Wolfshoes
Member
Here is my 2 cents worth on the topic. There is probably a lot of room for disagreement about connecting a sprocket to the bike. First of all before you begin a major disassembly, decide what size sprocket you want to install. You will not want to change to another sprocket later. The motor will scream at about 24 mph with the stock 44 tooth sprocket. Buying a aftermarket 36 tooth will add about 4 mph with the engine topping out at 28 mph. Don Grubee, the industry leader at gasbike.net appears to be about ready to introduce a new batch of 66's that accommodate front pipes up to 2 inches and has other technical tweaks. This could add another 2 mph bringing the bike up to the sweet spot 30 mph. Since you have already purchased a bike with a S curve front tube, the wider connector may not help you. It was made to fit a straight pipe. This motor is being made to match his new frame already in stock. This motor probably will be out soon since it is already referenced on their website. I would really like a slightly stronger motor without having to go with performance mods and if it was my decision; I would wait for it.
Installing the sprocket is a fairly major operation. Be ready with some metric tools. I think the rear axle nuts are 15 mm. The arm will have to come off the coaster brake requiring 15 & 17 mm flat wrenches. Care must be taken not to loosen the bearings & brake assembly. I don't know if this can be done without the bearings becoming loose. If a bearing falls out of a retainer cage into the greasy hub tube containing the brake assembly; what was the term for that??? I think it's you are f--k-d. I managed to get a coaster brake back together, but they are more complicated than they look, and I'm still not sure how it works.
On my first build, I made the hub adapter out of a hardwood plank using hole saws and a drill press, using the wood you normally throw away as the adapter, cutting it in half and reassembling it using two hose clamps. This build had a unusual hub diameter and was hour glass shaped requiring a custom hub adapter.
The second build I took the lazy way out and bought the $50 hub adapter off ebay.
The hub adapter did not come with instructions and hardware. The big problem is, steel fasteners cannot rub the spokes. Since you are clamping down on a hollow tube, it likely will not stay tight and centered. Plan on it moving. Spokes on low cost bikes or even medium price bikes are made out common steel not stainless steel. Several may all brake at the same time wrecking your day trip if not a lot more. I cut up the donut rag rubber with a dremel cutoff wheel and a pair of metal shears and packed them between the bolts and the spokes. The bolts were replaced with flat head hex cap screws to prevent chain jam in the event of a derailment. The sprocket is shimmed out, sprocket bevel side out with modified bitumen smooth roofing roll material from Menards away from the spokes to the extent the sprocket would remain centered by the hub.
This roofing material makes a waxy polypropylene 1/8 inch with a rayon core shim. The spokes nestle into it allowing the sprocket to align off the outside flat of the hub. I did not use a rubber donut between the spokes and the sprocket. This is my own technique and use it at your own risk.
Therefore with the rubber between the spokes against the plastic polypropylene, shims, it really is a rubber mount not metal from the hub to the sprocket. If it's a rubber mount in order to keep the spokes from rubbing metal bolts, perhaps you could get away with the rag mount. From what I have seen, your would want to replace the bolts and the crappy nuts that would damage the screws. I have faced the sprocket with another plastic shim described, beveled to match the flat head hex screws in order to provide a flat surface a derailment would not hang up on, The plastic shims were also cut with a hole saw.
Chains on the motorbike seem to pick up grit to a greater extent than a regular bike so I have switched from using light fan oil to dry chain oil from Walmart.
All the best
Installing the sprocket is a fairly major operation. Be ready with some metric tools. I think the rear axle nuts are 15 mm. The arm will have to come off the coaster brake requiring 15 & 17 mm flat wrenches. Care must be taken not to loosen the bearings & brake assembly. I don't know if this can be done without the bearings becoming loose. If a bearing falls out of a retainer cage into the greasy hub tube containing the brake assembly; what was the term for that??? I think it's you are f--k-d. I managed to get a coaster brake back together, but they are more complicated than they look, and I'm still not sure how it works.
On my first build, I made the hub adapter out of a hardwood plank using hole saws and a drill press, using the wood you normally throw away as the adapter, cutting it in half and reassembling it using two hose clamps. This build had a unusual hub diameter and was hour glass shaped requiring a custom hub adapter.
The second build I took the lazy way out and bought the $50 hub adapter off ebay.
The hub adapter did not come with instructions and hardware. The big problem is, steel fasteners cannot rub the spokes. Since you are clamping down on a hollow tube, it likely will not stay tight and centered. Plan on it moving. Spokes on low cost bikes or even medium price bikes are made out common steel not stainless steel. Several may all brake at the same time wrecking your day trip if not a lot more. I cut up the donut rag rubber with a dremel cutoff wheel and a pair of metal shears and packed them between the bolts and the spokes. The bolts were replaced with flat head hex cap screws to prevent chain jam in the event of a derailment. The sprocket is shimmed out, sprocket bevel side out with modified bitumen smooth roofing roll material from Menards away from the spokes to the extent the sprocket would remain centered by the hub.
This roofing material makes a waxy polypropylene 1/8 inch with a rayon core shim. The spokes nestle into it allowing the sprocket to align off the outside flat of the hub. I did not use a rubber donut between the spokes and the sprocket. This is my own technique and use it at your own risk.
Therefore with the rubber between the spokes against the plastic polypropylene, shims, it really is a rubber mount not metal from the hub to the sprocket. If it's a rubber mount in order to keep the spokes from rubbing metal bolts, perhaps you could get away with the rag mount. From what I have seen, your would want to replace the bolts and the crappy nuts that would damage the screws. I have faced the sprocket with another plastic shim described, beveled to match the flat head hex screws in order to provide a flat surface a derailment would not hang up on, The plastic shims were also cut with a hole saw.
Chains on the motorbike seem to pick up grit to a greater extent than a regular bike so I have switched from using light fan oil to dry chain oil from Walmart.
All the best
