CD175 Build

[drifterwanab]

Hi all

I have been a lurker for a while here now, but have been yet to post

I started racing Moto cross at 4yrs old until 14 (gave up due to cost), then at 16 got a Road bike Aprilia Rs50, then 17 Traded up to a Aprilia RS125 (great bike!) which i also tuned up and since then had a sports bike of some description on and off. But i have always had a hankering to build "something". So now at 29 time to pull my thumb out and do it

I picked up this Honda CD175 for pocket change, my first plans where to just use the frame and tank but soon as i got the bike home and got it running i liked the sound of the engine and the look of it so engine is staying - yes its gonna be slow! ha but this is a excercise for me in building something

Well Her she is

Plans are upside down forks with clip ons, motocross swingarm, external res twin shocks, spoke wheels probably super moto rims, and some engine tuning

Proably turn out a frankestein love hate thing, but iam going to try have fun building it, using stuff i can find cheap on ebay etc.
Will update as i do stuff

 

[sbaugz]

will be following this build. I thinks its great that people are bringing these old bikes back to life when they otherwise would be just rotting away somewhere.

 

[Erskine]

CD 175 are the dogs bollocks. It would be interesting to see one of these with the suspension mods but retaining not just the tank and side panels, but also the ultra cool mudguards.

 

[pacomotorstuff]

Good to see that there are 2 of us crazed enough to work on these things (Mine is going street tracker, though).
Suggest you check the rear frame tubes where the swingarm / footpeg plates bolt on - both of mine were rusted and broken through. Instead of repairing them, I elected to build new ones as the original were toast. Also check the lower frame tubes as they have a tendency to rust through as well.
If you need any bits, I've discarded a lot of the bike and might be able to set you up with something you need.
Have fun with this thing.
Pat Cowan,
Vintage Motorcycle Fiberglass

 

[dean owens]

looking forward to seeing more of this.

 

[mwm1977]

I paid $100 for it with no title and the valves stuck. I know it is not cd, but very similar. Stripped the bike to its frame and rebuilt the top end. This was a fun and simple bike to work on and ride. I have some extra parts if they will work with a cd.

 

[drifterwanab]

that 175 above looks slick! i like that rear fender, is that the standard one cut down?

Just to let you all know this project hasnt died, i have been gathering some super cheap parts together.

I went to do some work the other day but its a bit cold at the moment in my little wooden shed. There will be some progress hopefully a roller with my sourced front end setup )) just need it to warm up a bit!

 

[drifterwanab]

Also and advice / tips on getting more power from the engine will be grate if any one has any input

Are there any preffered carbs swap outs etc? cam off something else, that kind of thing

This model was 15bhp from factory.... I will be nice to get it to like 20+

 

[pacomotorstuff]

Things I have found out so far working on the Dad 'n' Daughter CD175.
Not a big amount of engine stuff available for what was the commuter bike of the 175 family.
The CD exhaust pipes were smaller inside diameter than the CL pipes we're putting on it. Don't know about CB pipes. If the CB's are bigger ID as well, get a set for a little less restrictive exhaust. Your mufflers look shot so replace with something that flows better.
Start with the existing carb and get it cleaned and rebuilt. It's easy to over carburate a single carb. Change to a less restrictive air cleaner. Jetting is available for the Keihin from a number of sources. You can try stuff like a longer carb spacer and / or velocity stack but honestly, I'd just get the bike running solid first and look at those things later on.
The CD camshaft has a different part number than the CB; I have the CB cam specs but haven't checked it against the CD yet.
The pistons are the same, CD/CL/CB/SL. I don't know if the combustion chamber volumes are different CD versus CB, though they take the same valves.
Valves, springs and seals are available for these bikes as well as guides if you need them. Expect to have to freshen up the head - both of the heads I have need work.
The CB/CL cylinder dual carb head will fit on the CD - but we're keeping the CD head for now.
I bought a 5 speed transmission complete with drum shifter and forks to replace the 4 speed but I haven't split the cases yet (putting in a newer crank as well). I'll let you know how it goes...
If you feel the need to upgrade the clutch like I did, heavy duty clutch plates and springs made for the CB will work.
Weight is the big culprit with these bikes. If you remove the electric starter and all the bits and replace that big 6 Volt battery with a little one from a Honda 50, you'll save around 12 lb right there. Probably another 10 lb in the fenders by the look of them. You get the picture.
I'll keep you posted on our progress.
Regards,
Pat Cowan

 

[drifterwanab]

Nice Bit of info, cheers Pat

Pipes are shot and i hve chopped em up already to get a idea of where i can run them on a new path. Iam going to get some pipes made up and are gonna be low level on the left side.

Bike is going to be stripped back and light weight, alloy swing arm, modern USD forks ally yolks etc

I myself iam 15 and hlf stone (6 1".... and need to lean down any way,so good reason to do it also or the bike wont move! ha

 

[drifterwanab]

Well the sun was shinning today in the uk, so the modifications got under way!

I pulled out the parts i collected and got the bike to a state where i can start mocking bits up.
First up was a trial fit of my aprilia rs125 front. So off came the cd front and to my suprise the steerer tubes are very similer, and after sliding the sterrer tube into the frame and having a look at things...... It cant be that simple can it?!?! I quickly discovered that all i needed to do was fit the top bearings off the cd as the top and lower on the rs125 tube and bamm it fits! All i need is a spacer machinging up as the tube is just a bit too long

Taking shape already!

Next to tackle the motocross ally swing arm!

 

[ffjmoore]

Any progress on this one? My friend just picked up a 69 cd 175 that we are going to fix up. Are you going to stick with 6v or make the switch to 12v?

 

[drifterwanab]

Well progress has been ultra slow due to me spinning too many plates

Regards to the 12v, yes i plan to upgrade but that will be some time after the bike is built, running and road legal - so a future mod

Heres a cheeky little sneak peak of progress. Iam still mocking up and problem solving stuff at present

 

[Chukoloco]

Any updates on this one?

 

[Green199]

Any updates on the fork swap?

 

[Chukoloco]

Too bad no kore updates on this one. Aint stoping me for posting my cd175. ;D