Muckroot

XS650 Addict
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Hello,

Bit of a newbie question but I recently bought an 1975 XS650B and subsequently discovered that the forks that were installed on the bike were XS400 forks, and totally don't fit the bike (the stem is too short). Because of this I've gone ahead and bought 34MM forks from a fellow forum user. I'm now at the point where I need to start mounting hardware related to the wheels and getting spacers made, refurbishing calipers, running the chain, and refurbing the wheels themselves. Before I do all that I would like to make 100% sure the wheels I have are actually XS650 wheels and not some rando wrong model wheels so that I will have the least potential issues when fitting these to my hardtail project. I've taken a bunch of pictures of the rims and I'm hoping some of the numbers mean something to somebody. If these cant be positively identified, in what other way's can I measure them/inspect them to ensure they will correctly fit my motorcycle?

Some info on the bike:
-I have a TCBro's hardtail kit that was installed by a pro with a jig so I know it's straight.
-I'll be installing 34mm XS650 forks without a fender, but most likely with a fork brace
-I'll be using a stock right disk caliper on the front and most likely a stock right disk caliper on the rear.
-I'll be mounting a static fender as is customary with a hardtail

Here are all the numbers I could think to take pictures of from the rear wheel:
IMG_9582.jpg IMG_9583.jpg IMG_9584.jpg IMG_9585.jpg IMG_9586.jpg IMG_9587.jpg IMG_9588.jpg

the seal and bearing from the rear wheel: (the text on the bearing is 6305Z Japan NTN)

IMG_9590.jpg IMG_9591.jpg

And the lettering from the front wheel:
IMG_9592.jpg IMG_9593.jpg IMG_9594.jpg IMG_9595.jpg

Best, Muckroot
 
The 650 never came with an 18" front wheel so yours is most likely from some other Yamaha model, maybe a 400 or 500. The hub may be narrower than a 650 one but you could probably make it work with the right custom spacers. The rear appears to be a 650 wheel.
 
The 650 never came with an 18" front wheel so yours is most likely from some other Yamaha model, maybe a 400 or 500. The hub may be narrower than a 650 one but you could probably make it work with the right custom spacers. The rear appears to be a 650 wheel.

Thanks for the info... but: S H O O T :banghead:

are custom spacers all I should need to make the front wheel work? will the XS650 brake caliper work on the rotor on the front, as long as I get the spacing right? or is rotor diameter going to be a factor as well? I'll take more pictures of the front wheel when I get home from work.
 
The 650 front discs have a diameter of about 11 3/4" or 298mm, the rears are smaller at about 10 1/2". But the mounting bolt patterns are the same so it's possible to stick a rear disc on a front wheel. So, measure yours to insure it really is a front disc. But there's more ..... there were two different discs used, an early two piece one and a later one piece like yours. They had different offsets (about 5mm) because the early and late calipers also differed. The 34mm forks use the early style caliper. The mounting bolt spacing differs from the later caliper so they won't swap.

So, I think you're going to have to partially assemble things to see just what you've got and what you'll need. Install the forks and set the wheel in there centered. You'll need the early style caliper and maybe the early style disc with the 5mm more offset.
 
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So, I think you're going to have to partially assemble things to see just what you've got and what you'll need. Install the forks and set the wheel in there centered. You'll need the early style caliper and maybe the early style disc with the 5mm more offset.

Will do! Excellent info! the forks arrive tomorrow so I'll double check the forks and the calipers fit each other, and then mock up the wheel and see how that pans out. Just to be sure, if I really had to I could get custom spacers made for the front to make the older style caliper work with the one piece disk I have on the front wheel, as long as the disk is the correct 12 3/4 in diameter? OR I could replace the disk with a two piece to fit the old style calipers so that the stock spacers will fit correctly. Am I correct in this?

Tomorrow I'll post an update with some measurements of everything I've got and take some pictures of it all mocked together.
 
Yes, you could do either, space out the newer disc or get an older style one. But if you're going to have to pay to have custom spacers made, it might be cheaper just to get an older disc. I'm sure you could find one for around $20 or less.
 
if you're going to have to pay to have custom spacers made

Well, the forks showed up today. the axle that came with the wheel does not fit the forks, and the axel that came with the forks does not fit the wheel. I wish I could just replace the bearings in the wheel to a different size but the tach drive and the bearing cover on the other side of the wheel are too small for the fork axle. Looks like this wheel won't work (unless anyone has any suggestions on how I could make the tach and cover fit the bigger axle?)

Thank you 5Twins for all the wonderful info.
 
