More stuff about sprocket ratios

Aprilia RiderSite (Riders Site) - The independent & international community website for Aprilia motorcycle riders with chat, discussion forums and much more: Falco SL1000: More stuff about sprocket ratios
By Molan on Tuesday, November 12, 2002 - 07:10 am:  View Molan's Profile Search for other posts by Molan Edit this post

OK - so I currently have the 15 sprocket on the front & a stock rear (43 I think?).

Would still like to get more flexibility around town so have been talking to my experts for some help.

they are not that keen on the 15 front as they reckon it can chew up chains faster & would normally recommend a 16 front 44 rear (this gives a slightly different overall ratio to the 15 / 43). They've said I could safely go to a 16 / 45 combination.

Just wondered if anyone else has ever tried this?  

By Befbever on Tuesday, November 12, 2002 - 10:42 am:  View Befbever's Profile Search for other posts by Befbever Edit this post


16/43 here.
Any over-zealous opening of the throttle in first gear will have you land on your arse. Apart from that, works great. Requires a longer chain tho.

16/45 is just too short IMHO.
Oh and stock rear is 41. 

By Hydropnik on Tuesday, November 12, 2002 - 11:09 am:  View Hydropnik's Profile Search for other posts by Hydropnik Edit this post

Most Ducati's are sporting a 15t front sprocket. I haven't had any chain issues since fitting the smaller sprocket.  

By Crmc33 on Tuesday, November 12, 2002 - 11:11 am:  View Crmc33's Profile Search for other posts by Crmc33 Edit this post

IMHO you wont have a problem with a 15T sprocket.
I prefer 16/42 post hairkitment, nice lightweight alu rear sprocket & gives good drive all round.  

By Geo on Tuesday, November 12, 2002 - 01:06 pm:  View Geo's Profile Search for other posts by Geo Edit this post

You have to look at the ratios that you have now are and decide what % more you really want.

One way to do this is if you do a lot of highway riding check out what your rpms are at your cruising speed. Then increase your rpms by 5% and 10% and see if it's not too "busy".
If you're looking for a higher top speed it's a different story than if you're looking for better acceleration (although sometimes you can get both.
On my VTR I was able to get better accel and a slightly higher top speed by incrasing my rear 2 teeth (+4.5%) instead of topping out 9k rpms it was able to run to 9.600 rpms.
Some people gear their bikes so high that their 6th gear is now what the 5th used to be and they love it (and 5th was 4th etc)
I don't see the point in that myself.
My US spec Mille does 83mph @5000, I wouldn't go lower than 80 @ 5,000 if I changed the sprocket for myself.  

By Dave on Tuesday, November 12, 2002 - 03:03 pm:  View Dave's Profile Search for other posts by Dave Edit this post

with the engine breathing properly (in my case that's rene cans/chip/airkit) finding comfy revs at any crusing speed is not an issue, and as I've not yet topped out, top speed not an issue either.

so for me, ratio is down to converting power/tourque into acceleration, while being happy with how light the front likes to get. I Don't like to have the front up, At All, and have to say that with 15 front and 41(std) rear, I don't always get my way, 'tis fun tho. End of the day, I like the setup when it matters, the rest of the time I'm used to it, and cope.

Molan, is your problem the clunkyness at low revs around town? if your on a 15 tooth front that should have improved matters even on std pipes and air, you can improve things further by using the clutch more at low revs to soften the pulses, if you haven't already let the engin breath properly then the sponsors of this site can help.  

By Cplus on Tuesday, November 12, 2002 - 06:47 pm:  View Cplus's Profile Search for other posts by Cplus Edit this post

I just switched from stock to 16/43 (+2 in back). The difference is very noticable and, IMHO, solves one of the Falco's shortcomings. The new ratio works well in the twisties in 1st through 3rd, and the top gears are better suited to highway work. There might not be much difference between 16/43 and 15/41, however, and you'd need to buy not only new sprockets but also a new chain.  

By Exdukenut on Tuesday, November 12, 2002 - 07:00 pm:  View Exdukenut's Profile Search for other posts by Exdukenut Edit this post

Just a quick question, but, has anyone tried a 16/42 combo? Why up +2 in rear? Or for that matter any higher? 

By Geo on Tuesday, November 12, 2002 - 08:18 pm:  View Geo's Profile Search for other posts by Geo Edit this post

A 15 front is 6.25% higher than stock.
Two plus rear is 4.6% higher, you can feel it more than you think in a roll on.
That's what I'd go with if I changed.
At 5000 rpms it would reduce the speed from 83mph to 79 mph (or the other way around I'd be 5250 @ 83mph). At a 90 mph cruise that's 5700 rpms.
I spend too little time at WOT, and too much time droning on the hwy to enjoy very high gearing.  

By Hansie on Wednesday, November 13, 2002 - 12:14 am:  View Hansie's Profile Search for other posts by Hansie Edit this post

I use 16/42 but Ive got the hairkit and TNT system remember.
Plenty of torque here and no need for shorter gears. Even thinking of trying 17/42 for even more forward instead of upwards speed!

In my life before the Renegade TNT system I used 15/41 and it lived for 22.000km . No change in fuellconsumption.

Hansie 

By Crmc33 on Wednesday, November 13, 2002 - 12:26 am:  View Crmc33's Profile Search for other posts by Crmc33 Edit this post

ExD, I also use 16/42 but you probably ignored me.... as usual. 

By Scotty on Wednesday, November 13, 2002 - 02:27 am:  View Scotty's Profile Search for other posts by Scotty Edit this post

Molan, I use a 16/44 combo... stock gearing is 16/41.
You were/are running 15/41 which is functionaly equivalent to 16/44. 16/44 gives better chain clearance against swingarm on the top run....

I initially ran 16/41 for the first 4k miles then changed to a 15 front up till about 12k miles when I replaced the chain and sprockets.

I asked to go to 15/42 when I was changing my chain and was told to switch to 16/44 instead again the difference in ratio is tiny.

16/44 is just about perfect for round town and out of town... 6th gear @ 6k revs = 95mph which is only a loss of approx 5mph with a change from stock 16/41.
You probably know this aleady assuming that you are riding on 15/41 currently.  

By Molan on Wednesday, November 13, 2002 - 07:27 am:  View Molan's Profile Search for other posts by Molan Edit this post

Thanks for all the pointers guys.

Decided that I might as well stick with my current 15 on the front & leave the rear alone.

This way I can keep the current chain & then maybe re-look at my options in a couple of thousand miles when they actually need replacing rather than just because the wheels & swing arm have been off this week  

By Bob on Wednesday, November 13, 2002 - 11:14 am:  View Bob's Profile Search for other posts by Bob Edit this post

That's what I have done. Now it is 16/43 and it performed the same as 15/41 so far I can feel.
It does make less mechanical noise.  


Add a Message


This is a private posting area. A valid username and password combination is required to post messages to this discussion.
Username:  
Password:

< <  back to previous page

Administrator's Control Panel -- Board Moderators Only
Administer Page | Delete Conversation | Close Conversation | Move Conversation