Barcroft / Sliding Boom

Ken Huizenga wrote:
<snip>

Quoted message said:

I would like some input regarding the sliding boom solution:

1. Is the sliding boom feature, in general, a good solution for

modifying

Quoted message said:

the size of SWB bent to fit different riders?

It's better than a moving seat, IMO, since weight distribution changes
less with leg-length adjustments.

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2. What, if any, are the disadvantages of this approach vs. using

different

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frame sizes?

Shorter riders are carrying extra weight, taller riders may experience
excessive boom flex. There needs to be some mechanism to allow front
derailleur cable length to remain fixed while the boom is adjusted.
Pinch bolts on an extendable boom need to be very tight to avoid
twisting the boom under pedaling pressure.

Quoted message said:

3. Does anyone here have experience with or currently own a Barcroft

with a

Quoted message said:

sliding boom? Likes? Dislikes?
4. If you are over 6' and 45" X-seam and have experience with other

makes

Quoted message said:

with one frame size and the sliding boom feature... Do you think with

Quoted message said:

sliding boom option works well for you? Like? Dislikes?

Ken Huizenga
Appleton, Wisconsin

I'm 6-foot-4 and I rode a Lightning P-38 for 12 years. Granted, it was
the largest of the 4 frame sizes that Lightning makes, but I
encountered very few problems with the boom adjustment (Details above.)

Given my experience and knowing Bill's bikes' qualities, I'd say you
have nothing to worry about.

Jeff

Quoted message said:

Ken Huizenga wrote:
<snip>

Quoted message said:

I would like some input regarding the sliding boom solution:

1. Is the sliding boom feature, in general, a good solution for

modifying

Quoted message said:

the size of SWB bent to fit different riders?

It's better than a moving seat, IMO, since weight distribution changes
less with leg-length adjustments....

Even better in that respect is the combination of telescoping frame and
boom, e.g. [Drum roll, hushed anticipation, dramatic unveiling] the
Earth Cycles Sunset Lowracer [TM].

--
Tom Sherman - Near Rock Island

Quoted message said:

Ken Huizenga wrote:
<snip>

Quoted message said:

I would like some input regarding the sliding boom solution:

1. Is the sliding boom feature, in general, a good solution for

modifying

Quoted message said:

the size of SWB bent to fit different riders?

It's better than a moving seat, IMO, since weight distribution changes
less with leg-length adjustments....

Even better in that respect is the combination of telescoping frame and
boom, e.g. [Drum roll, hushed anticipation, dramatic unveiling] the
Earth Cycles Sunset Lowracer [TM].

--
Tom Sherman - Near Rock Island

Ken Huizenga said:

I am considering the purchase of a Barcroft Dakota and have had some
discussions and emails with Bill Cook, the owner of Barcroft Cycles. I am
6'2" tall and have a 46" X-seam. Bill has told me that my height and X-seam
would require that I have the "sliding boom" option for either the Dakota or
the Virginia. I will also be able to vary the seat to pedal distance by
positioning of the seat bottom and to a lesser extent the seat recline
angle.

I am currently thinking that the adjustable boom solution will be fine. (vs.
having a completely different frame size for larger riders, which Barcroft
does not offer) However, it does not appear that I will be able to test
ride a Barcroft with an extendable boom anywhere near my area, although Bill
has referred me to an owner with a Dakota and a Virginia without the sliding
boom.

I would like some input regarding the sliding boom solution:

1. Is the sliding boom feature, in general, a good solution for modifying
the size of SWB bent to fit different riders?
2. What, if any, are the disadvantages of this approach vs. using different
frame sizes?
3. Does anyone here have experience with or currently own a Barcroft with a
sliding boom? Likes? Dislikes?
4. If you are over 6' and 45" X-seam and have experience with other makes
with one frame size and the sliding boom feature... Do you think with
sliding boom option works well for you? Like? Dislikes?

I have the sliding boom on my Virginia, even though I am only 6 feet
tall. I really like being able to adjust it so I get the weight
distribution I want (front and back). I have had no problems with the
boom shifting under pedal pressure during riding, although I am a
spinner, not a masher.

I don't need to use the boom to adjust for different riders, nt if you
did, you might have to add or remove some chain links with each
adjustment, depending on the amount of change required,

As others have said - I would follow Bill's advice - he won't steer you
wrong.

"Tom Sherman" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

[email hidden] wrote:

snip

Quoted message said:

Quoted message said:

It's better than a moving seat, IMO, since weight distribution changes
less with leg-length adjustments....

Even better in that respect is the combination of telescoping frame and
boom, e.g. [Drum roll, hushed anticipation, dramatic unveiling] the Earth
Cycles Sunset Lowracer [TM].

--
Tom Sherman - Near Rock Island

How does adjusting the CofG with respect to changing the wheelbase affect
handling, etc.?

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harv said:

"Tom Sherman" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

[email hidden] wrote:

snip

Quoted message said:

Quoted message said:

It's better than a moving seat, IMO, since weight distribution changes
less with leg-length adjustments....

Even better in that respect is the combination of telescoping frame and
boom, e.g. [Drum roll, hushed anticipation, dramatic unveiling] the Earth
Cycles Sunset Lowracer [TM].

--
Tom Sherman - Near Rock Island

How does adjusting the CofG with respect to changing the wheelbase affect
handling, etc.?

It is rather complicated to model mathematically [1], but in general,
high speed stability is improved as the CG moves rearwards. Moving the
seat back will also increase tiller on a direct steered bicycle, which
in general will improve high speed stability at the expense of low speed
handling.

Braking performance is improved by moving the CG rearwards, since it
increases the maximum braking force before the rear wheels lifts with
front wheel braking (and/or the available braking force from the rear
wheel before it locks up).

It also provides the opportunity to bring the Earth Cycles Sunset
Lowracer [TM] into the discussion. 😉

[1] Bill Patterson has done much work here with "Lord of the
Chainrings", but some respected bicycle designers have disagreements
with some of his work.

--
Tom Sherman - Near Rock Island