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How does having fork tubes extend past the top clamp effect the propensity for wheelies? [Full disclosure: every wheelie I've done in my life was unintentional, on road or off.]
Well; and I'm trying not to be a know-it-all but as you have said you are learning and folks on this forum are swapping front-ends back and forth at a prodigious rate. I'll risk me being called out and say that the forks sticking out above the top yoke does not really make the bike pop wheelies. This is because the length of the fork is part of the equation.

A very simplistic way to view this is where the wheels touch the ground are like the pans on a beam scale. If each pan had the same amount of weight then the beam would be level. Half way between each pan would be the bikes balance point. Now if you add weight to either end (either dynamically or statically) you change the angle of the beam and the end opposite where you added the weight will be easier to lift (pop a wheelie/do a stoppie) so you lower the front in the triples (slide the fork tubes up in the clamps) then the motorbike turns more easily (here I do not mean it takes less muscle; I do mean it will often turn-in quicker) , will do stoppies but will often tuck the front. Raise the the bike in the yokes and you put the weight on the rear. Here you tend to loose front bite (thus making it harder to turn, here again we're not talking muscle what you often get here is a motorbike that will run wide on exiting the turn ) but you can pop great wheelies.

How far the forks are proud of the top yoke is only relevant to that pile of parts. The length of the fork from end to end and what the length of the forks that the designer was working with when he first laid out the motorbikes geometry are what is important.

I tell you all this because when one looks at a picture of a bike such as yours (exactly what I did when I made my comment) it's easy to see all that fork tube sticking up and think that thing has no weight on the rear and the rider will be doing burn-outs at every corner. The inverse can also be true raise the yokes up to the top of the tubes and you move all the weight towards the rear. Good traction and great wheelies.

The thing is, because I have no idea how long the forks that came on your bike from the factory were. How far they stick out of the top yoke in your photo has little bearing on how the bike handles. I said they were out quite a bit because that was relevant to what handlebars you could use as the tubes could be in the way of the mounting for the bars.

The fun part of all this is that you have uncovered one of the main aspects of motorbike set-up. RAKE ! If the bike doesn't want to turn or turns too quickly you go back to our balance beam. Lift the rear or lower the front and you put more weight in the "front pan". Drop the rear or lraise the front and you put more weight in the "rear pan". So you can see that if the motorbike is spinning the rear wheel coming off the turns you change the rake one way. If it's going to pop wheelies at the drop of a hat then you can go the other way.

Now remember this is all about degrees of change and with modern suspensions there are a plethora of changes that one can make. Some can be done with the adjusters on the suspension or locating and rake changes others must be done by dissembling the shock/forks and changing the internals.

If you are at all interested in this aspect of building then you need to expand your motorbike library my suggestions are books on set-up by; Lee Parks; Total Control. Andrew Trevitt; Sportbike Suspension Tinning. These tend to be my go-to references if I feel myself starting down a dark handling rabbit hole .

One last recommendation is the Dave Moss motorbike site davemosstunning.com. Here he deals with everything from weather and how it pertains to set-up to riding gear. He will also answer your questions if you e-mail him. Well worth a look-see.

Cheers
 

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Discussion Starter #502
This bikini fairing would be better for wheelies, it's not going to get in the way much and it looks pretty light.
How can you ride a Bultaco and not wheelie, I've never ridden a Bultaco that I didn't wheelie intentionally, I thought that's what they were designed for.
I wheelied my race bike a couple of times at really, really inopportune moments. I endeavored to keep the tire in contact with the tarmac after that.
 

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Actually, if you want to see what a Bultaco feels like with faster steering, just ride a Bultaco trials bike, there are tons of them around still.

Wheelies save lives, it's the only way you can ride a motorcycle over something taller then your front axle, everything else results in a trip over the handlebars.
 

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Discussion Starter #504
Well; and I'm trying not to be a know-it-all but as you have said you are learning and folks on this forum are swapping front-ends back and forth at a prodigious rate. I'll risk me being called out and say that the forks sticking out above the top yoke does not really make the bike pop wheelies. This is because the length of the fork is part of the equation.

A very simplistic way to view this is where the wheels touch the ground are like the pans on a beam scale. If each pan had the same amount of weight then the beam would be level. Half way between each pan would be the bikes balance point. Now if you add weight to either end (either dynamically or statically) you change the angle of the beam and the end opposite where you added the weight will be easier to lift (pop a wheelie/do a stoppie) so you lower the front in the triples (slide the fork tubes up in the clamps) then the motorbike turns more easily (here I do not mean it takes less muscle; I do mean it will often turn-in quicker) , will do stoppies but will often tuck the front. Raise the the bike in the yokes and you put the weight on the rear. Here you tend to loose front bite (thus making it harder to turn, here again we're not talking muscle what you often get here is a motorbike that will run wide on exiting the turn ) but you can pop great wheelies.

How far the forks are proud of the top yoke is only relevant to that pile of parts. The length of the fork from end to end and what the length of the forks that the designer was working with when he first laid out the motorbikes geometry are what is important.

I tell you all this because when one looks at a picture of a bike such as yours (exactly what I did when I made my comment) it's easy to see all that fork tube sticking up and think that thing has no weight on the rear and the rider will be doing burn-outs at every corner. The inverse can also be true raise the yokes up to the top of the tubes and you move all the weight towards the rear. Good traction and great wheelies.

The thing is, because I have no idea how long the forks that came on your bike from the factory were. How far they stick out of the top yoke in your photo has little bearing on how the bike handles. I said they were out quite a bit because that was relevant to what handlebars you could use as the tubes could be in the way of the mounting for the bars.

