Topic: Structural integrity of Stock forks w/ out fender?

[mlinder]

Goo, people believe all kinds of things that break all the rules of "physics for dummies" if it suits their taste in aesthetics. I don't really get it.

I mean, sure, run without a brace, and admit to yourself and others that you have, in fact, compromised stability and safety, but own up to the fact that you are making this decision for the sake of aesthetics at the cost of performance.

Too many people trick themselves into believing stuff that isn't true so that something can look cool.

Like I said, it's fine to compromise the bikes integrity for looks, as long as you don't fool yourself or anyone else into thinking it hasn't compromised safety, stability and performance.

[nokrome]

get one of these http://www.fastfromthepast.com/servlet/the-Fork-Braces/Categories then you can look cool and still be safe.
   i run one and my bike is rock solid at 100+ mph

[bwaller]

Mark, I don't consider the fender bracket much of a brace, but that said it is better than having nothing on there, the evidence is obvious in the mentioned flex test. Having a real leg brace is even more obvious.

Guys should be more innovative, if they mount an aftermarket brace they can incorporate a fender too, it doesn't need to be one or the other.

While we're talking stiffness, a 20mm axle and an aftermarket brace is a huge step in that direction.

 

[mlinder]

Mark, I don't consider the fender bracket much of a brace, but that said it is better than having nothing on there, the evidence is obvious in the mentioned flex test. Having a real leg brace is even more obvious.

Guys should be more innovative, if they mount an aftermarket brace they can incorporate a fender too, it doesn't need to be one or the other.

While we're talking stiffness, a 20mm axle and an aftermarket brace is a huge step in that direction.

 

Not arguing that there are better braces. Arguing that the stock brace is in fact useful, important and safe.

[jakecb420]

Anyone have any pics of just the stock brace with the fender detached?

   i planned on using a two piece brace that bolts from one fork upper to the other and not using the stock fender and brace at all. (76 750f) maybe i should rethink my thinking. i am more concerned with handling than looks. but like everyone else, i am on a budget.

[Goofaroo]

Goo, people believe all kinds of things that break all the rules of "physics for dummies" if it suits their taste in aesthetics. I don't really get it.

I mean, sure, run without a brace, and admit to yourself and others that you have, in fact, compromised stability and safety, but own up to the fact that you are making this decision for the sake of aesthetics at the cost of performance.

Too many people trick themselves into believing stuff that isn't true so that something can look cool.

Like I said, it's fine to compromise the bikes integrity for looks, as long as you don't fool yourself or anyone else into thinking it hasn't compromised safety, stability and performance.

I understand the aesthetic thing and that is obviously the driving force on a lot of builds. You see cafe bikes that have been lowered to the point they look like they don't even need a kickstand. No problem if that is the look that you want and it will be immediately apparent when the pipe drags that you just can't ride at the same pace as you can with more cornering clearance No problem. As far as I'm concerned and for the purpose of this forum, when someone decides that they like the look of bar mounted pinwheels and rubber lizards glued all over their bike, we need to appreciate that in their eyes it a work of art, offer two thumbs up, and be glad that we don't all ride the same bike. If the people of this forum didn't have minds of their own they wouldn't be here, they would be at the Harley shopping picking out a new leather halter for the wife and a newly released shot glass for themselves.

My concern about the fork brace issue is that it is an integral part of the fork design. I'm sure that we have many riders here that will never push their bike to a point that the brace will even come into play but to accommodate riders of all skill levels, the message should be to please leave the brace in place or replace it with a suitable aftermarket item.

[mlinder]

Jake, here's one I did on a kz440.

You can barely see it if you paint it black. Blends in with the tire.

[mlinder]

Goo, people believe all kinds of things that break all the rules of "physics for dummies" if it suits their taste in aesthetics. I don't really get it.

I mean, sure, run without a brace, and admit to yourself and others that you have, in fact, compromised stability and safety, but own up to the fact that you are making this decision for the sake of aesthetics at the cost of performance.

Too many people trick themselves into believing stuff that isn't true so that something can look cool.

