Gear ratios

7 replies to this topic
  • jan

Posted June 26, 2002 - 09:08 PM


What sprocket rations do you guys use on the brp. I still have the standard 14/48 , but the bike could easily pull another gear on top end . Has anyone used a 15 front sprocket ? How does it affect low speed grunt ?



  • Craig_Mitchell

Posted June 27, 2002 - 09:04 PM


Jan, I'm currently running 15/48. The extra
tooth adds 7mph in theory. The downside is
you lose a proportionate bit of grunt and also
loose some engine braking. Last summer I tried
the Aussie gearing of 15/41?, the lower revs
for cruising and the improved fuel economy was
fine, but my wheelies all but dissappeared
and engine braking for steep off-road descents
was hopeless. If you are not into trying to
get 106mph from your pig, then 14/48 will
give you the most enjoyment.
I have the HRC piston and cam kit in mine
so I don't notice the loss of grunt I mentioned

cheers, Craig

  • qadsan

Posted June 27, 2002 - 09:26 PM


Here's some numbers to give you an approximate idea of the maximum speeds you'll get in each gear with the following sprocket combos. Please note these numbers are based on a maximum engine speed of 8,000 RPM among many other factors.

Gearing 13/48 14/48 15/48
MPH 1st....33.....35.....38
MPH 2nd...47.....51.....55
MPH 3rd....60.....65.....70
MPH 4th....75.....81.....87
MPH 5th....90.....97.....104

Gearing 14/50 14/51 14/52
MPH 1st....34.....33.....32
MPH 2nd...49.....48.....47
MPH 3rd....62.....61.....60
MPH 4th....78.....76.....75
MPH 5th....93.....91.....89

  • mwespo

Posted June 27, 2002 - 01:00 PM


Using your numbers would this mean if you were running a 15/47 your top speed would be 107.75? I was just wondering what the top speed was with my gearing.

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  • qadsan

Posted June 27, 2002 - 01:14 PM


15/47 would yield about...

Gearing 15/47
MPH 1st....38
MPH 2nd...56
MPH 3rd....71
MPH 4th....89
MPH 5th....106

  • dzrtracer400x

Posted June 27, 2002 - 05:42 PM


I run a 15/47 for racing and pre-running in baja and stock for district 37 races.


  • redrider650r

Posted June 28, 2002 - 10:36 AM


Where are the district 37 races held? And are all of these gear ratios for the stock 650s with just the manifold, jetting and baffle changes?

  • dzrtracer400x

Posted June 28, 2002 - 11:01 AM


The District 37 races are held out in Lucerne Valley and RedMtn. They are held in So Cal. For my bike I run (baja/pre-run(15/47)/district 37(stock))bike's gear ratios are w/ the power up kit and the spark arestor taken out and precision concepts suspension. Our race bike for baja runs 15/47 and it has the Pro Circuit pipe like what the factory honda guys run(not availble to public) and the power up kit, cam, holes in the air-box, and precicsion concepts suspension. Those gear ratios work great. Give them a try and you will proably like them but mess around with them and see what you like. Just about every 650 that races SCORE or Best In The Desert runs a 15/47 gearing.


[ June 28, 2002: Message edited by: dzrtracer400x ]

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