How tight should I tighten the sprocket bolts?

[SeattleMike]

I'm installing my 80cc on my mountain bike now. How tight should I tighten the sprocket bolts? I have a gut feeling that I should go tighter than it is said on these instructions:
Instruction Manual - Gas Powered Bicycle Engines, Motorized Fast Bicycles, Motor Gas Engine Bicycle, Bike Conversion Engine Kits, Motor Assisted Bike Engines 80cc and 49cc, Peddle Start Motorized Bicycle Engine and more!

What do you guys think?
~Thanks

 

[Ilikeabikea]

I used 1/4" drive ratchet and tightened about as tight as I could with one hand. I didn't get brutal or anything just good normal tight. I started out with them just snug and went round and round tightening them trying to keep sprocket straight. Hope this helps.......................

 

[SeattleMike]

I should have read the instructions that came with my kit instead of looking at those picture instructions from zippycycles.com ! The photo of the sprocket shows both rubber washers on the inside of the spokes, rather than one on the inside and one on the outside like my instructions say. I have a feeling my instructions are right, what did you guys do?

 

[paul]

yes one on inside and one on outside. here is a pictorial on installing the sprocket http://motorbicycling.com/f30/motorized-bicycle-44-36-tooth-sprocket-381.html the pictorial is about changing out site of you sprocket but great for initial installation also

 

[SeattleMike]

This forum is so great, you guys are really helpful and nice! Thanks

 

[bgoates]

The instructions I saw recommended a rubber washer on inside and outside only for bikes with coaster breaks. I'm not sure why that would make a difference.

 

[Norman]

Follow our instructions and you will be successful if you don't understand anything don't be afraid to ask. I use the fiber gasket on both sides to get a good grip on the spokes, keeps the sprocket off the spokes, provides space to aline the front and rear sprockets.
Norman

 

[Bikeguy Joe]

One on the inside, one on the outside, it's the only way it will work and keep working.

 

[Norman]

Listen to Joe.
Norman

 

[deacon]

I agree its the only way that makes sense. Metal and metal will never grip like that wrap around fiber.

I tightened mine till I felt like the nut stopped moving, not till the puller handle bent. But you should check it now and then, as it will probably get loose after a while. Everything gets loose after a while

 

[Dave31]

I used a inch pound torque wrench to be sure I got them all the same tightness, and loctite. For the life of me I cant remember what I tighten them too Do not use a ft. pound torque wrench or you will tighten them too tight.

 

[Bikeguy Joe]

I said to use the wrong torque setting here.....I change the post.

 

[cruiser66]

Did you mean 12 inch pounds??

 

[Bikeguy Joe]

I don't know what I mean...I've ever only used a foot pound wrench.

I have developed a "feel" for bolts and only use a torque wrench when doing something like the heads on autos.

If you are tightening the sprocket bolts, make them "reasonably tight" don't go apesh*t, but make sure they aren't going to come loose.

 

[HoughMade]

I tightened mine to about 12 ft/lbs (not inch pounds)- but that is working up slowly and with the 9 original bolts replaced with quality bolts. I take a Sharpie and number the bolt holes 1 through 9. then I tighten number 1 down a bit, then 6, then 2, then 7, then 3, then 8, then 4, then 9, then 5, then 1.... Sharpie comes off with laquer thinner. When I get close, say 9 or 10 ft/lbs, I put a straight edge across the sprocket at several places to make sure the sprocket is equidistant from the rim. I then adjust if necessary by tightening where necessary to equal it out.

Oh yeah, one rubber disk outside, one on inside, but my kit came with 2 metal split rings, one made of three pieces with 3 holes in each and one of two pieces, one 4 holes and one 5. I put both of those on the inside, overlaping the joints.

When I took the sprocket off of the old wheel to put it on the new one, the pattern impressed on the rubber showed that the bolts were neatly between the spokes and not resting against them- that is what you want. If you do not tighten them enough to have that happen and have the sprocket stay put, trouble will follow, especially if you are using standard 14 ga spokes.... imho, at least

 

[Bikeguy Joe]

12 ft.lbs is a little loose. I cranked mine down until they were "reasonably snug"

 

[nogoodnic]

I use almost exactly the same method as HoughMade, although I have never used a torque wrench. I tighten mine down pretty tight with usually 3-4 threads sticking out past the nut. The biggest thing is to keep metal off ot the spokes, I learned this the hard way with seven spokes worn through...Kelly

 

[HoughMade]

I tried to go to 14 ft/lbs and I broke 3 bolts- not the original soft ones- good quality stainless- I'll stick with 12.

 

[Bikeguy Joe]

Yeah, but in my experience, stainless snap like pretzels, so do grade 8.

 

[sisdavid]

My technique on torquing bolts on the rear sprocket is to count threads. How many threads are sticking out of the bolt after tightening. Tighten in a criss cross, like a car tire. tighten untill I have two threads showing out the top. Then criss cross tighten till three, and finally untill I have 5 showing out the top and make sure that all of my lock washers have colapsed, finger nail polish on the top of new bolts and threads seems like a good idea to me that red lock tight is kind of powerfull and the blue is kind of wimpy. I like finger nail polish. Hope that does not make me gay right?