Re: When Is Standover Height Insufficient?

On Sun, 31 Jul 2005 18:32:56 -0400, "Arthur Harris" <[email hidden]>

Quoted message said:

I happen to like large frames, and my bikes have less standover clearance
that most. But I still like to have at least 1-2 cm of clearance. The only
time it's a issue is when you're stopped at a traffic light, or when you're
"waiting up" on a group ride. But there definitely are times where I
straddle the frame with both feet on the ground.

When I'm stopped at a light, I have my ass on the seat, one foot on a
pedal (usually the left), the bike tilted, and the other foot on the
ground. Usually works for me.

Jasper

On Sun, 31 Jul 2005 18:32:56 -0400, "Arthur Harris" <[email hidden]>

Quoted message said:

Steve Sr. said:

I had a professional fitting done to in anticipation of ordering a
custom geometry bike. With the fitting I found out that I had a short
torso and arms which requires a geometry with a high front end and
relatively shorter top tube. The fitting was done on a Serotta Size
Cycle but the frame was done by another manufacturer.

The frame builder addressed these issues with a longer seat tube and a
slightly sloping (up) top tube and a taller head tube. Unfortunately
in dealing with these issues it appears that the stand over height was
missed by about 3/4" i.e. the bike is about 3/4" higher than was
recommended by the fitting.

I think you might have been better off with a stock frame. Modern frames
tend to have longish top tubes for a given seat tube size. So if you had
chosen a stock frame with an appropriately short top tube, you would have
had plenty of standover. A rising stem and/or a long steer tube (if a
threadless h/s) would have allowed you to get the bars up high enough.

I looked at stock frames and the common issue was that if I got the
top tube correct the seat tube would be too short making the front end
too low once the seat was raised to the proper height.

Quoted message said:

What does the custom builder say? He's the one who "missed" the target
standover height by 3/4". And with a sloping top tube and extended head tube
at that!

The standover specification was never given on the approval drawing so
there was nothing to really check. I did question the builder about
standover height when I saw a 60cm seat tube on the approval drawing.
I thought this seemed kind of large considering I wear 29-30" inseam
trousers.

The builder didn't think it was a problem and said that I should be
able to straddle the to tube with cycling shoes on so I defered to his
judgement (without ever seeing any numbers). It looks like this may
have been a compromise to get the rest of the frame correct.

Quoted message said:

Quoted message said:

So far I have had a test fitting on the new bike but haven't been able
to ride it since the seat post provided was too long (won't go low
enough). I can just barely straddle the bar with bike shoes on. I
would estimate that there is currently somewhere 0-1/4" clearance if I
stand just right. The bike currently has 23mm tires on it but I will
probably switch to 25mm when these wear out to reduce the chance for
flats. This will only make the stand over height worse.

Is this stand over height likely to be an issue? At what point would
you consider stand over height to be insufficient?

I happen to like large frames, and my bikes have less standover clearance
that most. But I still like to have at least 1-2 cm of clearance. The only
time it's a issue is when you're stopped at a traffic light, or when you're
"waiting up" on a group ride. But there definitely are times where I
straddle the frame with both feet on the ground.

I wouldn't want a bike with zero clearance, especially if I paid for a
custom frame. If you provided the frame builder a list of requirements that
included a particular standover height, then I would make him take the frame
back.

I assume the too long seat post is a Thomson set back model which needs
about 10cm (minimum) of exposed post. The fact that you need less seat post
exposed is another indication that the frame is too big.

Just out of curiosity, how high are you trying to get the bars relative to
the saddle? Unless you're trying to get the bars considerably higher than
the saddle, there shouldn't have been a problem. Hope you can work this out,
but don't accept a bike that you're not happy with.

The top of the bars is supposed to be about even with the seat. The
steerer is carbon which limits the amount of spacers. The stem is a
standard 10 degree road stem flipped up.

Steve

Quoted message said:

Art Harris

Steve Sr. said:

I looked at stock frames and the common issue was that if I got the
top tube correct the seat tube would be too short making the front end
too low once the seat was raised to the proper height.

"Compact" frames are very common these days. There is really no direct
relationship between seat tube length and handlebar height (or head
tube length). Some have a top tube that slopes at a greater angle than
others... or in other words your bars will end up higher for a given
seat tube length. Giant and Specialized come to mind; also some models
of Litespeed-Merlin, Airborne Torch, or Habanero Custom. I'm pretty
certain that you could have found a stock frame that fit you well, or
you could have had a custom frame made that had a much shorter seat
tube, giving you plenty of clearance.

Personally, I think that a sloping top tube is visually appealing if
you are angling the stem up anyway.... and you already have a 410mm
Thompson post!

I hope you get it sorted out to your satisfaction. You should be 100%
happy with a custom frame, but I don't know how much of your own input
(or lack thereof) may have contributed to the final product.

-Ron

Steve Sr. said:

I did question the builder about standover height when I saw a 60cm seat tube on the approval drawing. I thought this seemed kind of large considering I wear 29-30" inseam trousers.

Yep, that should have been a red flag.

Quoted message said:

The top of the bars is supposed to be about even with the seat. The steerer is carbon which limits the amount of spacers. The stem is a standard 10 degree road stem flipped up.

Better options might have been: A longer (steel) steer tube, a stem
with more rise, and/or a top tube with more slope.

You started off with the problem that frames with the right (short) top
tube length for you gave too much standover and too much drop from the
saddle to the bar. And you ended up with with a frame with proper bar
height and reach, but zero standover clearance.

I still think you could have found a stock frame that would have
worked. If you had gone to a frame with a slightly longer top tube (1
or 2 cm longer) and made up the difference with a shorter stem, you
probably could have worked out the position of the bars and saddle. A
stem length of 80 or 90 mm wouldn't compromise handling.

Art Harris