Gearing changes

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SlingVTR
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Joined: Tue Jun 15, 2010 6:00 am
Location: Chepstow/Coleford

Gearing changes

Post by SlingVTR »

I am gonna fit a 15 tooth front sprocket and a 43 tooth rear, will the speedo be out? :? ie over show the proper speed as this is going to take off nearly 20 mph off the top end. I did this before on my cb1300 with the same gearing change and the speedo showed 100 when in fact I was doing only 82 in real terms. :? :?
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Stratman
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Re: Gearing changes

Post by Stratman »

Yes.

Somewhere on here someone posted a chart with the %'s that one tooth less/more would affect the gearing by - might be worth a search. I went up two on the back and it's the best mod I made I think.
Two bikes, still only four cylinders!

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SlingVTR
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Joined: Tue Jun 15, 2010 6:00 am
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Re: Gearing changes

Post by SlingVTR »

yes I have seen the chart and stuff, but does the speedo show correct or not ................. :)
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marlbororman
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Re: Gearing changes

Post by marlbororman »

speedo on mine showed way out, you will need some type of speedo healer for correction (or a gps sat nav like i did, for the 30s 40s and 50s ;) )
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benny hedges
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Re: Gearing changes

Post by benny hedges »

SlingVTR wrote:I am gonna fit a 15 tooth front sprocket and a 43 tooth rear, will the speedo be out? :? ie over show the proper speed as this is going to take off nearly 20 mph off the top end. I did this before on my cb1300 with the same gearing change and the speedo showed 100 when in fact I was doing only 82 in real terms. :? :?
doesnt make 20mph difference. in fact you will probably find the bike is well quicker.
with a 15t on mine & standard rear (on my private track) it will go over 160 easy, just gets there faster.

as marlboro suggests, stick a satnav on the tank and go on a motorway run.
you can get speedo overlay stickers on ebay for a few quid - place it where you get true readings.
i thought it would make a big difference to the speedo when i put the 14 & 15 on, but in realit it's very slight, though even with standard gearing the speedo is 8-10% out

gearing commander is the active site that shows gearing v speed - but then again, you don't know how accurate the tacho is either!
http://www.gearingcommander.com/base/gc_main.htm
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Giddsy
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Location: Brighton, Sussex

Re: Gearing changes

Post by Giddsy »

I've gone 2 teeth up on back and reckon it is pretty much exactly 10% out...

Who cares tho? As long as you take it easy where necessary does it matter if you're doing 80 or 90 or 100?
SlingVTR
Posts: 182
Joined: Tue Jun 15, 2010 6:00 am
Location: Chepstow/Coleford

Re: Gearing changes

Post by SlingVTR »

Giddsy wrote:I've gone 2 teeth up on back and reckon it is pretty much exactly 10% out...

Who cares tho? As long as you take it easy where necessary does it matter if you're doing 80 or 90 or 100?

yes cos 105 = ban and 95 = a 4 hour patronising course........................
Giddsy
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Re: Gearing changes

Post by Giddsy »

Fair point...
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