Like I said, it's fine to compromise the bikes integrity for looks, as long as you don't fool yourself or anyone else into thinking it hasn't compromised safety, stability and performance.

I understand the aesthetic thing and that is obviously the driving force on a lot of builds. You see cafe bikes that have been lowered to the point they look like they don't even need a kickstand. No problem if that is the look that you want and it will be immediately apparent when the pipe drags that you just can't ride at the same pace as you can with more cornering clearance No problem. As far as I'm concerned and for the purpose of this forum, when someone decides that they like the look of bar mounted pinwheels and rubber lizards glued all over their bike, we need to appreciate that in their eyes it a work of art, offer two thumbs up, and be glad that we don't all ride the same bike. If the people of this forum didn't have minds of their own they wouldn't be here, they would be at the Harley shopping picking out a new leather halter for the wife and a newly released shot glass for themselves.

My concern about the fork brace issue is that it is an integral part of the fork design. I'm sure that we have many riders here that will never push their bike to a point that the brace will even come into play but to accommodate riders of all skill levels, the message should be to please leave the brace in place or replace it with a suitable aftermarket item.

Correct. I just don't like people saying that the brace doesn't do anything. It clearly does, and is an important safety feature. People can be steered wrong in this direction, and it may cause injury.

Experienced riders who make this decision knowingly, that's OK. But to people that dont understand the risk, I do not like misinformation being passed on to them.

[Goofaroo]

Anyone have any pics of just the stock brace with the fender detached?

I posted a pic earlier in the thread. Obviously with mine not mounted on the bike and my garage looking like a CB500 yard sale, I don't have a good look at the forks assembled with the wheel installed but I'm guessing that it is shaped like it is (bowed) for wheel clearance. The aftermarket brace on my BMW replaces a brace very similar to the one on the Hondas but it is comprised of two hoops that cross over the top of the fender instead of under it.

[Goofaroo]

Here's a pic of the aftermarket one on my BMW (my embarrassingly filthy BMW). It might give you some ideas if you wanted to fabricate something to replace the original brace. As you can see it simply moves the fender mount from bottom to top using the factory mounting holes and hardware.

[mlinder]

I posted a pic above of a stock fork brace on a kz. It'll look more or less the same on a cb.

[srook]

Goo, people believe all kinds of things that break all the rules of "physics for dummies" if it suits their taste in aesthetics. I don't really get it.

I mean, sure, run without a brace, and admit to yourself and others that you have, in fact, compromised stability and safety, but own up to the fact that you are making this decision for the sake of aesthetics at the cost of performance.

Too many people trick themselves into believing stuff that isn't true so that something can look cool.

Like I said, it's fine to compromise the bikes integrity for looks, as long as you don't fool yourself or anyone else into thinking it hasn't compromised safety, stability and performance.

Are you serious with this?  No body owes you an explanation for anything they do, period.  Own up to what exactly and to who?  If the fender mount is so integral to the correct action of the front forks then why did so many racers of the early 70s with single discs opt for a lighter weight fiberglass fender or none at all?  Wouldn't they be better served to run a lighter weight fender mount like the Honda one?

Harley Davidson KR and XR roadracers ran no front fender or brace.
BSA/Triumph racing Triples ran no front fender, a few ran with a brace but they were added much later.
In fact the pics of Dick Mann running around Daytona in 1970 show that the Honda was one of the few racers that even had a front fender but it wasn't held on by a brace.  Are you saying that racers and factory race teams left the fenders off for looks becuase they didn't understand "physics for dummies"?

The safety police thing gets real old.  We are all big boys and girls and we can make whatever decisions we want without having to justify them to you.

Scott

[MCRider]

Anyone have any pics of just the stock brace with the fender detached?

   i planned on using a two piece brace that bolts from one fork upper to the other and not using the stock fender and brace at all. (76 750f) maybe i should rethink my thinking. i am more concerned with handling than looks. but like everyone else, i am on a budget.

