Rear Triangle Alignment -- Will 6mm make a difference I can feel?

On 13 Mar, 12:56, jim beam wrote:
Ben C wrote:
On 2009-03-13, jim beam wrote:
Jeff wrote:
[...]
I measured the offset using a Park frame jig that grabs the frame at
the BB and has an adjustable "slider" arm (similar to the one on the
Park rear derailleur hanger tool) that you can adjust to pick up the
desired part of the frame. *The you reverse the frame (without
changing the slider arm setting) and pick up the same point on the
other side of the frame. *This is a nice heavy-duty stand that makes
coldsetting steel frames as easy as that operation can get. *(I'm not
sure Park makes that stand any longer -- couldn't find it on their
website.)
[...]
fwiw, i've seen frames with different thickness rear drops set
"centered" for their outside, not their inside, and thus they were
off-center. *apparently it's a simple mistake to make.

and yes, it does make a difference to ride.

Even if you re-dish the wheel?

not if you re-dish the wheel - but that would be a huge no-no - you
couldn't use a different wheel, and that wheel would be exclusive to
this machine.

Which makes me wonder if having the rear
triangle translated to the right a bit might actually be a good idea--
then you could have less dish on the wheel.

sure - if every other manufacturer did the same thing!

I think Thomson did this on their touring bikes(UK) but not on their
racing machines of which I was close to purchasing.
TJ

"Nick L Plate" aka Trevor Jeffrey wrote:
On 13 Mar, 12:56, jim beam wrote:
Ben C wrote:
[...]
Which makes me wonder if having the rear
triangle translated to the right a bit might actually be a good idea--
then you could have less dish on the wheel.
sure - if every other manufacturer did the same thing!

I think Thomson did this on their touring bikes(UK) but not on their
racing machines of which I was close to purchasing.
TJ

ATP Vision built their bicycles with a half-inch offset in the
chain/seat stays to reduce wheel dish.

--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll

6mm is HUGE, return it. Aside from the crank arm possibly hitting the
chainstay. The chainline will be way off, causing all kinds of problems.
If you can't return the frame (which would be a bummer!) best plan of attack
would be to play around with axle spacers and bb spacers to get the chain
line as dialed as possible then dish the wheel to the centerline of the
frame.
Dr. Deraileur
www.clarkecycles.com
"Jeff" wrote in message
...
I just bought a new carbon road bike frame, and when I measured the
rear triangle, I found it offset 6mm to the left.

The head tube is straight, and when I put a rear wheel in, it is
centered in the triangle.

Will this offset make a difference I can "feel", or should I just go
ahead and build up the bike?

Thank you.

Jeff Rininger

On Mar 12, 5:46*pm, jim beam wrote:
Jeff wrote:
On Mar 12, 2:47 pm, wrote:
On Mar 12, 5:38 pm, Jeff wrote:

I just bought a new carbon road bike frame, and when I measured the
rear triangle, I found it offset 6mm to the left.
[snip]
the wheel is centered because of spacers on the axle ? how did you
measure to determine the offset ? care to name the manufacturer of the
frame ?

I used the rear wheel from my current road bike. *The rear spacing on
the carbon frame is correct (130mm) so the wheel goes right in and is
centered left/right in the triangle. *Looks to me like the whole rear
tirangle was laid up wrong (jigging error) at the factory...

I measured the offset using a Park frame jig that grabs the frame at
the BB and has an adjustable "slider" arm (similar to the one on the
Park rear derailleur hanger tool) that you can adjust to pick up the
desired part of the frame. *The you reverse the frame (without
changing the slider arm setting) and pick up the same point on the
other side of the frame. *This is a nice heavy-duty stand that makes
coldsetting steel frames as easy as that operation can get. *(I'm not
sure Park makes that stand any longer -- couldn't find it on their
website.)

if it's the tool i think it is, are you measuring to the outside or the
inside of the drops? *if you're measuring to the outside, you can easily
measure a difference, yet the frame is perfectly straight. *different
thickness drops, etc. *what matters is that the two wheels are centered
wrt each other, and that's measured on the *inside* of the drops.



I guess I could take my current steel frame and introduce a similar
6mm misalignment to see if I can feel the offset when I ride it, but I
was hoping that someone would say "Nah, you won't feel it" or "Yeah,
it will be unrideable" to save me the work and mental anguish of
coldsetting an error into a perfectly good frame...

fwiw, i've seen frames with different thickness rear drops set
"centered" for their outside, not their inside, and thus they were
off-center. *apparently it's a simple mistake to make.

and yes, it does make a difference to ride.- Hide quoted text -

- Show quoted text -

Thank you for pointing that out -- I'll measure the dropout thickness
this evening. The "6mm" figure I stated was an eyeball; last evening
I actually measured the offset and it is 3.7mm. I still think that is
a lot...

