MJPriceisright
Coast to Coast
Re: 79 Honda CM400T - Nerdsports Racer
howd she ride?
howd she ride?
79 Honda CM400T - Nerdsports Racer - SHE'S DONE!!
- Thread starter nerdsports
- Start date
Frankenfe
Coast to Coast
Re: 79 Honda CM400T - Nerdsports Racer
Been meaning to ask, how was the CBR600 transplant?
I installed a '98 CBR600 front end onto a '74 CB750 and I had to also transplant the stem portion from the 750 lower triple to the CBR lower triple to get the right stem length and get the machined bearing surfaces on the stem to be in the right places. I was able to use a standard tapered CB750 bearing set.
Did you have to gather / make up a custom set of bearings?
Been meaning to ask, how was the CBR600 transplant?
I installed a '98 CBR600 front end onto a '74 CB750 and I had to also transplant the stem portion from the 750 lower triple to the CBR lower triple to get the right stem length and get the machined bearing surfaces on the stem to be in the right places. I was able to use a standard tapered CB750 bearing set.
Did you have to gather / make up a custom set of bearings?
nerdsports
Active Member
Re: 79 Honda CM400T - Nerdsports Racer
It felt pretty nice. Obviously the power wasn't very smooth because it's still on the stock jets but otherwise impressed. The suspension was smooth, the rear brake is useless in comparison to the front brakes, and I love the reversed shifter. Normally it's 1 down, the rest up but in a pinch I left the heel shifter and cut off the toe shifter and use it in reverse - it's awesome! Going through the gears you just mash down on the shifter but makes more sense than lifting up the shifter.
I bought a set of All Balls tapered roller bearings for the CM400. The bearing kit came with 2 washers, one thick and one thin. I put the thick one under the bottom bearing before it was pressed onto the CBR stem. Banged out the old bearing races from the stem then froze and installed the new ones for the tapered rollers. I had to put the thin washer under the top tree nut because the CM400 stem cap is closed whereas a CBR stem cap is open. So I just added a washer so it'll tighten down. I'll snap some pics of this for you.
MJPriceisright said:
It felt pretty nice. Obviously the power wasn't very smooth because it's still on the stock jets but otherwise impressed. The suspension was smooth, the rear brake is useless in comparison to the front brakes, and I love the reversed shifter. Normally it's 1 down, the rest up but in a pinch I left the heel shifter and cut off the toe shifter and use it in reverse - it's awesome! Going through the gears you just mash down on the shifter but makes more sense than lifting up the shifter.
Frankenfe said:
I bought a set of All Balls tapered roller bearings for the CM400. The bearing kit came with 2 washers, one thick and one thin. I put the thick one under the bottom bearing before it was pressed onto the CBR stem. Banged out the old bearing races from the stem then froze and installed the new ones for the tapered rollers. I had to put the thin washer under the top tree nut because the CM400 stem cap is closed whereas a CBR stem cap is open. So I just added a washer so it'll tighten down. I'll snap some pics of this for you.
MJPriceisright
Coast to Coast
Re: 79 Honda CM400T - Nerdsports Racer
haha gp shifter style, nice nice. yeah the first time i rode on the track with the gp shift it was a little weird but then you grow to love it!
haha gp shifter style, nice nice. yeah the first time i rode on the track with the gp shift it was a little weird but then you grow to love it!
longhorn717
Active Member
Re: 79 Honda CM400T - Nerdsports Racer
man this build is coming along nicely. Almost have my metal shop where it needs to be to start tearing into my 400. I have great things planned for her.
Thought I'd throw this out there. I found a picture on the web. I forget where of course, but the guy had taken the backbone out of his cb400t from the headstock all the way down to where it meets the swingarm. he brought up two pieces of tubing flared them out around a tank he had built (think Ducati) and welded them to the headstock. he added a cross brace where the seat meets the tank and then brought his tail section off that and braced it similar to what you have done Nerdsports. Looked really amazing.
man this build is coming along nicely. Almost have my metal shop where it needs to be to start tearing into my 400. I have great things planned for her.
Thought I'd throw this out there. I found a picture on the web. I forget where of course, but the guy had taken the backbone out of his cb400t from the headstock all the way down to where it meets the swingarm. he brought up two pieces of tubing flared them out around a tank he had built (think Ducati) and welded them to the headstock. he added a cross brace where the seat meets the tank and then brought his tail section off that and braced it similar to what you have done Nerdsports. Looked really amazing.
corncountrycustoms
New Member
Re: 79 Honda CM400T - Nerdsports Racer
Your build so far is exactly what I'm doing so far. I've got a 80 CM400T with a 82 CB450SC motor that I just got finished putting back together in stock dress minus flipped bars and shifter arm to delete the mid controls. Keep it up It looks absolutely sick!
