We Don't Need No Stinking Cush Drive...

[JZH]

I'm trying to sort out the rear-end mods to my FP to match the NR rear wheel (or at least not embarrass it) and I've come to loathe the RC36 cush-drive monster hub-sprocket-carrier-thing, or whatever it's called. I've considered fitting an entire RC30 swing arm, which would be the dog's bollocks, with its exotic brake torque arm and sexy good looks, but they are about 35mm shorter than the RC36 swinger (not to mention kinda rare on the second-hand market). And there's no place to mount the torque arm to the RC36 frame, either...

RC30 Swing Arm1.jpg

RC30braketorquearm2.jpg

And here's the OEM RC36 swing arm:

Hideous braced swingarm 2.jpg

(Okay, OEM doesn't look this bad, but I couldn't resist!)

But, I think I could simply replace the sprocket carrier with the one from the RC30. In fact, I may have to, as I'm using a modified RC30 axle/hub to fit the RC40 rear wheel. OEM RC30 rear sprocket is 40T, and RC36 is 43T, but it shouldn't be hard to find--or even have made--an RC30 rear sprocket with 43T, methinks.

The two-pot sliding brake caliper has to go as well. I've got an SP1 (RC51) rear caliper and m/c on the way, which is modern, gold and probably a lot lighter. I'd love to mount it below the swing arm (like on the RC30), but as the torque arm mount is on the top of the swing arm, that might be difficult...

RC36 cum RC30-04.jpg

I have collected a number of extra swing arms in the garage (I'm an aspiring BC Guy...) and yesterday I was pleasantly surprised to discover that the NC30 alloy torque arm uses the same mounting bolts as the OEM RC36 swiss-cheesed steel torque arm (though it is longer). You can see it peeking out from behind the rear brake disc on my 4-bolt-converted NC30:

PA250014x.jpg

I should be able to do something with that, the SP1 rear caliper, the RC30 sprocket carrier and some sort of peek-a-boo with the rear brake line...

Oh, back to the reason for my post: any reason I should try to keep the cush drive?

Cheers,

[Guest]

A cush drive is designed to save your transmission from the rigors of stop and go traffic. All those minute throttle adjustments would play hell on your transmission if you didn't have those little rubbers pieces in there to dampen those forces.

Race bikes don't have a cush drive but they are on the gas or not on the gas...and they rebuild the tranny every race.

You can leave it out but you will pay for it eventually.

[Guest]

I think I hear what you're saying, but i don't agree with why you're doing it. What are you trying to create, in the long run? An RC30 rep? Your bike's never going to be an rc30, and as close as you'll get to it, a cush drive isn't going to be the reason why it'll never be an rc30. things like magnesium cases, big bang motor etc will always be there to stop you actually 'making' an rc30, the cush drive is a tiny piece in the jigsaw, and from what some people say about the rc30 once they've stopped drooling, perhaps it needs a cush?

Anyway, tell me more about this sp1 caliper?

[Guest]

Why not use the NC30 axle /hub / brake disc / calipper / sprocket. Will fit with some tiny mods.

Lot easier than modifying an RC30 item and a lot cheaper (I bought a complete NC30 swiingarm for 90 pounds at ebay.co.uk)

[Beck]

Just a note, although it looks cool, the brake torque arm on the left side of the RC 30's swingarm has always seem to be the target for deletion by many modders/racers. If you look at many race RC 30s they are mostly gone, replaced by shorter subtitutions similar to what the street VFRs have.

I think the torque arm aytem on the 30 is just too needlesly complcated and adds to unsprung weight at the rear.

Beck

95 VFR

[JZH]

Thought it was obvious by now: this is all about the bling, man... I'm tired of having aesthetic pygmies inflicting their visions of VFR nirvana on me, and now its my turn! But, I don't want it to look "like" anything it isn't--I mean, it's a red RC36-I...not exactly the ideal canvas for rocking the motorcycle design world, but it's what I've got; it's what I know; and in the immortal words of Kevin McCloud, "it's got authenticity." (Somehow, I don't think Grand Designs has made it across the Pond--oh, well!)

