Time For A Gearing Change ?

[spike240]

For anyone interested, I fitted the 15 tooth front sprocket today.

Just been out to test it (about 15 milles) on a mixture of town, B roads and some A roads.

In my opinion the bike is much more useable. I can use 4th gear down to 30 before changing to 3rd.

To sumerise I found myself changing gear a lot less on this brief test ride.

[TKH]

If you're wanting to check your speed exactly, most local authorities have (or certainly did have) a measured mile. Speed = distance / time. I've never found sat navs to be that accurate. Or find a friendly speed plod to check with the speed gun. These are supposed to be accurately calibrated.

[spike240]

It was mentioned earlier about the ABS model speedo drive is not taken from the gearbox sprocket, so there is no change on the speedo reading. All the satnavs I have owned (car & bike) are more accurate than vehicle speedos. In fact the satnav always matches those community speed boxes you see in various villages.

[sayhello]

hello dear All 

 

many thanks for this geat and awesome thread: 

 

 

if we have a closer look at this options - then i guess thtat there are many many  various  options

https://www.gearingcommander.com
 
 
Custom Front sprocket
- 3  oder 13
- 2  oder 14 
- 1  oder 15
 
0  16
 
+ 1 oder 17
+ 2 oder 18
+ 3 oder 19
 
 
is this true - that we can choose from  such a wide rahge!?
 
 
look forward to hear from you 

[Kebab897]

I fitted a HealTech Speedo Healer to mine and from memory the Healtech App calculated a 5.2% variance for the standard 16-42 gearing.  Switching to a smaller front sprocket increases the inaccuracy even more, will be more like 8% off. Going the opposite way (17t front sprocket) blunts the acceleration but would make the speedo almost accurate. 

[sayhello]

hello dear Kebab - many thanks for the reply

 

awesome - thanks for sharing your experience. 

 

Have a greart day.

[fixitsan]

For anyone interested, I fitted the 15 tooth front sprocket today.

Just been out to test it (about 15 milles) on a mixture of town, B roads and some A roads.

In my opinion the bike is much more useable. I can use 4th gear down to 30 before changing to 3rd.

To sumerise I found myself changing gear a lot less on this brief test ride.

 

 

I found - 1 tooth to smooth out any jerkiness, and consumption only increased marginally

[sayhello]

good day dear Fixitsan 

 

many thanks for the reply - and for sharing your experience ideas and insights. 

 

 
update: see here the page: https://www.tdm-yamaha.heliohost.org/?page=RAT
 
 
with a awesome great range -
 
front sprocked from 13 to 19 teeth and besides that
rear sprocket  from 34 to 50 teeth 
 
this is overwhelmingly big

[fixitsan]

 

good day dear Fixitsan 

 

many thanks for the reply - and for sharing your experience ideas and insights. 

 

<div> 
update: see here the page: https://www.tdm-yamaha.heliohost.org/?page=RAT
 
 
with a awesome great range -
 
front sprocked from 13 to 19 teeth and besides that
rear sprocket  from 34 to 50 teeth 
 
this is overwhelmingly big
 

</div>

 

What has prompted you to look for a gearing change ?

[sayhello]

good day dear fixitsan 

 

many thanks for the reply   great to hear form you 

 

well i ride also a Suzuki VX 800 _ with 

 

5 gears and cardan - so far  less options to do any thing in that direction 

 

 

but the VX has got power enougth for a different gearing  - to lower the rpms 

 

cf: https://www.vx800.de/forum/viewtopic.php?t=7370

and of course:  https://www.volusiariders.com/threads/ho...50.185987/
 
and - besides that i have had a Suzuki GS 500  - where i wanted to do the same - lowering the rpms 
Adding a Tooth -- Going Up to a 17T Front Sprocket
https://gstwins.com/gsboard/index.php/to...#msg210981
 
so - i think the TDM is pretty good for thinking about these matters (too) 
 
i wonder _ which front sprockets fit on the TDM; 900 
and which rear sprocekts   _ 
 
stock is 16 / 43  isn ´t it !`?

[fixitsan]

 

good day dear fixitsan 

 

many thanks for the reply   great to hear form you 

 

well i ride also a Suzuki VX 800 _ with 

 

5 gears and cardan - so far  less options to do any thing in that direction 

 

 

but the VX has got power enougth for a different gearing  - to lower the rpms 

 

cf: https://www.vx800.de/forum/viewtopic.php?t=7370

<div>and of course:  https://www.volusiariders.com/threads/ho...50.185987/
 
and - besides that i have had a Suzuki GS 500  - where i wanted to do the same - lowering the rpms 
Adding a Tooth -- Going Up to a 17T Front Sprocket
https://gstwins.com/gsboard/index.php/to...#msg210981
 
so - i think the TDM is pretty good for thinking about these matters (too) 
 
i wonder _ which front sprockets fit on the TDM; 900 
and which rear sprocekts   _ 
 
stock is 16 / 43  isn ´t it !`?
 