Your build so far is exactly what I'm doing so far. I've got a 80 CM400T with a 82 CB450SC motor that I just got finished putting back together in stock dress minus flipped bars and shifter arm to delete the mid controls. Keep it up It looks absolutely sick!
nerdsports
Active Member
Re: 79 Honda CM400T - Nerdsports Racer
Progress has been slow. Working on a 2 to 1 exhaust. Need to make a collector next.
Progress has been slow. Working on a 2 to 1 exhaust. Need to make a collector next.
MotorbikeBruno
Over 1,000 Posts
Re: 79 Honda CM400T - Nerdsports Racer
Are you going to add some length to the pipe on the #1 cylinder? Both pipes "should" be the same length for tuning purposes, not that they have to. Great bends, and it really does look great.
Are you going to add some length to the pipe on the #1 cylinder? Both pipes "should" be the same length for tuning purposes, not that they have to. Great bends, and it really does look great.
nerdsports
Active Member
Re: 79 Honda CM400T - Nerdsports Racer
Made some changes in my warehouse. Added this pallet rack to have more floor space and it helped create a little area for my tool box and drill press. Also added much needed lighting.
Redid the pipes to tuck them in and make them tighter to each other.
Made a 2 to 1 collector.
I was going to add this little detail to the end of the exhaust but I fear it might create TOO much back pressure and lose power.
Mount I added at the collector. Plenty sturdy.
I liked the GP shifter so much that I decided to stick with it.
Decided to add details to the stator cover.
Made some changes in my warehouse. Added this pallet rack to have more floor space and it helped create a little area for my tool box and drill press. Also added much needed lighting.
Redid the pipes to tuck them in and make them tighter to each other.
Made a 2 to 1 collector.
I was going to add this little detail to the end of the exhaust but I fear it might create TOO much back pressure and lose power.
Mount I added at the collector. Plenty sturdy.
I liked the GP shifter so much that I decided to stick with it.
Decided to add details to the stator cover.
MotorbikeBruno
Over 1,000 Posts
Re: 79 Honda CM400T - Nerdsports Racer
Still concerned about the tuning because of the different lengths :-\ , but boy is it pretty ;D. And that exhaust mount looks absolutely fantastic!
Still concerned about the tuning because of the different lengths :-\ , but boy is it pretty ;D. And that exhaust mount looks absolutely fantastic!
nerdsports
Active Member
Re: 79 Honda CM400T - Nerdsports Racer
This is a budget build so I'm building with things I have or what I can get for dirt (or free). I had a limited about of bends so I couldn't go crazy on the left cylinder to make them equal length. I'm aware of its drawbacks - I'll have to deal with them.
Thanks for the kind words, fellas.
MotorbikeBruno said:
This is a budget build so I'm building with things I have or what I can get for dirt (or free). I had a limited about of bends so I couldn't go crazy on the left cylinder to make them equal length. I'm aware of its drawbacks - I'll have to deal with them.
Thanks for the kind words, fellas.
MotorbikeBruno
Over 1,000 Posts
Re: 79 Honda CM400T - Nerdsports Racer
I hear ya. Been there! Again, killer work, and that mount is too damn pretty, I'm going to have to steal that idea if you don't mind!
nerdsports said:
I hear ya. Been there! Again, killer work, and that mount is too damn pretty, I'm going to have to steal that idea if you don't mind!
nerdsports
Active Member
Re: 79 Honda CM400T - Nerdsports Racer
Go for it! I've seen it elsewhere... nothing is original these days. lol
Updates!
Taking the engine out and everything apart for paint, powdercoating, and polishing.
Bare frame.
More fiberglassing on the tail. Making the tail meet the tank so the upholstery would look tight up against the tank.
MotorbikeBruno said:I hear ya. Been there! Again, killer work, and that mount is too damn pretty, I'm going to have to steal that idea if you don't mind!
Go for it! I've seen it elsewhere... nothing is original these days. lol
Updates!
Taking the engine out and everything apart for paint, powdercoating, and polishing.
Bare frame.
More fiberglassing on the tail. Making the tail meet the tank so the upholstery would look tight up against the tank.
Re: 79 Honda CM400T - Nerdsports Racer
I think your swingarm definitely needs some support. The arms were never designed to run without the support of the twin shocks, so it will flex with verticle loads and with side loads. I suspect it will fail soon. That would be bad!
This is from the AHRMA rulebook, but clearly shows that it isn't hard to do. Since you don't have to meet the rules, I would use larger diameter tubing.
I think your swingarm definitely needs some support. The arms were never designed to run without the support of the twin shocks, so it will flex with verticle loads and with side loads. I suspect it will fail soon. That would be bad!
This is from the AHRMA rulebook, but clearly shows that it isn't hard to do. Since you don't have to meet the rules, I would use larger diameter tubing.