Okay, rant over. Thanks for the views. NC30 is an option--I know the RC30 uses the same sprockets. I don't have a spare NC30 sprocket carrier (though I do have a spare NC30), but I do have a spare NC35 sprocket carrier, and they appear to be similar, apart from the colour. The NC35's is gold, rather than RC30-black. That could be just the trick. I was actually hoping you might have used the RC30 part on your bike--why not? And, aren't you the same guy who told me the RC30 hub/axle would fit!?!

Here's the sprocket carrier on what used to be Rick Oliver's fine trackday VFR400R:

rick-7.jpg

(Note RC30 torque arm...)

And here's the NC35 version:

brochureswingarm.jpg

Joe, yes I know why most large bikes have cush drives, but the RC30 doesn't, nor do the 400s, so it's probably within the realm of compromise. I'm making a STATEMENT, here, dammit! But I hadn't heard of anyone complaining about the RC30's lack of cush drive, either. Nor have I seen any RC30 owners rushing to modify that aspect of their bikes. If RC30 trannys were dropping parts all over the place, something would have been done about it, methinks.

I agree about the torque arm, Beck. Of the four different brake caliper location techniques employed on the RC30, RC36, NC30 and NC35, the RC30's definitely seems to be the most complicated--and heavy. (But it is still the sexiest!) If I were going to use the RC30 swing arm, I'd weld a boss onto the frame in order to use it, but it's just not an option with the RC36 arm.

I actually spoke too soon about the SP1 caliper being "on the way", having mixed it up with the front calipers and discs I had already won on German eBay, but I actually did win the rear caliper today:

SP1 rear caliper.jpg

IIRC, the RC36 disc brake carrier is a fairly simple affair that could easily be modified for a different caliper, provided the offsets worked out okay. Another bit o' gold, too...

Thanks for the input, lads. :thumbsup: Once I've sorted out some more of the details, and I'm ready to begin zee modifications, I'll start a new "Frankenviffer" thread to document the work.

Ciao,

[Veefer800Canuck]

Re: the cush drive: PM Crazy Larry. He modded an RC36 rear drive unit to eliminate the cush drive.

But instead of using adapted Honda parts, he machined his own (naturally).

[JZH]

LOL. Larry doesn't return my calls...

Ciao,

[enzed_viffer]

IMHO, the NC30/NC35 hub is much kewler looking than the RC36/46 one (why are they so FUGLY!?!?), and reason enough for doing this mod.

And after having to replace cush-rubbers on several bikes (including VF500, VFR750 and VFR800), I reckon the reduction in driveline slop caused by not having them would be a GoodThing as well.

So, I say Go For It! :thumbsup:

[Guest]

Okay, rant over. Thanks for the views. NC30 is an option--I know the RC30 uses the same sprockets. I don't have a spare NC30 sprocket carrier (though I do have a spare NC30), but I do have a spare NC35 sprocket carrier, and they appear to be similar, apart from the colour. The NC35's is gold, rather than RC30-black. That could be just the trick. I was actually hoping you might have used the RC30 part on your bike--why not? And, aren't you the same guy who told me the RC30 hub/axle would fit!?!

Yes,the RC30 hub/axle will fit. On the time I did the mod I had no RC30 hub as a spare part (do/did not want sell the RC30's in parts...)

NC30 hub/axle/brakedisc/calipper on the VFR750F:

achterzijde..02Aklein.JPG

achterzijde..02klein.JPG

[The Phantom]

in the immortal words of Kevin McCloud, "it's got authenticity." (Somehow, I don't think Grand Designs has made it across the Pond--oh, well!)

We get it in Oz; it's one of my favourite shows.

In my view the cush drive is there because Honda knows a fair percentage of buyers are going to be a bit ham-fisted with their shifting, and it allows a bit of 'give'. A bit like the built-in straight-ahead steering freeplay in cars known as 'sneeze factor' - a performance driver would prefer that it was not there...

Got a Factory shift kit John? That combined with elimination of the cush drive would have to make for a tight tranny (oo err).

[JZH]

OEM, thanks for the pics. The NC30 sprocket is an MR7 part, as is the 38mm conical washer, so I suppose there is a good chance that the NC30 sprocket carrier will fit onto the RC30 axle/hub splines. What worries me is that the 38mm nut is a different part... Rick Oliver's got my RC30 hub/axle, so I can't really test anything. It looks like the worst case scenario is that the NC30 carrier won't fit on the RC30 hub/axle, and I'd have to use one from an RC.

