Help with chain tension on a single speed conversion.

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.

Any ideas?

"eric" wrote in message
...

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.

Any ideas?

Sounds like the QR is not clamping onto the dropout. How close is the
end of the axle to the outer face of the dropout?

PH

"eric" wrote in message
...

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.

Any ideas?

Sounds like the QR is not clamping onto the dropout. How close is the
end of the axle to the outer face of the dropout?

PH

Check that you're using an old style all-steel quick release, and not one of
the modern aluminium abortions that is incapable of clamping tightly enough.

Nick

"eric" wrote in message
...

I've "converted" a old road bike into a single speed.

[snip]

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.

eric wrote in message . ..
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

Yeah, get a quality QR or go to bolt-on hubs. This was happening on a
friend's recent SS conversion and a stronger QR did the trick.

Good luck,
Jeremy


Nick Payne Wrote:
Check that you're using an old style all-steel quick release, and not
one of
the modern aluminium abortions that is incapable of clamping tightly
enough.

Nick

"eric" wrote in message
...

I've "converted" a old road bike into a single speed.

[snip]

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.


--
jtill

jtill wrote in message ...
Yeah, get a quality QR or go to bolt-on hubs. This was happening on a
friend's recent SS conversion and a stronger QR did the trick.

Good luck,
Jeremy


Nick Payne Wrote:
Check that you're using an old style all-steel quick release, and not
one of
the modern aluminium abortions that is incapable of clamping tightly
enough.

Nick


But the OP says that his chain seizes up. A better QR won't solve
that. Also, if the QR didn't slip before conversion, why should it
now?

"eric" wrote in message
...

I've "converted" a old road bike into a single speed.

[snip]

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.

Andrew Webster wrote in message
. ..

But the OP says that his chain seizes up. A better QR won't solve
that. Also, if the QR didn't slip before conversion, why should it
now?

When one is constrained to one gear, one must push harder to compensate for
the lack of availability of a lower gear. The chain pulls the hub forward
in the slots because the pulling force upon the chain is greater and so is
to overcome the friction available at the locknut.

The correct answer may be to tighten the QR, change to solid spindle, change
to a lower gear or change rear ends to rear facing. I have never found the
last option necessary after changing to solid spindle and using an
engineers spanner.

Trevor

Andrew Webster wrote in message
. ..

But the OP says that his chain seizes up. A better QR won't solve
that. Also, if the QR didn't slip before conversion, why should it
now?

When one is constrained to one gear, one must push harder to compensate for
the lack of availability of a lower gear. The chain pulls the hub forward
in the slots because the pulling force upon the chain is greater and so is
to overcome the friction available at the locknut.

The correct answer may be to tighten the QR, change to solid spindle, change
to a lower gear or change rear ends to rear facing. I have never found the
last option necessary after changing to solid spindle and using an
engineers spanner.

Trevor

"Trevor Jeffrey" writes:

Andrew Webster wrote in message
. ..

But the OP says that his chain seizes up. A better QR won't solve
that. Also, if the QR didn't slip before conversion, why should it
now?

When one is constrained to one gear, one must push harder to compensate for
the lack of availability of a lower gear. The chain pulls the hub forward
in the slots because the pulling force upon the chain is greater and so is
to overcome the friction available at the locknut.

Nice try. Thanks for playing.
The higher the gear, the less tension in the chain.
You got fooled because it is harder to pedal, but it is
easier on the chain.