RPMs@60mph

[ratbyk]

Digital Speedo

I have a digital speedo on my FT500 Honda. ("lilRat") Works well except for being hard to see with polarized sunglasses on. It has a liquid chrystal display lens on it that turns completely black with polarized glasses.
The one I used is a Vetta, model #RT 55. Bought at a local bicycle shop. $40.00 Cdn. I had to get creative on the installation but enjoyed the challenge and it seems secure and accurate.
Vetta have a web site; www.vetta.com where you can check out their various models.The one I have will give me; current speed, average speed, maximum speed attained on trip, cumulative odometer, trip odometer, a 12/24 hr clock, ride timer, freeze frame memory and auto stop/start.
It consists of a magnetic button secure to a wheel spoke, a sensure secured onto the inside of the bottom fork leg slider. a wire up to the instrument head and the head itself that I mounted on top of the triple tree.
I find it a bit of a PITA to scroll through all of its various menus and use it mainly as my speedo and top speed attained. These two functions are automatic so I don't have to bother scrolling. Oh, also it can be set to display in mph or kmph.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"

[ratbyk]

Re: small digital speedo

Originally posted by UncleSpot
hey pgg - where did you get your small digital speedo? How did you mount it? do you have any fotos of yours? ...give us some more info - I'm ready to change my stock one out...

pgg, if you go to Specifications on the left side of this page. Then scroll down to Cycle Guide Jan. 79 you will find all kinds of neat info including the speed/gear ratio chart I refereed to.
Ken/Sooke

[foxjohnc]

Only thing that sucks about ratbyk's speedo is that the max speed is 75mph.

[ratbyk]

foxjohn, the RT 55 model that I have will read up to 139.9 mph or 199.9 kph. These limits are far beyond what my little 500 single is able to attain. Considering it is used mainly on logging roads and a twisty narrow rough coastal mountain highway it is away more than I need. At the moment it shows 124.4 kph as the highest speed that I have attained so far since mounting it. Anymore is going to require someone with a lot bigger b_lls than I have.
Also at 139.9 mph top indicated speed this exceeds the max. of an XS1100.
Ken/Sooke

[UncleSpot]

digital speedo / RPM = MPH

my speedo @ 5K RPM = 70 MPH (1980 XS1100 Special)
...is it THAT far off(?)

I'll be looking for a RT55 digital speedo to check out... thanks for the info.

[pgg]

Got mine at a pushbike shop. It's called a 'Sigma'. Reads to 300kph (180mph). Have yet to max it out! Bolted the pickup sensor to the mudguard mounts.

[foxjohnc]

Hey ratbyk, I looked up your model and went to the user's manual online. It said that the max speed was 75mph and some odd kmh's.

[ratbyk]

Digital Speedo

foxjohnc, don't know about the on-line manuel. The instructions that came with mine claimed, 139.9mph/199.9kph.
The highest reading that I have on mine is: 124.4.
That converts to: 124.4kph X .6213712= 77.2986mph. This is over the on line claim of 75mph. Don't know beyond that but it reads plenty high for the application that I'm using it in. Besides at those speeds on this little bike on our roads here in the coastal mountains. Who has time to look at the speedo. The time that I did have it wrapped out pretty good I remember glancing down and seeing 124. (that is what is recorded in the computer's memory as the highest speed recorded so far) That was just one quick look. At more normal speeds I do glance at it on a regular basis.
Another reason for watching the roads around here real close is that you never know when you will have to dodge a bear or deer. I hit a deer just about a year ago now on the Ratbyk. My wife hit one with the Trans Am 3 years ago. It is no joke around here. It can get real serious.
Ken/Sooke

[ratbyk]

Speedo Error

Unclespot, @5000 you should be reading 79 mph. BUT! who says your tach is right on? Tach or speedo could be out. Most likely both of them a bit one way or another. Nothing is perfect, an XS or me. Tee Hee
Ken/Sooke

[UncleSpot]

...I just noticed something... this was for a 17" rear tire. I have a 1980 XS11 Special (SG) with a 16" rear tire. THAT will change things with both different MPH/RPM *AND* MPG...

...that explains why this bike's so damn fast 'outta the hole'. I've never been on ANYthing faster. I love the acceleration! ...and I love the sound of the engine winding out thru the 4-into-1/Kerker - GREAT sound to my ears!

[Underdog]

Well for what it's worth, my Midhight has the optional 160mph speedo 16" rear. Went through one of those radar sign deals over the weekend and it was dead nuts on. Even more acurate than the electonic one on the Harley which is off a couple mph. I get 60mph at 4000rpm. Harley does 60 at 2700

[John]

Try spinning that h-d up to 8000 rpm. But do it from a distance, 'cause there will be pieces flying all over the place. Hmmm, now there's a thought...Actually, the 160 speedo was standard for 79. In 80 all XS's had an 85 mph speedo. My 80 SG has a 160 on it, but someone changed it before I bought the bike 13 years ago. Bless their hearts.

[UncleSpot]

Since I do have a 1980 XS11 Special (SG) with a 16" rear tire, is there an earlier Yamaha speedo that goes up to 160mph that will work? Mine does only go up to 85mph... it would be nice to see what this bike is actually doing out on some of our isolated roads...

[John]

The only option is the 160 from a 79 Special. The Standard has a square speedo. You could use a 140 from a 79 XS750 Special, or the 120 from an XS650 Special also. I used to own one of those before I 'upgraded'...

[Bill__Woods]

Hey UncleSpot,
I just bought a used instrument cluster off a xs750 special for 20 bucks on ebay. It is the 140MPH speedo. You just need to remove the housing and switch the wiring for the lights. The wiring unplugs, and it is very easy to change.

I had 2 problems with my speedmeter.
1. It was marked in RED from 55 -85
2. Never can tell how fast you are going in 4th & 5th. Why would they put a speedo on a bike that is only good for the first three gears.