My CBR 150 project.....

[Overandout]

Enjoy your journey... The CBR 150 Chronicles

CBR 150 rider 2

The journey at the moment is metaphorical!

[Overandout]

I hope I can remember how this goes back together when the time comes!!

[Overandout]

Back again!!

So the running bike was finally totally dismantled, leaving it looking like this:

And my balcony looking like this....

Having decided that I was going to use the 15mm swing arm pivot bolt from an NSR instead of the 13mm bolt from a CBR, logic told me that I was going to have to enlarge the holes in the frame spars to fit it.

However, upon closer inspection of the way the single sided arm had been fitted to the donor bike showed that not only had the sleeving down of the bearing internals to 13mm been a bit "home made", but also that the spacers had been made up so that while the chain run to the rear sprocket was straight, the rear wheel actually sat off-centre to the centre line of the frame by about 6mm!!

Where previously a longer than standard spacer had been used, I was going to have to reduce one of the new NSR original spacers by 3mm. The problem was that it only protruded from the swing arm by 3mm but the only alternative to get the swing arm mounted so that the wheel would be in the centre of the bike would have been to remove some of the steel pivot point on the inside of the frame... (the round protrusion on the inner side of the frame spar in the picture below)

I figured that it would be easier to modify the swing arm pivot spacers than the frame...

[Overandout]

Here is the swing arm with the original NSR pivot bushes and spacers, as you can see, only about 3mm can come off this...

So here is the swing arm with the reduced spacer for the pivot. Quite happy with that really considering I did it at home:

Then I had to enlarge the pivot hole in the frame.

First I filled the original holes with epoxy putty, and drilled a small pilot hole in it when set:

Then a 15mm steel hole cutter with a low speed drill and lots of water for cooling....

Took me about 4 hours to do both sides, but the result is a clean centered 15mm hole for the NSR pivot bolt to go through!!

So with the swing arm ready to go into the modified frame, it was time to turn my attention to the front end.

The first problem was that I couldn't use the "top hat" extenders that came on the USD forks of the donor bike on the Zoomer forks, which meant that, as the top yoke from the CBR would no longer grip onto a reduced diameter tube, it could not be used. I have to use the Zoomer top yoke, but that has bar risers / clamps but I want to keep with clip-ons...

So here is the yoke after removing the risers:

Happy with that too, but it cost me 400 Baht for the machine work.

So now to the forks...

As you can see, the original CBR forks are quite long (on the left, black "right way up" fork), the USD forks which were fitted to the donor bike were a few cms shorter (center, USD fork with reduced diameter adapter at the top), but the Zoomer forks are shorter still (on the right)... and as the "top hat" that you can see on the donor forks cannot be transferred, I need to come up with a way of lengthening the Zoomer forks to somewhere close to the original forks' length.

A trial bulid of an extended Zoomer fork should be complete this weekend.....

Edited June 12, 2015 by Overandout

[ktm jeff]

Im love this one-off project . Fantastic to see an engineer coming up with such intresting solutions to problems faced by everyone who embarks on a custom project . It matters not what bike , or its size , or its value . Your making a work of art .

[Overandout]

Im love this one-off project . Fantastic to see an engineer coming up with such intresting solutions to problems faced by everyone who embarks on a custom project . It matters not what bike , or its size , or its value . Your making a work of art .

Thanks for the compliments !!

I agree that it's the process of doing it that gives the satisfaction, the final result is just the end.

Sometimes I think about how much I'm spending and realise that I could buy a top condition NSR SP for the money, which, ultimately would be a better bike than I will end up with, but where's the fun in that?

One thing though... I'm no engineer! (I work in Contracts and Legal), this is just a hobby.

[ktm jeff]

Your not an engineer ! . Well , if your work ethic and attention to detail on this project is anything to go by , i know where to come should ( when ! ) i need legal advice LOL . Maybe keeping tabs on the cost is wrong , as one could buy a "better" CBR 250 for less - but that would be like all the other CBR 250,s , yes . It may not be about what your spending though , but about what your not , IE too much time and money down the pub / bar . Looked at that way , this bike may work out very cheap .

[Overandout]

So this is a Zoomer fork.