On Fri, 13 Mar 2009 10:10:11 -0700 (PDT), Jeff
wrote:

On Mar 12, 5:46*pm, jim beam wrote:
Jeff wrote:
On Mar 12, 2:47 pm, wrote:
On Mar 12, 5:38 pm, Jeff wrote:

I just bought a new carbon road bike frame, and when I measured the
rear triangle, I found it offset 6mm to the left.
[snip]
the wheel is centered because of spacers on the axle ? how did you
measure to determine the offset ? care to name the manufacturer of the
frame ?

I used the rear wheel from my current road bike. *The rear spacing on
the carbon frame is correct (130mm) so the wheel goes right in and is
centered left/right in the triangle. *Looks to me like the whole rear
tirangle was laid up wrong (jigging error) at the factory...

I measured the offset using a Park frame jig that grabs the frame at
the BB and has an adjustable "slider" arm (similar to the one on the
Park rear derailleur hanger tool) that you can adjust to pick up the
desired part of the frame. *The you reverse the frame (without
changing the slider arm setting) and pick up the same point on the
other side of the frame. *This is a nice heavy-duty stand that makes
coldsetting steel frames as easy as that operation can get. *(I'm not
sure Park makes that stand any longer -- couldn't find it on their
website.)

if it's the tool i think it is, are you measuring to the outside or the
inside of the drops? *if you're measuring to the outside, you can easily
measure a difference, yet the frame is perfectly straight. *different
thickness drops, etc. *what matters is that the two wheels are centered
wrt each other, and that's measured on the *inside* of the drops.



I guess I could take my current steel frame and introduce a similar
6mm misalignment to see if I can feel the offset when I ride it, but I
was hoping that someone would say "Nah, you won't feel it" or "Yeah,
it will be unrideable" to save me the work and mental anguish of
coldsetting an error into a perfectly good frame...

fwiw, i've seen frames with different thickness rear drops set
"centered" for their outside, not their inside, and thus they were
off-center. *apparently it's a simple mistake to make.

and yes, it does make a difference to ride.- Hide quoted text -

- Show quoted text -

Thank you for pointing that out -- I'll measure the dropout thickness
this evening. The "6mm" figure I stated was an eyeball; last evening
I actually measured the offset and it is 3.7mm. I still think that is
a lot...

Dear Jeff,

What's the alignment on your current bike on the same Park jig?

Cheers,

Carl Fogel

On Mar 13, 10:16*am, wrote:
On Fri, 13 Mar 2009 10:10:11 -0700 (PDT), Jeff





wrote:
On Mar 12, 5:46*pm, jim beam wrote:
Jeff wrote:
On Mar 12, 2:47 pm, wrote:
On Mar 12, 5:38 pm, Jeff wrote:

I just bought a new carbon road bike frame, and when I measured the
rear triangle, I found it offset 6mm to the left.
[snip]
the wheel is centered because of spacers on the axle ? how did you
measure to determine the offset ? care to name the manufacturer of the
frame ?

I used the rear wheel from my current road bike. *The rear spacing on
the carbon frame is correct (130mm) so the wheel goes right in and is
centered left/right in the triangle. *Looks to me like the whole rear
tirangle was laid up wrong (jigging error) at the factory...

I measured the offset using a Park frame jig that grabs the frame at
the BB and has an adjustable "slider" arm (similar to the one on the
Park rear derailleur hanger tool) that you can adjust to pick up the
desired part of the frame. *The you reverse the frame (without
changing the slider arm setting) and pick up the same point on the
other side of the frame. *This is a nice heavy-duty stand that makes
coldsetting steel frames as easy as that operation can get. *(I'm not
sure Park makes that stand any longer -- couldn't find it on their
website.)

if it's the tool i think it is, are you measuring to the outside or the
inside of the drops? *if you're measuring to the outside, you can easily
measure a difference, yet the frame is perfectly straight. *different
thickness drops, etc. *what matters is that the two wheels are centered
wrt each other, and that's measured on the *inside* of the drops.

I guess I could take my current steel frame and introduce a similar
6mm misalignment to see if I can feel the offset when I ride it, but I
was hoping that someone would say "Nah, you won't feel it" or "Yeah,
it will be unrideable" to save me the work and mental anguish of
coldsetting an error into a perfectly good frame...

fwiw, i've seen frames with different thickness rear drops set
"centered" for their outside, not their inside, and thus they were
off-center. *apparently it's a simple mistake to make.

and yes, it does make a difference to ride.- Hide quoted text -

- Show quoted text -

Thank you for pointing that out -- I'll measure the dropout thickness
this evening. *The "6mm" figure I stated was an eyeball; last evening
I actually measured the offset and it is 3.7mm. *I still think that is
a lot...

Dear Jeff,

What's the alignment on your current bike on the same Park jig?

Cheers,

Carl Fogel- Hide quoted text -

- Show quoted text -

Hello Carl!

When I built my current steel bike, I cold set it on the same jig for
equal measurments on each dropout. I built it with Campy dropouts
which are the same thickness on the left and right... That was some
years ago, but I haven't crashed the bike (or backed into it with a
car!) so I assume it is still square.

