Beefing up the crank & Gearbox in prep for 500cc.

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RC45
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Beefing up the crank & Gearbox in prep for 500cc.

#1 Post by RC45 » Wed Oct 24, 2018 12:07 am

Any ideas?

I want to pursue bumping up the displacement to 500cc and wonder how much of a weak link the crank and gearbox will be.
Last edited by RC45 on Wed Oct 24, 2018 1:52 pm, edited 1 time in total.
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
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silverstrom
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Re: Beefing up the crank & Gearbox

#2 Post by silverstrom » Wed Oct 24, 2018 1:31 am

The only weak link I can think of in the stock gearbox would be the 2nd gear shift fork. Early bikes were plagued with failures. Lots of blown up gearboxes. The fork was modified on later bikes. There is a casting mark on the modified fork to differentiate it from the early weaker version. If you have an early bike with an unmodified shift fork it could make itself know pretty quickly with a high HP engine.

Talk to Ian at CRR. He would be the authority on a big cylinder NS400R. The biggest I know of is his 475 cc motor. His 475 kit makes 85 RWHP with stock (bored) carbs and Lomas pipes. I don't know if he has modified the clutch, but they are known to be reliable. There isn't much written about cranks being a problem, but you'd be rebuilding it with the best parts available and welding it anyway if you plan to make serious power, and for that motor, 85 is serious.

What is your plan? Something like this :smt003
1985 RZ500 1GE Spec
1985 RZ500 47X Spec Project Bike
1986 RG500 ATR
1986 NS400R
1987 TZR250
1988 Honda RC31
1990 TDR250 Pre-Production # 000001
2007 DL650 VStrom
2014 Triumph Thruxton Modified

RC45
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Re: Beefing up the crank & Gearbox

#3 Post by RC45 » Wed Oct 24, 2018 4:18 am

That is a nice looking bike! But U am in love with the 3 cylinder NS500.

I have my eye on a DMR 500cc kit.

Image
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

Ade SYM
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Re: Beefing up the crank & Gearbox

#4 Post by Ade SYM » Wed Oct 24, 2018 10:12 am

RC45 wrote:That is a nice looking bike! But U am in love with the 3 cylinder NS500.

I have my eye on a DMR 500cc kit.

Image
Hi Hope your well?

Can you give us more information on this kit like the availability - Cost etc?

Thanks

Ade

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silverstrom
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Re: Beefing up the crank & Gearbox

#5 Post by silverstrom » Wed Oct 24, 2018 11:54 am

RC45 wrote:That is a nice looking bike! But U am in love with the 3 cylinder NS500.
That bike is a 3 cylinder. Notice how the upper pipe splits to 2 silencers under the tail. An homage I suspect to the NS500 which had 2 cylinders up and one down. The street bike required an airbox and necessitated the 2 down and one up arrangement to accommodate it.
1985 RZ500 1GE Spec
1985 RZ500 47X Spec Project Bike
1986 RG500 ATR
1986 NS400R
1987 TZR250
1988 Honda RC31
1990 TDR250 Pre-Production # 000001
2007 DL650 VStrom
2014 Triumph Thruxton Modified

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silverstrom
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Re: Beefing up the crank & Gearbox

#6 Post by silverstrom » Wed Oct 24, 2018 11:59 am

Ade SYM wrote: Can you give us more information on this kit like the availability - Cost etc?
https://store.shopping.yahoo.co.jp/dmr- ... 00201.html" onclick="window.open(this.href);return false;
1985 RZ500 1GE Spec
1985 RZ500 47X Spec Project Bike
1986 RG500 ATR
1986 NS400R
1987 TZR250
1988 Honda RC31
1990 TDR250 Pre-Production # 000001
2007 DL650 VStrom
2014 Triumph Thruxton Modified

RC45
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Re: Beefing up the crank & Gearbox

#7 Post by RC45 » Wed Oct 24, 2018 12:03 pm

silverstrom wrote:
RC45 wrote:That is a nice looking bike! But U am in love with the 3 cylinder NS500.
That bike is a 3 cylinder. Notice how the upper pipe splits to 2 silencers under the tail. An homage I suspect to the NS500 which had 2 cylinders up and one down. The street bike required an airbox and necessitated the 2 down and one up arrangement to accommodate it.
Oh I know the split upper pipe to fake the V4 layout very well - I know this bike as well. If I wanted to have 4 pipes I could just use an RZ500 motor in a Honda fairing :)

This bike just fakes the V4, the fairing and pipe layout give that away. the "wrong" layout of the NS400 has been the biggest thing for me. I might try to a early Japanese privateer NS400 race bike that used race NS250 bodywork that was really RS250 bodywork.
Ade SYM wrote:
RC45 wrote:That is a nice looking bike! But U am in love with the 3 cylinder NS500.

