Classic Triumph Bonneville

[mangocrazy]

I did actually consider that. I bet someone somewhere has done it.

If you're gonna bother with that sort of thing though you may as well get more modern carbs.

Modern carbs would help in lots of ways. I'd do it.

[Mr. Dazzle]

Feels kinda pointless though, it's an old bike and always will be. I have a CBR for being hassle free.

A CBR with slightly iffy carbs

[Le_Fromage_Grande]

Twin crabs.

There're no vacuum ports or anything like that, to balance em you stick er....sticks...under the slides and eyeball em to see if they move in synch.

That's how you balance Mikuni Smoothbores, 4 of them, it doesn't work very well.

Couldn't the old fag paper trick be employed here, in the manner of finding when contact breaker points open? Might be better than lollipop sticks. And crabs...

Alternatively (and this will probably be regarded as heresy) couldn't you drill and tap the carb bodies for vacuum take-offs?

Not with Mikunis, you have to take the top of the carb off to adjust them.

[mangocrazy]

Feels kinda pointless though, it's an old bike and always will be. I have a CBR for being hassle free.

A CBR with slightly iffy carbs

Take your point, but getting the carburation right makes such a difference to the feel and enjoyment of the bike. My LC has been completely transformed by getting the fuelling set up on Dave's dyno. Night and day difference.

[JackyJoll]

There're no vacuum ports or anything like that

Yes there are.

[crust]

Do it by ear and feel.

Set the tickover on both slightly higher than normal, then adjust the cable on one one way then the other, you'll be able to hear and feel when both cylinders are even.

On my BMW the engine smooths out and the front mudguard stops wobbling.

[JackyJoll]

Do it by ear and feel.

Set the tickover on both slightly higher than normal, then adjust the cable on one one way then the other, you'll be able to hear and feel when both cylinders are even.

I’ve found, through trying all the various methods, that vacuum gauges or manometer is the best way to adjust the throttle stop screws and to get synchronous opening of the throttle slides.

[Mr. Dazzle]

Using a proper tool rather works better than sucking your teeth?

Quelle surprise.

[David]

Try the old hose pipe in the inlet and stuck to your ear thing....it's a cheap manometer....

[Mr. Dazzle]

Manometer aren't exactly expensive to begin with


I need to take the rocker boxes off and put them back on anyway, they leak like seives. So then I'll redo the tappets, then maybe the carbs.

Tempted the take the head off and see how much crap is already in the cylinders, what with it being unfiltered. Last time I did it looked like the pistons had been tarmaced.

Other jobs needed over winter;

Fork oil replacement / fork rebuild. Needs new gaitors too.

Front brake shoe replacement, adjust and grease the mechanism. May as well get new PTFE cable too.

Maybe get the gauges sent off for rebuild. New drive cables there too.

Source and fit matching bolts throughout the fairing with new locking nuts. I'm down to about 50% presence!

Repair and refit centre stand. This is probably the first job because it will make the others much easier.

[KungFooBob]

How is the front brake?

Is it up to the task for riding in modern traffic?

I can't remember, is it twin leading shoe?

I'm idly thinking about an A65, but the idea of a single leading shoe front drum (on the council spec version) scares the heck out of me.

[JackyJoll]

How is the front brake?

Is it up to the task for riding in modern traffic?

I can't remember, is it twin leading shoe?

I'm idly thinking about an A65, but the idea of a single leading shoe front drum (on the council spec version) scares the heck out of me.

He’s got TLS.



I’ve got a Norton 8” single leader on a 650 and it’s not bad. Some drum brakes are bad though, and require to be set up.

[JackyJoll]

Tempted the take the head off and see how much crap is already in the cylinders, what with it being unfiltered. Last time I did it looked like the pistons had been tarmaced.

The first evidence of lack of filtration you’re likely to see, is scratches on the bores.

A “tarmac” effect is burnt oil.

[KungFooBob]

I read an article once on setting up the MZ TS250/1 front drum.

It suggested chamfering the friction material so most of it touched the drum inner when applied, apparently if you didn't then only a very small percent of the shoe surface actually ever touched the drum.

[Mr. Dazzle]

The brakes aren't too bad...I've locked the front a few times while getting the feel for it. It seems like it's not doing much when you pull the lever, but it does. Just super wooden.

TBF when commuting I often don't even touch the brakes for the whole ride, even on modern bikes. Or I just drag them slightly so the light comes on.

The other thing I've noticed is its much less consistent. Hydraulic discs self adjust, this doesn't.

I've also heard the reason to chamfer the leading edge of the shoes is so that they don't 'dig in' and lock themselves on. I think they'd need to be badly adjusted for that to actually happen, but it sounds quite scary!

[mangocrazy]

The Honda CB77 305cc I owned in the early 70s had TLS drum brakes. I could never get them set up to my satisfaction so sent them off to Joe Dunphy who regularly advertised in the motorcycle mags. When I got them back they were almost too good, especially in the wet. I remember grabbing a big handful of front brake when a dog ran out in front of me, locking the front wheel (d'uh) and falling off, scraping various bits.

And the dog jumped out of the way and came out of it completely unscathed...

So be careful what you wish for with TLS drum nrakes...

[Mr. Dazzle]

I theory like, drums are better than discs.

When cold. And new. And correctly set up

Plus they weigh a fucking tonne.

[JackyJoll]

My drum brakes are good enough, but I have no reason to say they’re better than discs, in theory or practice.

[mangocrazy]

I theory like, drums are better than discs.

When cold. And new. And correctly set up

Plus they weigh a fucking tonne.

Have you been drinking?

[Count Steer]

I theory like, drums are better than discs.

When cold. And new. And correctly set up

Plus they weigh a fucking tonne.

Have you been drinking?

Isn't he right - in theory? The interface area between drum and brake material is (should be) greater I would have thought - giving greater friction.