Murray, I see your point about the shifting (of course I have a Factory shift kit!), but I'm willing to see how it goes. If I'm crashing gears all the time, I'll have to reconsider, but this time, I think I've got to choose form over function...

(I love that line from Pulp Fiction in your sig. I think I'll steal it from you some day--like I stole the one currently in my sig--thanks Barry!)

Ciao,

[JZH]

(Oops! I see that my sig line isn't included on VFRD! Well, it matches the avatar: "What is a motorcycle for, if it isn't action?" --The Mouse and the Motorcycle, by Beverly Cleary.)

[JZH]

New kinda snag I thought of recently...sprockets! The RC30/NC30/NC35 line of rear sprockets are available only in 525 (OEM) and 520 chain pitches, but the RC36's OEM chain pitch is 530--a much stronger chain. It looks like I can fairly easily get 43T rears in 525 or 520, but steel is harder to find than alloy. I can also get a 16T 520 countershaft sprocket for the RC36 engine--not so sure about 525. So, really, the only obvious commonality is 520 chain and sprockets, which I >might< be able to get in all-steel, but more likely steel front and alloy rear.

The difference between the tensile strngth of a 520 and a 530 chain is significant--greater than the difference between a 525 and a 520, anyway. There is no issue with "race weight" on my bike, but I am concerned that a 520 would not be able to handle a torquey 837cc engine. Or am I being paranoid? Plenty of high-powered bikes use 520 chains and don't snap them left and right, do they? :unsure:

Ideally, I would just have someone MAKE me an RC30 43T 530 rear sprocket in steel (or alloy), but I don't know of anyone who could do that, much less for an affordable price...

Alternatively, I could take an OEM (or aftermarket) RC36 (or other bike) 43T 530 rear sprocket in steel (or alloy) and machine it to fit the RC30 sprocket carrier OD and bolt pattern...

Thoughts, commiserations?

Cheers,

[Burns]

yer being paranoid. the 520 conversion is fairly common for the VFR's... the 520's can handle most anything you'll be able to throw at them out of the VFR lump...

[Guest]

I'd agree with ss burns. A 520 is plenty enough, but it'll last a bit less time, that's all. Keep it clean and oiled and you'll have a chain that lasts for about a year and a half at least, I'd say. The alternative is to speak to renthal themsleves, rather than looking in catalogues, they're based a mile or two from me, it's not like the stuff comes form the other side of the world or anything. All bike engineering may be worth a shout too. Anyway, what's the problem with an alloy sprocket anyway? Get a renthal hardened one and it'll last almost as long as steel but it's about a quarter of the weight, plus you'll get a pair of big flourescent stickers to go on your belly pan too!

[Veefer800Canuck]

Ideally, I would just have someone MAKE me an RC30 43T 530 rear sprocket in steel (or alloy), but I don't know of anyone who could do that, much less for an affordable price...

Alternatively, I could take an OEM (or aftermarket) RC36 (or other bike) 43T 530 rear sprocket in steel (or alloy) and machine it to fit the RC30 sprocket carrier OD and bolt pattern...

Thoughts, commiserations?

Cheers,

Chain Gang out of Australia should be able to help you out with a steel sprocket:

http://www.chaingang.com.au/index.php

Or maybe these guys in aluminum:

http://www.rebelgears.com/

[Guest]

... but I am concerned that a 520 would not be able to handle a torquey 837cc engine. Or am I being paranoid? Plenty of high-powered bikes use 520 chains and don't snap them left and right, do they? :unsure:

No problem !

My VFR837F has a 520: RC30 steel front and RC30 "Wieres" alu rear sprocket.

[JZH]

Looks like I can get an AFAM 520 set "off the shelf"...

HONDA 520 CONVERSION RACE SPROCKETS

VFR 750F 90-97 16/43 PART #

16T 520 FRONT SPROCKET 20608-16

VFR 750R

43T 520 REAR SPROCKET 11601-43

...in the OEM ratio. That's a hard anodised alloy rear and a steel front. Couldn't find a Renthal 520 front, and I have AFAMs on my other bikes, anyway, so I may as well go with AFAM.

