tx650 front fork springs: Effective upgrade?

[The_heartbreak_kid]

So i recently picked up a new tx650 and have started going through the list of things that need fixing. Im planning on having this bike for a while so im trying do everything in stages so i dont need to go back and re-do things down the road.

Anyways, one of the the things i need to do is change the fork oil seals. I am considering progressive springs from mikes. The suspension seams a little soft but Im assuming that it is just because of the seals and that the original springs are fine. But if it would be a big improvement I would like to have it done.

A guy I know with a triple who owns a bike shop told me he thought they were usually too stiff and are a waste of money...that the bike would handle fine without.

I guess im just trying to get an idea of what to expect and what some opinions on the board are?

 

[CDNTX650]

i think they are fine, but only weigh 160lbs. 20wt fork oil i find to heavy in mine, gonne have to go to 15. But....i also don't push this bike super hard in corners either. It needs alot of upgrades for me to be comfy doing that.

 

[5twins]

Original springs are sacked many times or just plain weak from age. If the bike spent most of it's life parked on the side stand, that can do it. You really won't know until you ride it. Some things that might help are slightly more fork oil than stock and slightly longer preload spacers.

 

[shotgunjoe]

The seals aren't making you forks soft, its the dirty nasty fluid inside. On my cb750 I had the thing rode like a marshmallow, I rebuilt the forks using DEX/MERC ATF, and it rode perfect for me (200lbs).

I recently rebuilt my forks (78 xs650 forks on a 74 tx650), I lowered them at the same time and left the springs a little longer than than I lowered the forks to increase the spring preload. Its WAY too stiff. I will be pulling the springs back out and shortening them to a more comfortable level. The stock springs I took out were progressive rate.

I don't know if what years had progressive springs but I do know they came stock.

 

[5twins]

The 35mm forks ('77-on) had 2-way progressive springs for sure (27/36.4 lbs/in). Not sure about the 34mm forks.

 

[The_heartbreak_kid]

So anyone have any idea what type of spring i should got with.

 

[shotgunjoe]

So anyone have any idea what type of spring i should got with.

A good start would be to take the advice already given. If that doesn't solve the issues you are having, come back and go from there. You can swap out the springs very easily without disassembling the whole fork. Pull out the top cap, pull out spacer, pull out spring. You don't even have to remove the forks from the bike.

Just as a recap.

Change seals.
Fresh fork oil (dex/merc atf).
If that doesn't get you there, try longer preload spacers.
After that, new springs MIGHT be in order, but I doubt it personally.

 

[jbbishop2]

I just replaced my '81 fork springs and 1" spacers with Progressive springs (from 650Central) with no spacers, heavy duty because I'm 200 lbs and the rear is 2.5" higher than stock. It was a tremendous improvement over the old stock springs (which were progressive-wound), not too stiff at all. I also aligned the forks using the method at http://www.calsci.com/motorcycleinfo/Suspension1.html.

You may want to give Michael at 650Central.com a call (it's better to call than email, he often doesn't have time to get to the email) and describe your setup. The advice he's given me has been spot-on.

One addition to shotgunjoe's post, which you probably knew already: jack the bike up so the forks are fully extended before you pull the caps...