Rear Brake Useless?

Probably depends what you're used to...
Way better than a Multistrada (and most sports bikes), but not as effective as a typical older roadster.
Still good enough for the abs to kick in on mine on more than one occasion, although that would be the front taking weight of the rear to some extent.
You may not have abs but disc and caliper are probably the same.
Might be worth checking both pistons move freely in the caliper and sliders are well greased.
Pads may also be wrong spec?

 

mine is quite poor but does work try spinning wheel on stand and apply brake by hand,if it don't lock wheel up it deffo needs attention,doddle to work on try removing pads and pump pistons out but not too far get small toothbrush and either soapy water or brake cleaner give pistons a good clean,delboys garage has good videos if you are not sure.

 

I found that using soft organic pads (not sintered) worked best though of course you need your piston moving before the brake will work !

 

Speedtriple rear brake was rubbish around that era, had same probs on my 2004 and my old man did too on his ST which used the same rear master cylinder iirc

 

My '02 Daytona CE had a rear brake that was good enough to pass an MOT but very little else.

 

I had a 2000 S3 and the rear brake was hopeless, I had it checked and the mechanic said it was fine.

 

I’ve been motorcycling for over 45 years & the rear brake on my 2017 R is definitely the worst brake I’ve ever used.Had full brake service during 1st service ,,,still shite

 

My Speed triple RS had a rubbish rear brake, it was either doing nothing or kicking the ABS in with a jolt, After 3000 miles it is now working really nicely. Maybe they need more bedding in than usual?

 

Stick some super grippy pads in the back and use it a lot to bed them in should be acceptable then

 

Hope I'm not stating the obvious but when was the last time they were bled?
A mate of mine was complaining about the same thing and all I did was bleed it out. He could feel the difference straight away.
All you need is a length of 6mm ID hose and an 8mm spanner. Easy to do a one man job on the rear. While you are there check the pads and give the rear disk a good clean with some brake cleaner. Get the back end off the deck and run the wheel round with your hand and hit the brake just to check that it is working but just be aware that there's a lot more weight on the brakes when the bikes propelling itself (stating obvious for sure there) Don't forget to top up the reservoir. Brake problems on non ABS bikes are never a complicated fix. It's either worn pads, slippery disks, air in the fluid or drippy unions (Banjo bolts and crush washers)

ALWAYS PUMP OUT THE PISTONS AFTER DOING ANY WORK ON YOUR BRAKES

A lad I know took his for a service by a 'PROFESSIONAL' and they didn't pump them out and when we went to apply his brakes they weren't there...................