Author Topic: Close ratio trans for CB 500/550, can we build one from parts? (Read 32926 times)

kayaker43 · « **Reply #50 on:** October 14, 2009, 06:50:16 PM »

bwaller,.. The Yosh six speed uses shift forks on the drum, not on separate shafts. The fingers are all the same at .193 in. Two forks appear identical and one odd one.

Hope this helps??

bwaller · « **Reply #51 on:** October 14, 2009, 07:39:50 PM »

Thanks kayaker. I'm changing directions away from this 450 drum & will now use the 360 drum & forks. Took a look through different eyes tonight and it makes more sense.

ajracer · « **Reply #52 on:** October 14, 2009, 11:48:43 PM »

dose CAT have a web site? I might be interested in that 1st and 5th gear swap for my 550. unless you guys figure out how to do it with stock parts.

von_Wanderlust · « **Reply #53 on:** October 15, 2009, 02:31:30 PM »

I think it is this: http://cateng.co.uk/racing.html

Yeah, I'd be interested in trying out a poor mans CR. Not because I'm racing, just as a play toy. I guess that if one ever wanted to go to the full CR, they could fork out for the rest later. Would that make sense?

turboguzzi · « **Reply #54 on:** October 15, 2009, 02:43:20 PM »

Quote from: von_Wanderlust on October 15, 2009, 02:31:30 PM

I guess that if one ever wanted to go to the full CR, they could fork out for the rest later. Would that make sense?

not exactly

1 st gear is directly carved into the MS and rest of the gears are different, so the full 5spd CR is definitely not built on stock gears and shaft and that's the reason for the 800$ difference between the two options

von_Wanderlust · « **Reply #55 on:** October 16, 2009, 04:42:30 PM »

Ah, thanks TG.

bwaller · « **Reply #56 on:** October 21, 2009, 05:51:41 PM »

Kayaker would you do me another favour and measure the width of a couple gears in that Yosh 6spd please?

It appears as though they are all fairly similar in width, but lets say 2nd on both shafts.

kayaker43 · « **Reply #57 on:** October 21, 2009, 07:04:35 PM »

All gears are 11 mm wide,.... or narrow?

bwaller · « **Reply #58 on:** October 21, 2009, 07:22:56 PM »

Thanks, that's very similar to this 360. Had to reduce 2nd ms to 0.425" which matches its mates width. The rest are some wider. The mainshaft now fits.

bwaller · « **Reply #59 on:** October 28, 2009, 07:01:28 PM »

Just an update in case anyone might be interested. The 550/360 six speed gearbox conversion isn't complete, although slow but sure I'm getting there.

I'll post some pics soon when it's complete.

Sam Green Racing · « **Reply #60 on:** October 28, 2009, 07:22:32 PM »

Quality picture Brent

have a look at the pics that Benny took of our 3 gearboxes.

http://forums.sohc4.net/index.php?topic=46104.125

Sam.

paulages · « **Reply #61 on:** October 28, 2009, 11:34:44 PM »

looking good! more importantly, i can't wait to hear how the gear spread feels for you on the track. thanks for all the hard work.. i'm sure plenty of us will benefit from it later.

turboguzzi · « **Reply #62 on:** October 28, 2009, 11:55:16 PM »

WOW! Complimenti!

Are you going to use the 360 drum?

voxonda · « **Reply #63 on:** October 29, 2009, 12:15:25 AM »

Hey Brent,

Looking impressive! Ever thought of using the 6-speed cluster of the 400?

Rob.

bwaller · « **Reply #64 on:** October 29, 2009, 02:54:45 AM »

The final reason for choosing the 360 parts was the shift drum and the cam plate, which allows use of the 550 shift mechanism parts. It uses one selector fork on the drum and two on a separate shaft, like the 550. The 360 drum also has tighter selector fork track spacing which played a big part in fitting the 6 spd cluster in cases 6-7 mm narrower. I had to get a bit creative

with that drum to make it work.

The 400F has all three forks on a separate shaft and there wasn't enough space. The cluster width is very similar to the twin, but again the shift mechanism is very different. Except for 1st gear the 360 & 400 share 2 through 6 gear ratios but only one gear that I saw were identical.

1st in the 400 is 2.733:1, the 360 is 2.5:1..... another reason I thought best to try the 360, although as kayaker mentioned that is probably too low to be any benefit on the track. Kevin (ttr400) told me he had Nova make some new parts to tighten up the 400 ratios so it got me thinking. Then TG contacted Ellis at CAT about a 5spd CR gearbox and copied me in an e-mail with him, so I then asked Ellis if he could make five different tooth count gears for this box.

Long story short, some calculations and ratio choices, a new mainshaft (that'll also allow maintaining the 550 clutch) and five gears will yield an overall reduction between 2nd & 6th of 44%, with a bit better 1st to launch @ 2.125:1. Not Yoshimura 6spd territory but much improved from stock, so this is my plan, As soon as I finish this thing I'll send it off to CAT for some pixie dust treatment.

