Sprocket change?

[smithb9]

Hey @bigjay... Looks like this thread is a little older but I was just curious which 45t sprocket did you buy?

Any snags with installing it and are things still going well? I <3 this bike but feel it needs a little more zip somedays.

I put a 46t on the rear from "Sprocket Center", as recommended by bamamate. lightweight steel. You can buy a whole kit from them: front, back, and chain for $145ish.

 

[Deleted member 5383]

BTW, if it hasn't been linked yet it should be -- here's the easy toy for playing around with sprockets, chain length and tire size:

Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator

 

[Deleted member 5383]

I think it was said earlier in the post, and it is good doctrine: if you want shorter gearing, increase the tooth count (diameter) of the rear sprocket, don't put in a smaller front. You want the chain as far off the swingarm as possible. Smaller front also puts additional stress on the chain as it wraps that smaller diameter; decreases chain life.

This is a good article: Free Horsepower For The Taking! | Sport Rider

Yes. Early on in the life of the WR250R model, some people were going from the stock 13t front to 12t, and it also was wearing out swingarm sliders and even cutting into the front of the swingarm. With that much suspension travel it's important to get the chain tension right so this doesn't happen, even with the stock 13t front sprocket. When I got my WR it was set up with the too-small front sprocket so I bit the bullet and got a longer chain and went 14/50 instead (14 is the largest that will fit), and figured out the easy way to get the chain tension just right.

 

[Grrant1058]

I think it was said earlier in the post, and it is good doctrine: if you want shorter gearing, increase the tooth count (diameter) of the rear sprocket, don't put in a smaller front. You want the chain as far off the swingarm as possible. Smaller front also puts additional stress on the chain as it wraps that smaller diameter; decreases chain life.

Argh yes Mr Krampus you are correct. It would seem the only manufacturers of larger NC sprockets are Renthal and Superlite. Renthal didn't have 45 teeth available and I would have had to ship a 45t Superlite over as opposed to picking up a 1 tooth smaller front from the local Honda shop 10 minutes down the road. As I was merely experimenting to see how the lower gearing would work, the latter was my best option = I am very pleased with the result. Before I replace my chain I will get a 45t over from Superlite and go back to an OEM 17t front.

 

[Johny_me]

Hi everybody

I will have to change the chain and sprockets on my '15 NC750x EU/PT model. I'm considering sprocket size change, for a bit more acceleration. Usually I drive city and secondary roads, sometimes highway but I hardly exceed 150/160kph and when touring with panniers and pillion I always prefer secondary/backroads. I'm thinking trying a 44 or 45 rear sprocket renthal ultralight HA (43t stock) and keep 17t (JT steel) on the front.
I've already took a look at the gearing commander, but still yet decided.

I think the stock chain is 114 links, for 44 or 45t rear will I need a longer chain?

Any experience with renthal ultralight HA sprockets?? Do they wear fast? (I know they probably wear faster than steel)

Thanks

 

[Deleted member 5383]

if you've looked at gearing commander you can figure out what length along the swingarm any given chain length will put things compared to stock. no guesswork needed.

i wouldn't buy anything with aluminum teeth for these larger road-oriented machines.

 

[Johny_me]

if you've looked at gearing commander you can figure out what length along the swingarm any given chain length will put things compared to stock. no guesswork needed.

i wouldn't buy anything with aluminum teeth for these larger road-oriented machines.

I'm still trying to understand that part well

edit: From what I understand is that with 45t sprocket I need to move the rear wheel closer to the front by 8,5mm. My doubt is if with a new 114 link chain, there is enough free space in the swingarm to move it.

 

[Antarius]

There may not be, but you can always just remove a link from the chain. Or buy a new chain.

I'd wait until you need a new chain and then buy new sprockets and chain at the same time.

As I ride 100% freeway on this bike and ride at 75-80mph most of the time, I'll be putting a stock DCT sprocket on my manual -- which is a 39 tooth instead of 41. This will lower my RPM's by about 700rpm at my cruising speed.

 

[ncBunny]

I put a 46t on the rear from "Sprocket Center", as recommended by bamamate. lightweight steel. You can buy a whole kit from them: front, back, and chain for $145ish.

Ah snap... I didn't see your response and already picked up a JT 45t.

The 45t seems pretty good and I'd suspect 45t vs 46t would be pretty similar. It's not an OMG game changer but I can tell it's there... it just took that edge off... and I like it. I primarily commute and run errands with this bike (10mo of the year), but I'd suspect unless you told someone it was changed they wouldn't notice... they'd just say "hey this bike just works".

I hardly notice the RPM difference yet it feels a tad bit smoother... that wee bit of studder the bike had is gone now. Highway seems just fine.. if not a little smoother. Haven't tried on the Interstate (yet).

I don't really worry about MPG, I tend to just fill it up when it needs it.. but the bike does seem a little more able to get into higher gears around town so maybe my MPG will actually go up.

 

[ncBunny]

i wouldn't buy anything with aluminum teeth for these larger road-oriented machines.

Whoops.. I got aluminum also. Exact model was 45 JTA1303.45 for ~$28 on ebay.
From my quick reading online it sounds like sl vs st hold up about the same... but wow the bike sure went on a diet with that swap.

I'm only at 7k miles right now... but I'll report back if anything weird comes up.
Hopefully thats in a few years when all 3 need changing.

 

[Deleted member 5383]

aluminum teeth wear faster. but at that price --

 

[Deleted member 5383]

Here's a source for front sprockets.

