chain tensionor mounted upside-down on seat stays instead of chain stays?

[bfgmovies]

So my my seat stays on my Schwinn sidewinder are in such a way that the chain will hit against the stays if it were to be running, however if I mount the chain tensioner upside-down on the seat stays instead of the chain stays (where it is usually mounted) it pushes the chain to a region where the chain is cleared from the seat stays.. however I do not know if this will work and was wondering if this is a good or bad thing to do before I tighten everything down and actually try out my engine. Thanks!

 

[Venice Motor Bikes]

Maybe you can add some extra washers to the axle to space out the frame enough to work??

 

[bfgmovies]

I don't think that will work.. here's some pics to show what I mean, the first one shows how I mounted the tensioner, the second one shows how without the tensioner mounted on the seat stay the chain hits the seat stay, and the third one shows how with the tensioner it clears the chain from hitting the seat stay

 

[2door]

The main reason for the tensioner being mounted on the lower run of the chain is to help guide it onto the rear sprocket if there is any misalignment betwen the engine drive sprocket and the rear wheel/ driven sprocket and to take up the slack. Mounting the tensioner on the top run sort of defeats the purpose in that the top run is always tight under load and the bottom will have the slack. That's where you need the tensioner.
Tom

 

[bfgmovies]

The main reason for the tensioner being mounted on the lower run of the chain is to help guide it onto the rear sprocket if there is any misalignment betwen the engine drive sprocket and the rear wheel/ driven sprocket and to take up the slack. Mounting the tensioner on the top run sort of defeats the purpose in that the top run is always tight under load and the bottom will have the slack. That's where you need the tensioner.
Tom

so would the way that I have it set up work or does that mean that this wont work my my bike?

 

[killercanuck]

What kind of front mount are you using? Is there anyway you can lower your whole engine a bit?

If you're chain alignment is good, the only problem with a top mount is the pulley getting shredded from all the pressure on it(plastic is plastic). If you stick with that setup, you should look into an idler sprocket, or a hard skate-board wheel with bearings. That would last longer, I think.

 

[bfgmovies]

What kind of front mount are you using? Is there anyway you can lower your whole engine a bit?

If you're chain alignment is good, the only problem with a top mount is the pulley getting shredded from all the pressure on it(plastic is plastic). If you stick with that setup, you should look into an idler sprocket, or a hard skate-board wheel with bearings. That would last longer, I think.

huh yeah I might want to do that, because I can't get my engine lower without making it sit vertically, and then my mounts can't work

 

[2door]

huh yeah I might want to do that, because I can't get my engine lower without making it sit vertically, and then my mounts can't work

Read my first answer again.
When the engine is pulling and the chain is under the load of driving the bike the upper, or top portion of the chain is always tight. The way you have it now the tensioner wheel is under too much pressure and it is not keeping the slack out of the lower chain where it will do some good. There is a technical explanation for what happens when a chain drives a sprocket and what happens to it as it approaches a sprocket but to make it simple, suspend the rear wheel, start the engine and engage the clutch then watch the chain as the engine drives the rear wheel. You'll see the slack in the lower chain and the tightness in the upper one. The slack is what you're trying to control with the tensioner.
Also it appears that you could remove a link (actually 2 links) and get closer to proper tension.
Tom

 

[Al.Fisherman]

On a multi speed it is easier then on a single speed, but you don't need a tensioner at all. Mount the engine as low as you would like it. Remove links to get the chain as close to needed. Now make and insert a shim like these between the rear engine mount and case. Shim as needed for proper tension. When was the last time you saw a motorcycle with a chain tensioner? The higher the engine on the seat tube the further the chain will be from the frame at the wheel sprocket.

...

 

[mapbike]

The answer to your question about the tensioner working in the top position is a solid NO....! that tensioner will be toast very quickly and you will be on your back side when it is pulled into the spokes on your rear wheel.

I have 2 questions for you though: (#1) In the pics I notice that you have your engine mounted very high in the frame, WHY?

(#2) Question: Why is the intake tube mounted on your engine upside down?

If the engine was lowered into what I would call the more normal mounting position on that frame your chain clearence problem would likely be solved, if it is possible to lower it, it's hard to tell in the pics because the front of the engine cant be seen.

And you will need to mount that intake correctly by turning it top side up before the carb will fit onto the engine.

 

[killercanuck]

let us see your front mount bfg. mapbikey he's saying he can't go any lower and keep the rear mount flush(i think). What do you think of an idler sprocket on top though? In case he's stuck with it.

I think the intake is an offset one, that right?

Pics plz!

edit-Al, see pic #2 on post #3 to see where its hitting, would the shims help that? (depends on the front mount, I guess, eh?)

