Author Topic: CB400F top rear shock mount corrosion  (Read 502 times)

Offline rustywheels

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CB400F top rear shock mount corrosion
« on: June 23, 2020, 09:52:50 AM »
Was cleaning the bike after an evening ride (aren't the evenings amazing at the moment and were the headlights really that dim back in the day?) this week, and I noticed a small amount of corrosion on the frame.  Its the 'triangular' top mounting point for the near side rear shock.  Not horrific, but obviously a stress point.  Has anyone repaired this area before? 

Is it best to fabricate a new mount or use an off-cut from an old frame (anyone have such a thing hiding in a shed?)?

PS there are definitely more insects around following lock-down.  My jacket and helmet are literally 'furry' at the end of each evening ride

1977 Honda CB400F
1978 Yamaha XT500
1989 Mazda MX5

Offline bobv7

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Re: CB400F top rear shock mount corrosion
« Reply #1 on: June 23, 2020, 12:18:53 PM »
Dunno about your rusty bits but change the headlamp for a Cibie one if you want to see where you're going.

Offline GregShiv

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Re: CB400F top rear shock mount corrosion
« Reply #2 on: June 24, 2020, 05:41:43 PM »
I had mine repaired and it was only after the frame was blasted to remove all the old paint and rust that some of the rust damage could be seen. I took the frame to Maidstone Motorliner who carried out the repair. The 'Triangular' mounting point for the rear shock was cut out and a rust hole formed by water getting trapped between the frame tubing and the shock mounting plate was repaired , the also remade the triangular plate and the shock mount threaded portion. The frame and exhaust mount also needed to be straightened.
1983 Suzuki GSX550ESD
2013 Aprilia SL750 Shiver
1976 Honda CB400F

Offline rustywheels

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Re: CB400F top rear shock mount corrosion
« Reply #3 on: June 25, 2020, 10:28:11 AM »
Thanks for the replies. and the pics.

Looks like an excellent job on the frame, so I will give them a call to chat it through as suspect my welding skills aren't at that level.  I think it will be a winter job, as I don't want to take it off the road at the moment  :), but will keep a close eye on it.
1977 Honda CB400F
1978 Yamaha XT500
1989 Mazda MX5

 

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