Search results for:

Not classic but definitely sexy

Not exactly a ahead stem..

The Pepper is already narrow. I am talking about cutting wide (+600mm) riser bars down to 500 or less, which makes no sense at all.

But thanks for the advice, so it's 4 now

Will work great if you tend to ues copper tubes from your heating as handlebars!

doesn't the ID shrink and OD expand?

Nope, both ID and OD expand. Imagine the atoms next to each other forming the innermost layer of the ring. If the distance between each two atoms goes up due to heat, the ID naturally increases, too.

Sorry to disappoint you guys but cutting down wide bars to ~50cm is NOT the same. The position and angle of the bends in a narrow riser is completely different because it's much more narrow and steeper. Cut down wide bars and you end up with almost unusable crap.

Hi,
are there really only three narrow (<52cm) riser bars out there with a 31.8 clamping area?

All I can find is the silver-only Nitto B267, the ugly Deda Streetissimo and the cheap-ish BLB Mini Me OS.

Any others?

is properly calculated

as I can't do that, this will be done by rule of thumb. Do you think it's feasible at all (also taking into account the idea about the pre-heating of the cup before pressing)?

Yes but then Senor Bear will still complain that the cups are stretched loose by the steerer forces. I still really have no idea if that would happen or not.

I think I'd want the target circle to be R<50μm

Well ok, so you propose less than 0.05mm. Anyway, we'll see how it goes.

I just realized I could also simply braze on the cups (if machined from steel) and THEN apply a IS41 facer+reamer. Then everyone should be happy?

is getting the two ends sufficiently coaxial

what is the typical accepted coaxial tolerance when using (for example) IS41-compatible bearings? I can't imagine that I will end up with more than 0.1mm dislocation over 200mm headtube length, and that should really be fine? Also given the fact that (as you said yourself before) components generally deform under load here and there.

facers only face the top but not the sides of the tube

facer+reamer = yes, but I think gbj_tester is talking about coaxial external sides of the tube

I could convice Park Tool to manufacture an external reamer. For mass production 1" to 1 1/8" conversions ;-)

This is actually a brilliant idea.

The headtube needs machining

My idea is that the softer aluminium will be headset-pressed onto the paint- and residue-free but not-so-perfectly cylindrical steel heattube simply by brute force as soon as ID and OD roughly match. According to Park Tool, the difference of ID and OD can be up to 0.3mm for a press-fit to work.

Will report how it goes. If it's shit and goes loose all the time, I will machine another set from steel and simply braze it on.

By the way, what I really don't get: as there is no doubt that the brazed-on version would work nicely, why isn't this already available as a product in framebuilder catalogues.

Wanted: Nitto B267AA risers

No PM please, please email directly to magnusjetski@gmail.com

Nitto B259 = dangerous, the buyer please follow the recall:

https://www.euroasiaimports.com/productcart/pc/Nitto-B259AA-Recall-FAQs-d6.htm

That's what I meant too. Yes of course there is a limit as there are toptube and downtube in the way?

Of course it completely depends on the frame. In the drawing it's 3mm, on my frame here I can go 5mm deep at the top and 3mm at the bottom. Paint will of course be removed and cleaned.

The ricky feather is really nice, especially the position of the front bolt - but looks like a custom made thing that will be $$$expensive

I really wonder why there is no combination of the Syncros or Schindelhauer "central bolt" and a front end like on the Nitto CT81 or even better the ricky feather, all done as an affordable mass production item

It wouldn't act to loosen either cup from the headtube, which is the risk in your design.

We'll see. I get your point, but I could also imagine that it will only loosen after many thousands of km, or not at all, that's why I need to run this test.

Also because..

If you were going to all this trouble, could you swap out the head tube?

.."all this trouble" is actually just 20 minutes of lathe work, compared to the massive surgery of swapping the head tube.

Fairweather/Nitto MT31

Tange T5290

4 stems from a thread by Greasy_Paws:

Cinelli Grammo

3ttt Forged Ahead

3ttt Pro Titanium

Look Titanium

BLB Stealth stem (not really quill-like due to the ugly prints, but at least a hidden rear bolt):