384- Honda CTX-700, NC-700X/ XD 2012-15

 

[DCTFAN]

On my Ninja 250 (2009) I replaced the front sprocket at perhaps 10K miles to add one tooth and later replaced the rear sprocket to remove 1 tooth. The intent was to reduce RPMs for engine wear and improved gas mileage since this was my primary commute bike doing nearly 100 miles per day round trip. On this bike the engine turns about twice the RPM of a typical bike for a given freeway speed in high gear. I was quite happy with the results and figured I was reducing engine wear which would prolong the life of the bike. I estimate that I was turning 10-15% fewer RPMs at freeway speed (70-80MPH indicated being typical for my commute). Gas mileage was improved by these sprocket changes, with the acceptance of slower acceleration. Engine noise and vibration at freeway speeds were greatly improved.

About 2000 miles ago I needed to replace the rear tire, which was a 130/70-17. I happened to have a pair of 130/90-17 street tires gathering dust in the garage that were intended for a second set of rims on my KLR650. Curiosity got the better of me and I decided to see if if the larger tire would fit on the Ninja. Clearance was tight, but with a slightly longer chain the larger tire did fit. The last 10 fill ups prior to installing the larger tire were all in the 55-59 MPG range. Since changing to the larger tire I've gotten 71, 74, 68, 67, 68, and 74 MPG on my last 6 tanks. Yes, the bike does accelerate more slowly, though I haven't had any trouble beating the first cars off the line at the stop lights when I filter through traffic. I'm sure there will be some who would caution about the changes in the bike geometry, though for the style of riding I do on this bike I'm comfortable with how the bike handles -- which frankly is not noticeably different to me other than acceleration. If I were dragging a knee or doing track days then the changes might be an issue. The bike now has 61K miles on it.

Bottom line is this tire change resulted in a larger bump in MPG than the sprocket changes. From that experience, I have am pondering going to a larger tire on the NC700 when it is time to replace my original rear tire which now has 9000 miles on it.

I am dreaming this sprocket/tire size combination (change)
will enable DCT owners to attempt the changes without upsetting any tolerances within ECM parameters.
Essentially, what I want to do is go to 43T in rear and compensate with smaller tire/rim,
thereby fooling the ECM that nothing really changed.
Possible? I ran gearing commander numbers and mathematically it seems doable.

 

[Deleted member 5383]

So one change cancels the other out? Then what is the point of this exercise? To use a smaller rear tire and rim? If so, why would you want to do that?

 

[DCTFAN]

So one change cancels the other out? Then what is the point of this exercise? To use a smaller rear tire and rim? If so, why would you want to do that?

My question was actually for the Africa Twin- 21 front and 18 rear spoked tube type rims.
If my plan works, I'll end up with 19"/17" which gives me an entirely new bike as far as handling goes.
In fact, I'm thinking it will enable me to tap onto most of the unused power band of the 998cc engine and
allows for more rear tire choices. With stock 18" spoked rims, there is only a limited amount of tires to choose from.
An Africa Twin with supermoto setup, if you will.

 

[rippin209]

My question was actually for the Africa Twin- 21 front and 18 rear spoked tube type rims.
If my plan works, I'll end up with 19"/17" which gives me an entirely new bike as far as handling goes.
In fact, I'm thinking it will enable me to tap onto most of the unused power band of the 998cc engine and
allows for more rear tire choices. With stock 18" spoked rims, there is only a limited amount of tires to choose from.
An Africa Twin with supermoto setup, if you will.

Very interested to see how that works out, I was envisioning just such a setup.

 

[Fuzzy]

My question was actually for the Africa Twin- 21 front and 18 rear spoked tube type rims.
If my plan works, I'll end up with 19"/17" which gives me an entirely new bike as far as handling goes.
In fact, I'm thinking it will enable me to tap onto most of the unused power band of the 998cc engine and
allows for more rear tire choices. With stock 18" spoked rims, there is only a limited amount of tires to choose from.
An Africa Twin with supermoto setup, if you will.

Need to work through how this affects ABS.

 

[Old Can Ride]

My question was actually for the Africa Twin- 21 front and 18 rear spoked tube type rims.
If my plan works, I'll end up with 19"/17" which gives me an entirely new bike as far as handling goes.
In fact, I'm thinking it will enable me to tap onto most of the unused power band of the 998cc engine and
allows for more rear tire choices. With stock 18" spoked rims, there is only a limited amount of tires to choose from.
An Africa Twin with supermoto setup, if you will.

For every thing you change, expect opposite reaction of some type.

 

[TigerDude]

Yyou will also change the steering geometry. Reducing the wheel size will lessen the trail, giving you theoretically an easier turn-in, but less stability. I imagine somehow it would affect the rear suspension as sell.

 

[Deleted member 5383]

Yyou will also change the steering geometry. Reducing the wheel size will lessen the trail, giving you theoretically an easier turn-in, but less stability. I imagine somehow it would affect the rear suspension as sell.

Minimal effect if one compensated with a larger tire diameter/taller sidewalls. People worry about lowering links as well and moving the forks up in the clamps -- and sprocket changes that put the rear tire further up the swing arm (or back, which actually gives the swingarm more leverage on the shock and spring, which could be a problem in some cases if the suspension is already borderline). But if it isn't all that radical the rider quickly can accommodate in many cases methinks. I know I haven't been bothered by this, but moderation in all things, right? ; }