Commando Cafe Racer Rebuild

Re: Commando Cafe Racer Rebuild 3 May 2009

Dave, I'm building an S type replica from some miscellaneous bits and as far as I can ascertain an S and an early Roadster share many of the same details, the pipes are a very obvious exception. both bikes share the early frame which was also common to the first fastback models (not the very first ones with the missing upper cross tube that was recalled due to breakages). This frame has the centre stand mounted on a frame cross tube under the gearbox as opposed to the later models where it is mounted on to the gearbox cradle, the side stand is bolted to a square lug welded to the frame about half way along the left lower frame rail. It would appear that you have this frame. The S-type and Roadster also had the headlight mounted on a ring bolted to the steering head yokes which were also different to the later models, since your bike seems to have non standard yokes and forks (looks like very nice Cerriani units to me) we can't be sure what was on originally, although it would most certainly have had a front drum brake. The central oil tank and more angular side panels with ignition switch fitted to the left one are also a feature of both bikes and you seem to have these, the rear wheel would have been the bolt-up version rather than the cush-drive, the tank was generally a fibreglass Roadster style and the engine would have had a timed breather and outlet on the left side of the crankcase driven by the camshaft. There are quite a few other detailed differences but I wont bore you with these unless you actually decide to build it to S-Type spec.
I think you have some nice bits on your bike, the Dunstall stuff is well-respected (I myself have a dunstall tank, seat and fairing to install on a future project) the forks are quite sought after and the Interstate tank seems to be the model that fetches the most if you opt to replace it at any time with a 'pukka' cafe-racer style at some point. I would be inclined (no pun intended) to fit rearsets if you want a more comfortable riding position with clip ons, as I find standard Commando footpegs are quite far forward even for standard bars. Good luck with it and keep the photos coming.
Dave

Re: Commando Cafe Racer Rebuild 3 May 2009

Hi DaveM,

The wheels are from a chap called Peter Allen. The front forks are Seeley and the fairing, front guard and seat are Paul Dunstall. There's also a Lucas Rita ignition system, but I haven't fitted this as yet - I'll get it all running with the basic Kettering system and then see if I want to add the TAI. The rear shocks are Koni.
The bike came with a Peter Allen 2:1 zorst system as well, but the muffler was totally perished. I've still got the header pipes and joiner, but prefer the look of the new (original) headers and pipes I've fitted. (As I said, I could get to like chrome as long as it's not too over-the-top.)
There's a Dunlop front disc and caliper fitted, but a Suzuki master cylinder and twist grip and LHS switch cluster. I made the loom from scratch.
So as you can see it's a real bitsa. The last owner was rather keen on the Metric system, so many fasteners have been replaced with metric threads and I've kept them this way.
I'll have a look at the centre-stand mount tonight and get back to you one that.
Agree on the rearsets, I've sat on the bike from time to time and it's really not very comfortable. Might be fine for the pillion... Ah, to be honest, I'm just getting old and can't ride all day in a bad position - one of the reasons I stopped the rego on the Pantah and bought an old Yammy TRX to get around on.

Re: Commando Cafe Racer Rebuild 3 May 2009

I had clip ons and rearsets on my own Norton cafe-racer and found it wonderful to ride for about 15 minutes until my back started to ache, I eventually left all of the cafe racer stuff on it except the handlebars which I replaced with a moderate height and bend and this position with the rearsets is one that I think I may adopt on a future project or two.

Re: Commando Cafe Racer Rebuild 3 May 2009

Been flat out recently with work stuff, so muggins leaves it to the coldest (and nearly) shortest day in the year to get back out to the shed!

First up is to dismantle the gearbox and look at the kickstart ratchet. Thought it would be a pretty straightforward swapover of the gear, but now I see that the pawl that I put in only a handful of kicks ago has already started to wear away. Now I don't know if this is just bedding-in and it's still totally serviceable or not, but I'm thinking it's been damaged by the worn teeth on the ratchet and it would be prudent to replace it so both parts are new at the same time.


Whilst the gearbox is in bits the oil feeds to the engine are very accessible so I thought I'd give them the once over. I'd noticed a hairline crack where the steel pipe meets the brass block so removed it all and resoldered the junctions of both pipes. Luckily Ms Davamb was out at the flicks at the time, so I was able to run the part through the dishwasher to get the joint thoroughly clean before soldering with the gas torch and Bakers flux.


Hopefully I'll have a new pawl by the next weekend and can get this all re-assembled.

I've also been working on the sidestand. The shaft that the stand swivels on snapped off a couple of months ago, so I drilled it out, tapped in a (big) thread and used a bolt in place of the shaft. All seemed ok, but buggered if I can get it at the right position to support the bike. It swing out to about right angles with the bike, but this leaves the bike rather vertical and there's nothing stopping it from self-retracting with only the least amount of encouragement. I think it should 'park' forward of it's current position and I'll have to grind off some metal (I built up the stop position with weld some time ago) and construct some sort of adjustable stop for this. Answers on a postcard...

