Why haven't I seen more about this here on the 400s mecca?

You can fit Firestorm fork lowers to nc23/27/29/30/31/36 forks, retaining the original stanchions and internals from your 400, allowing you to fit the Nissin 4-pot calipers from RVF, firestorm, 92-97 Fireblade, etc without ugly adapter plates. If you take a grinder to the lower brake mount you can also fit later 4-pot nissin calipers eg. CBR600F4i, 900 98-04, 600rr3-4, etc. It is a straight swap. You can then use a Firestorm mudguard or, due to how the 400's mudguards clip on, you could most likely re-use that, and perhaps cut off the redundant mounts up the VTR fork legs.

I know this becuase I had my CB-1's forks apart ready to do it, but unfortunately could only assemble one leg as the damaged forks I got for the lowers, were also damaged on the lower. I did use the VTR springs (bit heavier and not as sagged) and fork caps for adjustable preload, which the nc27 doesn't normally have.

As far as I know the various assemblies from all Honda 41mm forks are much or less cross-compatible - it's a fairly well-known mod to do this swap on VFR750's, for example.

Swapped the entire Firestorm forks into a vfr750, but also needed the axle (longer) and spacers from the firestorm. Not a huge leap like 900rr/cbr6rr/cbr1k/rc51, but an impovement for sure, and the same length.

any lower swap, to a 400, would also need axle & spacers as the lowers are wider at the bottom.

slo12 wrote:Swapped the entire Firestorm forks into a vfr750, but also needed the axle (longer) and spacers from the firestorm. Not a huge leap like 900rr/cbr6rr/cbr1k/rc51, but an impovement for sure, and the same length.

any lower swap, to a 400, would also need axle & spacers as the lowers are wider at the bottom.

That's not true. The VFR750 has a narrower axle, this is because it only has one pinch bolt on either fork leg. The nc's all have two pinch bolts either side, and so they have a longer axle, the same as the one in the firestorm.

Thanks for that correction. good to know.

We've been here and talked about this before. do a search - apart from getting to use a different mudguard & not having to use brackets, there is no advantage, as you either need to buy brackets for calipers on nc30 forks etc or you'll need to buy vtr legs.
plus, some of us on here like to be a little more accurate with caliper fitting - taking an angle grinder to the legs aint really me, just to save £30 on brackets - i know its only a shave but its a shave too much for me.
i'd rather spend the £30 & know my caliper aint going to break off.

its a look thing only & vtr's are known for sloppy or comfy suspension so you wont be seeing any vtr forks, or lower legs on any of my nc30 builds.

force-v4 wrote:We've been here and talked about this before. do a search - apart from getting to use a different mudguard & not having to use brackets, there is no advantage, as you either need to buy brackets for calipers on nc30 forks etc or you'll need to buy vtr legs.
plus, some of us on here like to be a little more accurate with caliper fitting - taking an angle grinder to the legs aint really me, just to save £30 on brackets - i know its only a shave but its a shave too much for me.
i'd rather spend the £30 & know my caliper aint going to break off.

its a look thing only & vtr's are known for sloppy or comfy suspension so you wont be seeing any vtr forks, or lower legs on any of my nc30 builds.

You are grinding off decorative metal, nothing structural. Nothing is going to fall off. If you didn't want to grind anything off then don't grind anything off, and fit VTR calipers?

If you are just fitting the lowers, you re-use your own damping parts, so you don't get lumbered with any of the VTR's poor damping.

Meh, each to his own, but I think the VTR lowers look OK (mudguard is gash mind but that's just my opinion) whereas I think caliper adapters looks dodgy. You should also consider - with adapters the calipers end up further down, so most folk will have to buy new brake lines. That + brackets costs more than a set of bent VTR forks and new fork oil + seals (which most bikes would benefit from anyway)


Looks original.


Looks bodged up.

I just did do a search and it took til page 7/9 and a year ago, but I did find the thread you meant.

viewtopic.php?f=24&t=15616&p=108606&hil ... rm#p108606

The only point to this is to be able to fit 4-pot calipers without using an adaptor. Nothing more. It all just depends on if you like your mods subtle or look-at-me.

FWIW I ended up not being able to use the firestorm forks, and am going to fit some CBR900RRT forks to my CB-1. I had a bracket adaptor on my old CB-1 and it was useful but not pretty.

http://i74.photobucket.com/albums/i264/ ... ike001.jpg

If you were clever you would do this conversion then sell your VFR lowers on to the CBR400 boys, who would then likely use RO brackets to fit VTR calipers to them

amorti wrote:
Looks bodged up.

I wasn't keen on the look of adpater plates originally, but have grown to like them. I will probably paint the forks in the original colour along with the adapter plates one day.

FWIW the rc51 uses adpater plates for the calipers:

amorti wrote: If you are just fitting the lowers, you re-use your own damping parts, so you don't get lumbered with any of the VTR's poor damping.

Internally the late nc and vtr forks are the same, so damping on both in stock form is fair at best. The nc30 rebound damping needle is actually worse than the vtr, cuz the taper is too short.

Valved and tuned right they work a treat, at least on my vtr and vfr at medium pace (80-120mph) on the track and in the hills.

That said, my nc30 has stock forks with valves/springs/custom rebound needles/etc and caliper adapters from RO

Cammo wrote:I wasn't keen on the look of adpater plates originally, but have grown to like them. I will probably paint the forks in the original colour along with the adapter plates one day.

FWIW the rc51 uses adpater plates for the calipers:

Don't mean to pick on your bike personally, it was a google image - or so I thought!

The RC51 does use adaptor plates, but somehow they look correct. It gives an impession of race-bred cool. If you wanted to change the calipers you might buy eg. some of the eBay adaptors which replace that part, not bolt on to it.