Front master cylinder , how do I choose ?

[Mad]

I’m starting to visit the track with some regularity and the limits of the axial master cylinder are showing, I’m breaking hard, but the lack of feedback isn’t fun while trail braking or when the rear wheel is up.

How do I choose the size of a new radial pump ? 
What do you recommend for track use ? 

 

[scratchpad]

8 hours ago, Mad said:

I’m starting to visit the track with some regularity and the limits of the axial master cylinder are showing, I’m breaking hard, but the lack of feedback isn’t fun while trail braking or when the rear wheel is up.

How do I choose the size of a new radial pump ? 
What do you recommend for track use ? 

I recommend save your money and stick with the oem master. Its good and plenty for this bike. Upgrade the lines and pads,  lever if you wish. I use Galfer components with CRG shorty levers. Front GP kit and closest to oem pads as possible. 

More than enough brakes, actually too much at times. Not once in 4 years racing this bike has my lever faded either. I just changed the fluid for this season for the first time. Only reason to change the master would be for more room on the clip on, IMO.

 

 

[mossrider]

I raced the stock master like Scratch did for 4 years. Loved it. I used EBC EPFA-HH race pads in mine. Everyone likes something different. It was 2 finger strong.

When I built v2 he wanted the radial Brembo 19rcs caliper on his. It was 1 finger strong. This is the one that most radial must haves use.

I tried both but preferred the stock myself.

Here's the thing; if your rear wheel is up you have suspension issues that need attention. When you're on the brakes the bike should almost feel like a cat low-slinking just prior to pounce. W/o messing with it personally I'd bet you have too little rebound in back and too little compression in front, or a combination of both, or too little spring in front/back or whatever. It should almost seem to squat at both ends (more in front) when you're on the brakes. 

Sure I could get my rear wheel in the air but I'd really have to be trying to do it on purpose or screwing up. 

Have a good look at your suspension or have someone who knows suspension do it. 

The most common mistake made when folks want to go faster is to think they need more brakes or more hp when what they really need is better suspension, or just better adjusted suspension. It's the smart way.

If you doubt this follow a pro on a Ninja 300, no power/crap brakes and wicked fast.

[Mad]

Thank you! I was thinking of upgrading it as a way to gain a little sensitivity, the plan was to upgrade both lines and master cylinder, but if you tell me that the oem pump is plenty, I trust you and I’ll change just the lines (the wallet is happy too) 

I knew I had to change spring rate because I bottom out at the end of the straight but I didn’t instantly recognize that the lack of feedback was connected, but that makes sense, how can I feel anything in the front if the bike is being erratic ? 

 

 

Edited June 15, 2021 by Mad

[M. Hausknecht]

I agree that changing brake lines and pads is very likely to give you what you want. The stock pads felt like mush to me, but still had decent stopping power with braided lines. I switched to SBS Dual Carbon pads and got the feel I wanted and at lower effort levels. If you absolutely must change your master cylinder, the stock R6 master cylinder made by Brembo is a relatively inexpensive but non-adjustable upgrade ($220 or so new).

[klx678]

@Pursuvant did a Brembo 17 if I remember right, did a whole article on it here and in the XSR700 forum.  He got great results, needing more power due to weakness in his right hand.  Maybe he can post a link for you or you can do a search.   It was the one Brembo recommended.  I did some research and checked with Brembo in helping him with the possibilities and what would do the job.

[Loch]

On 6/14/2021 at 9:16 PM, mossrider said:

When you're on the brakes the bike should almost feel like a cat low-slinking just prior to pounce.

I love this analogy, never realized that's the feeling I've been looking for when braking. Even after installing DDC's and a Razor R Lite, it feels excessively divey and wants to lift the rear. What would your next step be with this setup?

I'm still on the stock fork springs, but the sag numbers seem *okay* although the forks are somewhat sticky so it's hard to get an accurate reading 

Should I dial up the rebound damping on the rear? Remove a couple mL's of fork oil and replace with higher wt?

I know I went with the semi budget option, and you do get what you pay for, but I'm not trying to build a race bike here. Just want a little confidence in the front end when braking into corners

Edited June 16, 2021 by Loch

[mossrider]

49 minutes ago, Loch said:

I love this analogy, never realized that's the feeling I've been looking for when braking. Even after installing DDC's and a Razor R Lite, it feels excessively divey and wants to lift the rear. What would your next step be with this setup?

I'm still on the stock fork springs, but the sag numbers seem *okay* although the forks are somewhat sticky so it's hard to get an accurate reading 

Should I dial up the rebound damping on the rear? Remove a couple mL's of fork oil and replace with higher wt?

