20 replies to this topic

[NEUK]

I'm used to sports bikes and bought the TDM900 which I love. However I feel that the gearing is wrong in that I need to select a much lower gear than I thought to maintain higher revs and smoother ride at slower speeds ie 2nd up to 30mph as 3rd chugs at 30ish. 6th is pointless unless over 70mph as that chugs too . Can I change sprockets to sort this annoyance?

[AzzA]

I'm using 15/43 and find it very good... we're locked to 100kph on most roads and 110kph on free-ways, so 15/43 suits the 900 much better than 16/42 IMHO. You'll need a speedo corrector... I can recommend the SPeedoDRD. (you'll want the "Y1")

 

If you still have a good chain and rear sprocket, just change the front to a 15 tooth; it's a cheap easy thing to do... you'll still need to correct the speedo.

[danresh]

Azza, do you think changing the sprockets will satisfy him?
Neuk is new to the TDM, so I suggest you let him into the chugging comprehensive solution....

Danresh

[Geordie Guy]

NEUK, that is exactly the range you should be in for the gear / speed.

 

I bet you want to change gear at about 3,000 rpm.

 

changing the sprocket  is only going to stress the engine and lower your fuel consumption dramatically !!

 

Stop riding your bike like it is a car,

 

my revs are normal 4,000 -5,000 rpm , mid range lets you pull away smoother and slow the bike by just throttling off.

[Pantboy]

NEUK, that is exactly the range you should be in for the gear / speed.

 

I bet you want to change gear at about 3,000 rpm.

 

changing the sprocket  is only going to stress the engine and lower your fuel consumption dramatically !!

 

Stop riding your bike like it is a car,

 

my revs are normal 4,000 -5,000 rpm , mid range lets you pull away smoother and slow the bike by just throttling off.

  I tend to change down when the revs drop below 3500 and only really ever let it drop below 3000 rpm when I am stopping

Edited by Pantboy, 06 October 2013 - 04:51 pm.

[dicky1]

The 900 does feel over geared at lower speeds and as suggested it needs more down-shifting than some bikes. The upside of this gearing is excellent fuel economy when touring & an engine that rarely feels stressed.

[PICARD]

Yep......you need to be in at least one gear lower than your mechanically sympathetic sub-conscience is telling you!!
I find short shifting smoothes out gear changing, but staying a gear lower than you'd think right, smoothes things out and improves engine braking while making progress...make sense??.....works for me !!

[Geordie Guy]

Yep Pantboy, change down at 3,000 and up at about 6,000.

 

But I bet NEUK is changing up to soon.

[NEUK]

Cheers all  I rode in lower gears today but cant help thinking im burning fuel too much however the alternative is chugging! I dont like the sound of engine stresses and speedo adjustments for changing teeth numbers on sprockets. So, look slike lower gears.  Years of riding sports bikes isnt helping as its taking a bit of getting used to! I love it though! Had riddena few TDM850's and loved them but the 900 is different re gears (6 and different ratio). 

[AzzA]

...

changing the sprocket  is only going to stress the engine and lower your fuel consumption dramatically !!

 

....

 

It wont and it doesn't; if he's finding that 6th gear is useless (due to being a conciousness law abiding citizen) then he might as well close up the ratios and make better use of the six gears.

 

Lowering the final drive ratio will not stress the engine; how you control the throttle will or wont stress the engine.

 

Lowering the final drive ratio will not consume more fuel; how you control the throttle will or wont consume more fuel.

 

Lowering the final drive ratio will change the road speed to gear number to engine RPM relationship, but only by moving the whole gearing spectrum lower by lowering the relative road speed in each individual gear.

 

If you're never/rarely going to ride the TDM900 over 70mph/110kph then the riding experience will benefit greatly by reducing the final drive ratio; this results in a more tractable bike at highway speed.

 

Why have a sixth gear if it all it does is bog down due to being under rev'd?!?! Bogging an engine down will result in increased fuel consumption and poor combustion, which has the potential to foul plugs and varnish the combustion chamber.... you'd be better off riding in 5th gear.