The fun part of all this is that you have uncovered one of the main aspects of motorbike set-up. RAKE ! If the bike doesn't want to turn or turns too quickly you go back to our balance beam. Lift the rear or lower the front and you put more weight in the "front pan". Drop the rear or lraise the front and you put more weight in the "rear pan". So you can see that if the motorbike is spinning the rear wheel coming off the turns you change the rake one way. If it's going to pop wheelies at the drop of a hat then you can go the other way.

Now remember this is all about degrees of change and with modern suspensions there are a plethora of changes that one can make. Some can be done with the adjusters on the suspension or locating and rake changes others must be done by dissembling the shock/forks and changing the internals.

If you are at all interested in this aspect of building then you need to expand your motorbike library my suggestions are books on set-up by; Lee Parks; Total Control. Andrew Trevitt; Sportbike Suspension Tinning. These tend to be my go-to references if I feel myself starting down a dark handling rabbit hole .

One last recommendation is the Dave Moss motorbike site davemosstunning.com. Here he deals with everything from weather and how it pertains to set-up to riding gear. He will also answer your questions if you e-mail him. Well worth a look-see.

Cheers
The rake and trail figures for this bike have been considered.
Repeatedly.
Extensively.
Ad nauseam.

 

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The rake and trail figures for this bike have been considered.
Repeatedly.
Extensively.
Ad nauseam.

That picture taken at face value make the bikes rake look just about right. I also try to avoid to many corner exit wheels on street bikes. I' told that it can help finish the turn and straighten you out but that's left for better men than I.

As I look at your motorbike Tanshanomi I must say that I kind of fall in love with the things simplicity. Looks as if it might be a wee bit front high but that may just be an optical allusion.

I'd have to make it a ton-up cafe racer but that's nothing more than Old Man craziness.
 

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Corner exit wheelies are the best ! don't know as it straightens you out much (you do that with balance) but it certainly improves traction to the rear wheel.
 

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Discussion Starter #507
That picture taken at face value make the bikes rake look just about right. I also try to avoid to many corner exit wheels on street bikes. I' told that it can help finish the turn and straighten you out but that's left for better men than I.

As I look at your motorbike Tanshanomi I must say that I kind of fall in love with the things simplicity. Looks as if it might be a wee bit front high but that may just be an optical allusion.

I'd have to make it a ton-up cafe racer but that's nothing more than Old Man craziness.
I realize that nobody is going to read through a 500-post thread, but if you go back and look, this bike has been mostly a self-taught practical lab course on how to build a motorcycle properly from the ground up, not a desire to make a fancy "custom." Though I don't want it to be agressively hideous, I have tried to think mostly about the appropriate construction and function of this bike, aided by a lot of really good advice and humbling input from the guys here who have more experience than I have (although, sadly, many of the best of them have disappeared in the 9-1/2 years I've been playing around with this).
 

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Discussion Starter #510
In keeping with my "do a little something every day" approach, I went down to the basement before work and made up a couple of little brackets to mount the front fender. Since the bike it came from (Honda 650 Nighthawk) had a leading-axle fork, and the GS750ES forks aren't, the bolt holes in the fender were too far to the rear and at a slight angle when properly positioned over the tire, so the bracket had to compensate for that. When I was all done, the rear of the fender is 1" away from the tire, and the front is 1.1". Good enough.

It's amazing how much attention it takes me to get these sorts of little details correct.




 

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In keeping with my "do a little something every day" approach, I went down to the basement before work and made up a couple of little brackets to mount the front fender. Since the bike it came from (Honda 650 Nighthawk) had a leading-axle fork, and the GS750ES forks aren't, the bolt holes in the fender were too far to the rear and at a slight angle when properly positioned over the tire, so the bracket had to compensate for that. When I was all done, the rear of the fender is 1" away from the tire, and the front is

It's amazing how much attention it takes me to get these sorts of little details correct.




In keeping with my "do a little something every day" approach, I went down to the basement before work and made up a couple of little brackets to mount the front fender. Since the bike it came from (Honda 650 Nighthawk) had a leading-axle fork, and the GS750ES forks aren't, the bolt holes in the fender were too far to the rear and at a slight angle when properly positioned over the tire, so the bracket had to compensate for that. When I was all done, the rear of the fender is 1" away from the tire, and the front is 1.1". Good enough.

It's amazing how much attention it takes me to get these sorts of little details correct.




Looks good . You might try some aluminum spacers and use ally strap to make the brackets. The reason is that ally will polish up and have a finished look. Does the fender (can't tell from the pictures) have a recessed area to keep the fender from rotating ? If it doesn't then the single bolt will allow it to rotate in the air stream. Just suggestions and things to look out for, yep mistakes I've made.
 

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Discussion Starter #512 (Edited)
Looks good . You might try some aluminum spacers and use ally strap to make the brackets. The reason is that ally will polish up and have a finished look. Does the fender (can't tell from the pictures) have a recessed area to keep the fender from rotating ? If it doesn't then the single bolt will allow it to rotate in the air stream. Just suggestions and things to look out for, yep mistakes I've made.
The fender is held on by two bolts per side. The rear bolts go through the fender's rear bolt hole into the fork legs, as normal.

Also, your posts all repeat the original message twice. You don't have to click both "quote" and "reply." The reply button automatically inserts the quote.
 

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This is a good approach! I need to learn that.
LOL nope I only hit reply and then "post a reply". I'm too old to be good with computers buy I'm also lazy so I hit as few keys as I can get away with. Don't know why this is happening ???
 
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