1975 XS650 fork rebuild puzzle?

inmotionphotog

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G'day all.

Today I took the opportunity to begin pulling apart the 34mm forks on my 1975 XS650 for a stock rebuild.

I took advantage of Hugh's fork lowering tutorial as an example of what to expect whilst dissembling my own. http://www.chopcult.com/forum/showthread.php?t=7330&highlight=xs650+forks

I instantly noticed a few significant differences with my forks versus Hugh's tutorial.

I have attached images below to help with my description.



Here you can see that my spacer is approximately 3.5" long compared to Hugh's which is approximately 1.5" long


100_5683 by inmotionphotography, on Flickr

My dampening rod is also a very different shape to Hugh's.


100_5690 copy by inmotionphotography, on Flickr


100_5695 by inmotionphotography, on Flickr

The new 34mm fork springs that I had received from Mikes XS is much longer than what I originally had. In fact, the new spring is the same length as the old one including the long spacer.


DSC_0524 copy copy by inmotionphotography, on Flickr

Here a two shots with the new Mikes XS 34mm spring and new Mikes XS fork tube assembled. Note that the spring reaches very close to the top of the tube.


DSC_0534 copy copy by inmotionphotography, on Flickr


DSC_0538 copy copy by inmotionphotography, on Flickr



I have four questions that I hope you gents may be able to answer.

1 - Can anybody recognise the dampening rod that I have, as it appears to be different to the typical 34mm unit?

2 - Can any recognise the bike that the shorter spring and longer spacer originated from?

3 - Can I get away without any spacer at all considering the dampening rod that I have? My gut instinct is, that I can ditch the spacer in my situation and just screw on the end cap.

4 - Is there a preference as to which way the new Mikes XS spring should be inserted within the tube, as the windings are tighter on one end?

Any feedback or help would be greatly appreciated.

Cheers.

Steve.

http://inmotionphotogxs650.blogspot.com/
 
Steve,

1. Your fork internals are exactly the same as my 76, springs, spacer etc ...all the same as mine.
2. Yes ditch the spacer if you are going to install the Mikes springs.
3. Tight windings go to the top of the fork, less unsprung weight for the fork to deal with.
4. Hugh or someone else might have to chime in as I have not had a set of 35's apart, I'm thinking maybe the photos are labeled wrong..?? or the the internals changed on the 34's over the years.

Cheers.
 
Thanks for the great reply Hotdog.

Much appreciated!

It does appear that there may have been differences with the internals of the 34mm forks as your reply and Hugh's tutorial would suggest.

It's good to know that I'm heading down the right path with the correct parts.

It seems that my bike really was just a bunch of XS650 and Yamaha parts cobbled together, now that I know the vintage of the forks. So far I've got a 1975 chassis, 1972 motor, 1973 TX750 rear hub and now 1976 forks.

Cheers

Steve

http://inmotionphotogxs650.blogspot.com/
 
Steve,

Are you happy with the new Mikes tubes? Mine are slightly pitted and I'm thinking of replacing them with new. I may just try the ones I have; what's the worst that could happen, I eat up my seals right?

Muggs
 
Muggs,

I have a pair of the Mikes 34 tubes & they seem fine. Was cheaper for me to buy them than to re-chrome the originals.
 
G'day Drew.

I followed Hugh's lead in his tutorial by grabbing a 17mm socket and cutting out some segments with a hacksaw. Now, I couldn't find a six sided socket and had to make do with what was available. As it turns out with the dampening rod that I had it wasn't such a bad thing.

DSC_0543

Initially I wasn't sure why the socket wouldn't grab anything, which after inspecting the tube more closely with a torch I'd noticed that the socket wasn't grabbing at all.

The good news was that the pieces that I'd cut out when placed back in the socket did grab the top of the dampening rod as I'd hoped.

I simply used a bit of very sticky tape to secure the pieces, being careful not to wrap the outside of the socket as it's a very tight fit.

DSC_0541

I inserted the socket on an extension rod, and held it in place whilst removing the bottom bolt.

I'm going to secure the small pieces within the socket with something along the lines of JB weld, and massage it to suit the top of the dampening rod for a more secure fit.

Hope this helps.

Cheers

Steve

http://inmotionphotogxs650.blogspot.com/
 
inmotion - my 34's off of my 74 are just like yours.
i used a 6 sided 12mm to grab onto the little part of the dampener.
you mess with the fork seals yet?
 
The damper rod in Hugh's photo is from a 35mm '77 set and a one year only type. Later rods had the 12 pt. socket deal on top. '76 and earlier had the smaller nub with flats as yours do.
 
I got the fork seals out destructively using big ol needle nose pliers. Prying them w a screwdriver etc can crack the edges.

Steve, when reassembling those forks, make sure to get a good hold on the damper rod; my tool sucked and let the rod slip at high torque, and it wasn't enough to get the damper rod bolts to seal correctly. After the front end is on the bike, I'd notice the forks leaking at the front axle. Pain in the ass.

On my 34mm forks, I used mikes progressive springs cut 2", no spacer, and Hugh's 2" drop kit with 15w oil. It's a little soft, I'll probably add a 1/2" spacer.
 
inmotion - my 34's off of my 74 are just like yours.
i used a 6 sided 12mm to grab onto the little part of the dampener.
you mess with the fork seals yet?

Good point cros36, I'll check my stash of tools to see if I have an appropriate sized socket and save my time stuffing around with the messed up 17mm that I have.

I did remove the fork seals, what a pain that was! The fork lowers have now been fully stripped for powder coating.

Steve, when reassembling those forks, make sure to get a good hold on the damper rod; my tool sucked and let the rod slip at high torque, and it wasn't enough to get the damper rod bolts to seal correctly. After the front end is on the bike, I'd notice the forks leaking at the front axle. Pain in the ass.

Blackbetty, I was somewhat surprised how little effort it took to remove the bottom bolt once I'd grabbed a hold of the dampening rod. The forks hadn't been leaking prior to the tear-down.

Are there any suggestions as to how tight I should re-assemble again to prevent any oil leaks or over tightening?

Cheers

Steve

http://inmotionphotogxs650.blogspot.com/
 
I think they just use a standard M8 torque value of about 16 ft/lbs but being fine thread and the fact that I re-use the old copper sealing washers, I usually go about 20. Start at 16 and you'll see, it doesn't feel very tight at all.
 
Inmotion i have the same internals you do but it seems like the 17mm socket wont fit around if after it was cut. I also tried to us the 12mm 6 point tgat someone else suggested. Not really sure what im doing wrong.
 
I have the same internals as well. I took my forks apart awhile back and now I can't remember how it goes back together. Does anybody have a photo of all the components laid out how theyre supposed to go back in the tube?
 
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