What size chains are teams using with the 450's?

[Kirk Feldkamp]

Hey guys,

I was wondering if anyone would be willing to share what size chain they're running with a 450 single. The bikes all come stock with 520 chains... but has anyone downsized to a 428?

-Kirk

[Kirk Feldkamp]

Hey guys,

I was wondering if anyone would be willing to share what size chain they're running with a 450 single. The bikes all come stock with 520 chains... but has anyone downsized to a 428?

-Kirk

[poweredbyvdub]

beat me to it.... thanks kirk!!

[Conor]

Just running the standard bike chain.. once again, I don't understand why people are making things more complicated than they need to be... Keep It Simple

[Kirk Feldkamp]

That's what I said too! http://fsae.com/groupee_common/emoticons/icon_cool.gif

[Ashley Denmead]

we use a 428 on our 525exc ktm, does the job! its not really complicated guys, its just smaller http://fsae.com/groupee_common/emoticons/icon_wink.gif

[HenningO]

We run a 428 with a turbo 600, however chain alignment is crucial to get it to work...

[Welfares]

I've seen a couple of teams running 0.5" pitch duplex chains, how did they work out?

Were you just using standard ANSI duplex chains?

[Big Bird]

Sorry for taking a while Kirk - we used 520 initially, but switched over to 428 in '05 (from memory). No major issues with stretch - designing a good tensioner was more of an issue.

Cheers mate, hope that helps

[LU-Bolton]

Kirk,

We have run a stock 5-20 chain on our WR-450 powered car since 2004. No major issues with the 5-20 chain during my time in FSAE.

However, after talking to some motorcycle racers, I believe our team may switch to a 4-28 for '08. One of the first things racers do before they hit the track is switch to a smaller size chain. I've heard claims of 2-3 hp gains just from doing this. Basically, you have a reduction in chain weight which is always good, but you also have a reduction in drag/friction from the smaller size chain.

Now, if this were your first time running a 450, I would recommend running a stock chain because it means you don't have to get a custom pinion sprocket. Also, it will take you a couple of years to even figure out the bugs in the 450 motor anyways. Why switch to a smaller chain just for a small increase in power or decrease in weight, when larger gains can be made elsewhere?

[Kirk Feldkamp]

Thanks for the input guys. I have a few follow-up questions.

In light of this little gem (http://fsae.com/eve/forums/a/tpc/f/125607348/m/98110037721?r=12710038721#12710038721) that I found...

Has anyone actually measured any appreciable power 'recovery' using a 428 vs. a 520? Any appreciable improvement in lap times? Any quantifiable decrease in chain or sprocket life?

Geoff,
I'm interested to hear your thoughts on the chain tensioner issue you mentioned. Did a problem show up once you switched to a 428, or was it a problem that was always there? You guys used a small pivoting carrier, correct?

-Kirk

[Big Bird]

Hi Kirk,

We have always seemed to have had some sort of tensioner problems, no matter what the chain size. Until 06 we had always had some sort of roller adjusted by a screw thread, tensioning the slack side of the chain (anchored against the chassis somehow). We often chopped out rollers (weak material), and I would also attribute this partially to the small sprockets we were using (like 11:22 or similar with the 520); small sprockets = greater chain tension for a given torque. In Detroit 06, after trashing every nylon roller we had brought to the US, Deano machined up an aluminium roller. It worked a charm (although even that "self-machined" some nice tracks in the roller across the event).

For the newer 06 car, Mark the drivetrain guy came up with this cool "floating" tensioner that had rollers acting on both tight side and slack side. You adjusted slack by adjusting the distance between the rollers, tensioning the slack side relative to the tight side. The whole assembly slid up and down on a linear bearing, and worked really well.

Cheers, and hope that helps,