Opinions please - are these fork tubes trash?

[5twins]

On the 35mm forks, you can only take it out on the '77 tubes. It and it's related parts are retained by a snap ring. The '78 and later tubes don't come apart, those bits are crimped in place .....

Even on the '77 tubes where you could take that stuff out, Yamaha never listed or sold any of the parts.

 

[eyewinder]

Ah, very revealing! Thanks for the pic and details.

 

[eyewinder]

Update 2

Was about to take the tubes in for re-chroming, when my dad sent me a Kijiji listing... Ended up getting a replacement front end off a '79 Special for $100. They look pretty decent after a good cleaning. Hoping there are no issues inside, but the top caps look like they have never been removed...

 

[Jim]

Score!!!
Hope you plan on taking em apart and cleaning them. If the caps have never been off, they probably have the original 79 oil. They'll be pretty nasty inside.

 

[5twins]

If they've never been apart then they are probably just really dirty inside is all. Lots of sludge builds up inside over the years and a simple flushing usually isn't enough to get them clean. You have to get in there with solvent dipped rags and swab them out .....

It's nice to have extra internal parts. Now you can Minton mod one set of damper rods, keep another stock. How about the rubber covers for the top caps? I feel they are essential for keeping dirt, water, etc. out of them. They can rust up internally and seize if not covered.

 

[eyewinder]

Definitely planning a full tear-down and cleaning – solvents, rags and all! Curious to see how dirty the oil really is. I heard the donor bike had been stored in a barn basically since 1979... Probably the coating of grease is what saved them!

Got the rubber caps too... good point about dirt and water.

Was on the fence about Minton Mods vs jumping straight to emulators... I guess there's room to experiment now

 

[5twins]

Yes, the Minton Mods won't stop you from doing emulators in the future if you decide to. You simply drill the oil holes out even more. That's part of the emulator install process. You drill out the existing holes in the damper rods really big, so big that they no longer do any dampening. The emulators do it instead.

But, you may not feel the need for emulators after trying the Minton Mods. I don't think I need them. I'm perfectly satisfied with the improvements the Minton Mods (and an extra ounce of oil) have given me.

 

[Jim]

If you go that route, here's how I did the Minton mod.

 

[eyewinder]

Ah, I didn't know that about the emulator install process! Thank you both for the info – lots of reading to do!

Since I've never ridden an XS before, I'll probably start out with a rebuilt stock setup and then progress through any revisions for a better point of comparison.

Jim – I'm looking forward to a ride report once it's on the road

 

[5twins]

If you read through the original Minton Mods article, you'll find Joe Minton's assessment of the 650 forks to be spot on - they work OK for the big bumps but aren't very responsive to the little stuff. His mods mostly address that. I can't say I really notice much, if any, difference at high speeds but the lower speed, day to day normal riding is much improved. Instead of the little bumps jolting you like they used to, the forks now soak them up. The forks operate much smoother.

 

[Jim]

Just in case you need more to read....
Here's a pdf of Joe Minton's original article.

 

[eyewinder]

Good to hear they are smoother over the little stuff, while not affecting the high speed function. Will certainly give the article a thorough read.

Thanks Jim, I've been archiving PDFs of manuals etc (just in case any of the host sites go offline)!

 

[eyewinder]

I had a read through the fork section of the Minton article... Makes sense. Think I will give these mods a try sometime.

What do you think of Minton's comments about 'excessive seal-drag' and 'dirt-scraper stiction'? Are modern/replacement seals any better in this regard? Any reason to stick with or avoid OEM seals, as opposed to All Balls or other brands?

 

[Jim]

I had a read through the fork section of the Minton article... Makes sense. Think I will give these mods a try sometime.

What do you think of Minton's comments about 'excessive seal-drag' and 'dirt-scraper stiction'? Are modern/replacement seals any better in this regard? Any reason to stick with or avoid OEM seals, as opposed to All Balls or other brands?

I put All Balls back in mine. And yes... they have a lot of drag. I remember OEM's being the same when new. I'm gonna put a few hundred miles on em then re-evaluate.

 

[5twins]

I never really found seal "drag" or stiction to be a problem on this bike. I think it's more important to assemble the forks correctly aligned. Doing that wrong will induce stiction for sure. I've dealt with this issue on many different bikes over the years. To me, the Yamaha doesn't have this problem compared to others I've dealt with. The old '70s BMWs are a nightmare by comparison.

 

[eyewinder]

Interesting, thanks for the feedback guys. It doesn't sound like the seals are worth being too concerned about... and it's doubtful that I'll start experimenting with ones intended for other bikes like the IT400, as suggested by Minton.

I'm pretty sure there were some fork alignment issues when I got the bike – the lower tubes were slightly pinched towards the hub. Have to check that nothing is missing from the hub/axle assembly before it's rebuilt...

Jim, hopefully the new ones settle in for you.