Chain tensioner of death

GoldenMotor.com

Rambler

New Member
Jul 25, 2009
48
0
0
U.S.A.
My chain tensioner will not stay put, i tried a #8 self tapping screw, but the head broke off, so I took it out, and tried a #10 self tapping screw, but that screw's head broke off too, it's still there (the headless shaft is working as a pin holding the two pieces together, but the tensioner assembly still moves, so i put in some leather patches for extra friction and it is staying put for the time being... Gahhh! Can I have someone weld on a bracket for the tensioner? What should I do, any suggestions? The chain tensioner is the only problem, but it is a pressing problem, because I feel that it is only a matter of time before it goes kerplunk into my spokes, and i wind up as a giant walking scab.

Oh, the cluch is squealing too. I've tried shooting some red grease in the hole for the clutch pin on the left side, but it still squeals. Should I adjust the little flower nut on the clutch, or what?
 
Last edited:

Qdot

New Member
Nov 11, 2008
58
0
0
Langley b.c canada
Weld the tensioner on, thats the only way to go. As for the clutch , you could try the flower nut but i find thats always a headache. Check your pads maybe theyre worn out.
 

jbabb

New Member
Aug 3, 2009
25
0
0
usa
When we built our first bike, on its first ride, the chain popped off and ripped the spokes out, After that we built a ring that bolts to the back side of the sprocket to keep the chain from getting caught in the spokes ever again.

We had to bend the tensioner bracket to get it to work well.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
The tensioner bracket is without a doubt the biggest problem most people face with a new build. It can't be stressed enough that proper alignemnt is critical to the tensioner working as it was designed to do. Every one I've encountered required a slight twist to get the centerline of the wheel to line up with the chain. The bike chainstays are not parallel with the chains so mounting the tensioner bracket without twisting it will assure misalignment and eventual failure. Looking from the left side of the rear wheel forward, sight along the chain and look for the angle that needs to be corrected to get the tensioner wheel to align with the chain. Clamp the tensioner bracket in a bench vise and give it the necessary twist before re-installing it. The self tapping screws seem to work for some but I elect to drill completely through the bracket and chainstay and install a grade 8 10/32 Allen head cap screw with a lock nut on the wheel side. You need to make sure the alignmewnt is right before drilling however. In addition the tensioner wheel must spin freely. Hope this sheds some light on your problem. If you elect to weld the bracket or fabricate your own here's an idea.
Tom
 

Attachments

Last edited:

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
If you are having that much of a problem with your tensioner, I am betting you run the chain too tight.
I have had no problems ever with the tensioner (stock, with the exception being a skate wheel) ever, I run the chain at 3/4" freeplay.
 

HoughMade

New Member
Apr 15, 2008
623
1
0
Valparaiso, IN
Agree, sounds like the chain is too tight...but even then, it should be pretty hard to move the tensioner.

2 things- have you replaced the tensioner bolts with grade 5 from a hardware store? If you do that, you can crank those things down tighter than you think you can. Second, have you bent the tensioner to line up with the chain? Wheel stays generally approach the rear axle at an angle. If you don't bend the tensioner to compensate so that the tensioner wheel runs straight with the chain, it will put undue pressure on the tensioner.

As you can see below, I use a screw on the tensioner (#10, hardened button head, allen), but that is more of a last resort. You can see I also run a spring tensioner. the original tensioner is mainly just for guiding the chain. With the spring, it takes up the slack without putting a lot of pressure on the chain.

Good luck!!
 

Attachments

captainrichhill

New Member
May 31, 2008
202
0
0
2Door,
That is an awesome looking bracket. I may need to go to one of those designs. That color looks great too. And yes, I think the tensioner is one of the biggest headaches on these bikes.
 

Rambler

New Member
Jul 25, 2009
48
0
0
U.S.A.
When the chain popped off, it popped off towards the frame, and did not go into the spokes, thank god, and I could still pedal it; thing is, I think it bent the spokes, because I noticed yesterday that no matter how I adjusted the sprocket mounting bolts it still wobbled, and it is concentric, I double checked, and if I put lateral pressure on the sprocket with my hand, it makes a slight popping noise, and the sprocket goes straight with no wobble, but the slightest amount of pressure will pop it out of place once more.

