completed today. Did not have time to sort today but it the first job tomorrow and it only skips under load. I used an 8 speed chain KMC Z82. Rear sproket is a single speed 18T (I forget the brand) and chain ring is a biopace 38T. The chain rings are the orginals but don't look worn and the sproket is new as is the chain. The ratio is perfect and bike is super light.

I suspect yours like mine has a chain line problem. I thought mine was all lined up, aparantly I was wrong or it something else but there really is nothing else.

I hope you sort your skipping problem and enjoy riding it.
 
It's the tensioner. I had the same problem with mine. I swapped it for a DMR one that pushes the chain up rather than down and now it's perfect :D
 
AdrianStreet1973 - it jumps because the chain is too long. You need the chain to wrap around more teeth on that 16T rear sprocket.
 
Ok, so it's not the chain line. The tensioner alignment did look a smidge out when I checked it. It's dead straight now, but still it jumps.

I'm suspicious about the SRAM 'snap lock' joining link as when I turn it backwards it makes 'click' when it goes through the jockey wheel. However when I pedal it forwards with the wheel off the ground (no load) it sounds fine.

I wondered about the wrap around, but this tensioner doesn't have a huge amount of range left in it. I could take out a link or two perhaps, but after roughly taking up the available slack to the limit of the tensioner by hand I bearly get an extra tooth wrap around on the rear sprocket.

I might try taking out the joining link tomorrow to see if that improves the problem. Otherwise I might be looking for a new tensioner. But it seems odd because this one seemed well recommended, and it's not fundimentally different to so many others.

Oh and I liked the gold jockey wheel! :(
 
I have the same [ish] tensioner and it will go tighter than that.

Ill have a look for one of my pics of my SS built






OOOO them knee's :(
 

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