Katdash for your R90S

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Darryl.Richman
Posts: 2087
Joined: Fri Oct 27, 2006 3:00 am

Katdash for your R90S

Post by Darryl.Richman »

I saw someone talk about the Katdash on the R90SWorldnet mailing list (http://groups.yahoo.com/group/r90sworldnet) last week, and after looking at the website, I sprung for one. The Katdash (www.katdash.com) is a reproduction part that replaces the circuit board that runs the lights in your dash.

The originals are no longer available, and they're a weak link in our bikes. The circuit board is a T shaped sheet of flexible plastic with traces on the surface and contact pads that power the lights. Light bulbs are installed in little plastic bases and inserted through holes cut the board. These holes are cut to leave triangular pads in the hole, that are then bent 90 degrees away from the surface. When the bulb and its holder go through the hole, the pads act as contacts to provide power and ground to the bulb. If you allow the tabs to be bent more than a few times, they can break off, and if you bend other parts of the plastic sheet, the traces can delaminate and break. Soldering is very difficult because the plastic can melt before the solder does.

The Katdash works just like the original, except better. All of the lights are LEDs, so probably they will never fail. There are no little tabs to break off. Once installed, the board should never need to be messed with again, so it shouldn't get bent or folded. And the Katdash has three separate LEDs each lighting up the speedometer and the tachometer, from three different points, instead of the single bulb that each gets from the stock unit.

[img=800x600]http://katdash.com/wp-content/uploads/2 ... 24x687.jpg[/img]
The original /6 unit is on the left and the Katdash is on the right.

They did not forget, BTW, that the Airhead charging system relies on the resistance of the charge lamp to excite the alternator. Now it's just a resistor on the board. And this leads to the one place where you can tell that the original unit is no longer inside (I mean, besides the better lighting for the gauges): when the motor is at or just above idle, that point where the charge light would produce a soft, glow and gradually going out, the Katdash charge light flickers crisply, faster as the motor speeds up, until the alternator is charging the battery and the light goes completely out. It's sort of like clock on my R90S, which failed and in which I had the later, more reliable, quartz movement installed. Instead of the smooth sweep of the original electric clock, it goes tick tick tick as the seconds hand jumps from hash mark to hash mark.

The Katdash is only $115 plus shipping, and so far I think it's a great piece of work!
--Darryl Richman

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schrader7032
Posts: 7389
Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX

Looks like a well thought out

Post by schrader7032 »

Looks like a well thought out product. It was discussed here as well:

http://vintagebmw.org/v7/node/13994
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Beemer54
Posts: 62
Joined: Sun Sep 07, 2014 1:07 pm

Katdash

Post by Beemer54 »

Kat has written an article in this month's 'The Airhead' about how this was developed. You wouldn't believe the problems she encountered and overcame. Fascinating reading.

All the effort to make these was well worth it in the end - the market's been crying out for something like this for years.

kirkpatrick3890
Posts: 57
Joined: Fri Oct 27, 2006 3:00 am

Re: Katdash for your R90S

Post by kirkpatrick3890 »

I installed a set of Katdash instrument lights in my R90S and several other bikes and they are fantastic. I am very grateful for them.
Mac Kirkpatrick
President, VBMWO

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srankin
Posts: 164
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA

Re: Katdash for your R90S

Post by srankin »

I have two Katdash units and from now on, any airhead that will accept them will get them. St.
Owner of a 84, R80RT and 78, R100RS

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