Barcroft / Sliding Boom

[Ken Huizenga]

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?

Ken Huizenga
Appleton, Wisconsin

 

[[email protected]]

Ken Huizenga wrote:
<snip>
> 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?

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

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

> 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?
>
> 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

 

[Tom Sherman]

[email protected] wrote:

> Ken Huizenga wrote:
> <snip>
>
>>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?
>
>
> 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

 

[Tom Sherman]

[email protected] wrote:

> Ken Huizenga wrote:
> <snip>
>
>>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?
>
>
> 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

 

[Bob Stan]

Ken Huizenga wrote:
> 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.

 

[harv]

"Tom Sherman" <[email protected]> wrote in message
news:[email protected]...
> [email protected] wrote:
>
snip
>>
>>
>> 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.?




----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---

 

[Tom Sherman]

harv wrote:

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