The Tester Approves thread (see first post)

Would much rather have cheap brakes and great pads than the other way round.

#tester_approved

You disapprove thread >>>>>>>>

Cheers. It's for an old muddyfox for commuting and slow touring. My other bike has discs for when stopping is more important

https://www.lfgss.com/comments/14600022/

Mmm... "purple anodised wank"

I have the tester approved cheap kalloy seatpost (several actually), and it's great. Is there a similar (cheap, silver) inline post that meets with approval? I can find anything via the search.

This Kalloy design is sound, you'll have to shop around to find it in silver, and it might well be branded as something else.

1 Attachment

They sell silver in velo vitality (27.2mm)

Is the black brand - x one also kalloy? More sizes and was quite cheap last time I checked

black brand - x one also kalloy?

Yes.

Great, thanks!

1z1 Whipperman 1/8 chain seems to be sold out all over the place.
What's the best KMC alternative?

1z1 Whipperman...KMC alternative?

The B1WideRB is the direct equivalent, but the S1WideRB is fine for everyday use and you can pick it up in a B'Twin box from your local Decathlon

What are the potential benefits of a 7075 welded frame over current alloys

http://newsroom.ucla.edu/releases/nanotechnology-welding-strong-aluminum-alloy-AA-7075

Stronger and lighter by the sound of it.

What are the potential benefits of a 7075 welded frame over current alloys

If 6061 or 7005 were strength-limited in bicycle frame applications, using 7075 instead would be advantageous. I don't think they are, I think in most areas the limiting factor is stiffness, and all three alloys are basically the same in that respect. 7075 is very expensive compared with 6061. For bicycle frames, I think this one is likely to fall into the category of "interesting exotics" alongside Magnesium alloys, Titanium alloys and stainless steels, by being both more expensive and worse than carbon fibre.

Does it need heat treatment after welding? Cheap 6061 frames which haven't been retreated after welding tend to fail in the area affected by the heat of welding.

Does it need heat treatment after welding?

According to the article they achieved about 70% strength in the HAZ without post-weld heat treat, and full strength after heat treat. For comparison, a bad 6061 weld might be as low as 20% strength without post-weld heat treat, but it might recover to over 50% if it comes from China by ship :)

Optimal 1" threadless headset? For cost Vs function?

UTFS
https://www.lfgss.com/comments/14369172/incontext

Any recommendations for carbon 1 1/8" forks with 43mm rake for quick release. Cheers!

If you can find one, 3T Funda is good. If your budget doesn't run that high, Columbus and Kinesis are reputable.

Is there a tester approved 28.6mm seatpost clamp? I think I remember seeing something recently but can’t find it

This is copy-pasted from the current projects thread:

The purpose of a band clamp on a shaft is to create a uniform circumferential tension in the band in order to generate a uniform radial pressure on the shaft. Anything which tends to disrupt his uniformity is a bad thing. Taking this into account, the tensioning device should as far as possible pull in a direct tangent to the band, and the band should have as little resistance to changes in diameter as possible consistent with having enough tensile strength to resist the circumferential tension. We can approach these ideal conditions witht he following design elements

1.Pivots for bolt the bolt and nut elements of the tensioning device, to align the thread for the best tension per tightening torque and to give the best approximation to a true tangential pull
2.A thin and uniform radial thickness on the band, to minimise resistance to bending. To achieve the required tensile strength in a thin flat band, the material should be chosen for high tensile strength per unit area, so carbon fibre with the fibres running mainly circumferentially or high tensile steel are good and aluminium alloys are very much a second best.
3.The axis of the tensioning device as close as possible to the axis of the shaft, which implies using the smallest bolt which will generate the required tension. A high strength (12.9) M4 bolt is big enough.

It's not rocket science*
This is the kind of design which is closest to ideal:

*It is rocket science. The Marman clamps used for interstage coupling meet the criteria above, although they then use a second inclined plane element (V-groove and tapered flange) to further convert the radial pressure into an axial clamping force.

Ah yep thanks that was what I had read. So far closest I could find is this https://www.sjscycles.co.uk/seat-posts/318mm-genetic-carbon-seat-clamp/ but doesn’t seems to be available in 28.6

BBB BSP-85 is widely available in 28.6 for under £10