Firmstrong Chief Build by Scottyo

So here's a summary of my build so far on my firmstrong chief. It has a 4 stroke Honda, with a skyhawk gearbox. The mounting bracket is a hybrid between the stock bracket and some welded on pieces. The chief has crank forward pedaling so the frame is not at all v shaped like most bikes. I added a spring loaded chain tensioner that some others here have used. I absolutely love it! I think it should be a part included in the stock kits.

1- side view not current but close
2- throttle hook up using governor pieces
3- fabricated mounting bracket
4- new spring loaded chain tensioner

 

[azbill]

nice looking build !!!
I have seen that frame and it is pretty big
gonna be a cool MB

 

[Will Snow]

Looks like a neat clean bike. How do you like the 4cycle? How is the gear drive noise level ? Some say very loud and other say quiet. I have a 4cycle that has the enclosed chain that is ok, but the gear box has a nice look to it.

Looks like a bike that you will enjoy. Good luck with it.

 

[scottyo]

I love the Honda 4 cycle!! After I greased the gears and reversed the clutch engager to "always on" it quieted down soooo much. It is an absolute blast to ride. I am still having some issues with the drive chain staying on. I'm thinking about switching back to the 415 chain instead of the regular bike chain. The narrower bike chain has no forgiveness if the sprocket or tensioners aren't perfectly aligned. I shouldve guessed that. Now I will have to spread the frame to accomodate the wider 415 chain.

Does anyone have any recommendations about doing this? I know some websites sell frame spreading tools but should I heat the frame first to avoid cracks? I think my frame is steel.

 

[chefdouglas]

Nice build! can you give some info on the chain tensioner. I've been planning on building one but haven't gotten around to it and I like your design. Where did you get the parts or did you fabricate it yourself? I've been looking for a roller like yours and can't find any.Thanks
PS spreading the frame if not done right will make it dangerously week. Heating is the only way to do it with out making microscopic cracks. My advice is don't do it if you can avoid it. Maybe have a pro cut and weld it to the shape you want.

 

[ocscully]

I'm afraid I have to disagree with Douglas bicycle frames are aligned cold all of the time in bike shops and frame builder shops every day. The bike in question is made from mild steel and should be no problem to cold set. I'm not sure just how much extra clearance you need and just where along the stay you need the clearance but what ever bending you do you want to do the same to both sides and then be sure to bring the rear dropouts back parallel with the center plane of the bike. Clamps like the one below could be used to spread the frame, or a medium sized turn buckle could be used to spread the frame as well.

ocscully

 

[ocscully]

I'm afraid I have to disagree with Douglas bicycle frames are aligned cold all of the time in bike shops and frame builder shops every day. The bike in question is made from mild steel and should be no problem to cold set. I'm not sure just how much extra clearance you need and just where along the stay you need the clearance but what ever bending you do, you want to do the same to both sides and then be sure to bring the rear dropouts back parallel with the center plane of the bike. Clamps like the one below could be used to spread the frame, or a medium sized turn buckle could be used to spread the frame as well.

ocscully

 

[scottyo]

chefdouglas-
I got the spring loaded tensioner from tractor supply company (a national chain store). You might try there website but if my memory serves me I think these items (the spring and the roller) were only available in store. They were like 13 bux total.

http://www.tractorsupply.com/vehicl...-motorsports-chain-tensioner-assembly-5510238

Take the product number with you and theyll locate in the store for you, bc I think its in an unlikely section.

I fab'd the mounts out of scraps of metal and spare nuts and bolts. AND I did slightly modify the spring by twisting around one end of it to fit on the mounting bolt.

I think Im gonna contact my local bike shop to inquire about my chain clearance issue, bc I dont wanna buy tools like this http://www.bicycle-engines.com/bike-frame-spreader-tool-p-117.html that Im only gonna use once.

 

[azbill]

some good frame spreading info here...
(I was thinking of making my single speed stretch a multi-speed)
http://www.sheldonbrown.com/frame-spacing.html

 

[scottyo]

Wow I didnt know you could actually bend a single speed frame enough to actually accommodate a cassette! Are you adding a cassette or an internal gear system in the hub?