Double disc front end

[Tim L]

Hi all,

Just bought a 79 XS650SG in boxes on e-bay. Loads of bits missing including front brake caliper and bracket.
The forks look to be fitted for brake calipers on both sides.
Does anyone know what I need to change from single front disc to double front disc. Are the brackets and calipers interchangeable in any way?

Many thanks.

Tim.

 

[nj1639]

I find this very helpfull on the interchangeability of yami parts from model to model. Just go to the bottom of the first page and click 'proceed to parts catalog'.
http://www.yamaha-motor.com/sport/m...L2hvbWUuYXNweA==/Parts Catalog/starthere.aspx

 

[irristeve]

left & right caliper & bracket are differnt youll al so need the correct master cylinder but youll have good brakes worth the trouble

 

[Tim L]

Which of the XS650's had twin discs?
Does anyone know?

 

[grepper]

Which of the XS650's had twin discs?
Does anyone know?

European models did. Not in the USA...

 

[Hairyblackdude]

When I added my 2nd disc.. I believe I used one from a Yamaha XS1100..

You'll need the rotor, caliper bracket & caliper. I dont think the caliper & bracket are reversible, so you'll have to get the correct side.

Also, I added a double banjo bolt to the brake "manifold" to split the lines to each caliper.

However, I was just lookin at my buddies' 2003 Z1000 & he has a jumper brake line from 1 caliper to the other.. Running a double banjo on 1 caliper to stack up the lines. I guess either would work.

 

[azman857]

It's also an excelent time to upgrade to stainless steel line too. Use new copper washers at all joints. Night and day difference. I wouldn't put it on the same level as a modern bike brakes, but a real improvment.

 

[650Skull]

Which of the XS650's had twin discs?
Does anyone know?

74TXA/75B were single disc bikes the twin disks started on the 76C's and later. This is for the Ocianania models

Twin Discs started on the 75B's in Germany Use a google traslater for this site. A lot of info here.

Never had the Twin disc models in the US or Canada to my knowledge.

 

[Davep]

I've just converted mine, get another XS 650 disc and a pair of XS 1100 calipers. It all just bolts on. I haven't changed the master cylinder yet but I do need to, the brake is superb with the standard master cylinder but the previous owner butchered the mirror mount threads.

 

[Benjamoid]

If your missing your stock parts then just find a whole setup off an xs850 or xs1100. There were some models that even came with slotted rotors for extra bling.. Thats what I did, all bolts right up.

Kinda hard to see, but its all there.

 

[XSLeo]

Benjamoid, How thick are your rotors, 5 mm or 7 mm? I have a set that the seller says came off an XS1100. Slotted just like those.
Most people on here says the XS1100 rotors they have are 7 mm. Mine are 5 mm thick, maybe mine came from the XS750 or 850.
Leo

 

[Benjamoid]

My tape measure is only in inches, but they are exactly 1/4 inch. I bought the wheel and discs as a combo off ebay. Supposedly off an 1100..

 

[Yamakazi]

Parts break-down for a dual disc set-up:

http://www.boats.net/parts/search/Yamaha/Motorcycle/1979/XS650SF/DOUBLE%20DISC%20BRAKE/parts.html

But caution on parts numbers when referring to these breakdown websites. Recently, it seems like a lot of these websites have consolidated parts from various years/models, and often, the parts in the pictures don't match the list below the breakdown picture. I'm thinking Yamaha probably puts out the lists/pictures to the various "NOS" parts sites, and Yamaha may've sent out some bad info.

 

[XSLeo]

Tanks. 1/4 inch would be the 7 mm thick rotor. 5 mm will be about 3/16 inch. I guess mine came off something else. They work good though.
Leo

 

[5twins]

5mm thick front discs .....

http://www.boats.net/parts/detail/yamaha/Y-2H7-25831-00-00.html

I have one SR500 disc on mine, works well.

 

[XSLeo]

Thanks 5twins. Now I have some idea what mine came from.
Leo

 

[5twins]

Slotted versions started in '90 on the 535. Different part # so not shown in that link.

 

[gggGary]

Xs750 850 maxim etc. front disks are smaller diameter.

 

[XSLeo]

I know the bikes with a leading axle used the smaller disc, as the XS750, 850 and 1100 Specials used, but didn't the standard versions use the regular axle at the bottom of the fork and use the bigger rotors?
Leo

 

[650Skull]

The forks, (non leading), for the 77 XS750 standard version has the smaller front rotors. They fit the rear of the XS650, same part no.. XS850 have the same sized rotors as the XS650, same part no. TX750 front disc has the same part no as the TX650A front disc. Ha, ha, sorry about the links, they only go to the counter.