# DIY Stem?



## thefragger (Apr 9, 2011)

I've been floating this idea for a bit, as a solution for a low stack height stem.

I've got loads of T6-6061 billet material. Anyone ever tried?


----------



## Blaster1200 (Feb 20, 2004)

Yes. I think some guy named Thomson tried. I think it eventually worked out ok.

I think I've seen other billet stems that seem to work out ok.


----------



## Clockwork Bikes (Jun 17, 2006)

Very cool: http://www.flickr.com/photos/bishopbikes/sets/72157625931201851/


----------



## Mr.Magura (Aug 11, 2010)

thefragger said:


> I've been floating this idea for a bit, as a solution for a low stack height stem.
> 
> I've got loads of T6-6061 billet material. Anyone ever tried?


If you wanna have something that is better than the average 50$ billet stems, the next step is to make it from 7075T6, which though requires more attention to details like fillets and edges.

Magura


----------



## febikes (Jan 28, 2011)

Mr.Magura said:


> If you wanna have something that is better than the average 50$ billet stems, the next step is to make it from 7075T6, which though requires more attention to details like fillets and edges.
> 
> Magura


7075T6 is easier to machine vs. 6061. The material costs are much higher but the material is actually easier to work with because it cuts cleaner.


----------



## febikes (Jan 28, 2011)

I machined some complete frames our of 7075 material.


----------



## thefragger (Apr 9, 2011)

Really? All I use is 6061! I'll see what the local metal supermarket has in terms of 7075. Thanks for the tip.


----------



## Mr.Magura (Aug 11, 2010)

febikes said:


> 7075T6 is easier to machine vs. 6061. The material costs are much higher but the material is actually easier to work with because it cuts cleaner.


What I meant was that 7075T6 requires fillets everywhere, or it will brake due to the kerf.

But yes, it's sure easier to machine, partly cause it cuts cleaner, partly cause it is harder, so clamping even small pieces is no problem.

Magura


----------



## febikes (Jan 28, 2011)

Good point about 7075, it does tend to crack rather then bend when stressed, really you should have fillets and rounded corners even with 6061 because anything that creates a stress riser can be an issue in something like a stem. 

I think 7075 is good for something like a stem but really I am no expert about material. The thing is that when making a stem you really need to focus on safety. For custom stems by small builders 4130 might be a safer material because it will hopefully bend and give the user a bit of safety factor vs. and abrupt failure. The concern is that when making one or two of a design you don't often have the time and/or resources to fully test all aspects. Working with steel you have a material that has a very predictable nature. 

You may want to consider using scandium for a stem.

What I really would like to do someday is TIG welded scandium integrated bar/stem. I have not seen others doing that but really I think it would look nice plus be light weight and strong at the same time.


----------



## Mountain Cycle Shawn (Jan 19, 2004)

febikes said:


> Good point about 7075, it does tend to crack rather then bend when stressed, really you should have fillets and rounded corners even with 6061 because anything that creates a stress riser can be an issue in something like a stem.
> 
> I think 7075 is good for something like a stem but really I am no expert about material. The thing is that when making a stem you really need to focus on safety. For custom stems by small builders 4130 might be a safer material because it will hopefully bend and give the user a bit of safety factor vs. and abrupt failure. The concern is that when making one or two of a design you don't often have the time and/or resources to fully test all aspects. Working with steel you have a material that has a very predictable nature.
> 
> ...


I think bar/stem combos are cool.


----------



## Mr.Magura (Aug 11, 2010)

Mountain Cycle Shawn said:


> I think bar/stem combos are cool.


This one is a lot easier to simply make of carbon like they already have done. 
That would also allow for some protective measurements like Kevlar inlays and the like.

Magura


----------



## Mountain Cycle Shawn (Jan 19, 2004)

I would love to see one in Ti, Al or steel with a bar that had a 1" rise.


----------



## Rody (Sep 10, 2005)

Mountain Cycle Shawn said:


> I would love to see one in Ti, Al or steel with a bar that had a 1" rise.


here ya go...


----------



## Adam_M (Aug 8, 2008)

Rody, your paint work really is awesome, great work dude.


----------



## Mountain Cycle Shawn (Jan 19, 2004)

That is nice! Was that at thre HMBS?


----------



## Thylacine (Feb 29, 2004)

Clockwork Bikes said:


> Very cool: http://www.flickr.com/photos/bishopbikes/sets/72157625931201851/


Yeah, those Critical Racing stems were so successful.


----------



## Linnaeus (May 17, 2009)

Clockwork Bikes said:


> Very cool: http://www.flickr.com/photos/bishopbikes/sets/72157625931201851/


Holy cow! That must have been a _long_ time to spend at the manual mill (and a small one at that). Finished results are nice but would hate to know the $/hr on that one.


----------



## Mr.Magura (Aug 11, 2010)

Linnaeus said:


> Holy cow! That must have been a _long_ time to spend at the manual mill (and a small one at that). Finished results are nice but would hate to know the $/hr on that one.


The $/hr on anything DIY is below the minimum wage anywhere but China, that's just the way it is.
I have at this point made a lot of bike parts for myself, and the $/hr on that is ridiculous on the easy projects, and downright scary on the hard projects 

Magura


----------

