Motor Assisted Bicycle Science

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New Member
May 27, 2008
724
1
0
Decatur,IL
Re: MAB Science

sweet! I dig your frame jig, is that something you came up with? how much cost do you have in it? I have my own style of a frame jig , but its all mounted on a workbench and sometimes makes it tough to do a weld.
 

mabman

New Member
Oct 4, 2008
258
0
0
In the wind
Re: MAB Science

The frame jig is in the shop of a friend of mine who builds about 200 bike frames a year in Ti, Steel, Aluminum and some Carbon Fiber even.

All the frame builders I know use different jigs....and I know at least 4. He was saying just this a.m. that it would cost about $1500 to replicate though. For sure it makes it all look fairly easy and the bottom line is that the frame comes out very well aligned. I have seen some pretty crude jigs produce some really quality frames as in the end machining is all about patience and precision.

The last hour was taken up with this detail:

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Walter F.

New Member
Jun 4, 2008
326
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Connecticut
Re: MAB Science

Very nice work, and you got it right, take your time and get it right the first time.
You must be a "young buck", an old fart like me would have tripped up in that bundle of snakes on your shop floor the first day. Be careful little buddy! Happy Trails Walter F.
 

mabman

New Member
Oct 4, 2008
258
0
0
In the wind
Re: MAB Science

Yeah, my buddy here does not run a very clean shop environment unfortunately. I am too busy with this project and don't have enough time allotted to make it right but we are talking about a future joint venture and if that happens there will be organization involved! Thanks for your concern and I'll be careful!

Here is a picture of the other one we are working on at the same time.
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mabman

New Member
Oct 4, 2008
258
0
0
In the wind
MAB Science continued

Well this is as far as we got with this session.
DSC00785.JPG

DSC00799.JPG
Unfortunately we had some vendor issues that slowed things down last week. The drivetrain parts I had ordered to be delivered were sent to my home address instead, and even in one case to a home that I haven't lived at for two years. Vendors need to get their crap together and pay attention! I filled out the online forms properly but somehow they both chose to follow their own directions. Oh well, the weather was nice and we compensated by working on his other projects and getting some really nice bike rides in.

I am pretty pleased with how the frames turned out. The hardtail was a much easier build than the suspended one for sure and in retrospect we probably should have kept it simple and done both that way. But for some reason we kept forging ahead and at least it is done to this point. I really enjoyed the process of helping designing and selecting the tubing and working them up to be welded by Q. His welding skills are really top notch. Sure helps having a fully equipped shop also, including a CNC mill, and we used about every machine in there to do this!

A big bonus is there is a young guy across the street that is a tuner. He specializes in 4 stroke motors and suspension for MX type bikes. He has a nice shop also and is an accomplished machinist too. He did most of the small parts on the lathe for the suspension setup on the one frame. Thanks Craig! Also he happens to have a dyno at his shop which we will end up using after we get the bikes running to see what can be done to heat up the motors, we are targeting using the Robin 4 strokes and we want to run ethanol homebrew in the near future and will need to raise the compression considerably so and his assistance there will be invaluable.

I have to go back home for now but hope to get back to this in December between real world work assignments.
 

sojudave

New Member
Oct 18, 2008
189
2
0
austin tx
Re: MAB Science continued

Well this is as far as we got with this session.
View attachment 2955

View attachment 2956
Unfortunately we had some vendor issues that slowed things down last week. The drivetrain parts I had ordered to be delivered were sent to my home address instead, and even in one case to a home that I haven't lived at for two years. Vendors need to get their crap together and pay attention! I filled out the online forms properly but somehow they both chose to follow their own directions. Oh well, the weather was nice and we compensated by working on his other projects and getting some really nice bike rides in.

I am pretty pleased with how the frames turned out. The hardtail was a much easier build than the suspended one for sure and in retrospect we probably should have kept it simple and done both that way. But for some reason we kept forging ahead and at least it is done to this point. I really enjoyed the process of helping designing and selecting the tubing and working them up to be welded by Q. His welding skills are really top notch. Sure helps having a fully equipped shop also, including a CNC mill, and we used about every machine in there to do this!

A big bonus is there is a young guy across the street that is a tuner. He specializes in 4 stroke motors and suspension for MX type bikes. He has a nice shop also and is an accomplished machinist too. He did most of the small parts on the lathe for the suspension setup on the one frame. Thanks Craig! Also he happens to have a dyno at his shop which we will end up using after we get the bikes running to see what can be done to heat up the motors, we are targeting using the Robin 4 strokes and we want to run ethanol homebrew in the near future and will need to raise the compression considerably so and his assistance there will be invaluable.

I have to go back home for now but hope to get back to this in December between real world work assignments.
What kind of tubing are you using for your project, and where did you find it. I'm starting to think of my next project, and it invovles cutting a Limosine frame.
 

mabman

New Member
Oct 4, 2008
258
0
0
In the wind
Re: MAB Science continued

I found the tubing in my buddies stock room. Most of the tubing was back stock that he had hanging around in there. It is all 4130 cro-mo. He told me he would kill me if I told anyone who his supplier was too btw. The best advice I can give you is to contact your nearest framebuilder because he might have what you need hanging around and if not then he will maybe be able to help you get it.