Introduction: SR (Sakae Ringyo) MTE-100 Adjustable Seatpost – Cleaning and Lubing a Used MTE-100
The reason for buying the MTE-100 is that it has 56 mm of adjustable setback. Most seatposts have from zero to 30 mm adjustable setback and seatposts above 20 mm adjustable setback are unusual. It is probable that the reasons for the lower setbacks are the adjustability of tracked saddles and bike frames that are fitted to the person. With an exercise bike, one frame size "fits all".
The MTE-100 came in 25.4 mm, 25.8 mm, 26.4 mm, 26.6 mm, 26.8 mm, 27.0 mm, and 27.2 mm stem diameters (and possibly others). It didn't appear to have been made in 28.6 mm, the size of my two exercise bikes.
I bought two 26.4 mm MTE-100's planning on shimming them up to 28.6 mm for two exercise bikes. Of course, after I bought them, I found out about the smaller seatpost sizes that would have been easier to shim. I also found a completely different approach that was easier and cheaper.
Since the MTE-100's are from the 1980’s, you may find a NOS but mainly you will find them used. Before using the used MTE-100, it is a good idea to clean it and re-lube it. The gear teeth need to be fully clean to mesh properly. Both MTE-100's that I bought were in decent shape but in need of cleaning (gear teeth) and lubing (clamp).
Step 1: Materials and Tools
Isopropyl alcohol (IPA)
Grease - Tri-Flow clear synthetic grease
Protectant - Boeshield T-9 Bicycle Lubricant
Step 2: Disassemble, Clean, and Lube
1. Release the pressure on the clamp. Unscrew the top nut and disassemble.
2. Unscrew the acorn nut from the clamp and disassemble.
3. Use a dental pick to clean out the gear teeth on the top of the stem, the adjustment block (top, long gear teeth and bottom, short gear teeth), and the bottom seat clamp (red arrows). I don’t know why people grease these non-moving parts, but I found hardened grease filling the gear teeth on both MTE-100’s I bought.
4. Rub down the parts with isopropyl alcohol (IPA) (caution, it is flammable), including the holes, nuts, and cap. I used paper towels and twisted them into points to get inside parts.
5. Lube the clamp (green arrows) and reassemble. I used Tri-Flow clear synthetic grease. Before you put on the acorn nut, test the clamp. You want the long movement when you close it, not the short movement. If you have the short movement, remove the handle, turn the bolt 180 degrees and reassemble.
1. Reassemble the saddle clamp. Push the clamp bolt up through the bottom of the seatpost. Install the adjustment block parallel to the seatpost top, with the short gear teeth facing down. Install the bottom seat clamp and then the top with the arrows “F” (front) facing forward. Install the cap with the recess facing up. Thread on the nut. Adjust the pressure of the clamp with the nut.
Note – if you are concerned about corrosion, put a on light coat of preservative, like Boeshield T-9 Bicycle Lubricant (it works!).
Note – if you want to replace the clamp bolt, use a M8-1.25 x 55mm (or 60 mm) Class 12.9 socket cap screw with a locking washer against the cap head and a flat washer against the body. The lock washer is only there to keep the bolt from coming undone. It is the gear teeth that keep the clamp from moving.