Ciao,

[The Phantom]

Hard anodised or not, it's still going to go through that sprocket pretty quickly.

You'll get a performance benefit to trade it off against, of course.

ChainGang in Oz will make you a 520 flame-hardened steel sprocket that will give you enormous mileage with good maintenance (ScottOiler is best) but they are not cheap. Let me know if you want more info.

[JZH]

Hard anodised or not, it's still going to go through that sprocket pretty quickly.

You'll get a performance benefit to trade it off against, of course.

ChainGang in Oz will make you a 520 flame-hardened steel sprocket that will give you enormous mileage with good maintenance (ScottOiler is best) but they are not cheap. Let me know if you want more info.

Thanks, I've been in touch with Chris Haggarty over at Chain Gang, and not only will they do a 520, they will do a 530, which means that I can simply use a (new) OEM front sprocket with a 530 DID X-ring chain and I'm done (though slightly lighter of pocket!). Might want to check the offsets before I order, though...

Btw, he quoted me AUS 125--do you guys charge VAT on exports? I assume that price includes VAT, or sales tax, or whatever, but at least here in the EU, exports outside of the EU do not attract VAT... As I'll probably have to pay UK VAT + customs duty on import into Blighty, I'd rather not pay Australian tax, too!

All in all, I'd still prefer to have a 530, and this now seems practical to achieve.

Cheers,

John

[The Phantom]

John, AB is the man for the VAT questions, he is gainfully employed in a related field. But from memory I don't think you'll be paying our GST.

$125AUD is about the usual price. They discounted for one of our group buys, but the discount was mainly in the free freight, not small change either with 10 sets of chains/sprockets going interstate.

When you next talk to Chris, if it hasn't already been discussed, ask him about the CNC lightened sprocket, they did ours for no extra charge (they just came up with a CAD design to make a one-off sprocket for their VFR750 shop bike). It looks good:

They left two panels in and drilled two holes in each of them, I suppose this was their solution to being able to screenprint their company name onto the sprocket. I've turned it in for now as it's neon pink! WTF. Ask them to cut out ALL the panels!

[douglasthecook]

Will the stock sprocket from the RC-36 not fit? In the very first/top picture, it almost looks like it could. I have been quite curious as to this. Especially as I just put a new chain and sprockets on my VFR. If I were to find these parts on eBay I would be willing to do these mods. If you get a definitive answer on the sprockets, as well as your other issues, please let me know. Thanks!!!

[JZH]

The RC30/NC30/NC35 sprocket carrier is a smaller diameter (by a significant amount) than the RC36's cushy carrier. So, no, they are not interchangeable. I've still got to figure out the offsets...and how to remove my spare NC35 sprocket carrier from where it's mounted--on a spare NC35 swing arm, not attached to a bike (and still torqued up tight indeedy...)

Oh, and I might be going to Dubai for 2 months. Can you say, "projects on hold"?!? :blink:

Ciao,

[JZH]

Oh, and I might be going to Dubai for 2 months. Can you say, "projects on hold"?!? :pissed:

BTDT.

Quick follow-up to a mystery mentioned above: The 38mm axle nuts are different because the RC30 doesn't use a staked nut, like the NC30 and RC36; it uses a safety wire-drilled nut. I discovered this upon my purchase of a polished RC30 swing arm, naturally...

VFR750Rpolishedswingarm1.jpg

And yes, I got an RC30 torque arm to go with it... :P

The swing arm clearly has a "history", but I'm not a party to it. Some of the brake parts are carefully marked "swing arm #2", suggesting it was once part of someone's race kit, and the arm itself is marked "SJ" on the top of the eccentric. It is also set up for running the rear brake line internally, so I may do that. I'm also thinking of powder coating it, rather than leaving it polished, but I'll see how it looks on the bike before making a decision.

Ciao,

[The Phantom]

Good stuff JZH, so you are considering running the RC30 arm despite its shorter length? Or can you slip the eccentric and related goodies straight into the VFR arm?

Racking my brains trying to put 'SJ' to a racer, no luck yet