Re: Commando Cafe Racer Rebuild 8th June 2009

Ms Davamb was out at the flicks at the time, so I was able to run the part through the dishwasher to get the joint thoroughly clea

Click to expand...

don't kid yourself: there will be evidence un-noticable to the male eye but rediculously vivid to the female eye.... you're in trouble and you don't even know it yet :shock:

I once used the microwave to season a piece of wood (I'm a guitar builder) and though I thought I had cleaned up all the incriminating evidence, I was busted in about 2 minutes of her return!

I return you to your regularly scheduled thread (which is great, BTW)
Karl

Re: Commando Cafe Racer Rebuild 8th June 2009

71basketcase said:

don't kid yourself: there will be evidence un-noticable to the male eye but ridiculously vivid to the female eye.... you're in trouble and you don't even know it yet :shock:

Click to expand...

I know exactly what you mean Karl - my friend has a phrase that describes this particularly male predicament exactly - he calls it "dead man walking".
Please don't tell Ms. D, here's that 20 bucks I owe you.

Re: Commando Cafe Racer Rebuild 21st June 2009

Got the gearbox back together this arvo, but Repco (like me) had no idea of what Castrol Hypoy oil is. All they had was some 80W gearbox oil for 2-stroke gearboxes. I recalled that the Tech Digest stated to use SAE90 so decided not to buy and went home to check the documentation. There's 8 other brands mentioned in the workshop manual, will try again during the week.

One thing that's really bugging me though is the lack of clearance between the kickstart lever and the exhaust pipe. There's none. I've tortured the rhs exhaust mounting plate a bit but the lever still just connects with the pipe. Been wondering if the whole gearbox is in the wrong position. That is, can the whole thing be moved towards the left hand side of the bike and thus make more clearance? Any ideas out there gents?

Again, this is something that makes me wonder if the bike was originally an S-type... I'll keep blundering on in the meantime.

Re: Commando Cafe Racer Rebuild 21st June 2009

You can move the kick lever out to the end of the shaft and maybe gain 1/8", but it will eventually tp the pipe.

I HATE when that happens.

Try loosening everything off again (not removing, just loosening), then rotate the kicker down and slip a chunk of 1/4" plywood or plastic in between and have a mate hold those two in place as you tighten everything back up starting from the head and ending at the rear bracket rubbers. Pop the starter back, lose the plywood, and check the clearance again.

Re: Commando Cafe Racer Rebuild 21st June 2009

I have in the past made slightly thinner spacers for the Z-plates to sit closer to the frame, this can give more clearance as the rear exhaust mount on the plate sits further in towards the frame with this altered position.

Re: Commando Cafe Racer Rebuild 21st June 2009

Try a MkIII kickstart lever. It sticks out a little further, plus its a little bit longer (I think) than the earlier lever. Mine had a 'Racing Spares' (RS053) lever on it when I got it, and it took a bungee around the pipe and frame before tightening down the exhaust to get it to just clear. With the MkIII lever, I've got over 1/2 inch of clearance.

Re: Commando Cafe Racer Rebuild 21st June 2009

Also try to hold the head pipe from rotating as you tighten it, This can be done near the frame by a friend as you tighten. I have had the same problem and wondered how and what changed? It was because as I would snug it up it would slowly rotate the header pipe to the right and pull the muffler with it. So try to loosen the pipe and hold it to the left as you tighten.

Re: Commando Cafe Racer Rebuild 21st June 2009

davamb said:

Got the gearbox back together this arvo, but Repco (like me) had no idea of what Castrol Hypoy oil is. All they had was some 80W gearbox oil for 2-stroke gearboxes. I recalled that the Tech Digest stated to use SAE90 so decided not to buy and went home to check the documentation. There's 8 other brands mentioned in the workshop manual, will try again during the week.

One thing that's really bugging me though is the lack of clearance between the kickstart lever and the exhaust pipe. There's none. I've tortured the rhs exhaust mounting plate a bit but the lever still just connects with the pipe. Been wondering if the whole gearbox is in the wrong position. That is, can the whole thing be moved towards the left hand side of the bike and thus make more clearance? Any ideas out there gents?

Again, this is something that makes me wonder if the bike was originally an S-type... I'll keep blundering on in the meantime.

Click to expand...

There seems to be quite a few different combinations of mufflers, pipes, and brackets to mount Peashooters. I've found that some of them move the muffler forward enough to make it get hit by the kickstart, due to the taper of the muffler itself. If the muffler is moved backward there's enough clearance because it's narrower where the lever swings.. I've made brackets that move the muffler back about two inches. There seemed to be plenty of header pipe left for the job. That made me think I had a mismatch to begin with.

