Modifications - Performance Discuss aftermarket and DIY performance modifications

RC51 Brakes vs VTR, Upgrade pics and review

Thread Tools
 
Search this Thread
 
Old 06-09-2007, 11:38 PM
  #1  
Junior Member
Squid
Thread Starter
 
Flight_996's Avatar
 
Join Date: Jan 2007
Posts: 28
Flight_996 is on a distinguished road
RC51 Brakes vs VTR, Upgrade pics and review

Hi all,

I thought id post some pics of my brake upgrade. I was able to score an RC51 caliper set and master cylinder for my baby hawk. The difference was astonishing, and well worth the investment.

I had to machine the calipers just like some of the other members on the forum. When I was researching it though, I found it hard to tell just how much to take off. Fortunately, I was able to bring my old bent VTR fork to the machine shop and continually test fit as I machined it away. There are some close up pics as well as a comparison between the caliper and MCs. Note the RC lever is bent--that is not normal and I fixed it since installing the MC.

http://combier.net/images/RCbrakes001.JPG.
http://combier.net/images/RCbrakes002.JPG
http://combier.net/images/RCbrakes003.JPG
http://combier.net/images/RCbrakes004.JPG
http://combier.net/images/brakecomparsion.JPG


I also sketched a subjective braking power "feel" diagram. The RC overall has much more powerful feedback. You really feel like you can endo the bike with one finger. Interestingly, the trail-braking is much more usable with the RC brakes as well. On the sketch there are the both the lever depress and lever release curves. I hope this plot makes some sense, keep in mind it is completely subjective. An engineer might say that they are equal (and I leave that open to debate).

Enjoy!

-Robert C.
Atlanta, GA
Flight_996 is offline  
Old 06-10-2007, 04:44 AM
  #2  
Senior Member
Superstock
 
Anto's Avatar
 
Join Date: Mar 2007
Location: San Diego
Posts: 268
Anto is on a distinguished road
Nice. I love the professionally made scientific graph chart
Anto is offline  
Old 06-11-2007, 06:41 AM
  #3  
Member
Squid
 
Babelfish's Avatar
 
Join Date: May 2007
Location: Akershus, Norway
Posts: 99
Babelfish is on a distinguished road
Originally Posted by Flight_996
Hi all,

I also sketched a subjective braking power "feel" diagram. The RC overall has much more powerful feedback. You really feel like you can endo the bike with one finger. Interestingly, the trail-braking is much more usable with the RC brakes as well. On the sketch there are the both the lever depress and lever release curves. I hope this plot makes some sense, keep in mind it is completely subjective. An engineer might say that they are equal (and I leave that open to debate).
If the actual feel were like the diagam those original brakes must have had some air inside or a very badly worn main sylinder.

To me it seems like brakes are almost like tires. People compare rotten apples and fresh oranges and the oranges always come out on top. Strange?
I'm sure the RC51 brakes are better. Larger pots and better main pump, non the less, without fresh, air free liquid, same hoses, same pads and rotors a comparison become tintet by those variables.

With my new EBC Rotors and pads I can't ask for more. Quite a difference from warped original rotor and worn, dirty pads. 2 fingers are never stressed to do a stoppie or a controlled front slide at with and no problem controlling them. And the lever position is more like your RC51 diagram: Just pressure deciding the power, little to no movement. Had a non warped rotor on for a few days with the dirty old pads and it was ok, just harder and less initial bite.
Babelfish is offline  
Old 06-11-2007, 09:27 AM
  #4  
Senior Member
SuperSport
 
SlowHAWK's Avatar
 
Join Date: Jun 2004
Location: Thornwood, NY
Posts: 817
SlowHAWK is an unknown quantity at this point
I did new EBC HH pads, Galfer Steel Braided Lines on the stock brake setup before swaping to the RC51 MC and Calipers (with a new set of EBC HH pads as well) and the same steel lines... and the RC stuff felt like a huge improvement...

So I'd say there is a noticable improvement between the two steups using the same playing field...

I haven't heard person who's made the swap say they brakes weren't vastly better... but that is all seat of the pants... so take it for what it's worth I guess.

