Author Topic: Café/brat CB500 K3 -77, can't hold my fingers from it (Read 24963 times)

AlBundy · « **on:** May 10, 2016, 01:38:21 am »

Hi,

I have already started a thread earlier for my bike where I asked for some tips and facts about my bike. I don't know so much about bikes and this is my first.
See: http://forums.sohc4.net/index.php/topic,157022.msg1801488.html#msg1801488

In this thread I want to ask questions regarding my build and the first question is about gauges. I have understood that the speedometer gauge for CB500 -77 has the ratio 100KPH = 2330RPM. Correct me if I'm wrong. What about the tachometer? Which ratio does it have?

calj737 · « **Reply #1 on:** May 10, 2016, 04:22:37 am »

2240:1

500/550 tachs are interchangeable. 650/750 tachs are interchangeable. To use a 650/750 tach on a 500/550, you must switch the clock (gauge) and the cam teach drive gear to get the proper ratio.

AlBundy · « **Reply #2 on:** May 10, 2016, 04:55:43 am »

Okey.

This speedo will work then: http://www.dimecitycycles.com/2-5-inch-black-mini-speedometer-with-black-face-and-led-indicator-lights.html

But what about this tacho?: http://www.dimecitycycles.com/vintage-cafe-racer-caferacer-bobber-brat-chopper-custom-motorcycle-electronic-parts-mini-chrome-tachometer-15-0031b.html

The ratio is 1:7 and not 2240:1? Will it work?

calj737 · « **Reply #3 on:** May 10, 2016, 05:13:54 am »

Yes it will. You will also need diodes to use that speedo to correctly isolate the turn signals from your bike bleeding over when you activate them. The speedo has a single idiot bulb input wire for the gauge face, and you will have two feed wires. Its well documented on this site on how/which diodes to use.

AlBundy · « **Reply #4 on:** May 10, 2016, 06:38:05 am »

Thank you for the info. Will search the forum when it's time for the gauges!

AlBundy · « **Reply #5 on:** May 10, 2016, 10:26:38 pm »

Anyone who has experience of these spedoos/tachos?

https://www.louis.eu/artikel/t-t-multifunction-instrument/10034806?list=175889329

https://www.louis.eu/artikel/t-t-multifunctional-instrument-with-black-dial/10036500?list=175889329&filter_article_number=10036500

I think they look good. I have looked at them on youtube but there are not so many videos of them. It seems that the tacho can't get synced with older cb:s but there must be a solution?

calj737 · « **Reply #6 on:** May 11, 2016, 03:41:43 am »

For most digital tachs, you simply use an input wire on the gauge tied into your ignition (coils) trigger. Then the gauge reads the firing speed (RPMs). They are generally very accurate.

I have no experience with these specific units, but I do use digital gauges (MotoGadget) on my CBs.

I pulled their installation document, and in fact, they should be quite easy to install as it appears they operate very closely to Acewell and Speedhut products.

https://cdn2.louis.de/content/catalogue/articles/zusatz/anl/T&T_english.pdf?_ga=1.209568469.614612047.1462962917

AlBundy · « **Reply #7 on:** May 11, 2016, 04:26:58 am »

Okey.

The videos I was referring to was these:

Problem:

Solution:

I'm curios why the tacho is like in the first video.

A complicated question maybe but it's good to know if other has the same problem like in the first video.

calj737 · « **Reply #8 on:** May 11, 2016, 04:39:12 am »

I watched the videos. It is easy to say that the first video may very well be due to improper installation, or signal interference. Impossible to know exactly. You can't even know what bike these are from those video clips.

I would wire the device up exactly as the Instructions say, without wiring it permanently and test it. If you encounter an oscillating needle, then you have a likely solution (signal filter). But as I said earlier, typically a proper splice into the coil trigger wire (yellow from the ignition point/plate) works perfectly well.

I have seen where folks use a gauge that the sensing wire wraps around the spark plug wire, and have had uneven readings. This is often attributed to surface grime and debris on the lead. But these will work, and they should be very accurate and stable while operating.

Ignore the full sweep at key ON, thats appropriate. Also, when you kill the engine, the needle may hold where it was last until you key ON/OFF. Again, this is normal and not a symptom of faulty function.

AlBundy · « **Reply #9 on:** May 11, 2016, 05:45:53 am »

Thank you. You are very clever man!

AlBundy · « **Reply #10 on:** May 13, 2016, 04:50:17 am »

Anybody who knows if a exhaust from a CB550 F1 fits my bike? Some modifications are ok.

Have found a nice 4-2 system on ebay Germany.

calj737 · « **Reply #11 on:** May 13, 2016, 06:59:35 am »

The head section of that exhaust will fit, you may encounter some interference with the rear brake lever. The F1 should be a 4:1, running down right side rails.