I have my eye on a DMR 500cc kit.

Image
Hi Hope your well?

Can you give us more information on this kit like the availability - Cost etc?

Thanks

Ade
DMR Japan designed this kit about 7 years ago. It uses new casting cylinders and pistons. Also requires a bit of case machining and NSR250 parts adoption.
I have reached out to DMR a couple times over the years - and they don't export at all so I am working through a local contact to determine how much of the kit is in the kit, how much needs to be fabricated from scratch and how much is adopted from existing parts.

Either way this is a complete custom endevour that may take a while :)

As to cost, the basic kit is about $2500, and then the real work would start.
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

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silverstrom
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Re: Beefing up the crank & Gearbox

#8 Post by silverstrom » Wed Oct 24, 2018 12:13 pm

What kind of power can the DMR kit make?
1985 RZ500 1GE Spec
1985 RZ500 47X Spec Project Bike
1986 RG500 ATR
1986 NS400R
1987 TZR250
1988 Honda RC31
1990 TDR250 Pre-Production # 000001
2007 DL650 VStrom
2014 Triumph Thruxton Modified

RC45
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Re: Beefing up the crank & Gearbox

#9 Post by RC45 » Wed Oct 24, 2018 12:17 pm

silverstrom wrote:What kind of power can the DMR kit make?
With dry clutch, custom pipes and MC21 PGMII timing 100hp. Closer to 80hp or less with NS400 pipes and stock ignition/timing.

The DMR dry clutch kit is a pretty rare setup, that can be yours for the princely sum of $4000... LOL
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

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silverstrom
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Re: Beefing up the crank & Gearbox

#10 Post by silverstrom » Wed Oct 24, 2018 12:41 pm

As usual, you have to pay to play. I assume you'd go all in and go for the max. Seeing your other projects you don't do anything just a little bit :smt003
1985 RZ500 1GE Spec
1985 RZ500 47X Spec Project Bike
1986 RG500 ATR
1986 NS400R
1987 TZR250
1988 Honda RC31
1990 TDR250 Pre-Production # 000001
2007 DL650 VStrom
2014 Triumph Thruxton Modified

RC45
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Re: Beefing up the crank & Gearbox

#11 Post by RC45 » Wed Oct 24, 2018 1:31 pm

Yes - I do seem go off the deep end a little at times LOL
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

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ns86
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Re: Beefing up the crank & Gearbox in prep for 500cc.

#12 Post by ns86 » Wed Oct 24, 2018 4:51 pm

Anyone know how much their dry clutch assembly costs?
Last edited by ns86 on Wed Oct 24, 2018 5:08 pm, edited 2 times in total.
1986 RG500
1985 RZ500
1986 NS400 HRC
1994 NSR250sp Rothhmans
1983 NS250 p
1987 RG250 WW p
1983 RG250 p
1992 RGV500 WW
1992 RGV500 Lucky Strike
1989 TZR500 Biaggi 3ma p
1984 RZV500 Rainey p

RC45
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Re: Beefing up the crank & Gearbox in prep for 500cc.

#13 Post by RC45 » Wed Oct 24, 2018 4:58 pm

ns86 wrote:Anyone know how much their dry clutch assembly costs?


$4000 to $5000 USD and you still need to source parts and do custom assembly etc. These are not plug and play kits at all. They are simply assemblies some of the hardest to find parts to work towards a particular solution :)
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

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ns86
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Location: ontario canada

Re: Beefing up the crank & Gearbox in prep for 500cc.

#14 Post by ns86 » Wed Oct 24, 2018 5:06 pm

I've liked their stuff for years and also want an NS500 type. A few you tube videos but always hard to find their parts for sale. I am watching closely. Spend on RC45
1986 RG500
1985 RZ500
1986 NS400 HRC
1994 NSR250sp Rothhmans
1983 NS250 p
1987 RG250 WW p
1983 RG250 p
1992 RGV500 WW
1992 RGV500 Lucky Strike
1989 TZR500 Biaggi 3ma p
1984 RZV500 Rainey p

RC45
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Re: Beefing up the crank & Gearbox in prep for 500cc.

#15 Post by RC45 » Wed Oct 24, 2018 5:14 pm

ns86 wrote:I've liked their stuff for years and also want an NS500 type. A few you tube videos but always hard to find their parts for sale. I am watching closely. Spend on RC45
Apparently early RS250 engine cases and clutch bits can also serve as a good donor starting point. Rather can cost $5000 the bits are probably rarer than a 27c coin lol.
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

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