These are not cartridge forks like most USD forks, they are "damper rod" forks, where the damper rod screws into the fork cap and the spring sits inside the lower fork tube and is compressed by the damper rod.

So to make the fork longer, I needed to extend the damper rod. To do this I decided to just use a longer bolt than the original, and sleeve that bolt with steel tube with the same outside diameter as the damper rod.

The difference in fork length to the original CBR forks is just under 8cms, so I bought some 10cm long bolts of the right head and thread size so that I could later cut them down, and had pair of sleeves made 8cm long by a machine shop.

Unfortunately, on the first trial fit, it became apparent that this would extend the lower tube too far out of the upper tube, causing the fork seal to run off the hard-chromed area onto mild steel. Not good.

So I cut the sleeves down to 6cm. This is as much as I can extend the forks, so even though they will be much closer to the original CBR forks' length, they will still be about 2cm shorter. Never mind, if its too low I'll have to re-spring the forks.

Then I had to lengthen the bump stop, which originally butted up against the inside of the fork stop. Using some old handlebars and aluminium parts, I made some sleeves to go round the extended damper rod for the bump stops to butt up against (the need a clean up because of the glue and paint on the handlebars!)

So the Zoomer forks will now be pretty close to the original CBR forks' length.. (2nd from the left)

I also cleaned the frame with petrol to get rid of all the old grease and chain lube... opinion on whether this was a good idea to do on the balcony was divided in my household:!

[Overandout]

A quick and dull update (no photos I'm afraid):

So my lengthened forks are now together and I'm on the hunt for some heavier weight fork oil. Standard oil for these forks is rumoured to be 5w or 10w, depending on where you are reading, but the stuff that came out was like water, so I'm going to try 20w and see how it goes.

Having had the top yoke prepared and the forks now built, I thought a trial fit of the front end was in order. I had, however totally forgotten that, although the steering stem diameters and threads are the same between the Zoomer X and the CBR, the Zoomer stem is much longer and could not be used to fit the botton yole in the CBR frame....

So off to the machine shop again to see if they could remove the CBR stem from the yoke, and transplant it onto the Zoomer yoke.... I am picking it up on Friday.

I also ordered a Zoomer X speedo drive for the front wheel which is required due the fact that the Zoomer forks require the caliper and disc to be mounted on the left and the speedo drive on the right.

If I am very, very lucky, the gear ratio will be close enough to give a reasonable speedo reading and the front spindle will not need any more spacers engineered to fit the NSR wheel in the Zoomer forks.

I am not counting on much luck with this project though !!

[Overandout]

Got a bit more done.

As I said above, the steering stem on the bottom yoke of the Zoomer couldn't be used, so the CBR stem was transplanted (the CBR one is already welded in in this photo, the Zoomer one which was removed from the yoke is on the right):

And, as the spacing between the threads at the top is a lot smaller, the top yoke also had to be machined again, so now its a bit thinner!

Also, the steering stops on the Zoomer yoke were in the wrong place. But luckily, the holes where the clocks / headlight support mounts onto the yoke were just where the stops needed to be. So I had a thread cut in the holes and some threaded stops made up.

You can see where the old stops have beed ground off and the new fabricated ones are:

So, with the forks now lengthened and rebuilt with new seals and oil, I could fit the forks in the modified yokes:

Then I had to get the NSR wheel centered in the forks. This only required that the new Zoomer speedo drive had to be machined down by 2mm and the crown that drives the gear in the front wheel had to be cut down by a few mm also. Not great engineering work so no detailed photos, but now the front end is almost complete:

Getting the brake caliper to fit (taking into account that it is now on the other side and the disc is much bigger that the Zoomer disc) is going to be a challenge....

[Rhys]

I have about 55k on the 2007 Version.... Still looks ok... Still a great little bike..

[Overandout]

So the project moves on!!

Now that most of the engineering has been done to get the rolling chassis in a state to be assembled, I set about putting the main parts together, making sure that they are all clean and painted

First up was the frame (my proposed colour scheme won’t fit well with a black frame, so I have painted the frame spars an aluminium metallic):

Then the yokes (now painted black) could be fitted:

Then I started fitting other ancillary bits to the frame (I started sorting through all the parts at this point to work out which was in the better condition of all of the duplicated ones):

At some point I will have to move the bike off the balcony and down to the car park, so I want to fit as much as I can onto the frame before-hand.

