Yes, definitely agree with you! The place We ride has creek crossings with lots of large rocks in the way and I am always concerned about hitting and bending the sprocket/axle. I thought about making a skid plate, but think I would get hung up on it a lot. My idea was to move the sprocket next to the tire for protection and add a middle bearing to help with possible rear axle "wrap".
It's got the yellow reverse wound spring and works great!you already answered the question
it's gerneally to be preferred to have the engine centered (weight balance and such)
and therefor it's easiest (least amount of parts needed) to center the sprocket as well.
moving just the sprocket overusully requires more parts
ONE exception:
YOUR TC!
that series 40 is setup incorrectly ..
terribly so in fact.. it's almost impossible that thing works at all as it sits
driver and driven must not both face outboard with the red spring.
the driven must point in the opposite direction.
so moving the jackshaft over flipping the driven would have the jackshaft point in the other direction,
automatically moving its sprocket and therefor the axle sprocket ..
'sid
I did try to use it without the yellow spring at first (used to a 30 series torque converter), quickly discovered the error of my ways!
Ahhhh painted by accident...in that case.. it's just a bad setup not a terrible oneIt's real hard to see, but if you blow the photo way up, it's the yellow reverse spring with red on it too (confusing I know!
)Thanks Sid! What is your opinion on protecting the sprocket by placing it near the tire (I will modify the jackshaft so the engine stays centered)?Ahhhh painted by accident...in that case.. it's just a bad setup not a terrible one
(that driven's not floating inboard obviously.. so you end up with a crooked belt as soon as the TC shifts)
Anyways..
since you are about to move the sprocket you can surely move the jackshaft
you should just flip the driven inboard and reinstall the red spring (remember to preload it in the right direction again
the belt will then always remain straight, thus causing less drag and belt stress than it does now..
meaning more power is actually reaching the axle plus the belt will live longer
the transmission efficiency will improve significantly giving you a bit of extra torque at the wheels
And as a bonus you will not even need an additional jackshaft but can reuse the old one.
essentially not even adding much weight
IF you insist on adding another jackshaft you should still reinstall the red spring
and instead flip the driver inboard (which is awkward I know)
but that way the belt will also remain mostly straight, thus reducing drag and wear,
and the additional drag you're about to add (the bearings add ~ another 2% powerloss)
should be more than compensated for so you might still gain a bit of transmission efficiency that way
'sid
Thanks, Sid! I did find this kind, but all it's going to do is bend the axle on a hard hit. Guess I will fab/weld a skid plate attached to the swingarm to cover the sprocket/brake rotor!well w/o suspension there's about the same amount of ground clearance
(minus axle flex difference that itself should be ideally zero anyways)
So the same size rock/debris in a perfectly inconvenient spot will it it just as before.
But I do agree that the closer it is to the wheel the more likely it is to hit it with the wheel first, thus clear it with the sprocket.
If you had issues with such happening those might get reduced.
But it's essentially as it is with the disc brake..
you hit some stump just barely on the edge and the wheel slips off again
you sit on the brake disc (or then sprocket) which is still unfortunate.
So I myself would not rule out adding a sprocket/chain guard (maybe additionally maybe instead)
from what I've seen you know how to weld..
so welding in a crash bar (basically an upside down barbie roll cage)
to protect the sprocket from such impacts is nothing I'd say you couldn't do in just a few minutes.
it might still hit the rock or stump of course but INSTEAD of the brake disc or sprocket
so while it might stop your ride temporarily it can't permanently, which is maybe what is most important on rough terrain
So.. since -as I said- I'd say you really should move the jackshaft you might as easily move the sprocket with it.
but the first time I get grounded because of such nasty unhappy circumstance
I'd add a lower sprocket/chain guard as well I think.
(funny.. I cannot seem to find an example pic currently.... I know we've seen several examples around.. not one shows up atm.. maybe I'm missing the correct search term *shrugs*)
'sid
Yes, that picture is very helpful, thanks!yeah, those are nice for lightweight road karts..
and true a hard hit could bend the axle.. just as much as without them
that's not the guard I had in mind though..
what I am talking about is indeed welded (seldomly bolted) to the frame itself,
I cannot seem to find a buggy with one.. (odd.. I saw plenty before...)
but I know vintage BMX had this kind of setup as well (for trial purposes)
new trial bike don't anymore... different story..
so to give you at least an idea what I mean...
View attachment 124573
Such (quite a bit beefier of course) I saw on some buggies in the past..
and to me it made sense to move the heavy impact to the swingarm/chassis ..
that way once you pushed the buggy off the obstacle the brake disc chain and sprocket will still remain fully functional,
and you can just continue your ride.
'sid
[EDIT]
And finally.... a crappy pic .. but if you look closely you can make out the sprocket guard (closer to a skid plate really)
that's a Trailmaster MID XRX for example
View attachment 124574