Touring - standover clearance rules of thumb?

I realize that preferred standover clearance can vary depending on physical build of the rider and frame geometrics of particular manufacturer, but are there some general rules of thumb on standover clearance for touring bikes with straight top tubes (not angled top tubes like many hybrids have).

If so, are these rules of thumb different for lighter, speedier road bikes with straight top tubes?

This information would be useful for me so I could at least rule out inappropriate frames as I plan my test rides.

Thanks.

There are a ton of different ideas about this subject! Most say that when standing over the bike, you should have a little clearance between your groin and the top tube. Personally, I subscribe to the ideas put forth by the folks at Rivendell. (http://www.rivendellbicycles.com/html/bikes_framesize.html) Click on the name and you can read the page. Basically, when I stand over my frame, I am firmly, but not painfully, in contact with the top tube. This works for me, but we are all different, so it might take a little testing to get what is right for you. But believe me, it will be worth it in the long run! Best of luck to you!

I agree with Nebill, I like to ride a large frame because they are more compliant and therefore ride better on long day rides. When standing over my bike it is tight to my groin but not painfully tight, this works well for me and I ride about 10,000 miles per year. I also perfer a touring type geometry because it handles much better when loaded, which my bike always is.
good Luck Pete

Racers tend to like smaller stiffer frames, as long as the top tube is the right length. Standover isn't an issue as long as it's not too big, and usually isn't an issue anyway because they'll choose a smaller frame, given a choice.

My own feeling is that standover clearance is not an issue unless it's just plain too tall, because it really has no bearing on fit. You need to get the saddle into the proper relationship with the pedals, and the handlebars into the place where your hands comfortably fall when you're mounted on that correctly-positioned saddle.

If you achieve all that on a frame that then turns out to have too much standover height, you might be a candidate for a sloped top tube.

RichC

These days, people are pretty generous with standover, and if the top tube fits, you are likely to have and inch or so.
The more important factor is the height of the headtube. Some racers want a very low bar position, so chose a short headtube, which makes for a low top tube.
Tourists may want a higher headtube to raise the bars (and extend headset life!!) , so go for higher TT .
There is nothing wrong with sloping top tubes, they give you a high headtube and plenty of standover, but Im not sure how easy it is to shoulder a loaded bike with a sloping TT.

Check out

http://www.sjscycles.com/thornbrochure.asp

Got to the 26" bike brochures section and have a read - they have a couple of pages on bike sizing

I agree with the suggestions to review the SJSCycles and Rivendell web pages, especially the latter.

I've toured on: mountain bike (ATB) with straight bars, conventional road bike, tandem, and a cross or hybrid bike.

My current single is an ATB set up for mixed riding including touring. I'm still dialing it in but it has more hand positions than you can shake a stick at, with Scott AT-4's and clip-ons with a remote shifter. My favorite positions were on a now-broken bike that had Nitto Dirt Drop handlebars with a clip on Profile aero bar.

Here are my reccomendations:

Don't worry too much about top tube height (within reason). Concern yourself more with the Pedal/Seat/Handlebar relationship.

Start with the bottom bracket location. You can't change it.

The seat should be set so it's both the correct height and far enough back that you don't slide forward, but not so far back that your torso won't bend over enough to get aerodynamic.

Once the seat and pedals are set, then you have to consider the handlebar position. Where on the bars though? When touring you want to be comfortable in all positions; tops, hoods, and drops plus the aero bar or clip ons.

I suggest conventional road bars and a clip on aero bar with forearm pads. Set the bars fairly high, with the top of the bar even with the seat top or maybe 3 cm below. Most people I see touring never use the drops, since the bars are too low. By setting the bars higher, the drops are fairly comfortable but still aerodynamic. In my opinion if you aren't comfortable riding the drops for an hour straight, they are too low.

I have a friend that suggests this method to set the distance from the seat to the handle bar: "With your elbow against the nose of the seat your fingertips should just touch the back of the bar". For me, the bar should be a bit further forward, around 3 cm. Make sure you don't use this rule in reverse, get the seat right first.

One consideration for an all-around bike is to use deep drop bars to go with a high/close bar top position. You will have a wide range of available positions, especially compared to a straight ATB bar.

If the bike has a conventional steerer with adjustable height stem it will make handlebar positioning easier.

Here's a quote from on high bar Rivendell's Rambouillet page: "If you want to get aero, it’s easy. Instead of riding the hoods, ride the drops. Or ride the hoods with more bend in your arms (more aerodynamic). That’s the idea with drop bars, anyway, and it’s only in recent years that too-small sizing has perverted it."




Jim

Standover measurements (where the rider measures the distance of the top tube to his/her groin) is an almost ancient method of measuring bicycles.

It goes back to the traditional diamond frame geometry that lasted at least to the mid 1980's.

These days, frame geometry has become much more creative - as has been allowed by newer engineering design and material considerations.

Today, standover measurements are not so critical. In fact, they never really were that critical except to prevent the rider from cracking their crotch when they slid off the saddle.

The critical size really is the distance from the post tube to the head-tube. You can raise and lower the saddle height with seat posts and you can do the same with handlebar stems.

However, the length of the bike has to fit the rider's body length. You can try to compensate with longer stem extensions or by moving the seat back, but both goof-up the weighting of the rider and the proper rider/machine geometry.

An old rule of thumb for measuring the proper bike length (with drop handles - road bike style) that still seems to work is to mount the bike with your hands on the top part of the handlebar. As you aim your line of sight toward the wheel, the axle should be hidden from your line of sight by the handlebar.