I ordered a 30t from sick bike parts and drilled it for the stock coupler using a stock sprocket as a tmplate for where the holes needed to be, I think I paid about $6-7 for the chrome sprocket.
7/8" tubing for exhaust?
- Thread starter SuedePflow
- Start date
Was the center bore the correct diameter? If so, do you have a link to the one that you bought? I'm all about saving some money and don't mind drilling a few holes.
The hole is plenty big, larger than stock sprocket, it is a sprocket designed for the 410/standard width bike chain, but it will still work great, I have one bike that has this thickness chain on it and I use the 415 chain, it has almost 1000 miles on it now with zero problems and no significant signs of wear.
here is a link to sprocket and a pic of the one I drilled recently, this will be what I plan to use on my next build which will have much stronger engine than is on my current bikes.
see what you think about it, it was a very easy mod, just center sprocket by using center whole in stock sprocket clamp very securely and drill, I use a numbered bit size (I) but I know that another standard size bit will work also, just cant remember off the top of my head which it is.
hope this helps.
Map
http://www.sickbikeparts.com/catalog/index.php?cPath=21&osCsid=00f100k3t6iq427bqqnav3aaf1
If it were me, I'd seriously consider bracing up the exhaust. That's a lot of weight hanging from the exhaust studs, and these HT's are made from recycled aluminum, so there's a risk of the threads pulling out of the jug. Remember, there's only 2 bolts holding that thing on, and even if you upgraded your studs with hardened Grade 5 fasteners or better and used loctite, it's still only hanging onto soft aluminum. Weld a tab onto the bottom of the muffler and attach it to the frame somewhere. Even if it's just held on with only nuts & bolts, ANY assistance to minimize the weight on the jug would be an improvement.
Check out THIS thread to give you an idea of the potential nightmares you could be facing if this issue isn't addressed.
http://motorbicycling.com/showthread.php?t=46555
Check out THIS thread to give you an idea of the potential nightmares you could be facing if this issue isn't addressed.
http://motorbicycling.com/showthread.php?t=46555
^+1 Just today I pulled an exhaust stud out just by over tightening the nut. The bike looks great though.
Has anyone ever tried using Timeserts to for added strength and support for the exhaust? I'd rather try something like that before a brace. I got some 6mm Timeserts in yesterday for a cylinder head project for my car, and I believe I'll have two left over.
Also, since the last time I was on here, I built a new fuel tank. Made it from scratch. It's aluminum and the capacity is roughly 1 quart. I didn't like how the original one sat so high and out of place. This one is laid down and sits about 6 inches lower. I also added a nice engine mounted chain tensioner. It was constantly jumping teeth without one.
Also, since the last time I was on here, I built a new fuel tank. Made it from scratch. It's aluminum and the capacity is roughly 1 quart. I didn't like how the original one sat so high and out of place. This one is laid down and sits about 6 inches lower. I also added a nice engine mounted chain tensioner. It was constantly jumping teeth without one.
It rides well. I'm a big dude, so I got to put alot of air in the tires every outting though. Top speed is 20-22 mph with this sprocket. And I've decided to not try to make it go faster. For a BMX bike with little 20" wheels, that's quick enough for me. 
That's my mock-up motor on the engine stand. It's a trashed block and head that I use for building headers only. And that header was built for a buddy to be used with a PTE6262 turbo on a '93 Eclipse GSX. I'm somewhat of a DSM junky. Been working on them for about 12 years now. That header turned out nicely though.A little off topic but what car are you working on and what's the turbo'ed engine in the background in one of those pics? (inquiring minds want to know)
PIC 1
PIC 2
PIC 3
I don't know a thing about what you're doing with those engines, but I just wanted to comment on the pix and say that is some nice looking work.
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