J.
SlowHAWK is offline  
Old 06-11-2007, 09:34 AM
  #5  
Junior Member
Squid
Thread Starter
 
Flight_996's Avatar
 
Join Date: Jan 2007
Posts: 28
Flight_996 is on a distinguished road
If the actual feel were like the diagam those original brakes must have had some air inside or a very badly worn main sylinder.
I highly doubt there was air. I replaced the fluid and bled the brakes not 2 months ago, and the feel hasn't changed since then. My bike has 40k, so yes, maybe my master cylinder was worn out.

To me it seems like brakes are almost like tires. People compare rotten apples and fresh oranges and the oranges always come out on top. Strange?
I'm sure the RC51 brakes are better. Larger pots and better main pump, non the less, without fresh, air free liquid, same hoses, same pads and rotors a comparison become tintet by those variables.
Good point, although it doesn't invalidate my test. I used the same exact rotors, with the same exact (stock) VTR lines, both sets of pads were EBC and not new.

What I was trying to illustrate was that it takes MUCH less lever effort (pressure) and less lever displacement to stop the bike. So much so that I was bottoming the forks for the first 10 miles or so until I got used to them.

I'm not bashing the VTR brakes. I always thought they were plenty good. However, for the $100 that I spent in used parts, (not including the income from selling the old parts), the difference is amazing. To me, stopping is as important as going (and turning), and I've already done a 15/43 520 conversion and a set of Pilot Powers, so this was next. Next up is suspension ($$$)...

I'm sure the RC51 brakes are better.
Well, I'm MORE sure. It is one thing for 'people' to talk about this is better than that, etc etc, but what I wanted to share was the information I was looking for--and didnt find--before attempting this upgrade.
Flight_996 is offline  
Old 06-11-2007, 10:41 AM
  #6  
Senior Member
MotoGP
 
mikstr's Avatar
 
Join Date: Apr 2005
Location: Montreal
Posts: 5,631
mikstr is on a distinguished road
Having made the switch as well to a RC set-up (and having run braided lines and HH pads prior to doing so), I can say that to try it is to adopt it. It is a definite improvement over the stock set-up (even with the lines and pads). I would be curious to try it back-to-back against the GSX-R (6 piston) modded set-up but I am more than happy with my present braking performance.
mikstr is offline  
Old 06-11-2007, 10:46 AM
  #7  
Senior Member
SuperSport
 
SlowHAWK's Avatar
 
Join Date: Jun 2004
Location: Thornwood, NY
Posts: 817
SlowHAWK is an unknown quantity at this point
I've heard buys on the Speedilla board were not to happy with the GSXR 6 pots over the stock RC stuff (from a few posts I read)... according to them... HRC pads are all you need to make the RC brakes outstanding...

But what do they know... they drive full fairing V-Twins!!! Hahahaha

J.
SlowHAWK is offline  
Old 06-11-2007, 11:26 AM
  #8  
Senior Member
SuperBike
 
killer5280's Avatar
 
Join Date: Aug 2004
Location: Atlanta, GA
Posts: 1,802
killer5280 is on a distinguished road
It's all about leverage ratios, but in my experience both the F4i setup and the 954 (same as the 600RR and RC51) setup are better than the stock VTR items. I'm not saying, however, that a well setup stock VTR setup with good pads won't give excellent performance.
killer5280 is offline  
Old 06-11-2007, 02:36 PM
  #9  
Senior Member
Back Marker
 
iscoot's Avatar
 
Join Date: Oct 2006
Location: silverlake,ca
Posts: 142
iscoot is on a distinguished road
are the stock brake really that bad? i just try to turn faster! lol...
iscoot is offline  
Old 06-11-2007, 02:41 PM
  #10  
Senior Member
Back Marker
 
iscoot's Avatar
 
Join Date: Oct 2006
Location: silverlake,ca
Posts: 142
iscoot is on a distinguished road
larger rotors, yes! radial pump, better pads, yes! steel lines, yes!
calipers,????
iscoot is offline  
Old 06-12-2007, 12:52 AM
  #11  
Member
Squid
 
Babelfish's Avatar
 
Join Date: May 2007
Location: Akershus, Norway
Posts: 99
Babelfish is on a distinguished road
Originally Posted by Flight_996
I highly doubt there was air. I replaced the fluid and bled the brakes not 2 months ago, and the feel hasn't changed since then. My bike has 40k, so yes, maybe my master cylinder was worn out.