Then I got to the point that I needed to do a trial fit of the suspension and wheels before sending the wheels off to be painted.

Forks and swing arm in:

Wheels in:

As you can see, when the rear wheel is fitted, it is obvious that the rear end is too high, the massive gap between the wheel and mudguard shows it clearly, but also note how far off the ground the side-stand is… when resting on the stand the bike is at about 30º off vertical!

The front end is more successful, particularly the bracket for the brake calliper which was made for me by my, now regular, local engineering shop!!:

So, back to the back end…

The shock that is fitted in the picture above is a YSS shock that was fitted to the donor bike (the one that came with the NSR Pro Arm) and is the only one I have with some damping… It seems to be a CBR 150 shock as the length (hole to hole) is 260mm.

Unfortunately, a standard length CBR shock is always going to raise the rear ride height because the shock mount on the swing arm is higher in relation to the spindles (wheel and swing arm pivot).

Here you can see that the actual difference is about 12mm, but not in an entirely vertical plane (nor exactly in the plane of travel of the shock compression) but it gives the idea that in order to compensate for the different swing arm geometry, the shock should be about 10mm shorter than a standard CBR shock.

I did also have this YSS shock that was given to me with the donor bike;

and although it is leaking, it is about 5mm shorter, so I fitted it to check the effect and it made a big difference, but not enough. So I am on the look out for a 250mm shock to fit.

Getting a bit fed up with chassis modifications and suspension woes; I decided to do something more rewarding, so I split open the two tail lights and used the best and cleanest parts from each to build up a new light unit.

Pretty pleased with that!

[ktm jeff]

Nice One. Great to see it coming together , amazing , considering your workshop !. Your attention to detail will make this bike really stand out. Not rushing will pay dividends later. . Can you build a shed in your parking space to keep things together when you move downstairs ?.

[Overandout]

Wheels back from the powder coaters:

I also had to get the old cush drives machined out of the rear hub and the new ones pressed in.

So I will get some new tyres and the chassis will then be able to be rolled around.

So when it finally leaves my balcony, the engine will need to be more or less ready to go in, so the good engine goes up on the bench:

While the old engine with the bent valves sits on the floor... giving up any bits which may be of use.

First donation is the clutch. I have no idea if the clutch in this engine is OK, but the one in the running bike was slipping like hell, so it's worth a try to swap them over:

Then I turned my attention to the top end. Checking the valve clearances on the running engine showed that they are all needing adjustment, but worse was discovering that the valve timing is out by one tooth! I had been riding it like that for over a year!

Anyway, seeing as I needed to change shims, I thought I would salvage the shims from the old non-running engine.

Here are the shims that came out of the exhaust side (look closely at the one on the right):

Yes, it had been packed out with an additional "shim" under the bucket!!

Now I wonder if the other exhaust valve was also "adjusted" in the same way in the past and it had fallen out, causing the damage that bent the valve....

[ktm jeff]

That additional shim looks like its simply a scrap piece of steel. Utter bodgers. Lucky your so diligent. Have a good look for the any other additional "shims" , and ensure you dont inadvertently transfer it / them. Great to see its progress.

[Overandout]

Thailand.... Zen and the Lack of Motorcycle Maintenance !!

[ktm jeff]

I believe theres a book of similar name.

[DLang]

That additional shim looks like its simply a scrap piece of steel. Utter bodgers. Lucky your so diligent. Have a good look for the any other additional "shims" , and ensure you dont inadvertently transfer it / them. Great to see its progress.

The sheer ineptitude, incompetence and utter buffalo-brained antics of Thai 'mechanics' never fails to amaze me.

It was probably done at an official 'Honda dealership' too.

Good luck with the build.

A lot of work for not a lot of bike.

I would like to do over a CBR400 here, but alas, don't have the time or expertize, and would not trust the Thais and their 'shims'.

Rock on.

[Overandout]

That additional shim looks like its simply a scrap piece of steel. Utter bodgers. Lucky your so diligent. Have a good look for the any other additional "shims" , and ensure you dont inadvertently transfer it / them. Great to see its progress.

A lot of work for not a lot of bike.

Ha ha !!

I like that! If I had a worshop I would write that above the door!!