I'll probably start a new thread with a few pics when finished so to keep this one clear for more "to the point" info.

paulages · « **Reply #65 on:** October 29, 2009, 12:23:13 PM »

very nice work, brent.

mlinder · « **Reply #66 on:** October 29, 2009, 01:02:02 PM »

Still wondering if I can fit one of those in the 350's

oily.tom · « **Reply #67 on:** November 04, 2009, 01:12:18 PM »

Quote from: bwaller on October 29, 2009, 02:54:45 AM

The final reason for choosing the 360 parts was the shift drum and the cam plate, which allows use of the 550 shift mechanism parts. It uses one selector fork on the drum and two on a separate shaft, like the 550. The 360 drum also has tighter selector fork track spacing which played a big part in fitting the 6 spd cluster in cases 6-7 mm narrower. I had to get a bit creative with that drum to make it work.

The 400F has all three forks on a separate shaft and there wasn't enough space. The cluster width is very similar to the twin, but again the shift mechanism is very different. Except for 1st gear the 360 & 400 share 2 through 6 gear ratios but only one gear that I saw were identical.

1st in the 400 is 2.733:1, the 360 is 2.5:1..... another reason I thought best to try the 360, although as kayaker mentioned that is probably too low to be any benefit on the track. Kevin (ttr400) told me he had Nova make some new parts to tighten up the 400 ratios so it got me thinking. Then TG contacted Ellis at CAT about a 5spd CR gearbox and copied me in an e-mail with him, so I then asked Ellis if he could make five different tooth count gears for this box.

Long story short, some calculations and ratio choices, a new mainshaft (that'll also allow maintaining the 550 clutch) and five gears will yield an overall reduction between 2nd & 5th of 44%, with a bit better 1st to launch @ 2.125:1. Not Yoshimura 6spd territory but much improved from stock, so this is my plan, As soon as I finish this thing I'll send it off to CAT for some pixie dust treatment.

I'll probably start a new thread with a few pics when finished so to keep this one clear for more "to the point" info.

Hi Brent,
Ellis here. Just to clarify, I have no connection with CAT and never have had. I am the sole owner of Moore Performance Engineering, www.mpe07.co.uk
The pics of your cluster are looking good, nice work!

Regards, Ellis.

turboguzzi · « **Reply #68 on:** November 04, 2009, 01:19:10 PM »

Hi Ellis

Welcome to the forum!

Brent is doing nice work indeed, let's see how it works out. You C/R boxes sound good too.

TG

bwaller · « **Reply #69 on:** November 04, 2009, 03:58:52 PM »

Well forgive me Ellis, I should have figured this out.

I need a couple hours and this will be ready to ship. I'll send an e-mail later.

paulages · « **Reply #70 on:** November 04, 2009, 10:18:47 PM »

Quote from: mlinder on October 29, 2009, 01:02:02 PM

Still wondering if I can fit one of those in the 350's

i was under the impression that the 360 trans would drop right into the 350, btu i could be wrong.

bwaller · « **Reply #71 on:** November 05, 2009, 03:34:08 AM »

I doubt it's a straight drop in. I believe the 350 and 500 might exchange so the 360 likely will not.

I have 350 cases so I'll dig them out and have a look.

lordmoonpie · « **Reply #72 on:** November 05, 2009, 04:50:54 AM »

Quote from: mlinder on October 29, 2009, 01:02:02 PM

Still wondering if I can fit one of those in the 350's

Jaeson Caunce slotted his 6-speed box made from the 360 into his 350 K4. Suspect they are close on the cases anyway?

bwaller · « **Reply #73 on:** November 05, 2009, 09:08:09 AM »

Actually the 350 case width is the same as the 500/550's so as is it's a no-go, but the modified clusters fit like a glove. I'll remove the shift drum tonight and have a peak. That will make or break the whole deal.

bwaller · « **Reply #74 on:** November 05, 2009, 06:38:54 PM »

OK concerning the 360 trans into a 350. The shiftdrum will be a problem. It can be made to fit easily enough, and the 350 selector forks fit the 360 drum. However the drum tracks are closely spaced enough to not allow room for three forks to follow the patterns without coming together. Another problem is that the three 350 forks use a removable pin to follow the drum track, the 360 center fork uses the same pin, but the two forks on the separate shaft have a wider pin cast in the fork thus a wider track on the drum. The 350 pin is too small & will be sloppy in those outside two tracks. And this isn't even checking selector fork offsets.

Clear as mud?

I'm not sure what the fellow LMP mentioned did in his, obviously it can be resolved. Maybe he used a shift drum from Nova. The problem would be the same for a 500/4.

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Author Topic: Close ratio trans for CB 500/550, can we build one from parts? (Read 32926 times)

ajracer