1. Dealing with inner tube rust
Rust on front fork inner tubes is a nuisance.
Once the plating has been broken, even slightly, the only thing left to do is to deal with it and slow its progress. (Except for re-plating.)
In the maintenance record ‘Inspection of delivered moto’, we unfortunately noticed some rust on the inner tube of the left-hand front fork.
Fortunately, the oil seal does not touch the rusted area, and it seems unlikely that fork oil will leak.
However, if left untreated, the rust will spread.
So, I decided to treat it.
From this article you can find out the following.
- Areas and extent of rust on front fork
- How to treat rust in areas not touched by the oil seal
| Date | 5th June 2021 |
| Subjects | Maintenance, Failure, Repair |
| Shop or DIY | DIY |
| Difficulty | |
| Working hours | 2 (Not including drying time) |
| Costs [Yen] | 0 (Use what I have) |
Goods to use：
| No. | Parts name | Manufacturer | Parts number | Quantity | Amouns [Yen] |
| 1 | Compound | 3M | 5986 | 1 | (6,487) |
| 2 | Rust converter | SOFT99 | B-204 | 1 | 1,320 |
| 3 | Brush | DAISO | – | 1 | (110) |
| 7,917 |
2. Dealing with rusted front fork inner tube (STEP 1-9)
Remove front tire
First, remove the front tire.
(How to remove them will be summarized another time.)
Rust condition
＜Rust condition＞
○：There are two areas of larger rust,
○：If you look closely, you can see multiple areas of fine rust.
The late 5D7 has inverted forks, but the inner tube is close to the ground, I imagined below.
- Easy to be hit by bouncing pebbles etc.
- Not only rainwater, but also salty mud, etc., can easily adhere to it.
The fact that only the front side of the front fork is rusted seems to confirm this.
In any case, I’ll be able to see how it’s scratched and dirty after riding for a while.
Cleaning of inner tube
＜Cleaning of inner tube＞
Wash the inner tube in water with car shampoo.
The wheel is removed so the inner tube can be washed thoroughly.
Cleaned inner tube
＜Cleaned inner tube＞
just washed it, but it removed a lot of rust.
I wonder if the rust components that flowed out of the rusted parts fell off?
Polishing of inner tube
＜Polishing of inner tube＞
Scrub the inner tube with a rag with compound on it.
As the compound is for finishing the body, I rubbed it a little harder, thinking that it would not damage the inner tube.
Polished inner tube
＜Polished inner tube＞
The rust is much smaller.
The surface plating still appears to be peeling, although slightly.
Rust converter
＜Rust converter＞
I found it difficult to remove the rust completely.
So, I decided to apply a rust converter to slow it down.
I don’t need to apply a large amount, so put a small amount of rust converter on the tip of a small brush.
Application of rust converter
＜Application of rust converter＞
Press the tip of the brush against the rusted area and point it.
Inner tube coated with rust converter
＜Inner tube coated with rust converter＞
It now looks like this.
After drying, apply a second coat to increase the thickness.
The top part might possibly touch the oil seal.
Well, even if it peels off, the rust is not too big.
3. Summary
I checked the rust, removed the rust that could be removed and treated the rust to prevent it from spreading.
In the future, the rust will only get worse, not better.
So, I have to check it from time to time.
- Washing the car can remove some of the rust.
- Polishing with a compound can remove some of the rust.
- Rust converter may slow the progress of rust (only possible where oil seals do not touch).