The brace of which you speak, is the ubiquitous aftermarket piece, likely stronger than the factory piece which is a multipurpose compromise. Going from the top of one fork leg to the other is best in my mind.

Problem with the earliest CB750s is that the tops of the fork leg is lower than the top of the tire by a fair amount, and the fender brace is the only option other than a custom piece.

[mlinder]

Are you serious with this?  No body owes you an explanation for anything they do, period. 

Never said they did. I said they had a responsibility to understand that the brace, does, in fact increase stability and safety, and to say otherwise is wrong and irresponsible. Many new riders might believe you.

Own up to what exactly and to who?  If the fender mount is so integral to the correct action of the front forks then why did so many racers of the early 70s with single discs opt for a lighter weight fiberglass fender or none at all?  Wouldn't they be better served to run a lighter weight fender mount like the Honda one?

Why do newer bikes, especially race bikes, have braces? Also, do you think that even for a minute that Johnny -Cafe-Come-Lately from Nebraska has ANYWHERE near the setup a CR 750 had in '70?

My guess is no.

Harley Davidson KR and XR roadracers ran no front fender or brace.

That's great. They would now if they had race bikes.

BSA/Triumph racing Triples ran no front fender, a few ran with a brace but they were added much later.

Interesting how braces keep getting added 'later'. Crazy, I know, right?

In fact the pics of Dick Mann running around Daytona in 1970 show that the Honda was one of the few racers that even had a front fender but it wasn't held on by a brace.  Are you saying that racers and factory race teams left the fenders off for looks becuase they didn't understand "physics for dummies"?

Still more of the 'added later' stuff. Maybe they started catching on  becuase they were, you know, better, safer, and made more sense?

The safety police thing gets real old.  We are all big boys and girls and we can make whatever decisions we want without having to justify them to you.

Scott

You sure are taking this personally. And, it's pretty screwed of you to assume that everone who has a motorcycle has enough experience to make a decision like this and compromise their safety.

There's a reason this question was asked.. It's because the person didn't know. And if you tell him the brace doesnt do anything fo the bikes safety and stability, you'd be wrong, lying, or delusional. None of which are safe for passing on information.

[mlinder]

Ah, srook, now I see why you are taking this personally. Your Dunstall build currently has no fork brace.

[seanbarney41]

looking at the most beautiful motorcycle falls far short of riding a properly performing motorcycle

[MCRider]

looking at the most beautiful motorcycle falls far short of riding a properly performing motorcycle

I mean really. All you've got to do is ride one with a brace and one without, the difference is amazing. Doesn't matter if its old or new, 35 mm tubes or 45 mm tubes. The advantages of a brace can be felt by the least sophisticated of riders.

The fact that a bunch never had them doesn't change that fact.

[Goofaroo]

Early telescopic forks didn't have a brace. As the development of the forks evolved the braces were added. In vintage road racing most organizations don't allow a brace on a bike that was not equipped with one in it's original state. That would be an unfair advantage.

[Retro Rocket]

Goo, people believe all kinds of things that break all the rules of "physics for dummies" if it suits their taste in aesthetics. I don't really get it.

I mean, sure, run without a brace, and admit to yourself and others that you have, in fact, compromised stability and safety, but own up to the fact that you are making this decision for the sake of aesthetics at the cost of performance.

Too many people trick themselves into believing stuff that isn't true so that something can look cool.

Like I said, it's fine to compromise the bikes integrity for looks, as long as you don't fool yourself or anyone else into thinking it hasn't compromised safety, stability and performance.

Are you serious with this?  No body owes you an explanation for anything they do, period.  Own up to what exactly and to who?  If the fender mount is so integral to the correct action of the front forks then why did so many racers of the early 70s with single discs opt for a lighter weight fiberglass fender or none at all?  Wouldn't they be better served to run a lighter weight fender mount like the Honda one?

