Yamaha TRX850 Enthusiasts Forum

Here's my situation. I brought my TRX with the blue spot calipers already fitted. I thought the brakes were pretty good. I then rode a standard Thunderace (also has blue spots) and the breaks on this were phenomenal compaired to my TRX set up. My TRX brakes feel dead and wooden in comparison.

From reading some posts via the search button it looks like i need a different master cylinder. My questions about this are -

Are all Bluespots the same?
If not how can I identify where mine came from?
I've always put early R1 pads on the bike, do blue spots all use the same pads?
Are all master cylinders on blue spot bikes the same - Thunderace/cat, R1/R6 ect?
Alot of post list the size of the master cylinder in mm, by knowing what size i need can I get good results from a master cylinder from a different bike/manufacturer (kawasaki/suzuki ect)?

I've got braided lines fitted, if anything the feel is worse with braided lines. If I can get the power and feel of the standard Thunderace set up i'd be happy with that. I've only got the bikes I've ridden as a comparison - how much better could I get the breaking to be? Are brakes now much better then the Thunderace ones?

Thanks.

666mph wrote:Here's my situation. I brought my TRX with the blue spot calipers already fitted. I thought the brakes were pretty good. I then rode a standard Thunderace (also has blue spots) and the breaks on this were phenomenal compaired to my TRX set up. My TRX brakes feel dead and wooden in comparison.

From reading some posts via the search button it looks like i need a different master cylinder. My questions about this are -

Are all Bluespots the same?
If not how can I identify where mine came from?
I've always put early R1 pads on the bike, do blue spots all use the same pads?
Are all master cylinders on blue spot bikes the same - Thunderace/cat, R1/R6 ect?
Alot of post list the size of the master cylinder in mm, by knowing what size i need can I get good results from a master cylinder from a different bike/manufacturer (kawasaki/suzuki ect)?

I've got braided lines fitted, if anything the feel is worse with braided lines. If I can get the power and feel of the standard Thunderace set up i'd be happy with that. I've only got the bikes I've ridden as a comparison - how much better could I get the breaking to be? Are brakes now much better then the Thunderace ones?

Thanks.

You need A.N. Other 14mm master cylinder off any bike, or a suitable sized radial m/c.

The Thundercat/Thunderace blue spots are different to the R1/R6 calipers- the banjos enter the caliper on top rather than on the side and they have a link pipe between the caliper halves. R1/R6 calipers are are 'better' (or they'd have stuck with the other type!)

I suppose giving your calipers a thorough service will improve them no end. I've got YZF750 6 pots on my bike and they've been cleaned up and they're fine. You can also get good results by scuffing over the discs with scotchbrite and giving them a good spraying with brake cleaner but you do need the right size master cylinder as a minimum.

Good luck

Thanks Kayla.

It looks like i've got the Thunderace/cat bluespots. I put new EBC HH sintered pads in today and gave everything a good clean. The holes in my discs were full of old pad so they've also been thoroughly cleaned with brake cleaner. New fluid too. Is there a way to check what size master cylinder I have already? I think it's standard, but to be sure before I buy. If I were to get a radial master cylinder, what is the 'suitable size'? Is there a favored choice by owners of older 'blue spot' Yamahas like Thunderaces/R1's ect?

Cheers.

I've a master cilinder from a 2002 R6. The difference is huge!!

I'm using a radial pump from a CBR1000, very nice.

I'm using a 19/20 brembo radial m/c. Simply awesome.

Hi 666mph!

666mph wrote: ... Is there a way to check what size master cylinder I have already?
...

Yes there is: Simply look on your master cylinder - if it's original it should read "5/8" on it

On the R1 master cylinder the size is also noted: "14 mm" ( - from memory or is it just "14"?)

Read greetings from Munich!

I have R6 blue spots on mine - which were just secondhand but looking like new. The cam with the same 100 miles used pads. When I changed them over (from the original) with braided lines, they were terrible. No feel and no better that the standard calipers. Then I put in brand new genuine Yamaha pads. The difference was immense. Now i have the best braking that I have on any of my bikes. I did NOT need to change the master cylinder from the original TRX system.

Update on what i've done with my brakes.

Since my original posting i've re build my blue spots with brand new piston and dust seals. I think the old ones were sticking slightly as the dust seals were begining to bulge out. Also when i pumped the pistons out some moved more easily than others. I guess I was never getting an equal push from them onto the pads. With the calipers rebuilt and sill using the original TRX master cylinder the breaking and leaver feel was way better than before, though still a little dead, but not bad. I then brought a Yamaha R1 16mm radial master cylinder. I chose this because it's a genuine Yamaha part and the size theoretically should give good results. From doing a bit of reaserch it seems that the smaller the mm = better feel but longer leaver travel. Looking at the radial calipers on the r1 they look a similar size to my Thunderace blue spots, so I gave it a try.
The radial master cylinder needs an adapter to re position where the brakeline banjos bolt to, this cost about £15 from Hel via ebay. I used the original TRX fulid resevior. Bleeding it up was easy, but the leaver travel is alot longer than the standard master cylinder, it's also alot easier to pull giving the impression that there's air in the system. There isn't though. The radial cylinder/leaver only need the lightest of touches to create loads of breaking power. The feel is very nice too. I was especting it to maybe be a bit twichey but the feel is really good. Like squeezing you wrist rather the squeezing a block of wood. So yes, very pleased with this - but... I parked up the other day near a late model r1 (same master cylinder) and gave the front brake a pull to compair the feel to my set up. The R1 felt much better, the kind of short leaver travel of my standard trx master cylinder. I can only assume that a 16mm radial master cylinder is too small for the blue spots. Still works though and the feel is great, but the leaver travel is maybe too long. I have mine on the maximum span setting. If i 2 finger brake i don't trap my fingers against the throttle but maybe smaller handed riders may pull the leaver that far back or even against the handlebar grip.

In summary the feel is better but the braking is not. I may get a standard Thunderace master cylinder and compare those. I'd like to try a few but that's gonna cost £££. If there's some TRX owners inside the m25 with different master cylinders attached to bluespots then i'm up for meeting up at the Ace Cafe to compare brakes and eat some rat burgers.