I know I went with the semi budget option, and you do get what you pay for, but I'm not trying to build a race bike here. Just want a little confidence in the front end when braking into corners

Once your suspension is mildly close to set the next step is learning proper brake application. We'll get back to suspension a bit later.

It's common to think 'late brake, brake hard' but that puts the bike on its nose and upsets the chassis and vaults the rear end up.  Try to apply brakes in a firm yet progressive fashion. You can be quite forceful but don't jamb in lots of brake in one motion (don't put 'x' amount of force straight into the brakes). By this I mean to put some weight on the front tire an instant before applying progressive pressure to the lever. This loads the forks a bit, flattens the tire to improve contact patch and allows the rear to settle in before your main brake application. This only takes an instant when you get it down. You can almost mash the brake lever all the way to the bar when mastered.

Next step is to learn to release some of this pressure as you roll lean into the bike approaching the turn. Wallah, you're trail braking. The trick here is not to release the brake lever suddenly or you'll unweight the front tire and go down or run wide. Ideally you'd will be off the brakes at apex and be rolling open the throttle simultaneously as you stand the bike up out of the corner. Zero coasting.

When you get this right it feels like the bike is trying to crawl backwards out from under you, not pitch you off approaching the corner.

Now get back to your suspension and check your numbers, spring rates, clicks n sh*t.

Some folks think of this process as 'lighter-longer' as opposed to 'mash and hash'.

Hope this helps.

[Loch]

1 hour ago, mossrider said:

When you get this right it feels like the bike is trying to crawl backwards out from under you, not pitch you off approaching the corner.

So you're saying the pitching-forward is most likely to do with my riding and application of the brakes, and less to do with the suspension and dynamics of the bike? 

Good to hear, I love learning about problems that I might not have to throw money at

[mossrider]

1 hour ago, Loch said:

So you're saying the pitching-forward is most likely to do with my riding and application of the brakes, and less to do with the suspension and dynamics of the bike? 

Good to hear, I love learning about problems that I might not have to throw money at ">

I'm saying it could be part of it. I haven't seen you ride personally. But I see plenty of riders make the same mistakes. If you get your braking down you'll find your suspension suspends better. When your suspension suspends your brakes work better too. It comes down to being smooth on the controls so you don't upset the chassis while it's doing its thing(s).

Think of it this way. If you drive a straight line at 60mph and grab the brake to the bars you'll lock the front, low side or go over the bars. Do the same thing and progressively pull the brake lever to the bars and you'll stop in 100 some odd feet like an anchor on bottom. You don't want to slam momentum down into the forks and up on the shock. More like squeeze um-stretch it.

Win-win.

[Loch]

@mossrider I've been focusing a lot on my brake application and how it is affecting the suspension. When I test rode the RS660 it blew me away how it handled, exactly like you described. Getting on the brakes it felt like the whole bike sinks down front and rear, and letting off the brakes mid corner it comes up together. I didn't realize at the time this is what I was trying to make my FZ feel like. 

Yesterday I rode my friends street triple back to back with my bike on the same section of road, and it felt just like the Aprilia. Braking into the corner and letting off the brakes going through the corner, the bike felt so much more composed than my fz, not pitching forward on the brakes and springing back as I let off. My first time ever riding his bike I felt more comfortable and in control than my own after 18000 kms. I'm not sure what the next step would be to try and correct this, but I feel like it's not all in my head anymore...

[stickshift]

2 hours ago, Loch said:

@mossrider I've been focusing a lot on my brake application and how it is affecting the suspension. When I test rode the RS660 it blew me away how it handled

Yesterday I rode my friends street triple back to back with my bike on the same section of road, and it felt just like the Aprilia. 

Aftermarket front cartridges would probably be a logical next step.

I went from Cogent's DDCs to Ohlins cartridges, much more feel and confidence in the front now.

Edited August 3, 2021 by stickshift

[XSR700Scrambler]

@twinstunts use the Magura HC-1    (15mm)  - $240

I bought that, and Goodridge ebony lines         - $150

Increase in front brake feel         =        PRICELESS

I still plan to uprgade pads, to someting more agressive, even though it's great already.

[mossrider]

21 hours ago, Loch said:

@mossrider I've been focusing a lot on my brake application and how it is affecting the suspension. When I test rode the RS660 it blew me away how it handled, exactly like you described. Getting on the brakes it felt like the whole bike sinks down front and rear, and letting off the brakes mid corner it comes up together. I didn't realize at the time this is what I was trying to make my FZ feel like. 

