tc
Full Member
Posts: 139
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Post by tc on Aug 28, 2006 20:24:00 GMT -5
;DI have a 1978 SR500 that to me seems to be undergeared .
Using standard rear sprocket and up one tooth on front sprocket it seems to be revving it's heart out at speed of 100 kph it's running at 5000rpm on tacho is this normal I dont know where to get a smaller rear sprocket here in Aust. any body got ideas ..T.C.
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Post by medic09 on Aug 28, 2006 22:47:07 GMT -5
tc, I'm new to this bike, but your problem does not sound normal. 100kph is about 60 mph. On my daily ride I hit about 70 mph at 5000 rpm (same rpm for your 60 mph), and I have reserve left to pass (albeit a little slowly) without downshifting.
BTW, a Yamaha mechanic in ABQ (Albuquerque) told me the other day that one tooth up front is equivalent to a change of four teeth in the rear.
Good luck!
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Post by wotavidone on Aug 28, 2006 23:08:47 GMT -5
tc
According to my manual standard 1978 gearing was 16 front 46 rear.
I'm running 17 front, 42 rear for an indicated 100km/hr at 5000 rpm.
The trick is, according to my GPS unit, when my speedo says 100, I'm actually doing 111 k's.
Unfortunately I have no idea where the back cog came from, it was on the bike when I bought it. I bought the bike in Adelaide so I'm guessing an Adeliade supplier.
If you do find a supplier, I would be most grateful if you would post the contact details, cause I'm quite keen to go to a 40 tooth rear.
Mick
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Post by StewRoss on Aug 29, 2006 4:14:01 GMT -5
Hi guys, The standard gearing for an earlier SR 500 (E,F,G,H) is 16/44...most people end up putting a 17 on the front and with that gearing, 17/44 (...from memory) I'm fairly sure that you are doing 100kmh at about 4,000, by the SR (...and Daytona) instruments...I'll check it again next weekend, just in case I'm wrong...  Not sure about the gearing on the later models... I'd be checking your gearing...usually going up to 17 on the front and leaving the 44 on the rear allows the SR to go along nicely. You can gear higher, but you then need to do other modifications to the pipe and inlet side to pull the gearing reasonably... SR  |
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tc
Full Member
Posts: 139
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Post by tc on Aug 29, 2006 20:59:55 GMT -5
Hi guys
Tanks for the info I am running 17 front and 44 rear at the moment .T.C.
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Post by milkman on Aug 30, 2006 1:17:12 GMT -5
Mate, I'm in Sydney, where thee is a shop called Deus ex machina. They cutomise a lot of sr500's into cafe racers etc, look them up on the web. I'd ask them (you can email them through their site) and then price around for the sprockets.
Also the sr500 club in AUS has a reccomendation on their site in tech tips. Google sr500 and its usually the first link.
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Post by tradrockrat on Aug 30, 2006 13:13:38 GMT -5
Where do you find the 17 front? that sounds like a very good mod to do.
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tc
Full Member
Posts: 139
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Post by tc on Aug 30, 2006 17:39:38 GMT -5
;D As for the 17 tooth front sprocket I just asked at my local Yamaha dealer and they supplied .T.C.
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Post by tradrockrat on Aug 31, 2006 18:39:12 GMT -5
cool!
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