[email protected] wrote:
>
> Chalo wrote:
> >
> > [email protected] wrote:
> > >
> > > Otherwise all Surly bikes are fairly pedestrian
> > > gas pipe tubing. I'd prefer to start with quite a bit higher level of
> > > frame at the price point you are talking about. If cheap is your main
> > > driver, then nashbar sells cheap aluminum frames for 1/3 the Surly
> > > price.
> >
> > Surly bikes are about uncommon but desirable features, not fancy
> > materials. Things like ample fat tire clearance and horizontal
> > dropouts are generally not available on cheaper no-name frames, even if
> > they are equally well-made.
>
> But why make it out of poor materials? I looked at the Surly website.
> The 58 cm c-t Pacer road frame is TIG welded and lists a weight of 4.75
> pounds. My Waterford 1200 lugged steel frame, 58 cm c-t, is 4 pounds.
> Why did Surly use extra, extra heavy gauge pipe for the frame? TIG
> welded frames should be much lighter than lugged frames due to the
> weight of the lugs. I figure there is 1 pound of extra steel in the
> Surly pacer tubing. Why? Is this one of those desirable features you
> mention?
If the desire is for a stiff, rugged frame rather than a light, limber
frame, then that implies a different choice of tubing diameters and
gauges. You don't know whether the properties of Surly's alloy aren't
actually superior to that of your Waterford, now do you? I haven't
bent my 1x1 frame yet, so I really can't say how strong it is except,
"probably strong enough". For me, that's better than average. I bent
the fork while fooling around doing nose wheelies, but that's par for
the course for the OEM forks I've had.
Dave Bohm spared no expense to make my bike's custom frame from the
best available butted tubing that would do the job. It weighs 7.25
lbs., but that is not a reflection on its build quality or materials.
It fits me better and rides better than my 5.4 lb. Surly frame, but I
guess since it's heavier it must be made of lesser materials. Right?
Note that Nashbar's cheap steel MTB frame weighs 1.2 lbs. more than the
superficially similar Surly 1x1 frame in an equivalent size. Both are
made from butted 4130 CrMo steel; I'd guess that the Nashbar one is
built heavier to make it easier to miter and weld quickly. The Surly's
weight savings come a lot cheaper than your Waterford's, but the
Nashbar frame is probably the stiffest, strongest, and most durable of
the three-- and only $130 for a 6.2lb. frame and 3.1 lb. fork.
> The fork for the Pacer is listed at a bit over 2 pounds. My Reynolds
> 531 fork is 1.5 pounds. The Pacer fork does have 1.125" steerer
> compared to 1" on mine. But still that is a lot of extra steel in the
> Pacer fork. Why use such heavy gauge pipe for a fork?
Maybe because it's stiffer and that feels right for the application;
maybe because it cuts down on JRA-type failures. Maybe because it's
cheaper to make that way. And maybe, just maybe, because the material
is weak enough that it must be that heavy to do its job. But I
wouldn't bet on the latter option. 4130 chromoly tubing and Reynolds
531 have almost identical tensile strength-- both about 120,000 psi
ultimate.
> I understand this desirable features thing. But when QBP puts these
> desirable features on a frame made out of heavy gauge pipe, doesn't
> that defeat the purpose?
No, it doesn't. No matter how strong the material might be, the
stiffness of a frame (and thus its resistance to twisting and flexing)
is directly related to how much material is in it. If you want to make
a steel bike of a given size stiffer, you can use one of two
approaches: make the tubes thicker-walled, or make the tubes larger in
diameter. Larger diameter means the tubes will be much easier to dent
or buckle, and much more expensive. But the only downside to making
the tubes thicker is that they get heavier, roughly in proportion to
how much stiffer they get.
The market that includes folks who want single speed MTBs-- and fixies
that can take fat tires, and 'cross bikes that can take _really_ fat
tires, etc.-- is not one that generally would trade durability for an
insignificant decrease in frame weight. Nor is it, I'd guess, a market
of folks who think a flexible frame is a sign of quality construction.
For an official Surly view on frame weight, see this rant:
http://www.surlybikes.com/spew1.html
> QBP is selling the options and accessories on
> the Surly frames, not a quality frame. And the people who buy them are
> paying for options and accessories, not a quality frame.
I think you underestimate the degree to which features (though not
necessarily _useful features) drive the price of most frames. And I
think you grossly overestimate the degree to which frame weight is an
indication of material quality.
Chalo Colina