Re: Commando Cafe Racer Rebuild 21st June 2009

Thanks for the feedback guys, found some 90W oil so can complete the gearbox re-assembly.

bpatton said:

There seems to be quite a few different combinations of mufflers, pipes, and brackets to mount Peashooters. I've found that some of them move the muffler forward enough to make it get hit by the kickstart, due to the taper of the muffler itself. If the muffler is moved backward there's enough clearance because it's narrower where the lever swings.. I've made brackets that move the muffler back about two inches. There seemed to be plenty of header pipe left for the job. That made me think I had a mismatch to begin with.

Click to expand...

That got me thinking BP, I only had one set of mounting brackets because the bike came with a 2:1 zorst, so I made CAD models of all the brackets and had facsimiles laser-cut. Breeze to extend the design by 1.5" and get new ones made. Thanks.

Re: Commando Cafe Racer Rebuild 21st June 2009

Gearbox is all back together today, so I thought I might be able to get a putter up and down the street. Couldn't get it to start though. New petrol and cleaned plugs but still no go. Moved the kickstart forward a couple of splines so that I could get more use out of the stroke, but still no joy. Half a dozen bangs and then it cuts. Dunno what's going on now. Might try retarding the ignition a couple of degrees and see if that improves matters. Sure I was right here nearly 6 months ago. I'll keep at it over the next couple of nights.

Re: Commando Cafe Racer Rebuild 26th July 2009

Dave, you aught to get that Rita ign sys out and dust it off. Check out britiron.com . Many think very highly of that system. There is info around that shows how it wires in.

Re: Commando Cafe Racer Rebuild 26th July 2009

Yeah, been thinking the same overnight Rich. Wanted to get it sorted on the standard system before adding further complexity, but I've had a couple of others tell me it makes starting a hell of a lot easier. I'll dig it out tonight and see what sort of condition it's in.

Re: Commando Cafe Racer Rebuild 26th July 2009

Well, i've since been told that I'm just silly running 50W oil in the bike - especially in the middle of winter! But I hadn't plucked the oil type out of nowhere. The manual says 20W50 is suitable, but I'd checked the Tech Ref:
Image
Clearly states SAE50W, no multigrade - so there. I'm not having a protracted senior moment.
And here's a little something special from tonight:
Norton Running
Getting late, so good thing it shut down, but just had to give you all a look and listen. Think it was loosing all the energy to the syrup I had in the crankcase!
Now one thing that worries me though is that the oil seems pretty frothy when it's being returned to the oil tank. Is that normal?

Re: Commando Cafe Racer Rebuild 26th July 2009

Hi all,

Well, despite my success a week ago, I've not had a lot of time to do more on the Norton until today. Had taken a day's annual leave for family reasons, but managed to find a couple of hours late this arvo to have a bit of a play. Still hard to start and when it did run it was farting and popping on the right cylinder.

Dropped the points cover and had a look at the points when running. LHS pot has a nice juicy blue spark when the points open, RHS has a weedy orange one. I clean the points anyways, but suspect the condenser. If the ar5ehole I loaned my oscilloscope to ever returns it, I could arrive at a diagnosis by a much more scientific method, but today it's spark colour - groan. Still, when I rebuilt the ignition, I used a couple of old condensors I found kicking around amongst the pile of stuff that came with the bike, so it's not unreasonable to suspect them as I knew the coils were good.

Close to 5pm and I hoof smartly up to the local auto elec, but he doesn't have one or even know what I'm talking about - wouldn't take my car there for quids! Repco has some Bosch ones as fitted to old Nissan 4WDs so I zip around and grab a couple just before the shop closes. I rebuild the ignition sub-assembly with the new parts and voila! She's purring like a kitten. Lovely. Starts are so so easy too.

All is not so good though when I engage the clutch and snick a gear - first or second there's a rather alarming noise:
Noisy Clutch? (movie)
It's coming from the back of the transfer case, LHS so I'm guessing something in the clutch is not too clever... Any other ideas?

Hopefully this weekend I can get the time to pull it apart and see what's going on.

Re: Commando Cafe Racer Rebuild 5th August 2009

Great looking bike, classic late 70's early 80's cafe racer style.
It is an unusual caliper mount. May well be stiffer than my RGM one.
I notice you only have one amal on there, and it seems to be mounted really close to the head...difficult to tell by the photos.
Don't know anyone that is happy with the performance of only one mk1 amal on a Commando....anyone out there that is?
Also on the Triumphs they used to say that you should try and get 7" from cylinder bore centre to carb centre to allow the gas flow to smooth out.
The tri-spark ign system is the one everyone raves about. I have a Boyer. You dont need to use the ballst resistor stuff with the electronic ign.
Good luck with the setting up.
Always like to see non standard stuff. Much more interesting.
Stu.

Re: Commando Cafe Racer Rebuild 26th July 2009

davamb said:

Yeah, been thinking the same overnight Rich. Wanted to get it sorted on the standard system before adding further complexity, but I've had a couple of others tell me it makes starting a hell of a lot easier. I'll dig it out tonight and see what sort of condition it's in.

Click to expand...

For postage only I have a complete Boyer MK 1 lying around the garage if you fancy it... :?: