Hi,

Could anyone who has completed this mod please help.

I have got some YZ forks to fit to my 59 plate tenere.
After looking a brake options: YZ with oversized disk is expensive to get a 320mm disk is �170.
A standard Tenere disk being 300mm i was going to try removing one disk and associated bits and run a single Tenere disk on standard wheel. After getting over the spindle size issues.

I know i will need to change the master cylinder but dont know what for? 11mm piston ???

If anyone can see any other problems with my plan please speak up.


I ride solo, very little kit and weight 80kg kitted and soaking wet.

thanks

Hi,

Think i have found the answer to my question.
Link below incase anyone else needs similar infomation.

http://vintagebrake.com/mastercylinder.htm

Cheers

Very interesting link, thank you.

What did you do with your brakes?

Hi,

I'm almost done with conversion to YZ forks. Just waiting for some inner parts of forks.
I was considering using 2 piston brake caliper but I switched to 4 piston because tenere is big bike.
In fact, pistons in Tenere calipers are the smallest ones:
Caliper cylinder inside diameter
32mm - 30mm � 1 in XT660R with Disc 298.0 � 4.5 mm
34mm - 30mm � 2 in XT660X with disc 320.0 � 4.5 mm MC - 12.7 mm
28mm - 28mm x 2 in XT660Z with Disc - 298.0 x 4.5 mm and MC - 16mm
So if you want to reuse some brake caliper I would use different ones then original Tenere. For example BMW f650GS has also just one brake caliper with 300mm disc.
Useful links:
http://www.f650gs.crossroadz.com.au/ForkUpgrades.html
http://advrider.com/index.php?thread...99113/page-271

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Yamaha XT 660 Z Tenere

I got a braking 320mm disk and used the original yz caliper and master. Tried Tenere caliper with YZ master but brake was very snatchy not much feel. Got an xt660x four pot caliper but would need to space the disk out slightly to allow it to clear the spokes. might try it one day though.
The pad coverage on the disk is smaller than with xt caliper but for my use its great. I know it will wear faster but not going around the world so should be fine.

Its a bit tricky to use 4 piston caliper with usual wheel, as you mentioned you need to use spacer under disc for clearance. I did that.
Good to know that original YZ brake is working ok with 320mm disc.
If I may ask which year of YZ fork have you used?
I used YZ250F 2008 and had problem with broken free pistons in cartridge.

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Yamaha XT 660 Z Tenere

Good info about the calipers, thanks.

My brake set up (with 48mm YZ forks/wheel) is 320mm disc, oem xtr caliper, oem master cylinder an EBC HH pads.
But I�m not happy. The braking power is good for me, but not the feeling, when braking, if I apply 20% power, it brakes 20%, but if I apply 60% power, it still brakes 20%... unless I apply more power, but then it�s all or nothing... Is this what english people call wooden brakes??

The pistons are clean, I�m going to try new pads, because it�s the less expensive.

The above "wooden" characteristics are the classic symptoms of a master cylinder that is too small a capacity/bore for the job in hand - it works but only at full pressure.

Although your caliper and master cylinder are matched (being from the original setup), the change from a 298mm to 320mm disc means more braking force is required to achieve the same level of friction. The stock master cylinder, from your description cannot meet the pressure required until it is nearly fully compressed. A larger master cylinder will give you more feel as their is a greater volume of fluid (and flow) to allow you to better control the hydraulic pressure with the lever.

Try pads with greater friction may help, but could make the "all or nothing" feel seem even worse and they may become "grabby" as well as "wooden". Worth a try though...

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Ernesto, which oem MC have you used? OEM from Tenere or from XTX? It is a big difference.
I read a lot about brakes last couple months but I would still go to some good moto shop and ask them for advice because they know best what should be better for your setup and it is mostly cheaper then trying different things.
For example I have complete motomaster setup on the front but I still kind of feel that there might be some air in system because first 1cm of lever travel makes nothing. I tried bleeding it many times. Brake has got enough power - I can lock front wheel on tarmac in about 60km/h speed with full power at lever but still I think it could be better. Motomaster MC is 11mm so maybe I need 12mm or that OEM 12,7mm from XTX.

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Yamaha XT 660 Z Tenere

Thank you Pleiades and Falcon1651, I�m using XTR master cylinder.
What kind of MC I should use? bigger or smaller?
I have a second hand MC from an old CBR at home (with square reservoir), should I try it?

Are the XTR an XTX MC the same?