Any question answered...

sooooo, last night I b0rked my super-stylish Sakae MTB stem by over-tightening the clamp bolt. Looking at this pic, I see a helical insert which means. this. is. an. alloy. stem? Seriously. Always assumed steel.
Which has me wondering two things: Why does it weigh so much? And why not steel in the first place?

I’ve replaced it with a parts bin Ritchey Pro and my bike is now 50% lighter (if only half as sexy).

Having consulted the Tester Approves thread,
I find: https://www.wiggle.com/brand-x-layback-6061-seatpost?
is out of stock in 31.6mm.
Is there an acceptable alternative?

A standard M5 bolt wobbles in the remaining thread.

If the bolt broke, the thread interface was overloaded. You would expect the female thread to be deformed to an oversize condition. You need to replace the nut part as well as the bolt.

You need to replace the nut part as well as the bolt.

Hmm, if I even knew what the 'nut part' was called I could try.
The 'nut part' does move a little, laterally,
so it does look as though it could be persuaded out.

Is there an acceptable alternative?

Find the equivalent Kalloy on ebay/amazon/aliex. I'm guessing that if you're after that one then the #tester_approved SP-248 has a bit more layback than suits your position.

Just been told this is what is going on

https://www.youtube.com/watch?v=CQGW46B6x_4

I think I've got the same BBB seatpost as @mespilus.
Or at least a model that uses the same size bolts.
I've also been looking for some replacement bolts as the current ones don't look that great...
Anyway, they really are some weird size that's not quite M5.
They are 5,2 - 5,3 mm in diameter and something like 0,68 - 0,69 pitch. Pictures below.
I guess these are proprietary bolts? Why would the manufacturer not use standard bolts?

2 Attachments

Very strange , something like 1 BA is close on the diameter but the pitch is something like 0.9mm

Why would the manufacturer not use standard bolts?

To eliminate the dangerous condition where a user replaces the stock screw with a standard one having a flat underside to the head.

Interesting! Hadn't thought of that because frankly I didn't know about BA screw threads.

But couldn't they just have used a standard M5 bolt with a concave washer?
No need to make your own bolts and no issues with customers who replace the bolt without thinking too much about it.

They are 5,2 - 5,3 mm in diameter and something like 0,68 - 0,69 pitch

In imperial that would be 7/32" × 36tpi, which isn't anything normal but would be easy to make on an imperial screw machine. I'm just surprised that they didn't go metric, even if you wanted to be difficult I'd have thought M6×0.75 would be a more likely choice in a bike factory as you already have 0.75 pitch set up for chainring bolts 🙂

But couldn't they just have used a standard M5 bolt with a concave washer?

Yes, that's the better way to do it, but then people assemble them without the washer and you're back to square one 🙂

Just for completeness sake.
The short 'barrel(?)' nut shown upthread in @wenzovic 's 1st picture.
Is there a consumer tolerant source of those in metric threads?
I promise to use a concave washer.

@wenzovic
Thanks for taking and uploading pictures to illustrate the oddness of the BBB seat post bolts.

Should anyone else consider contacting BBB,
they ask you to contact their local distributor, for the UK Windwave.
Windwave are not supplied with spares by BBB,
Windwave have, in the past, cannibalised a couple of seat posts for replacement parts under warranty,
but have no more available.
I have emailed the BBB HQ in The Netherlands to see if spares are available from the head office.

is this @JAH_tim?

https://twitter.com/tootingrastacc/status/1298678894598463488/photo/1

His bike is much nicer than that, and unless the stress is finally getting to me, white as well.

-edit, I just don't like orange..
No offense meant to Tim!

Now I am confused..

https://www.lfgss.com/conversations/172374/?offset=14400#comment13462028

Help @JAH_tim

I think he's posting under @JAHtim now.

Also:
https://www.lfgss.com/comments/15082558/

It looks the same size! And I have heard there are people with more than one bike (sounds nuts I know)

I have never seen him on an orange one .

-edited..

Can confirm that's Tim's Oak.

I have never seen him on an orange one .

having looked closely, they are the same bike. He's had a respray. @JAHtim looking good :)

Yep, the story is in @pastry_bot 's post.

Glad he got it rolling again.