Show me Your Tuning!

Discuss light weight issues concerning road bikes & parts.
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Joined: Fri Feb 21, 2003 1:00 am

by wally318

So, these next few pics are an expose of the rear derailleur on the light bike
found here:"
First 2 pics are of the derailleur when finished @ 67.7 grams
Pic 3 and 4 show a sort of explosion of the parts involved.
The derailleur is a hybrid based on the Huret Jubillee derr.
I had to dig through a few boxes, but found the parts, most of them anyway.
There are some parts not there, they were sold or disappeared. A few parts
there are of aluminum relacemants made way back in the mid 80's which
made a 120 gram version on a 14.75 lb bike. The pulleys are from the 67 gram
version, now replaced.
First all parts were removed/unbolted.
Next rivet heads on the body were drilled out and body dismantled
and pins/pivots pressed out.
The 4 body forgings were machined for larger pins, over sized pivot bolt
w/13mm hex, and excess material removed where not needed/lightening. Also
shaped and polished.
New hollow pins/pivots made from 6-4 titanium with miniature screws 3mm x .5mm
thread used in place of rivets. These were very difficult to machine, in a non production
setting. Titanium heats up very quickly and will seize on a drill or tap. Sometimes
breaking. And then you start over. The only parts made using CNC are the the thin
brass precision washers spacing the 4 body pcs. when joined together w/pins and screws.
Titanium springs had to be made using bike spokes 1 for return spring
and the other for cage pivot. The most difficult was #2. As you can see from the #3
pic., the spring has 3 1/2 windings internally and another 2 1/2 externally as well as
the end pcs.
The lower half or pivot cage assembly is based on the Shimano 7800 derr.
The biggest improvement here is that the original design had 2 pulley bolts
with the upper one threading directly into the derr. body and locked with a nut.
The pulley cages actually pivoted on the shaft of this bolt.
The cages were reshaped/lightened and machined for an oversized aluminum
pivot bolt that has a large flange head which is recessed into the outer cage
and bonded into place with a titanium pin protecting the epoxy in shear.
So all steel was taken out of the derailleur except 1 part was actually added.
The oversized pivot bolt allows for the use of a thin low profile bearing inserted
in the lower housing that the cages pivot on. The pulleys are actually remachined
shimano upper pulleys with the ceramic bushing/bearings. They can be seen in pic
#4. Endcaps were made by machining a mould and pressed out of Coke cans, as
well as the shim spacer/washers.
As I was nearing the end of the hill climb project, I decided to black anodize everything.
So the derr. was dimantled, pins pressed out, pivot unbonded, and then anodized.
Then reassembly. The parts lost a bit of weight during stripping of clear anodize
and some fit problems.
So...How does it shift? Well for a 6 spd old school derailleur, non indexed actually quite
well. The new narrow chains and cassettes w/ shift indents help a lot. Major difference
is that the body parts aren't quite long enough and the body spring wether steel or ti,
isn't strong enough to push out to the smallest cogs on a 10 or 11 spd.
On an 11 spd set up it can get the 9 cogs on the inboard side if you give it an extra
couple links. Which for a hill climb bike works quite well.
The ceramic bushing pulleys were replaced because they were a pain. The oil would dry out too quickly requiring dimantle & oil. And the dust caps had too deep a shoulder on 1 or 2
and would rub/add friction. So I made new one of delrin. They look a bit like the Extralite,
because I just visually used them as a pattern for hole placement. I don't know the differences
in the guts, but I can tell you that mine have 2 small ceramic bearing each and 3 spacers.
The derailleur now weighs 64.6 grams.
There are probably 150 or more hours into this derailleur.
AEROLITUS-defender of the faith

by Weenie

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Joined: Fri Feb 21, 2003 1:00 am

by wally318

My last post had huge verbage content, so will use this separate post
to say: It's nice to see others joining in and showing their work.
AEROLITUS-defender of the faith

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by dereksmalls

wally318 wrote:
There are probably 150 or more hours into this derailleur.

:shock: :shock: :shock:

Absolutely outstanding!

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by weeracerweenie

:beerchug: :thumbup:

This people is how you do it :smartass:
I guess there's worse hobbies than making a bike light? Right?

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by BobSantini

Wow. That's jewellery, only better.
r o y g b i v

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by kavitator

Good job

And intresting topic

in the industry
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by bm0p700f

Well I will start of modestly I think with my front mech and a dremel. It is a FD-1056 braze on and weighs 99g. Th clamp is pretty bulky too. Also for th rear mech set srews are easy to find in aluminum but where can I find the M10 mount bolt. I currently have a RD-6600 rear mech that I want to loose weight from. Fibre lyte can supply the cage and pulley wheels and I might take the dremel to it.

