Rear brake bar mod

Always thought the brake bar was to close to the tire so I did a simple modification see photos

If you check regularly, that everything is in place, that's fine. I can't calculate the braking force on that bolt, but at least it should be some calculation using the weight of the bike + weight of the rider + inertia of the wheel .... only that before, that was divided into "two supports" of the screw, and now that same force is in "only one support" .... something like a lever on that screw, which eventually "maybe" bends the screw, or deforms the hole of the caliper, whatever Softer....But the job looks good

Did you ever have the tire actually rub on bar? I have not ,yet.

Well, I wouldn’t mess with Yamaha’s engineers calculations as well. It looks a good job but way to dangerous. Like @Jlq1969 said the “lever effect” on that bolt is unpredictable.
BTW the “weight” is “mass” actuality. The mass remains the same, the weight shifts to the front when brakes are applied and then you have less friction (tire/road) on the rear wheel.The amount of friction/grip is what it counts on this, since no mass is supported by this bar/bolt.
Ok enough of this technical (I hope it makes sense, English is not my language)

Fordf350 said:

Did you ever have the tire actually rub on bar? I have not ,yet.

Click to expand...

I don't think it would ever rub, but it does prohibit mounting a wider tire on the wheel. I have to assume there's a reason that Yamaha doesn't want a wider tire mounted on the back.

Don't remember who and the photos were years back, but there is at least one of our bikes with a welded addition to the brake link to allow a wider rear tire.

Checkswrecks said:

Don't remember who and the photos were years back, but there is at least one of our bikes with a welded addition to the brake link to allow a wider rear tire.

Click to expand...

It is the closest I remember. If it's a long time before, I already erased it from my brain. It is that my brain only has 2Gb of capacity and I use 1Gb just to not forget the anniversary of my marriage

Sierra1 said:

I don't think it would ever rub, but it does prohibit mounting a wider tire on the wheel. I have to assume there's a reason that Yamaha doesn't want a wider tire mounted on the back.

Click to expand...

I believe that nearly all adventure bikes, for example the R1100, 1150, 1200GS and any others with the 19” front, 17” rear wheels all had similar size tyres with a 150 section rear being more or less the category standard for that era. It is only relatively recently with the advent of more and more powerful motors that adventure bikes have started to wear a 170 section rear tyre. It is to handle the power on tarmac roads not necessarily for the dirt. The SuperTen is from the earlier era of less powerful adventure bikes. Personally, I’ll stick with what Yamaha designed and supplied.

I was looking to mount a wider tire for a greater lean angle. With the OE 'stones, I could only lean so far before they began to wiggle. Looking at the chicken strips, the front tire still had some useable tread left. . . . the back tread was being used completely. And, even leaned over enough to use the entire tread, at no time have I dragged a peg. My guess is that's due to having the preload cranked up for my lard ass. I have noticed that my A41s have a similar amount of tread being used on both front & back. It has to be a tire profile thing. She leans over far enough for 99.99% of my riding, so yeah, I too am sticking with Yamaha's design.

I think the reason for the brake arm mod is for the very popular modification of fitting a 175/55R17 tire on the back. This tire is so popular that all the local Yamaha dealers are having a hard time keeping them in stock for the Super Tenere. I'm kind of odd as I choose to use the OEM size.

Seems like if that actually was the case there would be all kinds of Tenere owners attempting this modification but this is the first time I remember seeing anything about it.

ballisticexchris said:

I think the reason for the brake arm mod is for the very popular modification of fitting a 175/55R17 tire on the back. This tire is so popular that all the local Yamaha dealers are having a hard time keeping them in stock for the Super Tenere. I'm kind of odd as I choose to use the OEM size.

Click to expand...

this mod above, has been done buy somebody else on here last yr but can,t remember who it was

rob

yer,
found it

rob

Sierra1 said:

I don't think it would ever rub, but it does prohibit mounting a wider tire on the wheel. I have to assume there's a reason that Yamaha doesn't want a wider tire mounted on the back.

Click to expand...

Just ran across this video

Yeah, I've played with the numbers, sizes, on cars. . . . but they are nowhere near as critical as a bike.

I definitely would NOT do that.

As I see it the brake torque arm is integral to the strength and efficiency of the braking system. You really need to know what your'e doing if you are safely going to modify your brakes and would rather trust the Yamaha technicians especially as I can't recall reading about a single failure of this component.

Would the modification put more pressure on the caliper mounting point?

I think the OP has created a solution for a problem that does't exist

Disclaimer....The OP might be a very highly qualified engineer and my opinions could be absolute tosh!

Mike

bimota said:

yer,
found it

Rear brake torque arm mod

Howdy folks, All this time at home likely has many of us doing projects. Does the tight torque arm clearance bother anyone else? I wonder what problems could come from moving it outward? Maybe tack weld a sleeve to reinforce the opposite end? How much torque does this thing really experience...

www.yamahasupertenere.com

Click to expand...

Nope. Different bike. The one I'm thinking of had a car tire which was why the owner modified the bar. iirc he cut a piece of square aluminum bar and welded it to the outboard side of the original which was then cut away for the tire to clear. The result was solid, pretty slick, and would be easy for somebody with a welder.

As for the OP photos, it's going to put torsion (twisting) loads on the ears of the caliper at the rear and the swing arm at the front. For most of us in normal use it probably wouldn't matter but I'd not want to put repeated heavy braking loads on it for a long period of time.

no,
i just ment somebody else had done that mod similar to the op's on here before

rob

There are north of a million miles on brake torque arms replacing the Yamaha design with a steel or stainless steel flat bar. The most common form is 3/16" thick x 3/4 wide flat bar, mounted to the outside of the tabs. It's stronger than the OEM and there have been zero incidents of deflection or deformation. All it takes is a foot of flat bar, use the OEM part for a template to mark and drill three new holes. Note that the hole for the tie wrap is a different size than the bolt holes. Round off the ends after trimming to correct length so they don't bind when the swing arm moves.

I pioneered this on the FJR and tested it myself for 70k miles under all conditions, on and off road. Zero issues. The arm is in tension on the FJR, on compression with the Super Ten and there really isn't much room for side to side movement in the suspension. I've seen some modified OEM bars that I would not choose to use. I've also seen as thin as 5/32" thickness of steel bars used w/o incident for over 100k miles.

These steel arms have been used on track days and just about any form of extreme use you can think of w/o failure. Risk assessment is a personal thing, but from my actual, first hand experience, this is not a big deal. I would not choose to do what the OP has done, but I don't think there is any risk of failure either, since I've seen that exact mod done and survive tens of thousands of miles of abuse and normal street use.

Edit - The reason for the mod on the FJR was to run, or be able to run, a car tire in the 205/50-17 size, the narrowest commonly available size. Some riders did this prior to an Alaska trip or 48 state ride so if they got in a bind and needed a tire, the CT was at least an option they were prepared to choose if they couldn't get a moto tire. Others just did it for the longevity. 30-40k rear tire life instead of ~10k.

EricV said:

The arm is in tension, not compression

Click to expand...

True for the FJR, but not true for the Super Tenere.