600rr M/C. Spongy Lever?
 

So I recently did the F4i Calipers & 600rr M/C with my existing stainless lines & Galfer HH pads. I bled the system three times & the lever is still slightly spongy.

I have the lever setting to 2, and when I brake the lever sinks down much more than i'd like it to.. It feels a little like my old superhawk lever.

A friend of mine is running SS lines and the same pads on his 03 R6, and his lever is STIFF.

Anyone have experience? Is the 600rr lever supposed to be a tad spongy?

I have a 954 MC on mine with RC51 calipers. I had thought they were the same specs, but also have more travel than I'd prefer. Once through the travel they are not spongy, but it does require the lever is positioned out aways. I'm guessing the piston is smaller and moves less fluid per unit of travel. I'm going to find an RC51 MC over the winter and compare. I might guess you might have a similar situation if its travel and not simply 'soft' indicating some air remaining in the lines.

Yeah, it's not so much spongy as it is more initial lever travel.
I have to pull on the lever 2/3-3/4 of an inch before the pads start grabbing caliper.
I can pull on the lever 2-3 inches back total.

954 MC & 600rr are 17mm
929 & RC51 are 19mm if i'm not mistaken..
I'm not sure on the piston sizes in the calipers though. I know 929/954 are different, but i'm not sure about F4i. I've read they have similar piston sizes to the 929, 34mm/32mm or something like that.

I'm going to try to overnight bleed with a zip tie to the M/C and also fully bed in my pads. I think after that the lever will be firmer, i'll report back.

2003-2004 CBR600RR mc 11/16” (17.4625 mm)
caliper pistons 32mm/30mm

2000-2001 CBR929RR mc 19mm
caliper pistons 34mm/30mm

2002-2003 CBR954RR mc 11/16” (17.4625 mm)
caliper pistons 32mm/30mm

2000-2001 RC51 mc 19mm
caliper pistons 34mm/32mm

2002-present RC51 mc 11/16” (17.4625 mm)
caliper pistons 32mm/30mm

1999-Present CBR600F4(i) mc 5/8” (15.87mm)
caliper pistons 34mm/32mm

thanks, anto and killer. then those numbers make sense. moving less volume of fluid with smaller piston diameter - I have the SP1 setup. I've bled mine and used stainless lines and am convinced its merely travel not air. betting you find the same anto.

Yes, a smaller mc piston will generate more braking force at the expense of more lever travel for a given amount of lever pressure. For what it's worth, I currently have a 600RR setup on mine, but I liked the F4i setup I had on there previously a little bit better; the braking power was awesome with the F4i setup (I have a 954 front end.). I suspect I still have a bit of air in the lines with the new setup, so I haven't switched back to the F4i setup yet.
I will add that I have friend who had a 2003 600RR that I rode and the brakes were awesome--really firm lever, easy to modulate and plenty of power. I know great brakes can be had with a 600RR setup.

I just added HEL stainless lines to my bike and I was having trouble getting them bled and feeling firm like every other bike I have ridden. I was bleeding the lines at the calipers which took almost a whole bottle of fluid before the lever got firm. Finally a shop called me back that I had called earlier cause I needed a banjo bolt, and I asked him what the problem could be.

I had pressure on the lever but it was still pulling in to far. He said to bleed the banjo bolt at the top and then bleed the calipers through the nipples. I bled the banjo twice and got perfect brake pressure for the first time ever.

you mean just opening the banjo bolt and treating it like a bleed valve? I did that when I first put lines in but have not recheched t ever - good reminder though.

Yeah, just pump the lever a few times, wrap the banjo bolt with a rag and loosen the bolt while squeezing the lever the rest of the way in. Then tighten and release the lever. Then bleed the lines at the calipers.

Not a bad idea. I think i'll do that when I install my 190 main & bleed the radiator again.