Yamaha TRX850 Enthusiasts Forum

hi just got a email off the last owner of my bike,said she had the bike downgeared said it will not have its top speed but will be much peppier!! and smoother at low revs, not into flying around at 130 miles a hour but how much speed will it lose in this set up,is it a good idea if not how do i reverse it,cheers

What gearing is it running? Stock is 17/39.

youngy wrote:What gearing is it running? Stock is 17/39.

carnt get to me bike at mo

i run 16/42 which gives me about 120mph ,

Most common mod is swap the front sprocket for a 16 tooth one. Only loose 10-15mph top end (so what?) but much better acceleration, so she's probably done that, the cheeky minx!

If you wanna swap it back, a new front standard 17 toother is about £15 from http://www.bancexpress.co.uk plus the cost of a new lock washer (£2?)

You can't tell unless you take off the front sprocket covers, but it's not a big job.

Alternatively she may have swapped the back sprocket for one off a TDM with 42 teeth, the next most common mod. You can check this just by wiping all the shite off and taving a good looking at the sprocket as they are stamped with a number for the number of teeth they have.

Dave.

trixynut wrote:Most common mod is swap the front sprocket for a 16 tooth one. Only loose 10-15mph top end (so what?) but much better acceleration, so she's probably done that, the cheeky minx!

If you wanna swap it back, a new front standard 17 toother is about £15 from http://www.bancexpress.co.uk plus the cost of a new lock washer (£2?)

You can't tell unless you take off the front sprocket covers, but it's not a big job.

Alternatively she may have swapped the back sprocket for one off a TDM with 42 teeth, the next most common mod. You can check this just by wiping all the shite off and taving a good looking at the sprocket as they are stamped with a number for the number of teeth they have.

Dave.

cheers dave think leave it the way it is,ill not be chasing blackbirds on the straights anyway might be up his back side on a twistie road tho

get yourself up the hill with Hartside man, see if trixy can give his TDM a run for its money

the TRX is approx 15mph better top end than my mk1 TDM
gearing is the same, so i'm guessing its the weight & larger fairing that slow the TDM down

TonyDevil wrote: the TRX is approx 15mph better top end than my mk1 TDM
gearing is the same, so i'm guessing its the weight & larger fairing that slow the TDM down

Different gearbox, CDI, firing order and exhaust probably have a little to do with it as well

I have a 16 tooth front sprocket and standard rear, and the bike still pulls all the way to 130 mph on the speedo (apparrently), which is about what the theoretical calculation says it should do. I have no idea how accurate the speedo is but mates with newer bikes seem to agree (I also have a 70 profile front tyre which should make the speedo under-read very slightly).

I should add that the bike is revving at just under 6k at 100 mph on this gearing (not that I ever go that fast).

I changed mine because I wanted better 1st and 2nd gear ratios for town work, because the bike used to chug in second, but I rebuild the engine and carbs at the same time and its much smoother now and I often wonder if it would be OK on standard gearing with everything else in order.

TonyDevil wrote:get yourself up the hill with Hartside man, see if trixy can give his TDM a run for its money

no way he knows every lumb and bumb on that road pluse hes a canny rider