 

[Al.Fisherman]

Looking at the rear mount a rather LARGE gap is between the mount itself and mount clamp, this tells me that the rear mount is not flush and needs to be reamed out which is rather easy. Below is a rear mount instillation as it should be. After the rear mount is mounted correctly then that is the time to figure out what needs to be done to the front mount for proper fit.
...

Correct mount to tube fit.... Incorrect mount to tube fit....

Incorrect engine mounting will over a period of time do one of four things
1) Break the mount
2) Break the case
3) Shear the studs
4) Strip stud threads on stud or in case.

 

[mapbike]

let us see your front mount bfg. mapbikey he's saying he can't go any lower and keep the rear mount flush(i think). What do you think of an idler sprocket on top though? In case he's stuck with it.

I think the intake is an offset one, that right?

Pics plz!

edit-Al, see pic #2 on post #3 to see where its hitting, would the shims help that? (depends on the front mount, I guess, eh?)

Yes it may be that he cant go any lower, if so there is a way to fabricate an idler for it but it will take more than average tools and average skills to do so.

On the intake, No the one in the pic is not the offset intake, I have the offset intakes myself that I dont use anymore but they still hold the carb. at the correct angle and they are twice as long as the standard, they offset out to the side not down.

 

[mapbike]

After going back and looking at the pic again, it does look as though the intake could possibly be the offset one maybe.....! but if it is it is still upside down and will not work in that position.

 

[2door]

Offset or not, the carburetor will not sit level enough to ever get a proper float level.
He really needs to reevaluate his engine mounting. It needs to be lower and possibly aligned better with the frame centerline. Relocate the tensioner to the chain stay or do away with it completely.
I've seen several engines mounted high in the frame like this and it is usually the result of trying to attain clearance for the front derailer, which most of us do away with with, or they have not, as Al Fisherman says, made the mounts fit the frame tubes correctly.
Tom

 

[mapbike]

Thats very true 2door you are correct on all points made, intake in wrong position and engine mounted too high......2 things that are easily seen in the pics that need to be addressed before anything else is done on build, especialy the engine position on the frame.

 

[bfgmovies]

The answer to your question about the tensioner working in the top position is a solid NO....! that tensioner will be toast very quickly and you will be on your back side when it is pulled into the spokes on your rear wheel.

I have 2 questions for you though: (#1) In the pics I notice that you have your engine mounted very high in the frame, WHY?

(#2) Question: Why is the intake tube mounted on your engine upside down?

If the engine was lowered into what I would call the more normal mounting position on that frame your chain clearence problem would likely be solved, if it is possible to lower it, it's hard to tell in the pics because the front of the engine cant be seen.

And you will need to mount that intake correctly by turning it top side up before the carb will fit onto the engine.

Ok here are some more pictures so you guys can see why it's mounted so high, the V frame is at a very acute angle, which makes it impossible to get to the ideal position. I actually just modified my mounts and managed to lower the engine just enough to clear the seat stays so I hope this works.

Also there isn't enough clearance for the Carb on my bike so i got an offset intake manifold from spookytooth (which I did accidentally mount upside-down) but it's actually useless, because it wasn't angled enough anyway so I've had to make an offset intake manifold from the original intake manifold and some metal pipeline (and I think this should work if I use plumbing adhesive sealants and some thread seal tape)

lemme know what ya'll think of this setup thanks!

 

[2door]

You're certainly on the right track. We'll have to wait to see how your intake manifold works and your sealing methods hold up to the vibrations but you've made the right moves so far. Keep us posted, please. Good luck.
Tom

 

[mapbike]

It looks like your rear mount is still not sitting flush with the seat post down tube, if it is not flush top and bottom your rear studs through the mount will break very quickly while running, it is very important that the rear mount sit flush and snug on the down tube.

Question: is the front down tube that runs from the fork tube down to the cranks too large for the front mounting of the engine to fit over it?

The reason I ask is that it looks as though you have a mounting plate of some type on front of engine which is not needed if the engine itself will saddle over the front tube, if it will saddle over it that will allow your engine to be lower and also would probably help to resolve the issue with the rear mount not setting flush on the seat post tube. I may be off the mark on this here but I cant see clearly enough in the pic to tell the size of that front tube and what you have on the front of your engine.

 

[mapbike]

You're certainly on the right track. We'll have to wait to see how your intake manifild works and your sealing methods hold up to the vibrations but you've made the right moves so far. Keep us posted, please. Good luck.
Tom

2door look at the angle of the rear mount in relation to the seat post tube, it is no where close to being mounted flush on the tube, this will not work as we already know from our own experience.