Sportster gearing and speedo

First off can someone confirm that if I up the gearing on my 883/1200 conversion I need to change the speedo for the 1200 version in order for it to read right.

At the moment, with the conversion, cams and single fire ignition it's great as it is. However if next years planned trip comes off I'm going to want cruising gearing, even though I'll probably change back as soon as I get home. With this in mind is there any way of keeping the recorded mileage accurate?

Would fitting the 55 tooth Buell rear sprocket be feasible? Bearing in mind I wouldn't be doing a lot of city riding. If so, what do I do then to get the speedo right?

Finally, I'll be fitting a more comfortable (read thicker), touring seat. Being vertically challenged (shorta**e) I would like to get my feet back closer to the ground. It's a 2001 custom so lower shocks are out of the equation so the only thing I can think of is a lower profile tyre. Does anyone know if anybody makes one that fits or can be made to fit? And if so how?

[llew]

On the speedo gearing question, check/search the previous threads, this one might answer some of your questions

http://www.harley-davidson-hangout.c...ghlight=speedo

[Alan B]

Got that T-shirt. Get down to your local Indie with a Zodiac catalogue. Zodiac do two speedo adjustment gizmo's. They fit under the seat easily they are not very big (approx 10-15mm square x 40mm long). You unplug the connector to the harley box and plug the gizmo in. There was two sorts when I bought mine a couple of years ago. One was about £100 and the other was about £120. The more expensive one is the best. The cheaper one is set in the garage by setting the percentage adjustment that is required in whole numbers, which from memory 883 gearing to 1200 gearing is 7.25%. The more expensive one is better because you can get better accuracy for only a few quid more. I bought the expensive one. All you do is plug it in and the plugs are on a long enough cable to reach from under the seat to sit on the tank between your legs. You then ride with a mate with an accurate speedo on a safe bit of very empty road. When your mate has reached an agreed speed you just push either the up or down button on the gizmo until your speedo reads the same speed as your mate. Takes about 1 minute. The box saves the setting when a button hasn't been pressed for a certain amount of time. Then just tuck the gizmo away under the seat and forget about it.
Alan B

Hmmm, interesting. Now considering that your speedo is only required to be accurate within 10% I reckon that if I only do the 29 tooth front I probably won't bother. By keeping the needle at or just below the posted limit should be safe enough. Especially as most speedos read a little fast anyway.

Will have to look further if I make any other changes though.

[Alan B]

Don't kid yourself on the 10%. The specs cameras book you for 2 or 3 mph over the limit. I don't think it's worth the risk. I had bits of tape on the speedo untill I got the Zodiac gizmo. I was glad to have a accurate speedo back.
Alan B

Originally Posted by Alan B

Don't kid yourself on the 10%. The specs cameras book you for 2 or 3 mph over the limit. I don't think it's worth the risk. I had bits of tape on the speedo untill I got the Zodiac gizmo. I was glad to have a accurate speedo back.
Alan B

Interesting ......... if the law does state that your speedo only needs to be within 10% (I know it used to but I suppose it could have been changed??) how do they justify booking you when as far as you know you were obeying the law? Apart from people not knowing about it and it allows them to raise more cash that is!!!! That's why the old formula used to be 10% plus 3mph.

Was reading on an Americam site that their law states that a speedo must NOT read slow. To cater for this Harley (and most others) made their bikes read about 7% fast. It also coincidently and purely by chance made their bikes appear faster than they really were. Therefor changing from 27 to 29 teeth actually made the speedo read more accurately. Would be interesting to know if they do the same with the bikes sold over here. I suppose the only way to find out is to find a helpfull traffic cop with a freshly calibrated speedo (or a flying pig, whichever comes first).

[Alan B]

I can't remember the exact arguement used when I read about it in the press when the victim appealed but needless to say the conviction stood.
Alan B