TX750 Swaps

[Chito]

So... I've read some of the other posts, but it doesn't seem to be working out like I thought.

I had some bent forks on my xs650 and many other broken parts. A 73 tx750 came up for sale for cheap and I went ahead and bought it. I thought I could use the forks and also do the swing arm upgrade while I'm at it. It's actually a pretty complete bike with a title... almost a shame to tear it apart and use it.

My question is this... I'm seeing all over that my xs650 should have 35 mm and the tx 750 should have 35 mm forks, but they don't seem to be the same size at all. I can't get the 750 triple trees to hold onto the 650 forks and I can't even get the 750 forks into the 650 trees. So, I'm going to go out on a limb and say they're not the same size.

I'm guessing I'm going to have to swap the whole front end. Anyone had any experience doing that? All Balls Bearings gave me a list of about 6 bearings to do the swap. I'm not really sure if they mean I need to buy them all or just buy one of the 6.

I'm probably also going to use the wheels. The spokes are a good look. The shouldered rims are really nice. Bigger back break... I figure it's an all around win/win.

Any other parts I should use?

Suggestions?

 

[5twins]

I think the TX750 has 36mm forks. Your 650 would be 35mm if it's '77 or newer, 34mm if it's older. Put the year and model of your 650 in your signature if you want more than just guesses.

 

[nj1639]

Yeah, sounds like the TX has 36mm forks. Compare the length of the neck spindle between the Special and the TX...you might get lucky and they'll be the same. If the TX is shorter, and most likely it is, you'll have to swap out the spindle to make it work.
What is the overall length comparison of the 2 fork sets? Measure from the center of the axle to the top of the tubes. TX may be a bit longer.
Swapping up to 36mm can be done, not a bad improvement but a little involved.
http://www.xs650.com/forum/showthread.php?t=3390

 

[gggGary]

Those TX750 forks are old tech though, 73 74 build years. I have set of the TX750 forks and can look at differences. yes the wheels and rear swing are a direct swap.

 

[gggGary]

TX750 has 36mm tubes, the stem appears to be a swap in to a 77 up XS650 neck, the triples have a deeper offset than the XS650 triples, that would decrease trail which means??? Not sure of overall length because the TX fork I have has extended tubes. But that TX motor was a tall son of a gun so the forks are probably plenty long.

 

[ReycleBill]

TX750s are pretty rare birds-- I think I'd keep it in one piece or sell parts to other TX750 owners in need.

 

[gggGary]

TX750s are pretty rare birds--

The TX750 by Yamaha
is smooth and slick as a Bananaha.
Counter weights revolve hard
on chain by the yard
And oil leaks thither and Yanaha.

They are rare because they tended to frag almost immediately, if not the oil leaks would lube the rear tire and............
The scrap heap is a good spot for them.
Rumor has it that the TX750 is why Yamaha (had to) invent Yamabond.

 

[ReycleBill]

Ah, so you're a poet too. Don't make the mistake I made.

 

[gggGary]

Nah just one of those things that got stuck in my sad excuse for a mind. It was in Cycle World back in the day. Yamaha must have stopped buying ads or something.

" Don't make the mistake I made." Do tell, I love to hear of others misfortunes....

Oh I see your Avatar, never mind.

 

[Shipper]

I think the TX750 has 36mm forks. Your 650 would be 35mm if it's '77 or newer, 34mm if it's older. Put the year and model of your 650 in your signature if you want more than just guesses.

1975 650xsB. Thanks for whatever more you can offer. Bike was all set up and timed, ready to go until I detected the movement in the front end.

 

[gggGary]

does the steering stop on the frame clear the lower triple?

 

[Shipper]

does the steering stop on the frame clear the lower triple?

Nope. The stops on the lower triple meet the stop on the front of the frame.

 

[5twins]

I just test fitted a TX750 lower tree into a late model 650 frame. It fits in fine , the bearings are the same and so is the stem length. There are other issues though. The steering stops on the lower tree are located farther out and they miss the stop on the 650 neck completely. That could be fixed easy enough by welding a bigger stop piece on the neck, but the other issues would be harder to deal with. First up, the handlebars solid mount on the top tree. That may not work well with the way a 650 vibrates. Then there's the offset between the tubes and stem. It differs which means the forks would have a different rake. I don't know if that would effect the handling for the better or worse.

 

[Shipper]

I just test fitted a TX750 lower tree into a late model 650 frame. It fits in fine , the bearings are the same and so is the stem length. There are other issues though. The steering stops on the lower tree are located farther out and they miss the stop on the 650 neck completely. That could be fixed easy enough by welding a bigger stop piece on the neck, but the other issues would be harder to deal with. First up, the handlebars solid mount on the top tree. That may not work well with the way a 650 vibrates. Then there's the offset between the tubes and stem. It differs which means the forks would have a different rake. I don't know if that would effect the handling for the better or worse.

Now that's real interesting!! My stop bars meet perfectly at the front of the frame (see pic). Could it be the stem is bent maybe? Either way, there is a slight play sideways. If there is nothing obvious, I'll be tearing it down next week.

Send me any other possibilities you may come up with.

Thx

 

[Shipper]

Nope. The stops on the lower triple meet the stop on the front of the frame.

More pics. Stops fit well at bottom.???

 

[5twins]

Sorry, can't see the pics. They download but are just thin slivers of the whole pic, no help. Why don't you just post they normally?

 

[Shipper]

Sorry, can't see the pics. They download but are just thin slivers of the whole pic, no help. Why don't you just post they normally?

 

[Shipper]

 

[Shipper]

does the steering stop on the frame clear the lower triple?

 

[5twins]

I think the stops on your 750 tree have been modded, made wider by welding more onto them. Here's my 750 tree. The stops are about 16mm wide. Yours look wider than mine. I bet if you measure them, you'll find they are .....