Good point, although it doesn't invalidate my test. I used the same exact rotors, with the same exact (stock) VTR lines, both sets of pads were EBC and not new.

What I was trying to illustrate was that it takes MUCH less lever effort (pressure) and less lever displacement to stop the bike. So much so that I was bottoming the forks for the first 10 miles or so until I got used to them.

I'm not bashing the VTR brakes. I always thought they were plenty good. However, for the $100 that I spent in used parts, (not including the income from selling the old parts), the difference is amazing. To me, stopping is as important as going (and turning), and I've already done a 15/43 520 conversion and a set of Pilot Powers, so this was next. Next up is suspension ($$$)...

Well, I'm MORE sure. It is one thing for 'people' to talk about this is better than that, etc etc, but what I wanted to share was the information I was looking for--and didnt find--before attempting this upgrade.
Sorry for using the tire comparison, it was not really pointed to you. RC51 should should and must be an improvement. It's just that I'm so happy with my brakes and the lever movement didn't seem right to me. It's not at all the way my brakes work. At 1/4 - 1/3 movement the lever more or less totally stop moving. And I also got those unwanted quick dives in the begining.
But then again, old OEM rubber lines, a little contaminated pads and I see how you could get a feel looking like a diagram.

Some might suspect me of not knowing what really good brakes are, but Aprilia RS250 with braided lines, SBS carbon pads and brembo calipers stop almost by thought control :-) and that was what I was racing with. Thing is, I'm still very happy with the VTR brakes now. And mind you, it's with EBC rotors, that is a substantial difference.

And just like you my next upgrade will be suspension.
Babelfish is offline  
Old 06-17-2007, 07:05 PM
  #12  
Administrator
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,287
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
Having switched off with a couple Superhawks with stock brakes at the Rally I think I know the problem with the stock master cylinder. It seems like there is a lot of lever movement before you actually get pressure buildup. I have not taken a stock one apart but I think it's due to too much distance between the resting position of the master cylinder piston and the bleed hole to the reservoir. I rode L8RGYZ's bike and other than the free play in the lever the brakes were wonderful....and all stock (dunno about pads or lines actually). A slightly longer piston would do wonders with the stock system. You guys follow what I'm saying here?
Hawkrider is offline  
Old 06-17-2007, 07:27 PM
  #13  
Senior Member
MotoGP
 
nuhawk's Avatar
 
Join Date: Sep 2006
Location: Austin, Tx
Posts: 4,138
nuhawk is on a distinguished road
I did the gixxer 6 pots and pro-lites rotor upgrade this winter. I have fully drained the system twice and still have a spongy lever. Even did the lever compression over night with a cable tie - no improvement. The bike is massively more stable in braking than it was and it's VERY progressive - stoppy progressive! I just don't like the feel of the lever so I think I'll start watching for a MC setup next. I just don't think the stock MC can push enough juice for the six pots or I'm flexing the metal. Either way - the setup is going to be changing!
nuhawk is offline  
Old 06-17-2007, 07:29 PM
  #14  
Administrator
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,287
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
M/C too small for those calipers! Doug, you never returned my phone call!
Hawkrider is offline  
Old 06-17-2007, 07:51 PM
  #15  
Senior Member
MotoGP
 
nuhawk's Avatar
 
Join Date: Sep 2006
Location: Austin, Tx
Posts: 4,138
nuhawk is on a distinguished road
Oh, sorry! I saw I had a message but I have been ***-deep in this big mower again for most of the day. I thought the gear motor was a challenge now I discover another gearbox that was supposed to be checked every 50 hours and oil change every 500. The machine has almost 600 hours on it and I must admit that I didn't even know it was there. I don't think we've damaged anything but I'm really sure it's out of lubricant. Problem is I can't even touch it. It's very buried inside the compartment and looks like I will have to remove several components to get to it. Why the hell would anybody manufacture something this fugging hard to maintain.
nuhawk is offline  
Old 06-17-2007, 08:44 PM
  #16  
Senior Member
MotoGP
 
