Anyone ever tried machining their own titanium parts?

[ljamesb]

I could try an alu bolt, but again it seems to be pretty difficult to find them. It's such a specialist item. I'll keep an eye out for syncros stems though.

I found these aluminium gear shift rods, which would work and are lighter than titanium. Not sure though about using m6 aluminium for the stem bolt. I've had alloy bolts snap on me before.

Threaded ti bar stock could work, but is very expensive (£40 for some threaded m6).

I've ordered an m6 stainless bolt for now to use with the lighter wedge I've got. I think I'll also order a 300mmx6mm titanium rod and try threading it myself. If this fails I'll probably try and make a set of 3 titanium allen keys out of the rod .

 

[FluffyChicken]

Re:

I think the Z-Bolt of the MPR system as Syncros called it (it was zircal alloy and ceramic coated to give a golden colour)
It was M8 1mm pitch.

The wedge was followed out too
18g for bolt and 9g for a 1" wedge, fraction more for the other two sizes of wedge.

No idea of length, no idea what stem you are tying to use, no idea if you could use the 8mm or just machine you other wedge out or Chop the unneeded parts of the stem extension of (to save weight and use a shorter bolt)

 

[ljamesb]

Re: Re:

I think the Z-Bolt of the MPR system as Syncros called it (it was zircal alloy and ceramic coated to give a golden colour)
It was M8 1mm pitch.

The wedge was followed out too
18g for bolt and 9g for a 1" wedge, fraction more for the other two sizes of wedge.

No idea of length, no idea what stem you are tying to use, no idea if you could use the 8mm or just machine you other wedge out or Chop the unneeded parts of the stem extension of (to save weight and use a shorter bolt)

I need quite a long stem bolt of 150mm (was 190mm before I modified the stem). I expect this is quite longer than the syncros. The stem is just a random 'etc' one chosen because it's very tall (need height as it's for a touring bike build), but still relatively lightweight, and has a 2 bolt handlebar clamp thing (needed because may use butterfly bars). It's gonna be 265-286g for the stem which I reckon is not too bad.

That's very light for the wedge! The one I have is an alloy one from a Marin Lite stem (1994), takes m6 bolt and weighs 14g.

 

[FMJ]

Titanium stuff is so expensive because it is so hard to work with

Ti is relatively easy to work with if you're using the right tooling. The cost increase is marginal when amortized out. Ti is expensive due to the refining costs (especially when you start adding elements like palladium and ruthenium to the alloying process). The process consumes large amounts of energy. Far more than steel or aluminum.

Was sure I had a Tioga Ti stem bolt or three in the bolt storage rack in the garage. Unfortunately they're too short for the OP's application.

 

[one-eyed_jim]

Re: Re:

I need quite a long stem bolt of 150mm (was 190mm before I modified the stem). I expect this is quite longer than the syncros.

Bikepro to the rescue: the Z-bolt is only 133mm long:

http://www.bikepro.com/products/stems/stem_hard.html

I know it's not about practicality, but is it really worth all the effort to save a few grams on a touring bike?

 

[FMJ]

Re: Re:

I know it's not about practicality, but is it really worth all the effort to save a few grams on a touring bike?

QFT

 

[royboy2cv]

Re:

One thing to remember when machining Ti , is the cutting oil a very good one that with stand cutting pressures of Ti and not brake down so the Ti will not stick to the tap or die .

 

[ljamesb]

Re: Re:

I know it's not about practicality, but is it really worth all the effort to save a few grams on a touring bike?

For me, it's DEFINITELY worth it. Even more so for touring, where you might be cycling for 8 hours or more some days. I cycle to have fun and I know from experience that cycling up a mountain when it's 40 degrees outside is far more enjoyable when you are carrying less stuff. You enjoy the ride more, take in more of the scenery etc. Also means you can more easily justify taking luxuries with you which makes it even more pleasant. I also enjoy the challenge in making some of my own equipment or modifying stuff to make it better or lighter. I also really appreciate the difference weight can make to the handling of my bike.

Ride your own ride though. We all have our own ways of doing things.

So far I've saved 2.3kg from my Pine Mountain and it's cost £138(the bike's now 9.4kg). The difference it makes to the ride is just immense. Especially when I switched out the tyres and tubes which I think made the biggest difference (570g saved per wheel )

I've also saved 4.7kg from my touring kit (panniers, different clothes, tent, rack etc) recently and again this hasn't cost all that much.

So that's 7kg saved total to my fully loaded touring weight. Totally worth it in my opinion .

 

[ljamesb]

Re: Re:

Bikepro to the rescue: the Z-bolt is only 133mm long:

http://www.bikepro.com/products/stems/stem_hard.html

So close! Some really nice stuff in their catalog. Only $15 for an M8 143mm Ti bolt and $9 for an M6 one . That's not bad! Such a shame it's not a bit longer.

 

[FluffyChicken]

Re: Re:

Bikepro to the rescue: the Z-bolt is only 133mm long:

http://www.bikepro.com/products/stems/stem_hard.html

So close! Some really nice stuff in their catalog. Only $15 for an M8 143mm Ti bolt and $9 for an M6 one . That's not bad! Such a shame it's not a bit longer.

Such a shame it's ~20 years out of date, perfect for us retrobikers but a bugger to buy from without a dalorianMTB