Opinions on front brakes

[TX650XSR700]

I recently acquired some parts from an 81 xs650 to build my 73 tx650 the way I want. The forks didn’t come with calipers but the front wheel has the oem rotors installed. I’ve seen threads with people upgrading a single front caliper to a brembo unit for better stopping power.

Should I go with oem replacement calipers? Are they plenty or do they leave something to be desired?

I did find a big brake kit but it’s a nice chunk of change. https://www.roguemotorcycles.com/products/copy-of-yamaha-xs750-big-brake-kit

Basically what I want to know is what’s the best option for one and done front brakes?

 

[Its been a long time]

Depends how much you want to spend? Braided brake line and smaller master cylinder will improve the front brake using stock caliper and disc. I'm more than happy with that, but I'm not an aggressive rider these days. Never go more than 60mph.

That front brake conversion. Is it a bit over braked, 2x 4 pot calipers and 2x 320mm discs? There's no speedo drive on that bike, best check one can be fitted unless you have other ideas.

 

[TX650XSR700]

Depends how much you want to spend? Braided brake line and smaller master cylinder will improve the front brake using stock caliper and disc. I'm more than happy with that, but I'm not an aggressive rider these days. Never go more than 60mph.

That front brake conversion. Is it a bit over braked, 2x 4 pot calipers and 2x 320mm discs? There's no speedo drive on that bike, best check one can be fitted unless you have other ideas.

My plan is to put vintage style tires on this bike anyway so I won’t be corner carving or anything. I was leaning towards OE calipers and discs with braided lines and a different master cylinder but wanted to see what others thought.

 

[Its been a long time]

My plan is to put vintage style tires on this bike anyway so I won’t be corner carving or anything. I was leaning towards OE calipers and discs with braided lines and a different master cylinder but wanted to see what others thought.

I think your plan is sound. Some owners swap the disc to a more modern one as they're much lighter than the stock boat anchor type one. I haven't done that. Yet.

 

[arcticXS]

I recently acquired some parts from an 81 xs650 to build my 73 tx650 the way I want. The forks didn’t come with calipers but the front wheel has the oem rotors installed. I’ve seen threads with people upgrading a single front caliper to a brembo unit for better stopping power.

Should I go with oem replacement calipers? Are they plenty or do they leave something to be desired?

I did find a big brake kit but it’s a nice chunk of change. https://www.roguemotorcycles.com/products/copy-of-yamaha-xs750-big-brake-kit

Basically what I want to know is what’s the best option for one and done front brakes?

My opinion is that the early OEM calipers are better than the -77 onwards calipers. Two 48 mm pistons vs a single 38 mm piston and sliding pins. And the early OEM disc/ discs look much better as well.
So I guess it all comes down to fork preferance, 34 or 35 mm. For me, the 76 650C would be the preferred setup.
As for single or twin disc, I'd rather have one 298 mm disc than two 267 mm discs, due to unsprung weight affecting the suspension.

 

[TX650XSR700]

My opinion is that the early OEM calipers are better than the -77 onwards calipers. Two 48 mm pistons vs a single 38 mm piston and sliding pins. And the early OEM disc/ discs look much better as well.
So I guess it all comes down to fork preferance, 34 or 35 mm. For me, the 76 650C would be the preferred setup.
As for single or twin disc, I'd rather have one 298 mm disc than two 267 mm discs, due to unsprung weight affecting the suspension.

For me to build my bike the way I want to I have to go with the 35mm forks. I was inspired by a 79 xs650 built in Japan that I found on pipeburn’s site. I’m shooting for this but with the patina that my bike has. The front wheel that I bought with my forks came with dual discs.

 

[Its been a long time]

That's a nice motorcycle. I can understand why you would build something similar.

 

[arcticXS]

For me to build my bike the way I want to I have to go with the 35mm forks. I was inspired by a 79 xs650 built in Japan that I found on pipeburn’s site. I’m shooting for this but with the patina that my bike has. The front wheel that I bought with my forks came with dual discs.

Dual discs do look nice, but also means a ridicoluos amount of unsprung weight, especially is you plan to use stock discs and calipers.

 

[MikeyDeepXS]

I’m a fan of my dual disc setup. Plenty of stopping power! My tires are the limiting factor now forsure.


I can’t tell you much about it’s origin because it was setup with dual rotors on the bike since I bought it, but I kinda assume it’s at least semi-stock because it used left and right calipers that match compatibility with the suzuki piston rings pictured, and I learned about that option here on the forum!

 

[RC4MAN]

In your provided photo the builder is using late model forks with the appropriate disc and caliper

 

[TX650XSR700]

Dual discs do look nice, but also means a ridicoluos amount of unsprung weight, especially is you plan to use stock discs and calipers.

As I said, the wheel mounted to the forks I bought has dual discs already so dual caliper would be the easiest route. I don’t know that the needed parts are available to switch to a single rotor and caliper setup but if they are it wouldn’t be out of the question.

 

[TX650XSR700]

A quick Google search reveals that in order to run one rotor I’d need a different wheel entirely. I guess that answers my question.

 

[willis]

A quick Google search reveals that in order to run one rotor I’d need a different wheel entirely. I guess that answers my question

Why would you need a different wheel to run one rotor? You would just unbolt the unused rotor and caliper and put a cover over the mount holes on the wheel. There are a few different styles of hole covers that Yamaha used. They had a stamped chrome cover, a flimsey plastic cover, and a rarer machined aluminum one. Once upon a time there was a member here that made some really trick machined aluminum covers. I'll see if I can find a picture of my old tracker for reference.

 

[willis]

Here are some pics of some rotor mount covers from my archives. I can’t find a picture of the plastic one but pretty sure I have a few in my parts stash somewhere. Second picture shows the stamped chrome vs the custom machined version.

 

[TX650XSR700]

Here are some pics of some rotor mount covers from my archives. I can’t find a picture of the plastic one but pretty sure I have a few in my parts stash somewhere. Second picture shows the stamped chrome vs the custom machined version.

Oh ok. That would most likely be the route I’ll go then. Thanks!

 

[TX650XSR700]

Found another post where someone just put button head screws in the holes. I suppose that’s an option too.

 

[arcticXS]

Found another post where someone just put button head screws in the holes. I suppose that’s an option too.

Alloy or nylon screws to minimize unsprung weight is my preference in that spot

 

[TX650XSR700]

Alloy or nylon screws to minimize unsprung weight is my preference in that spot

Noted. Now to just figure out the caliper and master cylinder.

 

[willis]

I've got a few of those chrome stamped covers if you are interested. Feel free to PM me if you are.

 

[Its been a long time]

Noted. Now to just figure out the caliper and master cylinder.

With a '77 style caliper an 11mm master cylinder is often suggested. I went with a 12.7mm (1/2") master cylinder on my 77 650D. With braided brake line it's fine. Not up to 2026 motorcycle standards, but the tyres will be the limit with more braking power.