Hi MR, you might be able to swap the bearings to ones that fit your wheel but also have the right inner diameter for your axle, I think the alballz website has info about which bikes have which size bearings, I know they have it for steering head bearings to help with fork swaps, but if you measure them carefully you might be able to find them at your local bearing store, or if you don’t have a vernier caliper you could pull one bearing and take it with your axle and tell the helpful gentleman at the shop what you are trying to do, just make sure they are clean first otherwise he may not be so helpful, it’s just a matter of whether bearings are available with the correct combination of diameters for your application, or you could put your measurements up here and one of our knowledgeable members might already have the info you need tucked away in their grey matter waiting for just such an occasion!
 
you might be able to swap the bearings to ones that fit your wheel but also have the right inner diameter for your axle
I've got a little experience sizing bearings, so I feel confident that I could make it work in that regard, but im concerned because the bearing covers, (the tach drive on one side and a simple cap on the other side) that fit into the rim on either side on the axle seem to simply ride the axel metal to metal with the grease from the bearings keeping everything from grinding together as the wheel turns. Because the covers fit the smaller of the two axels I'm hoping I can possibly drill out the hole on each cover so it'll accept the larger axel, but I don't know anything about how well that would work. Any info on that would be wonderful. If that route costs more than 20$ or so, I think my best bet is to pick up a new front wheel from an XS650 that is the same style as the rear that I have.

I'd also like to take some measurements of the back wheel to confirm it is a 650 wheel. I'll measure the axel diameter, hub width, disk diameter, and rim width. If someone could have a look at those values and let me know if it is within spec for a 650 wheel that would be excellent. thank you everyone for your inputs
 
I guess if you’re not set on having an 18” wheel buying an XS650 wheel would be the easiest route, you might be able to sell the 18” one so you break even, never looked into boring out the speedo drive etc so can’t help you there. what’s the difference in size
 
No question the stock 19" front wheel is simplest way forward. Used on XS650, 750, 850 1100's both specials and standards there's tons of them 'round.
Another heads up; there were two different stem lengths used on 34mm XS650 forks. Make sure you now have one that fits your neck.
If you change rear wheel bearings be SURE to swap over the spacer press fit inside the sprocket side bearing.
 
there were two different stem lengths used on 34mm XS650 forks. Make sure you now have one that fits your neck.

How do I know that I've got the right stem? can I just measure it with a set of calipers?

Also thank you everyone for your inputs, I'll take some pictures of the rear wheel tonight as well as get some measurements the best I can to make sure I can use it with stock parts.

UPDATE: I am going to a rust yard next week to look at a XS650 front mag wheel. I called, and the guy in the parts dept. said it is a front mag wheel made for disk brakes that came off a XS650. What things can I do to verify it is actually an XS650 wheel, and that it will correctly fit my forks? I will be taking the entire fork assembly with me to dry fit the bugger because I'm really fed up with having parts that are suuuuper close but unusable because they don't actually fit lol. I'll have the forks assembled in the Tree, the axel, and the caliper I plan on rebuilding. how should everything Line up if the wheel is the correct wheel? what shims/spacers and other parts should I look for as well so that when I leave the rust yard I will have a complete front assembly (as far as everything below the tree)?
 
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That stem is out of my 75 so if your frame is a 75 it should fit, the earlier ones had a shorter stem.
20200503_213722.jpg
This is the style rotors from the 34mm front only I drilled these, and the one on the right is a mystery.
 
The speedo drive acts as the spacer on the left side. The right side will have one spacer with a tin dust cover pressed on it.
 
Here are the pictures of the rear wheel. I'm hoping someone can say for certain that this darn thing will work with the stock rear caliper and stock wheel spacers. The wheel spacers aren't as much of an issue because it's going on a hardtail, and it's possible that stock spacers wouldn't work out right anyhow, but it'd sure be nice.Also need to make sure the chain will line up properly, but I wasn't sure how to measure for that.
IMG_9678.jpg IMG_9679.jpg IMG_9680.jpg IMG_9681.jpg IMG_9682.jpg IMG_9683.jpg

Also, in the picture where the tape is through the wheel, that is from bearing to bearing. I pulled the opposite bearing seal for that so I could get an accurate measurement.
 
There's still a chance you could use that front wheel if you want the 18" you can source the correct bearings fairly easily, and there's a good chance that you can ream out the speedometer drive to fit the larger axle.
20200509_162725.jpg
This is an adjustable reamer, I was able to open up my stock speedometer drive to 20mm to fit my gsxr axle. I got the reamer from Amazon for less than $20.
 
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Note: in Europe the discs are of different diameters as the calipers mount lower on the fork leg.
The fork legs are a different casting than what was used in North American 650's. I owned a bike
wrecking yard with 500 plus bikes and all i can say is that very little interchanges. Whole wheel/front end
swaps are much easier.
 
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