5th gen chain/sprocket fitment

[codyc123]

Couldn't find anything specific using search so i thought i would throw it on here. I'm looking to do a chain and sprockets this year, i know the 6th gen front sprocket is a nice upgrade for low end grunt however I cant find anything on if the 6th gen chain and rear sprocket fit as well. According to partzilla they are a different part number but i know sometimes this comes down to just a supersession in numbers. If possible i'd like to just pick up a 6th gen complete set but wanted to know if any of you guys have tried this. 

 

On a side note, anyone have personal experience with dropping a tooth up front? Worth it?

[RobF]

I can't speak directly to your question of whether or not the 6th gen rear sprocket fits the 5th gen, but I would assume it probably does.

 

In either case, folks who want to change sprockets often buy after-market products that will fit a wide variety of bikes:

 

http://sprocketcenter.com

 

I believe the stock sprocket gearing on the 5th gen is 17/43. On the 6th gen, stock is 16/43, so the 6th gen is geared a little lower in this regard, as you noted.

 

I went a step further and dropped mine (-1/+1) to 15/44. This is about an 8% reduction in gearing. One advantage of doing a symmetric adjustment like (-1/+1) is that it leaves the stock chain length unaltered. You can check the chain-length and gearing calculations here:

 

http://sprocketcalculator.com

 

I'm happy with the switch. Some people will caution against dropping teeth in the front if you can avoid it (maybe by adding even more teeth to the rear) because the tighter drive circumference creates additional wear on the chain. Something to consider if you are a frugal, high-mileage rider. You would need to add around 3T in the back to have the same impact as dropping 1T in the front. Also, there are fuel-efficiency and tank-range considerations, but (unless you are always in 6th gear on a freeway) these are a little trickier because many of us habitually keep the bike in the "power band" and a lower sprocket gearing might in some case permit a higher (more fuel-efficient) selection in the gearbox for a given sense of "in the band".

 

Another thing to consider is that any change in gearing will impair the accuracy of your speedometer and odometer by the same amount. The 6th gen speedo is already around 10% high (at least mine was) so after the mod I was showing nearly 20% high on indicated speed. I ended up buying a SpeedoHealer:

 

https://www.healtech-electronics.com/products/sh 

[DannoXYZ]

JT lists same part# for 5th & 6th gen: JT339. So you should be able to switch front easily.

 

 

[Cogswell]

For reference, here are the part numbers with tooth count for 5th and 6th gens:

6th Gen    

 

5th Gen    

 

Additional context for the difference can be found in the transmission gear sets from Honda FSM's:  (Driven / Driving): 

 

6th Gen      1st     2.846  37/13

                   2nd   2.062  33/16

                   3rd    1.578  30/19

                   4th    1.291  31/24

                   5th    1.111  30/27

                   6th    .965   28/29

 

5th Gen      1st    2.846  37/13

                   2nd  2.062  33/16

                   3rd   1.631  31/19

                   4th   1.333  28/21

                   5th   1.153  30/26

                   6th   1.035  29/28

 

Primary reductions for both are identical - 1.939  64/33.  Starting with 3rd gear the ratios for each on the 6th gen are slightly higher than for the 5th gen (with the 6th gen's 6th ratio being ever so slightly over-driven).  It is  interesting that the transmission ratios for 3rd through 6th are slightly higher for the 6th gen and the final drive is 1 tooth lower.  If I have figured correctly, in 6th gear it would seem to keep the overall ratio of mainshaft to rear wheel rotations very close (to two decimal places) to the same.  Of interest to me is why Honda would do this.  Was there a point to it?  Seems like a lot of trouble to re-engineer the gear stacks for little to no overall change.   At any rate, considering that both use a 43 tooth rear sprocket, it would not seem chain or sprocket wear would be noticeable or significant between the two - I can never recall a 6th gen owner observing added chain wear vs 5th gens. 

 

 

 

[DannoXYZ]

yeah, lots of work for minimal gains. Here's site that lets you play what-ifs with gearing.

 

https://www.gearingcommander.com/

[JimMoore]

-1/+1 is a FANTASTIC mod for the 5th gen. I can't recommend it highly enough. It totally transforms the bike from "Meh, this thing is kinda pokey" to "Holy crap, this thing is pretty fast!"

[JZH]

IIRC, the reason for the 5th and 6th-gen chain OEM pn. being different could have to do with the fact that the 6th gen swing arm is slightly longer than the 5th gen swing arm--30mm?

 

Ciao,

 

JZH

[Mohawk]

As JZH said the only difference is the 6th gen swingarm length & IIRC the 5th gen is 108 link chain & the 6th gen is 110 link chain to compensate for the longer swingarm. 

[adkfinn]

I went +2 on the rear sprocket on my 5th and like the change. I will consider modifying the gearing further next time around, but +2 on the rear doesn't seem to have any downside on my street ridden 5th gen, in fact quite the opposite. I still think my bike has a lot of under utilized top end for spirited but responsible street riding in New England.