TBR7 Fork Oil Change Problems

[Nospark]

Thought I was pretty mechanically incline until I started working on a Chinese motorcycle. Managed to turn the fork oil change into a all night project.
The drain screws were difficult to remove. I found if I kept downward pressure on them while spinning with my cordless impact I could get them to back out.
Then drained the oil. Went to the drain screws back in and they just push the bottom of the internal steel tube they screw into out of the way. When I do get catch a couple threads, the tube just spins with the drain screw.
Being the genius I am, I stuck a long wooden dowel down through the top of the tube thing I could push down on the steel tube while applying upward pressure with the drain screw. Nope! Did sick down in steel tube though which pulled long spring and steel tube. Now I cant get the steel tube past whatever else is designed in there to the bottom of the fork tube.
I just wanted to assemble a damn bike, not build one.
I think I'm at the point where I have to remove the entore fork tube and start over but, that still doesn;t solve the problem of the threaded steel valving tube from spinning when trying to screw the drain screw into it.
No body talked about this crap in their 10 minute fork oil change vidoes

[Nospark]

Never mind. I got it. Had to put the bike down off the stand and weight the front wheel to get the dampening tube to drop all they to the bottom of the fork tube. Then saw thread where others suggested broom handle. The dowel diameter I used slipped inside dampener and stuck in it when it hit the small dampening holes.
I'll figure it out from here. This is very humbling. Arrrgh!

[Thumper]

There is no drain screw on my son's new 2021 TBR7. Drain screws were/are normally on the side of the lower fork housing on Jap bikes, etc. I guess the only way to drain is by disconnecting the dampening rod (allen wrench). Gee.

Maybe wait and drive the bike a few miles before doing all the maintenance?

[Nospark]

Thumper thx. Yes, it was the hex screw in the bottom of the fork tubes I removed to drain and replace the fork oil. The hex head screws are back in and tight. I have the new oil in. Now I can't remember if the springs go in small coils up or down?

[TxTaoRider]

The easiest way is to remove the caps, slide them out of the trees and tilt the tubes down into a bucket.

[Thumper]

Originally Posted by TxTaoRider

The easiest way is to remove the caps, slide them out of the trees and tilt the tubes down into a bucket.

Standard old forks. Japanese brands had drain ports at the bottom. Wouldn't be difficult to drill tap and install drain ports.

[Megadan]

Originally Posted by Thumper

Standard old forks. Japanese brands had drain ports at the bottom. Wouldn't be difficult to drill tap and install drain ports.

They stopped putting the drain bolts on the fork lowers on those after a while too. Too many problems caused by them, such as being broken off from impacts, or simply seizing in place. They were rather handy though.

[Thumper]

On my old Suzukis, they were small philips head bolts, like 2mm 0.5 thread pitch or something. But I am sure they could be buggered somehow

https://ridermagazine.com/2016/01/10...l-drain-plugs/

I will install drain ports on my son's TBR7 after changing the oil and perhaps installing cartridge emulators. OH yeah !!

[Nospark]

It really isn't a bad job after you know how to do it. If I hadn't had your help learning about the boom stick thing I'd still be motherf*%^&*$g those forks.

[tknj99]

If the forks are inverted style, never never never remove the bolts on the bottom of the tubes. I learned that the hard way on my Brozz and had to use an impact wrench in addition to straps to compress the tube to get the bolt screwed back in.. A nightmare as well to say the least and quite the mess..

[Nospark]

tknj99, As with most mechanical projects, it's always much more difficult the first time. I had never been into a motorcycle fork tube before. I didn't thnk this oil change was going to create the project it did. Now that I understand all the components in the tube, the order and orientation of assembly, and how to attack things, it's not so bad. I had no idea the dampeners could spin with the bottom bolt. I didn't even know there was a dampener in there. A simple exploded view of the fork tube assembly would have saved me a lot of time. I was thinking there was nut in the bottom of the tube that should be captured in notches cast inside the tube. I will, make up a dampener tool next time. upside down bolt, into one side of barrel nut. Threaded rod into the other side of barrel nut, double not the other end of rod. Zap barrel nut ends and double nutted end with mig welder to avoid coming apart.

[Thumper]

Originally Posted by tknj99

If the forks are inverted style, never never never remove the bolts on the bottom of the tubes. I learned that the hard way on my Brozz and had to use an impact wrench in addition to straps to compress the tube to get the bolt screwed back in.. A nightmare as well to say the least and quite the mess..

Replacing the allen bolt in the Bashan USD isn't that bad. The key is to remove the caps (12mm open end wrench and a 22mm wrench for the cap).


Here are the components laid bare once the allen bolt is removed (cap is not removed yet).



To get the damping rod back down to the bottom, 1) remove the cap,



and 2) use a longer bolt with same threading as the allen bolt to fish the damping rod and pull it into position, then carefully replace it with the allen bolt.

But, the damping rod has a ~1/4" extension with flat sides that drop into the axelrod cuff which prevents it from turning (to allow loosening or tightening the allen bolt). It is in the picture below right next to the allen bolt:


When you have the longer bolt on the dampening rod, wiggle it around until it is set into the recess and can't turn, and THEN carefully replace it with the allen bolt and tighten the allen bolt.

[Nospark]

Thumper, Thanks for all the pics. When I get to changing fork oil next time, and I make my dampener tool, I'll make one for you as too. Just promise not to file for a patent on my design.