On 13 Mar, 18:25, Jeff wrote:
On Mar 13, 10:16*am, wrote:



On Fri, 13 Mar 2009 10:10:11 -0700 (PDT), Jeff

wrote:
On Mar 12, 5:46*pm, jim beam wrote:
Jeff wrote:
On Mar 12, 2:47 pm, wrote:
On Mar 12, 5:38 pm, Jeff wrote:

I just bought a new carbon road bike frame, and when I measured the
rear triangle, I found it offset 6mm to the left.
[snip]
the wheel is centered because of spacers on the axle ? how did you
measure to determine the offset ? care to name the manufacturer of the
frame ?

I used the rear wheel from my current road bike. *The rear spacing on
the carbon frame is correct (130mm) so the wheel goes right in and is
centered left/right in the triangle. *Looks to me like the whole rear
tirangle was laid up wrong (jigging error) at the factory...

I measured the offset using a Park frame jig that grabs the frame at
the BB and has an adjustable "slider" arm (similar to the one on the
Park rear derailleur hanger tool) that you can adjust to pick up the
desired part of the frame. *The you reverse the frame (without
changing the slider arm setting) and pick up the same point on the
other side of the frame. *This is a nice heavy-duty stand that makes
coldsetting steel frames as easy as that operation can get. *(I'm not
sure Park makes that stand any longer -- couldn't find it on their
website.)

if it's the tool i think it is, are you measuring to the outside or the
inside of the drops? *if you're measuring to the outside, you can easily
measure a difference, yet the frame is perfectly straight. *different
thickness drops, etc. *what matters is that the two wheels are centered
wrt each other, and that's measured on the *inside* of the drops.

I guess I could take my current steel frame and introduce a similar
6mm misalignment to see if I can feel the offset when I ride it, but I
was hoping that someone would say "Nah, you won't feel it" or "Yeah,
it will be unrideable" to save me the work and mental anguish of
coldsetting an error into a perfectly good frame...

fwiw, i've seen frames with different thickness rear drops set
"centered" for their outside, not their inside, and thus they were
off-center. *apparently it's a simple mistake to make.

and yes, it does make a difference to ride.- Hide quoted text -

- Show quoted text -

Thank you for pointing that out -- I'll measure the dropout thickness
this evening. *The "6mm" figure I stated was an eyeball; last evening
I actually measured the offset and it is 3.7mm. *I still think that is
a lot...

Dear Jeff,

What's the alignment on your current bike on the same Park jig?

Cheers,

Carl Fogel- Hide quoted text -

- Show quoted text -

Hello Carl!

When I built my current steel bike, I cold set it on the same jig for
equal measurments on each dropout. *I built it with Campy dropouts
which are the same thickness on the left and right... *That was some
years ago, but I haven't crashed the bike (or backed into it with a
car!) so I assume it is still square.

Just run some twine from one dropout, around the headtube and back to
the other dropout. Measure with a rule the distance between seat tube
and twine on each side.
TJ

On Mar 12, 6:26*pm, Jeff wrote:
On Mar 12, 2:47*pm, wrote:

On Mar 12, 5:38*pm, Jeff wrote:

I just bought a new carbon road bike frame, and when I measured the
rear triangle, I found it offset 6mm to the left.
[snip]

I guess I could take my current steel frame and introduce a similar
6mm misalignment to see if I can feel the offset when I ride it, but I
was hoping that someone would say "Nah, you won't feel it" or "Yeah,
it will be unrideable" to save me the work and mental anguish of
coldsetting an error into a perfectly good frame...

Um, cold set will work for steel only.
http://www.sheldonbrown.com/frame-spacing.html
Aluminum and carbon fiber cannot be cold set, Titanium is not
mentioned.

On Mar 13, 12:37*pm, wrote:
On Mar 12, 6:26*pm, Jeff wrote:

On Mar 12, 2:47*pm, wrote:

On Mar 12, 5:38*pm, Jeff wrote:

I just bought a new carbon road bike frame, and when I measured the
rear triangle, I found it offset 6mm to the left.
[snip]
I guess I could take my current steel frame and introduce a similar
6mm misalignment to see if I can feel the offset when I ride it, but I
was hoping that someone would say "Nah, you won't feel it" or "Yeah,
it will be unrideable" to save me the work and mental anguish of
coldsetting an error into a perfectly good frame...

Um, cold set will work for steel only.http://www.sheldonbrown.com/frame-spacing.html
Aluminum and carbon fiber cannot be cold set, Titanium is not
mentioned.

Yes, hence my dilemma: keep the frame and ride it with the offset rear
triangle or send it back.

Thank you for pointing that out -- I'll measure the dropout thickness
this evening. *The "6mm" figure I stated was an eyeball; last evening
I actually measured the offset and it is 3.7mm. *I still think that is
a lot...

Note that it would very easy to be measuring _twice_ the alignment
error.

If you set the probe to touch and the flip it to the other side the
gap will be twice the error.

-Brian