Threaded to threadless

[MikeD]

"The Stem" made from magnesium - sub 100 grams and quite an elegant design





I don't understand why magnesium isn't used more in the bike industry, the technology has moved on (the alloy blends and anti-corrosion coatings)

American Classic's super light wheels are no longer available, the disk brake standard would make them the perfect material for rims.

Magnesium is inferior to aluminum for bicycles. It's lighter, but has less strength, less stiffness, and poor fatigue life. I would use an aluminum stem. I think a Kalloy Uno aluminum stem is just almost as light, and Wren is lighter. Both are pretty inexpensive.

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"The Stem" made from magnesium - sub 100 grams and quite an elegant design





I don't understand why magnesium isn't used more in the bike industry, the technology has moved on (the alloy blends and anti-corrosion coatings)

American Classic's super light wheels are no longer available, the disk brake standard would make them the perfect material for rims.

Magnesium is inferior to aluminum for bicycles. It's lighter, but has less strength, less stiffness, and poor fatigue life. I would use an aluminum stem. I think a Kalloy Uno aluminum stem is just almost as light, and Wren is lighter. Both are pretty inexpensive.

I don't think it's accurate to generalise like that, different magnesium alloys have different properties

https://matmatch.com/learn/material/magnesium-alloys

https://alliteinc.com/super-magnesium/

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This BMC stem isn't too bulky and the design is very simple like the old Cinelli quill stems, some design work to 3D print some finishing bits where the spacers should be and the cable holes in the sides would be a good idea.

https://bmc-switzerland.pl/innowacje/ic ... it-system/

It's a bit heavy though at 190 g for 100mm

[schlafen]

@joejack951

Great stuff, please keep going with the weight reductions. How about using "drillium" on some parts?

I discovered your product during my research for a future "restomod" Peugeot, Reynolds 753 project. The bike currently weighs 9.7 Kg and with the parts I chose, I can get it down to below 6.7Kg without spending too much (in my mind, less than €2000 isn't bad for a sub 7 Kg bike)

The Cinelli Grammo or a brand new Ibis titanium stem with a light alloy headset, is the target to beat. http://www.bikepro.com/products/stems/ibis.shtml or a total 290-300 grams for the system.

The recent weightloss has made your product the optimum solution, with the new minimum weight of 185 grams, you still have the lowest system weight with stems up to 110-115 grams. Any more grams you can remove will maintain this position as "the lightest" but with a larger choice of stems, unfortunately the better looking or older aheadset stems weigh around 130 grams and above.


This is the cheap 100 gram stem I mentioned in my previous posts: https://www.rosebikes.com/rose-osc-stem ... hape=black
I bought a 100mm one for a previous build and fitted titanium bolts to get the weight down to 90 grams. Have you thought about selling the same stem with Innicycle branding?

I've had my local frame builder replace the steerer tube with a non-threaded one. Very common and safe operation. Inexpensive as well, I paid £60.

Then I used a 1" threadless headset and a shim.

This works if it's not a unicrown fork. If it is, talk to your frame builder first.

Sent from my SM-T813 using Tapatalk

My forks are chromed and constructed around a Fork lug with nice Peugeot lions engraved into each side.
What is the process?
Do they just heat up the crown brazing with a blowtorch and pull out the steerer tube?
Would rechroming be necessary in your opinion?

As far as I'm aware the higher end 531 Peugeots were silver brazed, not brass brazed, which means that a lower temp is required to work with. However, not sure on the 753 frames.
I would suggest you contact a frame maker. It may need rechroming, it may not.

On the ones I've had done they needed new paint anyway so wasn't bothered.

The alternative is to find a fork with a long enough steerer and chop the threaded part off.

I'm currently restoring a Puymorens, will use a quill stem with a full custom modern groupset.

Just my personal opinion but Peugeots don't wear threadless stems graciously. It will look off as they have generally very thin tubing and the 31.8 stuff will make it front heavy and bulky. But then again I like the compliant ride of a classic front end, something carbon will never touch.

Threadless plays well with 1 1/8" steerers/headtubes because they are thicker.

Sent from my SM-G981B using Tapatalk

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My 1987 Peugeot Perthus currently has the original Shimano 600ex headset and a Cinelli XA stem (110 mm).
The headset weighs 140 grams and the stem weighs 293 grams making a total system weight of 433 grams

To lose the maximum amount of weight keeping the threaded headset and quill stem, I would have to find a Cinelli Grammo stem or similar titanium equivalent which weigh from 180 - 220 grams



The lightest 1" threaded headset is the Stronglight A-9 which weighs 80 grams



So that modification makes a total weight of 260 - 300 grams and a weight saving of 173 - 133 grams - which is quite substantial.


