Yamaha TRX850 Enthusiasts Forum

ok just found out today after, well while oiling the chain the im missing the heads off about 6 of the teeth on the rear sprocket.

so im going to have a go at fixing it myself.

now i've done a little bit of research on chain and sprockets. i currently have stock sprockets on at the moment which i believe is 17f/39r yes?

sprockets- i want to get a bit more pick up out of my trx. so was thinking something like 16f/43r does this sound right? will this cause any problems?

chain- after a little bit of research/going through my last invoice from the mechanic, i found the chain i currently have is 525x-ring . i did a bit of search on here and found some using 520. what would be better for the combo im after?

these are what im looking at
front sprocket
https://www.slipstreamperformance.com.a ... s_id=28913
rear sprocket
https://www.slipstreamperformance.com.a ... s_id=29202
chain
https://www.slipstreamperformance.com.a ... s_id=22885

what do u guys think?

Bearing in mind that you have let you sprocket get to the point that you have 'lost' six teeth, are you sure that replacing the C&S is within your ability?

if yes (or you have help), have you got a chain riveter and a socket that will fit the front nut - chances are you will probably need an air ratlle gun to get this off (or a big breaker bar and a mate hanging on to your bike).

17 / 39 is indeed standard - going to 16 / 43 is a big leap (roughly the same as 17 / 50) but no issues with doing it if you want gearing like that

i hear what ur saying, working long hours recently and had slipped my mind to oil my chain. the chain/sprockets are just over 2years old. i do ride everyday. averaging 500k's a week

so that would be a little bit to much you think?? would u say keep the std 17f with the 43r be better. i just want a bit more pick up off the line. not sky bound all the time

16/39 or 17/43 . . . both good setups.
17/43 needs a longer chain than 16/39.
the soft link needs to be set correctly, or you risk stuffing the lot.
both front and rear sprockets need torquing down, with the front needing a new lock washer, and the rear needing a cross pattern tightening sequence and thread locker on the bolts.
70nm on the front nut and 60nm on the rear sprocket nuts.
rear axle nut is 117nm.
std chain is a 525 and has 110 links for 16/39 or 17/39 .
cheers
fung

so if i was to get a 16f/39r it would give me a bit more poke?

with the items i'm looking at above would the suit my need?

The only issue with the smaller drive sprockets 16`s or even 15`s, is that unless you`re fastidious about chain maintenence the chain cuts into the rubber swingarm protector as it moves through it`s travel arc due to the suspension movement. I ran with 15 / 39, great fun but chain adjustment is after every other ride or your rubber protector suffers! and you don`t want a compromised rubber protector now do you?
I would go for 17 / 42 or 43 personally.
Oh and the 520 conversion? It`ll be less reciprocating mass, sap a little less horsepower, and weigh a little less too but if maintenance is not your forte will wear out quicker than the 525.

Here's a handy link ..The old trusty gear commander..just dial in all the info and bob's your uncle to give you a ballpark on speed and RPM with assoc.. gearings
http://www.gearingcommander.com/

Mincehead wrote:I would go for 17 / 42 or 43 personally.
Oh and the 520 conversion? It`ll be less reciprocating mass, sap a little less horsepower, and weigh a little less too but if maintenance is not your forte will wear out quicker than the 525.

+1

http://www.ebay.com.au/itm/Yamaha-TRX85 ... 202wt_1107

any good?? or stay clear of ebay bargins?

D.I.D chain is ok, it is the X ring type too I see. X rings sap a tad less power from the transmission that the older O ring types.
But wait for other Aussie members to chip in, that set is from the UK!!!
There will be chain and sprocket suppliers in Aus, cheaper than that and perhaps selling as good or even better quality kit.
Here is just ONE I know of:

http://www.chaingangchainsandsprockets. ... ut-us.html

yer just sent him a P.M on it mate...

On the sprockets, I'd try 17/41 first, that's what I'm running, 16/43 is a big jump...

I see you're in Melbourne, let me know if you get stuck or want someone to run through it with you, I've got all the tools required, & some OK home brew.

Cheers, Mick.

nice one MV
thats the spirit
and the reason most of us are here eh
sounds like a good reason to drink home made too !!
cheers
fung

Any chance to show off my rattle gun mate, those things are fun