Harley Davidson KR and XR roadracers ran no front fender or brace.
BSA/Triumph racing Triples ran no front fender, a few ran with a brace but they were added much later.
In fact the pics of Dick Mann running around Daytona in 1970 show that the Honda was one of the few racers that even had a front fender but it wasn't held on by a brace.  Are you saying that racers and factory race teams left the fenders off for looks becuase they didn't understand "physics for dummies"?

The safety police thing gets real old.  We are all big boys and girls and we can make whatever decisions we want without having to justify them to you.

Scott

Srook, sorry mate but you are completely wrong, and comparing what we know about suspension now to 40 year old technology just  doesn't cut it. I am no racer but ride hard {or i used to  } and have experienced exactly what mlinder is talking about several occasions and i mean several.!! I always use a brace and a steering damper and so did my mates that raced these bikes and that was in the late 70's and early 80's.
Instead of posting flawed information at the risk of someone believing what you say, go do some research or reading on the subject. There is a huge amount of flex in these bikes if ridden hard especially in the flimsy front end. No one who races these bikes these days does so without a brace, our understanding of suspension performance has gone through major changes since these old bikes were made and my concern is the same as mlinders, that some one will believe what you say and injure themselves in the process. My Gsxr had far more substantial forks and clamps than my Honda's, 43mm, and they have a far stiffer brace, so have the rest of the bikes i have owned. Do you think that the manufacturers got it wrong.? Do a little reading mate, you will soon find all the answers that you need.....

Mick

[Goofaroo]

Well Free Booter, you opened a can of worms. Now what is your plan? 

[Retro Rocket]

Well Free Booter, you opened a can of worms. Now what is your plan? 

You know , its not a can of worms at all, its a great chance for the members to learn a bit about suspension function and what you can do to improve the handling of our bikes. It is quite obvious that there is a lot of Misinformation doing the rounds and any chance to clear up a few misconceptions has got to be good. There will still be guys that don't believe what we are saying but that is going to be their problem, not mine. Taking the brace off a bike with matchstick forks doesn't take much thinking to realise that it WILL effect the handling of these bikes.....

Mick

[jakecb420]

here is a picture like the one i have. it came off a parts bike i bought that has what im guessing are 4" over forking by frank forks.
has anyone run one of these? or is this kind of brace really just for extended forks?

The brace of which you speak, is the ubiquitous aftermarket piece, likely stronger than the factory piece which is a multipurpose compromise. Going from the top of one fork leg to the other is best in my mind.

is this the ubiquitous piece you speak of? thanks

[Retro Rocket]

They are mainly for extended forks Jake, on standard forks they would have to sit directly under the bottom triple clamp and in that position it may add a small amount of stiffness but any brace will be more effective closer to the top of the wheel, mid way down the forks.

Mick

[MCRider]

here is a picture like the one i have. it came off a parts bike i bought that has what im guessing are 4" over forking by frank forks.
has anyone run one of these? or is this kind of brace really just for extended forks?

The brace of which you speak, is the ubiquitous aftermarket piece, likely stronger than the factory piece which is a multipurpose compromise. Going from the top of one fork leg to the other is best in my mind.

is this the ubiquitous piece you speak of? thanks

No, What you have is/was referred to as a "tweak bar" rather than a "fork brace". The tweak bar goes between the tubes, rahter than the legs. The one you show is one of the weaker ones as it only clamps to the inside of each tube. Where the clamp wraps around, there should be another clamp to really keep the tubes from twistig. Tweak bars are normally used with extended front ends, but as the text says in the CycleX tweak bar posted earlier it will positively affect stock length tubes as well. Problem is it may foul the fork lock, or brake hoses etc on a stocker.

The one I'm referring to is like this:
http://www.superbrace.com/index.asp
Going from the top of one lower leg to the other. Doing this makes a structural rectangle out of the legs, axle, and brace. Very rigid.

[MCRider]

Any time you grab more tube, as with the tweak bar on a stocker, even on our skinny tubes you will quickly improve the stiffness. Often when guys go/went about improving the old forks, one way is to weld another clamp to the bottom of the lower clamp making it double thick. Holding just a bit more of the tube can do a lot.

But best is the top of lower leg clamp.