Yesterday I rode my friends street triple back to back with my bike on the same section of road, and it felt just like the Aprilia. Braking into the corner and letting off the brakes going through the corner, the bike felt so much more composed than my fz, not pitching forward on the brakes and springing back as I let off. My first time ever riding his bike I felt more comfortable and in control than my own after 18000 kms. I'm not sure what the next step would be to try and correct this, but I feel like it's not all in my head anymore...

Ok, ready for phase 2. Keep in mind both those bikes you reference have far superior stock suspension. And my disclaimer that I am sage in nothing of substance. 

You need to get both ends of the bike to compliment one another. Ideally they should compress a like amount at a like rate and return a like amount at a like rate from an input (bump). So spring rates must be complimentary, rebound and compression damping should be similar end to end. 

Forks:

The simplest way to get there is to upgrade the stock forks. A fluid change to fresh, and probably a bit heavier, fluid is first. Adding Cogent or Race tech emulators to the forks is an affordable and effective next step. Follow the manufacturer instructions. Make sure your spring rate is close to your needs. Maybe add preload adjusters if you're close on the stock spring. You can certainly move up to cartridges in the stock forks, fork swaps, front end swaps, money, money, etc. 

Shock;

Chuck the stock shock and go for whatever aftermarket version is available in your area. Wilbur's, Ohlins, K-Tech, whatever you pick, just make sure it is at least adjustable for rebound damping. They will generally come with compression damping set close to ideal if it is non-adjustable. You can get these ranging from $350-$? usd. Add compression capability if you're willing put in the work to learn as it is easy to get lost in adjustability. 

Now;

Here's a little drill to help set up the suspension end to end that takes some practice to execute properly. Stand facing the bike on one side or another, one hand (heel) on the steering head, one hand (heel) on the back end (hard part by seat), one foot on footpeg. The bike must be as vertical as possible. Now practice imparting a healthy stomp into the chassis. Simultaneously jamb a good vertical downward shove into the steering head, the tail and the footpeg. These equal forces must all be timed and imparted simultaneously and vertically through the chassis into the ground.  Feel the bike respond with a microlight touch that does not interfere with it's motion. When the suspension is properly adjusted it should feel like it takes the same amount of force at all three points to compress, it should travel the same speed and amount down and up at all three points. It should return to static starting point immediately with no bounce. With a lot of practice you'll start to feel when everything works in harmony. Try riding it at different adjustment settings to learn the correlation to your static tests. 

Anyway, this aughta keep you busy for a while.

Good luck.

Edit: it was late and we just got back from MotoAmerica round at Brainerd last night and I've had a chance to reread your posts. 

Having practiced the above exercise it's time to adjust your boingers. You want it to compress for a 2 count after a good solid stomp and rebound at the same 2 count for starters. Each end should feel similar in it's response both down and up. They should reach bottom and return to top at the same time and travel the same distance during the stomp test. Add or remove compression and rebound accordingly to get these numbers and go from there. It takes practice, feel and testing to confirm your adjustments. The DDC's will take a few minutes to adjust so take your time. Once set they should be good for most spirited road use and not require constant fiddling. Your Razor is easy to adjust so spend a day monkeying around and enjoy the new handling bike and your new skills with suspension set up. 

[Loch]

I measured my front sag and the numbers seem ok. I'm 170 in my birthday suit, are the stock springs good?

I did a little riding around this morning in the city paying close attention to the front/rear loading and unloading as I brake, and even with Cogent DDC's and ktech razor lite I feel like I'm riding a rocking horse. I used Belray 5W in the forks to Cogent's recommended 150mm. I'm not aware of the tuning parameters with DDC's, what would I be adjusting to get the desired damping?

I bought the rear shock from a forum member, and ordered a new spring through a local dealer. I know I need to mess around with the preload a bit as it seems quite harsh, even though my sag numbers seem correct. Is it normal for your ass to get boosted off the seat over medium sized bumps? Is this a compression, rebound, geometry, or rider issue? 

I don't know why I'm surprised by this, but the more I try fixing things the less satisfied I am

[Loch]

I fixed it... I feel stupid.

I set my sag a few months ago, and then proceeded to lengthen the rear shock to raise the tail up without checking the sag again. I checked it today because it was feeling a little harsh, and found that the steeper angle meant that my preload was cranked way too stiff. Softened it and turned the rebound damping up a few clicks and it rides like a completely different machine