If I was to keep the Stronglight threaded headset and managed to get hold of a super rare Cinelli quill adapter which weighs 76 grams according to the listings here,
The total system weight would be 156 grams + the weight of the stem I would choose: The Darimo IX2 (70 grams) to the BMC ICS 01 Aero stem (200 grams) so 226 - 356 grams

So the total weight saving would be 207 - 77 grams - from very impressive to worthwhile.


If I couldn't find a Cinelli quill adapter, a Deda adapter would have to do at 142 grams, it adds 66 grams to the system.

So the total weight saving would be 141 - 11 grams - Still very impressive to barely worth it.

If I just wanted the bike to looks good with that BMC stem it would be fine, but the goal of this project is maximum weight reduction, without losing the vintage appeal.


If I was to install the Innicycle headset adapter, The slammed and chopped 185 gram weight + 70 - 200 gram stems gives a total weight of 255 - 385 grams.

So the total weight saving would be 178 - 48 grams - from very impressive to worthwhile.

This puts everything into perspective, the difference in weight reduction potential between the solutions is around 66 grams.

The Innicycle solution is much better than a normal quill adapter but requires a sub 100 gram stem to be competitive with the titanium quill stem. The lightest of all but also the most challenging is the Cinelli adapter solution, I can't find any for sale anywhere in the world. If the Innicycle was 30 grams lighter, it would be the lightest solution of all.



EDIT: An additional comparison after finding the small quill adapter in the following post.

The Mini quill adaptor + titanium bolt, I estimate at 90 grams, + 80 g (headset) + 70-200 g (stems) = System weight of 240 - 370 grams

So the total weight saving would be 193 - 63 grams - very impressive to worthwhile

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It's amazing that the Cinelli quill adapter is half the weight of modern equivalents.



It might be due to the fact that it is for 1" ahead stems and not 1 1/8" stems in which case a shim will be needed (so an extra 5-10 grams?)

Otherwise it's size is smaller than current adapters.

I found this one below which is much shorter in length and weighs 111 grams - still that's way more than the Cinelli, how can this be? Lighter alloy, thinner walls?


https://www.aliexpress.com/item/4000019 ... 6062%23177

Add a titanium stem bolt and a new wedge (if it's lighter) and it'll be close to 90 grams



https://bikerumor.com/2017/06/19/ti-cyc ... draw-bolt/

https://www.ticycles.com/store-all/stem ... tem%20bolt


I noticed that Ti Cycles have a titanium quill stem on their website but their price is competitive with a Darimo stem + Inncycle and their design doesn't look that light.
https://www.ticycles.com/store-all/cust ... nium-quill

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This is one of the prettiest ahead stems available today, no idea about the weight.

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The 3TTT Forge Ahead stem is a very elegant design, shame it weighs over 200 grams

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Interesting thread in a fixie forum about good looking ahead stems

https://www.lfgss.com/conversations/354751/

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Shame these Gios stems are so rare





There's one close to my size for sale here: https://www.cycling-vintage.com/deda-ro ... 2x30521967

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This is perfect! Elegant looks and around 100 grams.



https://www.extralite.com/vintage/UltraStemUL_anglo.htm

The above page is still up on their website but that stem isn't included in the store section, I wonder if you can still have one made.

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I was wrong about the UNO stem in a previous post, I gave the Chinese supplier's link, it appears that the stem is actually a Taiwanese product unsurprisingly, here is the manufacturer's website.

http://www.mtb.com.tw/en/product.html

http://www.mtb.com.tw/en/product-634498 ... S025N.html

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This Ritchey WCS Chicane stem looks pretty compact and clean, not too big for thin steel tubed frames. Weighs 175 grams - all the smooth, nice looking stems seem to be over 150 grams

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This mountain bike stem looks minimalist and clean, unfortunately the length is limited to 100mm, it exists in -6° and R2bike seem to have -17° versions. At less than €100, it is reasonably priced.
https://r2-bike.com/NEWMEN-Stem-Evoluti ... -17-100-mm

The weight is impressive, 96 grams for the -6°, 100mm stem. https://www.newmen-components.de/en/51/ ... n-sl-3182/

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That Aliexpress mini stem adapter's main bolt appears to be hollow and internally threaded to accept the second top cap bolt.
The main bolt is M10 x 100 mm and the cap bolt is M6 - It looks like only the latter can be tuned with a lighter aluminium or titanium bolt.