AlBundy · « **Reply #12 on:** May 13, 2016, 11:21:42 am »

Quote from: calj737 on May 13, 2016, 06:59:35 am

The head section of that exhaust will fit, you may encounter some interference with the rear brake lever. The F1 should be a 4:1, running down right side rails.

Thx m8. Will order it then. I'm just out after the headers. The price of the system is to good to not buy. I prefer 4-2 system over 4-1.

AlBundy · « **Reply #13 on:** May 17, 2016, 04:45:41 am »

Time for some new tires and I have been looking at Continental Classic Attack in original size. These tires are radial and made for classic bikes but they are also tubeless. Do I need to use tubes or not? Also, can I use tubes with these tires? I want safety to be in first place!

calj737 · « **Reply #14 on:** May 17, 2016, 05:25:08 am »

You need to use tubes as the spoke penetrates the rim and creates voids for air to escape. Cover the spokes with rim tape first, then a tube.

Tubeless tires can be used on tubed rims, but the tire itself is designed for a taller side walled rim, so full seating of the tire can be an issue. There are many great tube tires on the market that you can consider also.

70CB750 · « **Reply #15 on:** May 17, 2016, 05:27:45 am »

The rule of thumb is lower speed rating by one for using tube in tubeless tire.

AlBundy · « **Reply #16 on:** May 17, 2016, 06:04:21 am »

Quote from: calj737 on May 17, 2016, 05:25:08 am

You need to use tubes as the spoke penetrates the rim and creates voids for air to escape. Cover the spokes with rim tape first, then a tube.

Tubeless tires can be used on tubed rims, but the tire itself is designed for a taller side walled rim, so full seating of the tire can be an issue. There are many great tube tires on the market that you can consider also.

Do you have a link to some tube tires that are good? From what I've read the classic attack have been praised to the skies by vintage bike riders. Isn't it better to use radials that are designed for vintage bikes than biased?

calj737 · « **Reply #17 on:** May 17, 2016, 06:05:40 am »

Sorry, I wasn't suggesting they're not great tires, but if you are concerned by them being "tubeless" in their design, I was pointing out there are options. You can also run a tube in a tubeless tire, so the spoke issue is mooted.

AlBundy · « **Reply #18 on:** May 17, 2016, 06:21:22 am »

Quote from: calj737 on May 17, 2016, 06:05:40 am

Sorry, I wasn't suggesting they're not great tires, but if you are concerned by them being "tubeless" in their design, I was pointing out there are options. You can also run a tube in a tubeless tire, so the spoke issue is mooted.

Oh okey. But which is the "safest" alternative of these two? Radial tubeless tires designed for vintage bikes with tubes, or non radial tube tires?

calj737 · « **Reply #19 on:** May 17, 2016, 06:22:52 am »

Too subjective. I doubt there is an empirical answer to this, but doubtless anecdotes. If they come recommended by those with similar bikes, use them with confidence.

SOHC4 Cafe Racer Fan · « **Reply #20 on:** May 17, 2016, 06:56:13 am »

Quote from: AlBundy on May 17, 2016, 04:45:41 am

Time for some new tires and I have been looking at Continental Classic Attack in original size. These tires are radial and made for classic bikes but they are also tubeless. Do I need to use tubes or not? Also, can I use tubes with these tires? I want safety to be in first place!

It all depends on how you ride. If you want a period correct, restoration or if you want a performance-oriented tire. There are a LOT of options.

Bankerdanny · « **Reply #21 on:** May 17, 2016, 07:49:59 am »

The Classic Attacks are designed to also be used with tubes.

Don't obsess over tires. For general street riding just about any tire will do. I had Shinko 711/712's on my 550K and was very happy with them. The performed well in the rain and I think I paid $100 for the set including shipping.

Motorcycle tires have short lives, often well under 15k miles. For low tech, relatively low performance bikes like our 550's spending big money on tires is not necessary.

That said, I am thinking about the CA's for my new F because I have also read great things about them.

SOHC4 Cafe Racer Fan · « **Reply #22 on:** May 17, 2016, 08:37:45 am »

Many newbies also do not know that tires have a shelf life, too.

Avons, Bridgestones, Pirellis, Continentals all make good tires that will work well with tubes for these classic bikes. If you are looking at Classic Attacks, you are not likely looking to do a restoration.

calj737 · « **Reply #23 on:** May 17, 2016, 09:36:39 am »

See what I mean?

SOHC4 Cafe Racer Fan · « **Reply #24 on:** May 17, 2016, 09:37:48 am »

The best advice we can give you is to avoid Firestones!!

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Author Topic: Café/brat CB500 K3 -77, can't hold my fingers from it (Read 24963 times)