</div>

 

http://www.carpe-tdm.net/ipb/index.php?s...0&p=398747

[sayhello]

good day dear  Fixitsan 

many thanks for the reply - i did not get it - you link to exactly this (!!) thread

 

look forward to a fruitful discussion of all things gearing and gearing ratio

 

perhaps we can discuss all that things with regard of this great page

 

https://www.tdm-yamaha.heliohost.org/?page=RAT

 

 

Interesting topics

 

what options do we have to change the gearing ratio

 
with a awesome great range -
 
front sprocked from 13 to 19 teeth and besides that
rear sprocket  from 34 to 50 teeth 
 
which tires do you use - which are possible
 
this is overwhelmingly and awesome thread.
 
i look  forward to hear from you
 
with a aw
esome great range -
 
front sprocked from 13 to 19 teeth and besides that
rear sprocket  from 34 to 50 teeth 
 
this is overwhelmingly big
 
 
-BTW . i am interested in all that things related to the grearing change. 

Tires 

sprockets - size - and adresses where to obtain!?

and all that things.
 
 
 

<div> 
varuios rsprockets for the front - of TDM 900
https://www.wemoto.com/bikes/yamaha/tdm_...ain_length
 
 
 
</div>

This post was last modified: 18-06-2023, 03:14 PM by sayhello.

[fixitsan]

 

good day dear  Fixitsan 

many thanks for the reply - i did not get it - you link to exactly this (!!) thread

 

look forward to a fruitful discussion of all things gearing and gearing ratio

 

perhaps we can discuss all that things with regard of this great page

 

https://www.tdm-yamaha.heliohost.org/?page=RAT

 

 

Interesting topics

 

what options do we have to change the gearing ratio

<div style="margin:0px;color:rgb(40,40,40);font-family:helvetica, arial, sans-serif;"> 
with a awesome great range -
 
front sprocked from 13 to 19 teeth and besides that
rear sprocket  from 34 to 50 teeth 
 
which tires do you use - which are possible
 
this is overwhelmingly and awesome thread.
 
i look  forward to hear from you
 
with a aw
esome great range -
 
front sprocked from 13 to 19 teeth and besides that
rear sprocket  from 34 to 50 teeth 
 
this is overwhelmingly big
 
 
-BTW . i am interested in all that things related to the grearing change. 

Tires 

sprockets - size - and adresses where to obtain!?

and all that things.
 
 
 

<div> 
varuios rsprockets for the front - of TDM 900
https://www.wemoto.com/bikes/yamaha/tdm_...ain_length
 
 
 
</div>
 

</div>

 

 

I was just trying to point back out to you that you already have the ratio information, now all that's required is for you to try them

 

Without knowing your main use it's just guesswork. Dropping one tooth at the front, for example, gave me higher revs at lower speed, something which makes the bike more comfortable and easier to ride slowly in first gear. Sometimes I go up steep inclines and tall gearing doesn't suit it that much

[sayhello]

hello dear Spike240 

 

many thanks for the reply and for sharing all your thougths - this is a great idea. 

 

Hi and thanks. There is a link earlier in the thread to a site gearingcommander which is very very good. It does all the maths for you, but there's nothing like experiencing the change - if you know what I mean. Can't help thinking if  a 15 tooth sprocket was better than standard 16 then Yamaha would have done it. Having said that, my mate (mentioned earlier) is a dinosaur biker/racer/mechanic and reckons for the losses on top speed the bike will be more useable.

So for the cost of a sprocket I will try it (don't know when tho). When I have done it, and  road-tested it I will be sure to let you know.

atb

 

well i also like gearingcommander. 

 

its is backed up with tons of data - very nice. 

 

i look forward to hear from you - i love to see a fruitful discussion of all the thigns that are possible

 

 

have a great day 

 

greetings 

[sayhello]

g day daer firiends 

 

 

was riding the last 2 years - love the TDM 

 

did not change anything yet: 

 

but some questions

 

does a 38 rear sprocket has any harm to the swing arm!? 

This post was last modified: 05-08-2025, 05:28 PM by sayhello.