Front end options: FZR400 3EN1

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Bike owned: FZR400 3EN1
Front end options: FZR400 3EN1

Post by kagari15 » Wed Jul 29, 2020 4:57 pm

So...My bike had a pretty harsh past.
This time, it is about the forks. To fully explain this, I would need to lay 'em all out, from the beginning.

When the previous owner(s) seen that they already worn down their brake discs to the limit, they cannot easily get a new or used rotors, since, this is a 3EN. What happened? They decided to modify things to use the 1WG discs.

First, since the 1WGs are smaller than the 3ENs they began by cutting the caliper mounts and re-welding them to align with the discs. But, that's not it. Since the 3EN discs have more mounting offset position (deeper) than the 1WG discs which are shallower, they did a reaaallly bad thing.

They decided to grind down the left fork leg (the one where the axle screws onto) to pinch the forks closer, bringing the calipers about close to the discs! :o
What a massive blunder it is! :oops:

The wheel bearings were seized, and since they seized, the wheel kept rotating against the axle and the speedometer gear drive. Axle is scored.
Brake calipers are in okay shape, but one of them has their thread area ground down to fit the pinch on the right fork leg.

Now, what could be my options? A front end swap(upside-downies sure delish) sure is common and easily doable, but keeping the stock ones as much as possible saves budget. Could it be possible to re-weld those mounts to use the later FZR600 or even FZR1000 discs? The calipers can be had from older R1, R6 and perhaps even MT-07s.

Hoping to NOT give up on my very first solo project bike :lol:

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Re: Front end options: FZR400 3EN1

Post by Evilchicken0 » Sat Aug 01, 2020 10:55 am

Jeeeeeez !!!!
Um I would definitely want to swap all that.
The ThunderCat front end bolts straight in and uses a 41mm dia fork with rebound + compression adjustable cartridge forks. This is probably the easiest one to do.
The early R6 uses 43mm dia forks but I'm not sure if it's a bolt in, you might need the steering stem pressed into the R6 yokes. I dont think theres a speedo drive so you might need a different wheel or go for a GPS speedo ... the cdi will limit the bikes rpm to 12,500 in all gears so you would need a MMax derestriction box (there are other makes)

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