katana speedo drive from a gsxr front wheel

[alboo]

hi all its a long time i have been on hear though i do check in on a regular basis.

Now to the question i have just purchased a used full front end from a gsxr1000

their does not apear to be any way of fitting a mechanical speedo drive to the front wheel

what options have i got using the kat speedo

thanks in advance for any info

Albie

[coombehouse]

I've had a similar problem & not found a solution. I did wonder if it was possible to take a drive from the front sprocket but I never went any further. Perhaps you'll have better luck in finding a solution. 

[Suzukian]

This is going to sound really f*cking retarded, and dumb "American" like,  if I were in your situation, and wanted to stick that speedo drive in, I would see where the tabs mount against the seal of the wheel bearing.  I would, with a Dremel tool, sharpen the points on the Speedo drive, and penetrate the seal, use Butyl Rubber to seal around the entry points of the pins into the seal, and go from there. 

The worse thing that could happen is it wouldn't work and you might have to do some grinding or, if all else fails, get a new bearing on that side. If the pins do not line up with the seal, you could make a washer shim and cut out the drive pins, then bend as necessary to engage the drive, and then insert into the side of the bearing and the opposite side into the speedo drive.  Since this will all be torqued together, you don't really have to go so deep that you enter into the bearing space, just through the wall.  Those seal walls are thicker than you might think.  So that's the official way I'd try to hack in a speedo left with no other recourse.  I apologize beforehand. 

[rodneya]

You need to find something like this to use gps sensor to mechanical drive

https://www.jegs.com/i/JEGS/555/41800/10002/-1

[Suzukian]

For  $375, I'd try the mechanical method first. You can buy speedometers that use GPS and cost around $75 bucks off of Amazon.

Edited March 14, 2023 by Suzukian
grammar

[Gixer1460]

10 hours ago, coombehouse said:

I did wonder if it was possible to take a drive from the front sprocket but I never went any further. 

Front sprocket won't work as a) it continually changes speed as you change gears and b) its geared lower than road wheel so would always read low anyway!

BUT a speedo drive on the rear axle would work as (unless spinning) the wheel is always at road speed - can't be anything but!

[bluedog59]

1 hour ago, Gixer1460 said:

Front sprocket won't work as a) it continually changes speed as you change gears and b) its geared lower than road wheel so would always read low anyway!

BUT a speedo drive on the rear axle would work as (unless spinning) the wheel is always at road speed - can't be anything but!

Sorry to contradict you but,

A. Front sprocket speed is directly proportional to road speed ( as it is linked via the chain ) and doesn't vary according to what gear you're in.

B. It would read "high" as it is spinning much faster than the wheel.

[Duckndive]

 

Good Luck with a mechanical drive on the front there is barely 10mm between wheel and fork bottom on thou front ends from K4 to date

Rear Wheel is an option as suggested "old brit stuff often used that"  

 

[Gixer1460]

1 hour ago, bluedog59 said:

Sorry to contradict you but,

A. Front sprocket speed is directly proportional to road speed ( as it is linked via the chain ) and doesn't vary according to what gear you're in.

B. It would read "high" as it is spinning much faster than the wheel.

No - contradiction is fine, when as in this case you are correct! Yes brain fart time, of course front sprocket is proportional to rear wheel speed DOH! The high / low rotational speed is the real issue having a drive off of it. As said a 'normal' front wheel speedo drive would work if on the back wheel axle.

[coombehouse]

1 minute ago, Gixer1460 said:

No - contradiction is fine, when as in this case you are correct! Yes brain fart time, of course front sprocket is proportional to rear wheel speed DOH! The high / low rotational speed is the real issue having a drive off of it. As said a 'normal' front wheel speedo drive would work if on the back wheel axle.

Finding a speedo drive which could take a large diameter rear wheel spindle could be a challenge though. Any ideas?

[bluedog59]

I'm guessing the root of your issue is that you want to retain the distinctive Katana Speedo housing so the options boil down to,

A. Wider yokes to give you space to squeeze a Speedo drive in ( causes more problems than it solves ).

B. GPS to mechanical converter. Expensive, can you get one that gives the correct drive ratio and you'll need to get a cable made.

C. Take a drive off the rear wheel. Doable if you can find the space to squeeze one in and you'll need a cable making. Spindle size could be an issue.

D. As you're running an O/C engine, use a sprocket cover with an electric Speedo pick up and some sort of converter to cable drive ( I have no idea if such a thing even exists ).

E. Drive the mechanical Speedo drive off the front sprocket with a reduction box to bring the rpm down to wheel speed. Technically possible but.........

F. Build an electric speedo into the Katana housing and use a pick up on the sprocket cover.

I think C and F are the only "real world" options with F being my personal option.

