Let’s think about the rear brake configuration.
I’ve been thinking about what to do with the rear brake for a while now.
This time the wheel is a Marchesini 18-inch for the GSX1100S. Using a Katana rotor was too easy, so I ruled that out. A cool rotor means a small one.
So I was stuck thinking about it and feeling a bit lost.
While patrolling auction sites and similar marketplaces,
“( ,,`･ω･´)ﾝﾝﾝ？ I found an F1 rotor!
I grabbed it right away and it arrived.
On my GS1000S, I’m using a ventilated rotor from an RGB500. As you’d expect from Suzuki… the PCD for rotor mounting is the same. (The center bore is different in shape, so I need to enlarge it and there’s a step.) Since I knew about this trick, it worked out perfectly this time.
• The rotor looks cool
• No need to make a rotor inner hub
• Result: time savings and cost reduction
The problem is there’s no spare. I guess worst case I could have one made from 4130 steel.
Could it be? Since the hub is so similar, would the ventilation work too?
If they were identical, this would be a bonus three times over, maybe? But when I checked with the spare, there were slight differences. It’s not that easy.
Well, let’s call it good.
The wheel side has a stepped 56mm diameter, so I want to fit it to this.
This rotor uses a somewhat unusual modern method with bearings on the hub side. I’m going to push ahead with this, even though it’s a shame.
I remove the bearings and… there’s a bittersweet feeling about cutting into a rare part. After machining, it’s magnesium, so I really need to clean up the area thoroughly or it could be serious.
The inner diameter is a perfect fit.
The back side is cut until the step is gone. There’s plenty of clearance around the wheel, so it’s easy. I could push it further, but let’s consider balance.
After enlarging the inner diameter and cutting the step, it now fits on the wheel.
*It’s covered in chips because the compressor is still acting up and I can’t blow it clean with air.
Another shortcut idea.
Making a caliper bracket is quite labor-intensive. This time, I’m using one where the rotor outer diameter and caliper pitch matched, and adjusting the positional relationship. For customers, making one from scratch might be more efficient.
Thankfully, the OEM bracket is only about 4000 yen. I’m grateful.
The caliper bracket is from a GSXR1000. There are two types, and after deliberating, I chose the later version positioned as close to the swingarm as possible.
Since the axle is thick, I use a stepped spacer to match the inner diameter and center it.
*This is still a dummy spacer. The real one will be press-fit.
The caliper is from a ZZR1400.
Suzuki doesn’t seem to have this gray anodized aluminum piston version. When I searched, it looked like MOS calipers might have the same pitch too, which I thought was interesting.
This time I wanted to keep it simple, and since I don’t like noise or uneven wear, I’m going rigid.
The outer pillow ball fixing on the caliper bracket is now acceptable in recent times.
When the OEM uses rod fixing, it seems to be at the caliper center. “If you’re pulling the rear caliper straight, center it” is the safe bet.
OEM parts are made with careful consideration by the manufacturer.