I bent the tensioner so it lined up before I put the self tapping screw into the frame, the #8 tore out the threads when i removed it after the head snapped off, so I went to a #10 and somehow the head broke off of that one too but it was pretty much flush with the tensioner bracket, so I left it, and i cranked down the bolts as tight as they'd go, i torqued off all four of the stock ones easy as butter, and replaced them with stainless for now.

The bike is a Schwinn Windwood.

2door, that welded tensioner mount design looks sweet, if I do opt to weld up a tensioner in that manner, I can weld the screw hole shut, can I not? I'm gonna ride the bike to work today and hope to God I don't die, it's my only form of transport at the moment.

As for the the clutch pad, I don't think it could be worn out, I've only had the bike for a week.

Does anyone have experience with the Grubee HD axle? I am seriously considering getting one but want to know as much as I can before I buy one. Thanks for all of the Tech Support guys.
 
Last edited:

floridaboy

Member
Apr 25, 2009
139
6
18
Hudson, FL.
If you would like a chain tensioner that is easy to make and will not cause any problems you can make one like i did. Get you a piece of alum. 1/8 inch thick by 2 1/2 inches wide and cut it to fit. You can get the clamps at Home Depot in the elec. department. You will need four 1/4x20x3/4 inch bolts and lock nuts. Drill your four holes for bolts and make a slot for your tensioner wheel. When you install the bracket it will go between the ears on the clamps with the bolts through it. I have made three of these sofar and they work out good.
 

Attachments

matt167

New Member
May 20, 2009
420
0
0
usa
here is the tensioner I have on my bike... my stock tensioner went thru the spokes on a wheel, and the spring loaded tensioner twisted into a mess.... this is some simple steel stock, and a spring tensioner from TSC.. it's not spring loaded, it just slids on the track.. several washers space it out correctly due to the design of the tensioner.. soon, I will have to lengthen the track but for now, it's ok... drilled and bolted it in place with 6mm bolts.. nuts space it out from the chainstays due to clearence issues..

it was $10 for the tensioner, and like $8 for the steel + the time it took to drill the holes out for the slot, and dremel them out.. it's not pretty, but it works great
 

Attachments

wog383

New Member
Oct 11, 2009
18
0
0
Australia
Do you actually need a chain tensioner? I got a gt 1 cruiser grubee bike and all i did was made the chain to exact length and the back wheel mounting area is slotted so u can move it back or forth to get the desired tension..Seems ok last 2 months of riding..
 
Last edited:

darrick

New Member
Nov 14, 2009
49
0
0
South Texas
here is the tensioner I have on my bike... my stock tensioner went thru the spokes on a wheel, and the spring loaded tensioner twisted into a mess.... this is some simple steel stock, and a spring tensioner from TSC.. it's not spring loaded, it just slids on the track.. several washers space it out correctly due to the design of the tensioner.. soon, I will have to lengthen the track but for now, it's ok... drilled and bolted it in place with 6mm bolts.. nuts space it out from the chainstays due to clearence issues..

it was $10 for the tensioner, and like $8 for the steel + the time it took to drill the holes out for the slot, and dremel them out.. it's not pretty, but it works great
Yours too!? I thought I was the only one that horrible tensioner raped.. my rear wheel is missing spokes and the frame got eaten up by the chain. I need a better tensioner design that the stupid straight stock one. Even tried bending it to fit, and it helped slightly. But it still moves around too much because of the rubber gasket. :-||
 

Xiodinc

New Member
Oct 15, 2009
171
0
0
San Jose CA
When we built our first bike, on its first ride, the chain popped off and ripped the spokes out, After that we built a ring that bolts to the back side of the sprocket to keep the chain from getting caught in the spokes ever again.

We had to bend the tensioner bracket to get it to work well.
Please explain. This just happened to me, 5 spokes down.
 

rotted

New Member
Dec 10, 2009
36
0
0
new mexico
clutch squealing.... i took off my flywheel the part that the clutch pad makes contact with.... the flywheel looked like it was stamped out of a big sheet of metal.... the edges had flash on them which caused my clutch pads to get grooves worn into them also i filed the flashing off the edges of the flywheel reassembled my engine and after about a block of riding the squealing stopped and has not returned
 

rotted

New Member
Dec 10, 2009
36
0
0
new mexico
i like this except for the fact that holes need to be drilled into the frame. i wonder if u bolts would work to hold one of these on good