 

The other benefit of lowering the final drive ratio is that first gear will be lower too, and this means more rev's at lower speed which is exactly what the TDM900 needs (as has been argued for above). This results in a more tractable bike at low speed.

 

Lowering the final drive ratio also closes the ratios between relative gears; this benefits the rider of the TDM900 by being able to shift sooner through the gears to maintain the ideal RPM range.

 

To conclude, when abiding by 110kph/70mph limits:

Gearing down the final drive on the TDM900 results in a more tractable bike, across the entire speed range, at no loss to fuel economy and without any increase in wear or tear. The net result is a far happier rider.

[JBX]

I personnaly do not agree with changing the original ratio because I find it nearly perfect for almost any riding conditions : highways, A/B-roads, mountain roads, single or dual riding. I only find the first gear too long for town riding, but I don't practise this a lot.

The engine has enough torque at any revs to handle many different roads without the need to change gear too often, even on mountain roads when the 6th or even the 5th gear are not often used. With a lower final ratio I would need to change gear more frequently.

 

I'll add that in France the final ratio is part of the bike homologation and so on bike insurance.

Changing the ratio here will get you into trouble in case of an accident due to a loss of control : the insurance expert will check the ratio & conclude that the damages will not be covered !

[muddy]

As said, 30 mph in 3rd is just fine and at it shouldn't chug at all. Stating the obvious really, but it's a twin, not a sports bike, so it won't sound as lively (which is why I prefer 'em). I like to get good MPG figures, so I short shift between 3-4k and the bike rides dead smooth.

[gordons]

I dont understand the problem....here in Malta I ride almost always on 3rd and 4th gear, very limited 5th and 6th I didnt realise I had it until I rode the bike abroad... When it chuggs just downshift..and the Tdm is such an easy smooth rider....

[AzzA]

... I only find the first gear too long for town riding, but I don't practise this a lot.

...

 

 

... so I short shift between 3-4k and the bike rides dead smooth.

 

Ditto... to both, however... in the case of regular town riding and "relatively" low speed limits and no silly insurance issues, the TDM900 rider can benefit greatly from gearing down the final drive ratio; it makes short shifting even smother between 3-4k RPM whilst riding around town and through low speed twists and turns. It's so smooth it like having a shaft drive, especially with a 530 chain.

[NEUK]

well, it appears that some say change the sprockets and others not for various reasons. I am aware this bike isnt my sports bike however it is quite irritating going into a higher gear and realising its too high and so downshift again. Something to get used to I think! Great bike though, only done 200 miles on it so far so plenty riding to get used to it yet Appreciate all the responses, thanks. Touring screen coming this week , spot/fogs to decide on next...........oh, and the nightmare of hand guards for this bike!

[AzzA]

Careful now... don't go talking about changing screens, not unless you really want to open a can of worms. :-)

[Rallyist]

Well I have gone the other way by gearing up to make top gear a true overdrive, I don't do commuting now so most of my riding is on open roads and I found the vibration point in the rev range was just where I sat at speed so put a 39 tooth on rear which means the speedo now reads correct speed, bonus,

[Limbo]

I already changed the chainring to 44 Spokets.
It is so wonderful to ride in the mountains, but on the Motorweg it is not good.
I took the Spokets back after a summer.
From the 2008 model you must to change the Spokets no more SpeedoHealer install. The speedometer gets its signal from the rear wheel ABS.

Limbo

[AzzA]

I wrote a piece on the different gearing ratios for the TDM

 

Chain & Sprocket Options: What Works Well, What Doesn't, And Why..

http://www.carpe-tdm...showtopic=27959

[Rallyist]

I wrote a piece on the different gearing ratios for the TDM

 

Chain & Sprocket Options: What Works Well, What Doesn't, And Why..

http://www.carpe-tdm...showtopic=27959

Never looked at gearing up though Azza by just altering the rear sprocket. tut tut 1/2 a job