nuhawk's Avatar
 
Join Date: Sep 2006
Location: Austin, Tx
Posts: 4,138
nuhawk is on a distinguished road
Yeah, like I said - the stockers just do not move enough juice. Although I will credit them and the stock MC with saving my life. Credit as well to the missing slam-down-diving of the front suspension upon hard braking which was corrected by you - makes for a much-improved package and extended life for the rider - but not perfect. I think the MC is probably the final touch to make it right.
nuhawk is offline  
Old 06-19-2007, 09:42 AM
  #17  
Senior Member
Superstock
 
trinity012's Avatar
 
Join Date: Oct 2006
Posts: 277
trinity012 is on a distinguished road
BRAKE M/C F4i,954,929,RC51.

Originally Posted by killer5280
It's all about leverage ratios, but in my experience both the F4i setup and the 954 (same as the 600RR and RC51) setup are better than the stock VTR items. I'm not saying, however, that a well setup stock VTR setup with good pads won't give excellent performance.
Hi Killer52, can you tell me more about f4i m/c, will it bolt straight up or need some mod? I currently run stock VTR m/c with GSX-R 1000 (01) calipers feel a lot more confidence w/this set up but still not sactify. over last winter there are many of m/c available and cost much lower. (I saw 1 on ebay 954 m/c from salvage yard run now more than $100+ship when i can buy new for $155). So does it 2mm diff of m/c between f 4i and vtr will make braking improve better like 954rr, man that bike can stop w/1 finger squeeze.
trinity012 is offline  
Old 06-19-2007, 10:03 AM
  #18  
Senior Member
MotoGP
 
mikstr's Avatar
 
Join Date: Apr 2005
Location: Montreal
Posts: 5,631
mikstr is on a distinguished road
All hydraulics aside, don't forget that the 954 has 330 mm rotors whereas the VTR's are 296 mm. There is quite a bit more leverage on the 954, something no caliper or MC will be able to overcome.
mikstr is offline  
Old 06-19-2007, 11:23 AM
  #19  
Senior Member
SuperBike
 
killer5280's Avatar
 
Join Date: Aug 2004
Location: Atlanta, GA
Posts: 1,802
killer5280 is on a distinguished road
Originally Posted by mikstr
All hydraulics aside, don't forget that the 954 has 330 mm rotors whereas the VTR's are 296 mm. There is quite a bit more leverage on the 954, something no caliper or MC will be able to overcome.
A point which was made clear to me when I swapped the brake system from my stock VTR forks to the 954 forks. Same pads, calipers and m/c, but braking was much improved just from the increased rotor diameter. Still, the setup worked well with the stock VTR rotors.

Trinity012--
Most master cylinders will bolt right up, and the F4 m/c is no exception. It uses the same lever as the VTR, which makes it an even easier swap. The RC, 954, 929 and 600RR master cylinders use a different lever.
killer5280 is offline  
Old 06-19-2007, 06:58 PM
  #20  
Senior Member
Superstock
 
trinity012's Avatar
 
Join Date: Oct 2006
Posts: 277
trinity012 is on a distinguished road
Thanks killer52, I saw 1 set of f4i m/c and 600RR m/c 05 kind of confused which one i should go for.
trinity012 is offline  
Old 06-20-2007, 09:59 AM
  #21  
Senior Member
SuperBike
 
killer5280's Avatar
 
Join Date: Aug 2004
Location: Atlanta, GA
Posts: 1,802
killer5280 is on a distinguished road
Because of its smaller piston, the F4i m/c should give more brake system pressure for a given amount of effort at the lever at the expense of slightly more lever travel than the 600RR m/c. The stock Suzuki m/c is the same bore as the F4i m/c.
killer5280 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Bandit400man
Rider's Gear
18
05-30-2013 08:35 AM
sleepyq2227
Modifications - Performance
3
08-02-2010 05:58 PM
skokievtr
Everything Else
6
03-12-2010 03:48 PM
CentralCoaster
Modifications - Performance
12
08-21-2009 06:40 AM
Speed_Demon
Classifieds
0
02-02-2006 09:00 PM



Quick Reply: RC51 Brakes vs VTR, Upgrade pics and review



All times are GMT -7. The time now is 08:20 PM.


Top

© 2024 MH Sub I, LLC dba Internet Brands



When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.