Hi all,

I've bought some '95 CBR900RR forks for my NC23 project, but the forks don't look like they'll go into the yokes. Should they fit with a little persuasion? Or do I need to fit fireblade yokes too?

Any help much appreciated!
Thanks,
Ryan

Measure the diameter of the Fireblade forks then measure the diameter of the NC23 forks what are the results?

The problem is your question doesn't fill me with confidence, what sort of research have you done for this, what set up are you going for, wheels, brakes, etc?

You're completely correct, there is a distinct lack of research on my part...the forks were cheap and I heard that it was a popular modification. The forks are a couple of mm wider in dia. than the yokes.

I don't know what others have done regards brakes, wheels etc, but I'm sure it'll get resolved through trial and error and with some help from those on here who've done similar :-)

Right to do this you need to be precise, a couple of mm is not the correct answer, the numbers are whats important. However I think the answer here is going to be no they will not fit the yokes.

So you need a set of yokes to match the forks, be that the ones from the Fireblade or from another bike with the same style of forks and fork diameter. The trouble here is now you are altering the geometry of the bike, this may be what you are going for it may not. But the yokes now present a different problem, what is the length of the stem of the replacement yokes compared to the standard ones, will they fit? Will the lockstops line up, no lockstops is an MOT fail, can they be made or machined?

Next is to consider the wheels and brakes. The easiest option is to use the Fireblade set up complete. Using combinations of wheels, brakes, etc opens up lots of questions and issues that would need some work to solve. So if you do the Fireblade front end are the wheels the same size, will any of the front end fowl the rest of the bike?

There are lots of considerations. I'm not trying to put you off, but its not easy. It takes time and money and you have some interesting problems to solve. If you're not experienced in this then its not a quick and easy job. Go for something that has been done before such as the CBR600 internals if you want to improve the front end using tried and tested methods. But if you do want to do it then go for it I'd be interested to see the results. But I think the first thing that you need to do is go and get the price of the wheels, brakes, yokes, spindle, etc of the Fireblade and decide if you want to do it.

So you're trying to fit circa 41-43mm forks into yokes designed for 37mm forks? This should be interesting

thunderace wrote:So you're trying to fit circa 41-43mm forks into yokes designed for 37mm forks? This should be interesting

Helpful, thanks.

squirrel_hunter wrote:Right to do this you need to be precise, a couple of mm is not the correct answer, the numbers are whats important. However I think the answer here is going to be no they will not fit the yokes.

So you need a set of yokes to match the forks, be that the ones from the Fireblade or from another bike with the same style of forks and fork diameter. The trouble here is now you are altering the geometry of the bike, this may be what you are going for it may not. But the yokes now present a different problem, what is the length of the stem of the replacement yokes compared to the standard ones, will they fit? Will the lockstops line up, no lockstops is an MOT fail, can they be made or machined?

Next is to consider the wheels and brakes. The easiest option is to use the Fireblade set up complete. Using combinations of wheels, brakes, etc opens up lots of questions and issues that would need some work to solve. So if you do the Fireblade front end are the wheels the same size, will any of the front end fowl the rest of the bike?

There are lots of considerations. I'm not trying to put you off, but its not easy. It takes time and money and you have some interesting problems to solve. If you're not experienced in this then its not a quick and easy job. Go for something that has been done before such as the CBR600 internals if you want to improve the front end using tried and tested methods. But if you do want to do it then go for it I'd be interested to see the results. But I think the first thing that you need to do is go and get the price of the wheels, brakes, yokes, spindle, etc of the Fireblade and decide if you want to do it.

Thanks, I think it's pretty clear I'll need to fit the yoke set from the 'blade. I'm not going to worry about the rest of the set-up yet - from my experience, if you think things through too much, you'll find too many obstacles and never do it. If it doesn't look/feel right when it's all finished, then I'll put the standard set up back on and put it down to experience :-)

You'll need the 900 yokes and brake calipers and handle bars. Front wheel may fit my mixing and matching wheel spacers. Not sure but think earlier cbr900 yokes with the steel lower yoke should fit ok into your headset bearings.
As you say , with a bit of trial and error you should end up with a decent front end with good brakes for little money.
Oh, you'll need new brake hoses so may as well get some braided ones.

thunderace wrote:So you're trying to fit circa 41-43mm forks into yokes designed for 37mm forks? This should be interesting

I'm gonna go ahead and call you on your lack of knowledge, again. Tri-arm has 41mm forks. Fireblade has 45mm forks.

They will not fit, don't try and "persuade" anything as you'll knacker the lot.

Get fireblade yokes, clip ons, axle and wheel spacers. That gets you rolling again.
Yokes: 92-95 are slab style, 96-97 and lighter, stronger, but don't look as cool. Your call what to get, both types fit the same. 98-99 are a bit wider, and would require the 98-99 wheel spindle and spacers, also the calipers would need spacing in 5mm each side, it's too much hassle to get an alloy bottom yoke IMHO. All types use the same bearings, which are same as your 23.
Clip-ons: 92-93 are a bit lower, 98-99 are a bit higher. IDK which type was used between 94-7, ie, where the crossover was. You can check out part numbers at online fiches, or just pick up what comes up cheap. It's only about 10mm different but if you struggle on fairing clearance either way it might be all the difference. 600SRAD, T595 and ISTR one year model of R6 also have 45mm forks so those clip ons might fit and will all be lower if you want/need that.
Axle and spacers: they're a bit longer on the blade, you can't use yours. ISTR the axle is about 10mm longer over all, and another 10mm longer again (exactly) on the 98-99.

You can use your wheels and discs 1 to 1 fit. This based on me using a nc29 wheel no problems, 23 is the same fitment IINM. This is true for yokes 92-97.

As far as brakes go, I strongly recommend 929/954 calipers and a 5/8" master cylinder such as off an RRW blade. Calipers from all carb blades fit, but early ones will be suffering corrosion by now. 929/954 has teflon coated alloy pistons and hold against corrosion exceptionally well. 600F4i has same calipers with steel pistons. 5/8" master (or bigger) is essential with all these calipers, you cannot use the 1/2" one off your bike it won't work right (lever to bar). You could also use early blade calipers (same as VTR1000f, RVF400 and others) with a 14mm master.

Here's my CB-1 with blade forks conversion so you know that I know what I am on about. I understand the stems are the same on nc23 and nc27, but I can't help regarding the steering lock stops. On the CB-1 I just filed off a bit from the ignition switch mounting posts and it fit 1 to 1, even kept the steering lock.

I used the blade mudguard bracket hacked up a bit, IDK what you can do with your mudguard but something similar might work.

Update; I've fitted a Fireblade front end, minus the wheel.

Simple job in the end; just had to get the stems pressed out and swapped over and it's not a perfect fit. Calipers were spaced out 5mm too.

I'll put a write up in the projects section once I've made a fair bit of progress with the whole bike, otherwise updates will be sporadic.

Thanks,
Ryan.