Current Projects chat and miscellany

Picked up a Volare 853 recently. Justified it to myself as a comfortable all-day-ride kind of bike.

Plan is 3T/SRAM Red from the parts box. Cant afford anything ENVE to match the forks, though I will get a Hope seatclamp to match the headset. Wheels will be 50mm Chinese carbon shared with my other road bike or a pair of shallow alloy wheels with gumwalls.

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I will get a Hope seatclamp

Don't. It's a terrible design, whatever generic clamp is on there already is almost certainly better because it would take real effort to be worse.

Ooh do elaborate?

Me and my OH have both used these type Hope clamps

Ie not the ones with the huge bolt on. Been using them a year now without problem with the bolts opposite side of the tube to the slot

Installed the bmx bars on a whim but quite like them, feel rock solid. Been looking at braced bars with about half as much rise on eBay as I think these are just too high

Anyone got a 9 speed long cage derailleur for sells?

I like it !

Try searching for motocross bars as some of them are 22.2 clamp as well and often come with around 100 mm rise.

#slamthatstem

do elaborate?

I was going to...

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 (all of which are missing on the Hope)

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*
   
   
   
   

*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.

This is the kind of design which is closest to ideal:

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ftfy

This is the kind of design which is closest to ideal:

That's certainly closer to ideal than the Hope one 🙂

I don't think you get a pull direction closer to tangential than with that one.

Ha ha, good old cat3memes. I've spoken to him, it looks very much like a graze from being against a wall and it's scratched the clearcoat. Doesn't seem like a bad guy who'd sell a fucked fork. I need to get a frame ultrasounded so maybe I'll get a 2fer.

Picked up this at the weekend. Will build a clunker with Paul components everything and motocross bars.

Not technically an NDS fail:

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That sounds like an awesome idea!

Ooh v nice!

Came with some very nice tyres with minimal wear, but unfortunately rubber has degraded.

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Got some cheap as chips disc wheels and hydro bakes en route for my orange.

Which of course means I have spare rim brakes and v brakes.

And I also have a spare fork.

So I guess I need to buy another frame to put them on.

Its hard work being an idiot.

It's okay I'll take the frame and fork :)

SRAM X7 2x10 front derailleur questions. This is a mtb part. Is the cage going to struggle with road size rings? I'm wanting to use my 48/38T setup on my existing cranks. Some places quote some ring sizes e.g. 36/38T - is that its upper tooth limit? Then on SRAM's site there's High direct mount and Low direct mount. Is that the derailleur itself or where the mount is attached to the frame? On the datasheet it's got like a matrix with 42/28 and 39/26 above and below each other. Does that refer to the maximum capacities on each mount? So confused.

This is just telling you which of SRAM's pregonfigured chainring options on their complete cranksets it can shift.

If it can shift 22/36 which is a 14 tooth difference then it can shift the 10 tooth difference of your 38/48 no problem, providing you can mount it in the correct place in relation to the larger chainring (regular FD setup).

Some manufacturers adjust the curvature of the FD plate to ensure better shifting with smaller rings but in reality this makes little difference.

Road cranks with mtb FD?

This is just telling you which of SRAM's pregonfigured chainring options on their complete cranksets it can shift.

Ah, that makes a bit more sense. Still not much wiser whether I'd want a low or high clamp and if it's going to reach, though :(

Road cranks with mtb FD?

Yes. I'd go for a 1x but it's 130bcd and all the narrow/wide chainrings in that bcd look ridiculous. I'm considering sticking a chain catcher on instead.

The chainrings are further inboard on a road crank than a mtb one. I don't think you'll get a MTB FD set up correctly to work with road cranks

My mountain bike runs road cranks with an XTR front mech. It was easy to set up & it works beautifully ...

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