Any question answered...

I have lost one of my Diadora cycling shoe heel pad.

I contacted Diadora and they don't have spares. CRC is sold out. The only place with stock is in Italy and they are about 25€ for a pair all in.

I can buy a new pair of low-end Diadora shoes on eBay for about £20 and they will come with the pads.

I found this link which has the 3D model of said heel pad:
https://www.thingiverse.com/thing:136661/

How much does 3D printing costs and does anyone have access to a 3D printer in London?

I could also just use an old brake pads...

Right, same thing, yeah. But almost certainly expressed better. So what I'm wondering is whether gain ratio + downwards force or cadence is more important. Probably a bit of both really - if you increase either too much you're going to hurt yourself

It's the gain ratio that changed.

I.e. With shorter arms each complete revolution takes a shorter time.

But you loose slightly on the leverage of the longer cranks.

I think Makers space in Herne Hill has a 3D printer, don't know for sure, maybe check with them?

I'll let @mdcc_tester summarise his experiments with short cranks and cadence

Obviously not. It does have enough scope to cope with the sources that most people will be playing through a portable bluetooth speaker though.

Has anyone had to replace a B limit screw on a rear derailleur before? Are they standard M2/3/4? Could I pick one up from a hardware store?

Yes, yes (or maybe M5) and yes (except you may not find the exact length and head form). The exception would be some SRAM dérailleurs with plastic B knuckles which use special threads to suit the material.

I'll let tester summarise his experiments with short cranks and cadence

If you keep gain ratio constant, you'll do the same speed, within any practical range of crank lengths. There might be marginal differences from the following sources:

1. Shorter cranks reducing effecting frontal area and therefore reducing drag
   
2. Higher cadence increasing downstream turbulence and therefore increasing drag
   
3. Higher cadence increasing metabolic cost due to more frequent muscle firing
   
4. Higher pedal force increasing metabolic cost due to greater muscle force and length of contraction
   
   

If 2 didn't cancel out 1, and/or 4 cancel out 3, there would be a clear choice between long cranks/low cadence and short cranks/high cadence for racing cyclists :)

I doubt he'll be worrying about drag for polo but interesting nonetheless

Plus this is polo so just fit them and have another beer.

On 3DHubs it seems to be £7.85 shipped to your front door. If you need help ordering I'd be more than happy to guide you through the process.

Marginal gains Rob! Just like Tennant's or super Tennant's!

Thanks all.
Another pointless question: some single speed trials bikes have a fixed cog on the back, and a LHD freewheel on the crank. What's the advantage to this, rather than just having them the other way around?

I bought a new pair of shoes for £13 on eBay so my problem is kinda solved.

Will resell the shoes with mo heelpads...

I had one on my trials bike back in the late 90's and I'm not sure what the benefit was. I just remember it eating my jeans a lot when I freewheeled it. I know it had a lot of points of engagement, but then regular trials hubs have that too.

Weight more centred?

You spend as much time on the back wheel as you do on both/resting on the BB shell in trials.

Seatpost keeps slipping. Currently using Thomson 28.6mm clamp but it’s max torque spec is 2.8Nm. Also Thomson seatpost but having measure it the 27.2 claimed isn’t the actual size - which is 27.1. I have greased the bolt and copper slipped the seatpost/seat tube.

Is there a 28.6 equivalent to the surly constrictor clamp?

Seatpost keeps slipping

Lay off the pies, tubby :)

Currently using Thomson

You have only yourself to blame

You'll probably be able to solve the issue with a cheap generic clamp with an M6 bolt which will happily take 8Nm. Otherwise you'll have to trawl the internets to try to find a 28.6/27.2 version of either the stepped bolted clamp or bolt/collet type

2 Attachments

Any suggested generic clamp?

Any suggested generic clamp?

If you want a "branded generic" one, BBB BSP-85 has all the desirable features, but while checking that out I noticed that they have a fix for you which will let you keep your poxy Thomson and just add the supplementary clamp above it, BSP -97

I should get one of those so I never installed the seatpost too low again...

For polo, I'd expect changes to the bike dynamics when accelerating from near-zero and at spinout to be more important.

@n3il You're not particularly short, so if you're worried about pedal strike, fit narrower slimmer pedals or get a frame with a higher BB. Or fit bigger tyres.

Selle Monolink seatposts...
I have one with the dual rail adapter on a new bike. I'm trying to change the saddle.

It's got one bolt and removing it seems to do absolutely nothing. Nothing budges. Is there some knack or does it just need more force...

This sort of thing
(the adapter for the dual rails being the pieces on the left that replace the thing that's already in the seatpost on the right)

minus the Budweiser

Those semi circular sections are rough and if it’s been done up for some time it might just be stuck. If you’ve got a saddle on it still, undo the bolt and try to rotate the saddle nose up or down with some force