[bluedog59]

Re option E.  Not all manufacturers use the same mechanical speedo ratio between wheel and cable rpm. There may be one that gives you an acceptable reading without needing a reduction box. It's a long shot but it moves the option up the rankings.

[coombehouse]

14 minutes ago, bluedog59 said:

Re option E.  Not all manufacturers use the same mechanical speedo ratio between wheel and cable rpm. There may be one that gives you an acceptable reading without needing a reduction box. It's a long shot but it moves the option up the rankings.

I considered using a late vfr750 Speedo drive as that runs from the gearbox shaft. Finding the ratio has proved difficult though.

[Duckndive]

1 hour ago, coombehouse said:

Finding a speedo drive which could take a large diameter rear wheel spindle could be a challenge though. Any ideas?

Yes largest i found was the Trumpet one i used on Izzy because she has 955 Forks 

[Isleoman]

Wouldn't any measurement off the front sprocket also need to know what gear the bike is in?  That's the way it works on my Yamaha.  

 

[Dezza]

Some aftermarket electronic speedos are pretty small and unobtrusive, e.g. some Koso units. If one is mounted optimally, the original speedo could be left redundant and only the tacho used, thus retaining the look of the original Kat clocks.

[bitzz]

Swap front wheels with one with a speedo drive

[coombehouse]

49 minutes ago, Isleoman said:

Wouldn't any measurement off the front sprocket also need to know what gear the bike is in?  That's the way it works on my Yamaha.  

 

The gear the bike in does not affect the Speedo gearing. This is mentioned above. 

Your Yamaha can't work like that. 

[coombehouse]

Been doing a bit of thinking on this. I wonder if a gearbox driven vfr750 rc36 drive with one of those km into mph adapters for a mechanical Speedo would slow the thing down enough to be accurate. I might have to try & see 

[Suzukian]

What year and model did the front end come off.  I think a front wheel that has the drive unit is a very practical way to go, it's a matter of finding a wheel that the discs will work with your brakes, and the spoke pattern matches.  I've spent so much time on Ehag  looking for the right combo, and found a very inexpensive set up, the post was up for 1/2 half hour.  I have some spare time and could go hunting for you.  It's amazing how much stuff looking at the sellers other listings that the search engine didn't pick up.

[coombehouse]

2 minutes ago, Suzukian said:

What year and model did the front end come off.  I think a front wheel that has the drive unit is a very practical way to go, it's a matter of finding a wheel that the discs will work with your brakes, and the spoke pattern matches.  I've spent so much time on Ehag  looking for the right combo, and found a very inexpensive set up, the post was up for 1/2 half hour.  I have some spare time and could go hunting for you.  It's amazing how much stuff looking at the sellers other listings that the search engine didn't pick up.

The original poster has gsxr1000 forks & wheels already. I guess he won't want the added expense of buying a 1200 bandit wheel & discs & the possible associated hassle of making the brakes line up, different spindle diameter etc. Just a guess though. Perhaps he will comment 

[Suzukian]

I guess it depends how cheap you can get the parts for.  I would tend to agree with you though.  Around here, the cops can be real assholes, and they will pull you over while being 5 feet off your rear end for 5 miles if you go 2 miles over the limit.  An accurate speedometer is a necessity, if it's slightly off, at least have marked at 25 , 35, and 55 mph, mark where the needle should be.  

Edited March 14, 2023 by Suzukian

[GSX1100dreamn]

Saw this on Japan Yahoo awhile back.

『M1』良品 GSX1100Sカタナ ウイニングラン スプ... - ヤフオク! ※Ｔ０１ＨＱ２０※ 【　追加画像　】 商品の追加画像をご覧いただけます 【　車体画像　】 商品説明 【商品データ】 取外車両年式：1982年 メーカー：ウイニングラン 備考：VFR400R(NC30)

 

 

https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpage.auctions.yahoo.co.jp%2Fjp%2Fauction%2Fc884210072&data=05|01|Andrew.Kneeshaw%40downergroup.com|e624877441cc426d3b3108db24cee895|fa4bc6e2c0ed43ec9d6d145e7e36a1a5|0|0|638144243307960680|Unknown|TWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D|3000|||&sdata=Y7WT3b9nUDlr%2BHuspmZpcADAFOOLF2koWtwu8BVkGw4%3D&reserved=0

 

Or this, particularly if you could drive it using the Suzuki front sprocket electronic speedo drive used on 1250 Bandit etc.

 

https://m.roadkillcustoms.com/electric-to-mechanical-speedometer-cable-drive-conversion/

 

Edited March 14, 2023 by GSX1100dreamn
added info

[coombehouse]

The link is not available to UK 

[GSX1100dreamn]

I cannot open the link here down under either, the auction site run by these guys (mukeidou) does not open anymore ? Used to be able to open and view their auction stuff not now.

 

But the picture gives an idea of what is possible.

Edited March 14, 2023 by GSX1100dreamn
added info