Other area to loose weight from are the d/t shifters. I am struggling to find alloy mounting bolts of the right type. Any ideas A dremel can loose weight from the levers themselves preety easily. I might get a local enginerring firm to make some some alloy parts for these.

However where can I get a Ti 1" locknut for threaded steerr. The bike I am loosing weight on uses a threaded steerer and I am not changing it.

Ther is crtainly inspiration and Wally the rear mech you have done is certainly very impressive bit of engineering you have posted so far. If only more us had access to the machine tooling you have.

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by kgt

This tuned rd is a monument of patience and dedication! Again... respect.

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by wally318

The funny thing is that I'm not a machinist.
Had an interest in making things, so took machine shop in high school.
Ironically working on go-karts mostly. But I was a runner back then.
Gravitated to cycling later and would never think of building go-karts today.
Too noisy. Was an apprentice after high school for a short gig. Didn't work out
so did most of my working life assembling Western Star trucks, another irony.
Conflict between bikes/trucks, you get the idea. But when my interest in
lightweight bikes really took hold, I saw the need to get my own equipment
although much larger than what you see in the pics in my present shop.
Had to downscale that because of family economics.Eventually I saw the need to start up another shop. I had lots of ideas some that I sat on for more than 10 yrs, till I got around
to bringing them to fruition. There were so many things I wanted to do, that were so involved, I could see that I wasn't going to be able to pay to get it done. There was a long list of other projects, as well as time to develop the skills needed to acomplish some of the projects. When Freightliner bought Western Star and eventually took our jobs to Portland, OR. ironically it was the skills that I developed working in my home shop that helped me land/cope with the job I have today.
Basically working as a machinist, at a place where we make radios/communication equipment for helicopters. Machinery doesn't have to be huge or expensive. It certainly costs more
than a dremel. But there is so much machines/tooling coming from China/Taiwan
these days, that it is much less expensive than say 20 yrs. ago.
My machine cost only 1300.00 in 95. I've don many mods to it to be more versatile
and efficient, and have more mods on the way. Some of them only because I've got to the point of: Just because I can. So It doesn't cost tons of money. You can buy a 7x12"
mini lathe for 4-600.00 these days and a small mill for 5-700.00.
Tooling can add up. But if you're careful and don't let that side of the cycling/lightweight
bike building take over. A lot can be accomplished for a very little.
I once had a Stereo salesman in one of the most Expensive audio boutiques in
Vancouver,BC see my Colnago cycling jacket, so we started a conversation about
bikes. He a MTB'er and me a Roadie. I told him about some of the projects I was working on
and he swore that you had to use CNC to accomplish them. I was only planning on a
bike that weighed 10-11 lbs then, not the 7-8 lbs it ended up as. When he couldn't get me
to come to his way of thinking, he literally started swearing at me in the middle of the store,
in front of customers. He even threatened to kill me if he saw me out riding. The point is:
you don't need CNC to accomplish things. I think I've proved that. The old addage is true:
AEROLITUS-defender of the faith

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by artray

:thumbup: awesome

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by weeracerweenie

For me the school workshop is my workshop until I fully convince dad we need a lathe and mill in the man cave at home. :wink:

I've done "metal tech" which is the same as machine shop for 3 years now, and I'm heading into building next year which should keep me interested. Machining is nearly as fun as riding for me at the moment. I really enjoy it.

Sorry that I won't be posting for a while, I'm away racing a small tour and travelling, but I'll post some of my CAD drawings and concepts when I get home...
I guess there's worse hobbies than making a bike light? Right?

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by maxle

I'm not sure, if there are any MTB parts welcome in here. So i'm sorry, it's my second post.
First of all, my tuned Manitou MDR R7 fork. In former times 1358g. For my stealth sub 6,8kg MTB ( see my first post ;) )

Solo air damping, without Lockout ;) ( No Need for it, Rider weight 67kg )

Second fork: Cannondale Lefty Sl Opi Carbon from 1250g to
with Lockout, 29er Kit selfmade inside and all 88 Bearings
You only own a bike when you've violated every single term of guarantee.

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by lechat

Don't really think you need a lathe for parts tuning. Just look at the complex work some jewelry makers turn out freehand. I'm planning on getting some diamond grit bits and have a go at gemstone carving myself.

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by wally318

Actually, most serious jewlers/watch repair have lathes.
Jew. Lathe.jpg
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by Weenie

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by lechat

Wasn't really what i had in mind. Watches are much more precise than deraillers. Meant artistic jewelry design/fabrication. Some carve wax for casting, but others forgo the extra steps and carve metal blanks.

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