eric <[email hidden]> wrote in message news:<[email hidden]>...
Quoted message said:I've "converted" a old road bike into a single speed.
What I've done:
Grind off all hangers on my frame. (bad idea in hindsight)
took off all brakes and derailleurs
took off large chainring.
I kept the old 6sp chain and freewheel on the rear wheel.
Its quite light looks quite good as is. However, I cannot get the
chain to stop "seizing up". I can pedel for a few seconds, and it
would seize. I can pedel backward for a quarter turn and I'll be ok
again.
I find that I cannot tighten the QR tight enough to prevent the wheel
from moving forward a little bit during hard pedelling. This frame
has a horizontal dropout. (Older type, wheel moves backwards into drop
out.
I believe the chain is seizing due to chain tension. However, I can't
simply add something like a Surly Singulator or even an old derailleur
to remedy this.
Your diagnosis sounds very likely.
You may be trying to apply too much tension. What happens if you
reduce the chain tension a bit? Unless everything is perfectly
aligned chain tension will vary a bit on full rotation so you need to
set it allowing for this. About a half inch "slack" movement at the
tightest spot is what I would go for.
If your QR is moving due to excess tension then that is a "good thing"
as the alternative is a snapped chain.
Is your freewheel well aligned? Multiple freewheels (at least the
ones I use) are often a bit off-centre (spin the freewheel and see if
the sprockets wobble in relation to the wheel). This could cause
enough movement for a tight spot. If so you could buy a new single
speed freewheel and try that.
Is your chainring round and true? Again, this might cause a tight
spot if it is not.
You ~could~ add a derailleur (one that doesn't need a hanger) or a
chain tensioner (chain stay attachment) - if I read right you are
still using your freewheel, so there is no imperative not to. That
would somewhat defeat the object though.
Andrew Webster
