Rear caliper

[Jlq1969]

Why in the S10 the rear floating caliper, is attached with this bar? .. My opinion is that it is to prevent the rear fork from compressing when braking whit the rear brake only, and with the bar, transmits that compression force of the wheel to the swingarm axis (i.e. towards the front wheel) I see that other yamaha (v max or fjr) .. share similar caliper, but are anchored to the tip of the swingarm. And if it is to prevent compression of the rear spring, why others do not use it? .... that is my doubt

 

[azb]

Some bikes do use the rod. It's a bit more effective on bikes with longer swingarms like the S10 as it makes the rod longer, and as it's essentially a lever, a longer lever has more leverage.

Yamaha was brilliant in this part of the S10's design, as it's so simple yet so effective.

 

[OldRider]

The only thing that rod does is keep the brake caliper from spinning with the disk when the brake is applied.

 

[Jlq1969]

The only thing that rod does is keep the brake caliper from spinning with the disk when the brake is applied.

So why didn't they just anchor him to the tip of the swingarm like other adventure motorcycles of other brands with a long swingarm?
The guzzi stelvio also has the bar, but anchored to the rigid final transmission, such as the s10. In the case of the Triumph 1200, it also has the bar, but the final transmission is mobile like the GS,in this case it is understandable

 

[Sierra1]

Good question. But, I also noticed that the picture(s) without the rod are chain drive.

 

[blitz11]

It's because of the shaft drive. With a chain, you can slide everything in one motion into the swing arm. With the shaft, you have to keep the wheel to the right (on the Tenere) to clear the final drive pumpkin, and the slide the wheel to the left to engage the bosses into the final drive rubber dampers. Once the bosses/damper is/are engaged, then you can slide the caliper carrier into its proper space, and insert the axle.

 

[WJBertrand]

Dynamically, I don't think it makes any difference where the caliper is anchored on the swing arm. There may be some strength advantage anchoring it to the beefed up area near the pivot as opposed to what is probably a thinner section out at the tip of the swing arm.

 

[OldRider]

So why didn't they just anchor him to the tip of the swingarm like other adventure motorcycles of other brands with a long swingarm?

It's like blitz11 said above. With a chain drive you can slide everything out the back, but with the shaft drive you have to remove the caliper in order to slip the wheel off the splines. That bar has nothing to do with the suspension, it just holds the caliper in place.

 

[Clawdog60]

Thank goodness my DS tire clears it by a couple of mm. Thanks yammie maamie.

 

[Jlq1969]

I don't think that simple bar is to hold the caliper in a swingarm with chain

 

[OldRider]

I don't think that simple bar is to hold the caliper in a swingarm with chainView attachment 63560

I don't think that's a simple swingarm with chain.

 

[blitz11]

I don't think that simple bar is to hold the caliper in a swingarm with chainView attachment 63560

There are two different ways to react against the moment generated by the brake reacting with the disc - "ground" the caliper to the frame, or "ground" the caliper to the swingarm. On the road race bike, the brake is being grounded to the frame of the bike.

In the 1970's & 80's the big "deal" was to ground the brake to the frame on dirt bikes to "isolate" the torque reaction. If you do the math, the effect is small, which is why dirt bikes today all "ground" the caliper to the swing arm. Jeff Ward's KXin a motocross de nations from the early 1980's shows the "ground" to the frame.

Jeesh. That swingarm is tiny! must be a 125.

 

[Highwayman]

I miss those days of "works" bikes. Especially HRC stuff!

 

[Jlq1969]

I don't know if the effect of the “rear brake torque arm” is small or not, but, if the motorcycle has the rear caliper anchored to the swingarm, and someone presses the rear brake, you can easily push and compress the rear spring. In a caliper anchored with a torque bar, you can press and compress the rear spring, but if someone applies the rear brake, it will no longer be so easy to compress the rear spring (pushing down the body is the same effect as the swigarm is lifted, the spring is compressed)

 

[OldRider]

I don't know if the effect of the “rear brake torque arm” is small or not, but, if the motorcycle has the rear caliper anchored to the swingarm, and someone presses the rear brake, you can easily push and compress the rear spring. In a caliper anchored with a torque bar, you can press and compress the rear spring, but if someone applies the rear brake, it will no longer be so easy to compress the rear spring (pushing down the body is the same effect as the swigarm is lifted, the spring is compressed)

None of this road racer brake stuff has anything to do with your original post.

"Why in the S10 the rear floating caliper, is attached with this bar? .. My opinion is that it is to prevent the rear fork from compressing when braking whit the rear brake "


The S10 brake holder rod has no job other than to hold the caliper in place.

 

[Clawdog60]

Yeah it’s not a torque arm. No effect on chassis forces at all.

 

[Sierra1]

That's ok, I'm still not understanding why the caliper is different between shaft and chain. It still looks like the axle is going through the caliper assembly. And, I still don't understand why shaft drive bikes can't secure the caliper to the swing arm like chain drive bikes. For the most part, I don't care, 'cuz it works. But, if wasn't for that bar, I could put a bigger (wider) tire on the rear.

 

[Jlq1969]

That's ok, I'm still not understanding why the caliper is different between shaft and chain. It still looks like the axle is going through the caliper assembly. And, I still don't understand why shaft drive bikes can't secure the caliper to the swing arm like chain drive bikes. For the most part, I don't care, 'cuz it works. But, if wasn't for that bar, I could put a bigger (wider) tire on the rear.

https://en.wikipedia.org/wiki/Shaft_effect

 

[OldRider]

That's ok, I'm still not understanding why the caliper is different between shaft and chain. It still looks like the axle is going through the caliper assembly. And, I still don't understand why shaft drive bikes can't secure the caliper to the swing arm like chain drive bikes. For the most part, I don't care, 'cuz it works. But, if wasn't for that bar, I could put a bigger (wider) tire on the rear.

Here's the deal. On chain drive bikes you can pull the axle, set the chain aside and pull everything straight out the back.

On "most" shaft drive bikes you pull the axle, take off the caliper holder arm, remove the caliper, slide the wheel to one side and pull it out.

You said "I still don't understand why shaft drive bikes can't secure the caliper to the swing arm like chain drive bikes" Well a lot of them do. Take the Honda 1500 Goldwing. It has a bolt that goes through the swingarm into a hole in the caliper to keep it in place. It's the same on the VTX 1300 and VTX 1800. Honda has a lot of models that use a bolt through the swingarm instead of an arm to hold the caliper in place. It works the same as the slot chain drive bikes use except you can remove it.

 

[Jlq1969]

These types of motorcycles (1500-1800)are heavy, long wheelbase and the shockabsorves are anchored in the tip of the swingarm, the compression effect of rear swingarm, using rear brake by shaft transmission are diminished
I take this opportunity to correct what has been said above. The FJR does have an arm that holds the caliper, but hidden between the wheel and the swingarm