Here's yet another question for the expierinced MBers

Carl Walichnowski

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Below are some photos of a Mongoose Mac frame & it's chain clearance issues. I believe I'll need a top hat adapter to make this bike work but I'd love to avoid it. Does anyone have any suggestions I can try and if not at least tell me a link where these adapters can be found for a good price?
 

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Carl Walichnowski

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Oh I forgot to mention, I seen a kit installed on this exact frame without that adapter so I'm sure it could be done it's just beyond my experience level to make it work.
 

Frankenstein

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All I can interpret is that the left side chain is too close to the chainstay, are you using a sprocket with the "dish" or the toothed edge that's offset from the rest of the sprocket? I used one on the Nel lusso and had to install it with the sprocket "dished" inward, with the chain closer to the wheel than not for proper alignment and to clear a chainstay.
 

gary55

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Oh I forgot to mention, I seen a kit installed on this exact frame without that adapter so I'm sure it could be done it's just beyond my experience level to make it work.
You could try gaining enough room with washers between the chain stay and the hub. Scratch that. On second look the top hat seems to be the answer. Then you could have a rear disc brake too. It's a win win.
 

Frankenstein

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Even personally if I felt that I could get away with it to remove a bit of the hub right at the bolt on point.... As long as I thought I could get enough anchorage with the bolts.

Gary has a good point though, you could maximize the potential for the bike by having both front and rear disk brakes with a direct drive, would probably be a nice riding experience knowing stopping is going to be reliable.
 

KenM

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I had the same trouble , I just put some washers in to widen the chain stays .
Has worked good for over a year and a half now. Hope this helps! Ken.
Keep looking up!
 

Carl Walichnowski

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You could try gaining enough room with washers between the chain stay and the hub. Scratch that. On second look the top hat seems to be the answer. Then you could have a rear disc brake too. It's a win win.
Ok so my plan is to use the washers until I buy a top hat. Back disc brakes aren't hugely important cause I just installed the caliper brakes on the back and I have disc brakes on the front. Now if you notice where my nut is at the hub there's barely any threads left, will the washers still fit on there you think? I know the washers would go between the hub and chain stay therefore widening the chainstay and allowing my chain to clear but if I put the washers on would that also push out that bolt? It's securely on there now but if you look close there's only around 2-3 threads left to play with???
 
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gary55

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Ok so my plan is to use the washers until I buy a top hat. Back disc brakes aren't hugely important cause I just installed the caliper brakes on the back and I have disc brakes on the front. Now if you notice where my nut is at the hub there's barely any threads left, will the washers still fit on there you think?
Like I said I don't think the washer fix will work for you. Not so much due to the shortage of threads though that is a serious issue, but because of the type of drop outs you have won't allow you to align the rear hub to a location that will allow proper chain alignment of the rear sprocket to the engine sprocket.
If you look down the face of the rear sprocket I believe it will be lining up at or near outside of the engine. Since your axle has to be in a set place the only simple way you can correct this is to move the rear sprocket inward via a top hat. That is what I'm getting from your pics. The sprocket has to set inboard of the face of the rotor mount.
 

Carl Walichnowski

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Like I said I don't think the washer fix will work for you. Not so much due to the shortage of threads though that is a serious issue, but because of the type of drop outs you have won't allow you to align the rear hub to a location that will allow proper chain alignment of the rear sprocket to the engine sprocket.
If you look down the face of the rear sprocket I believe it will be lining up at or near outside of the engine. Since your axle has to be in a set place the only simple way you can correct this is to move the rear sprocket inward via a top hat. That is what I'm getting from your pics. The sprocket has to set inboard of the face of the rotor mount.
Ok I hope to get back riding soon and then switch out for the top hat when it arrives. Problem is I can't find a retailer that has them. Maybe I'm using the wrong search terms. Do you have a link or a store that sells them?
 

gary55

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Ok I hope to get back riding soon and then switch out for the top hat when it arrives. Problem is I can't find a retailer that has them. Maybe I'm using the wrong search terms. Do you have a link or a store that sells them?
I honestly don't think you will be able to get the chain to align well enough to stay on. If it comes off to the inside (which it will) It could really screw up that nice looking mag. wheel.
Custom motored bikes has adapters, and I'm sure a bunch of others do as well. Bicycle designer.com has them. The only ones I have used are ones I made myself so I can't say who is best. You should be patient on this. Their is a guy on here goes by fury on the inside. If you can catch him hit him up on this. Chances are he has already looked at the available options, and he knows a shitload about bikes.
 
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