Hi,

Anyone here knows how can I differentiate a normal gearbox and a HRC ones? and what can I expect from these gearing ratio? Any help would be very much appreciated!

1st 3LINES C-1-2 Main 18 Counter 38 Ratio 2.235
2ｓｔ M2-2 C2-2 Main 21 Counter 35 Ratio 1.666
3ｓｔ M3-2 C3-2 Main 23 Counter 32 Ratio 1.391
4st M4-2 C4-2 Main 25 Counter 30 Ratio 1.200
5ｓｔ M5-3 C5-3 Main 26 Counter 29 Ratio 1.115
6ｓｔ M6-3 C6-3 Main 27 Counter 28 Ratio 1.037

Regards
Jarrod

i have a pic of my hrc gearbox next to my old standard box but cant post pic as photobucket nows wants money to let you post pics
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ive seen more tarts than mr kipling

Hi There
The HRC gear clusters I have, have nf5 on the selector forks and the gear cogs themselves have a part number on that matches the RS 250 parts book,
All the bikes I have with them in have an extremely long first gear and very close throughout the shifts,
I doubt if you could visibly see a difference unless you spent a lot of time around nsr gear kits,
All the best,
jonmac
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John

NSR standard cogs look totally different to their HRC counterparts. The NSR parts look like production parts. The HRC stuff looks like HRC stuff....nicely finished.

The location dogs on the NSR are rounded, whereas the HRC dogs are undercut and square.

they are not compatible so it's all or nothing.

Johnnymac wrote:Hi There
The HRC gear clusters I have, have nf5 on the selector forks and the gear cogs themselves have a part number on that matches the RS 250 parts book,
All the bikes I have with them in have an extremely long first gear and very close throughout the shifts,
I doubt if you could visibly see a difference unless you spent a lot of time around nsr gear kits,
All the best,
jonmac

Wouldn't happen to have an hrc gearbox and a dry clutch to sell would you??

Hi Guys!
Thanks for the input, so if I were to get my hands on the different gears of nf5, I would be able to play around with the gearbox? Thanks for the info!

Regards
Jarrod

Jarrodlim wrote:Hi Guys!
Thanks for the input, so if I were to get my hands on the different gears of nf5, I would be able to play around with the gearbox? Thanks for the info!

Regards
Jarrod

No its a bit more involved than that, the F3 transmissions changed a bit through the model years.

The 87 (mc16) transmission is pretty much a complete nf5 transmission, clutch and primary drive with a special clutch case which is basically an nf5 case with an additional cast section that extends to cover the kick start housing.

The 88 (mc18 r2j) nf5 transmission with nh3 (hrc f3 parts designation) main shaft, clutch drive gear, clutch assy and clutch case. The clutch assembly and case look similar to standard nsr parts but bearing in mind production bikes did not have a dry clutch untill 89 means these are f3 only parts.

The 90 (mc21) has mostly nf5 transmission but some gears and the main shaft are nh3 specific parts, the clutch assembly and case are all standard nsr parts.

All 3 years mentioned (only have parts books for these) use the standard nsr output shaft and yes I do need to get a life and spend less time reading hrc parts books

So not really possible to mix and match the nf5 and kv3 gears. Even the later models which use the standard nsr clutch etc still need the nh3 parts to allow the use of the nf5 parts.

Best bet is really to look out for a complete late model f3 box although if you are just looking for different gear ratios these changed a lot between models so you could mix and match these but thats a whole different set of parts books to work through

Glad to see youv'e been a good boy and are doing your homework Paul.
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Proud Father of , 05 ktm 400exc supermoto 2018 honda crf rx supermoto

Lesviffer750 wrote:Glad to see youv'e been a good boy and are doing your homework Paul.

Keeps me out of the pub Les