Bike designs which should be binned

[Stevek76]

Why do so many people exaggerate? You can remove the bearing shells with a drift (unless you are really cack handed) and I made a bearing press out of two bits of plywood, two penny washers and a scrap of threaded rod. These tools cost me nothing (sorry Park Tool).
OK some people are really cack handed but they probably get their LBS to service their bikes.
You actually do need a special tool for threaded BBs but funnily enough nobody moans about that.

Yes, bodging. Not sure how many people have suitable bits of threaded rod lying around either to be fair, I certainly could've used one for the headset when I put my pub hack together but in the end went for the even more bodgy bit of wood and a hammer...

Threaded BBs do require a tool, but it's inexpensive and you get one in practically any starter tool kit. And if we're into bodging, I'd imagine a pair of alligator grips with a strip of rubber would do well enough to get external BB cups out

[mattsccm]

Why is this bodging? Implication is that it has been a incorrectly done job. To my mind it has been done properly with tools handy without having to recourse to buying something specialist.

[cycle tramp]

Quite. Thanks to running friction I recently changed my gravel bike from a 9 speed 11-30 to a 10 speed 11-34 by pulling a part used 10 speed chain & cassette from my parts bin. Try doing that on on indexed system.

Sounds great, what size wheels and chainring are you using?

[geomannie]

Quite. Thanks to running friction I recently changed my gravel bike from a 9 speed 11-30 to a 10 speed 11-34 by pulling a part used 10 speed chain & cassette from my parts bin. Try doing that on on indexed system.

Sounds great, what size wheels and chainring are you using?

I have a triple up front, 24, 34, 46, giving me very useful low gear with the 34 at the back. Wheel size is 700c aka 29", with 50mm tires.

[RickH]

9t 10t and 11t sprockets are an abomination and should be banned for all bikes.
If you want higher gears, use a bigger chainwheel.

This makes complete sense due to mechanical efficiency. The smaller the sprocket, the more friction produced, plus small sprockets wear out.

I had an 11t on Moulton and I got through three of them even though the rest of the cassette was fine. Good job 11t only cost a few quid each. That cassette was 11-28 10sp, and now I'm using 12-30 10sp .................... much better.

Must be the way you (ab)use them!

I've not worn out the 10t on a 10-42 1x11 cassette in over 4 years (since Feb 2017 & should pass 10,000 miles this week). But then I only use it when doing around 30mph or faster & wanting to keep pedalling.

[gxaustin]

Yes, bodging. Not sure how many people have suitable bits of threaded rod lying around either to be fair, I certainly could've used one for the headset when I put my pub hack together but in the end went for the even more bodgy bit of wood and a hammer...

Threaded BBs do require a tool, but it's inexpensive and you get one in practically any starter tool kit. And if we're into bodging, I'd imagine a pair of alligator grips with a strip of rubber would do well enough to get external BB cups out

You can buy threaded rod extremely easily and cheaply - you don't have to have it hanging around - (more exaggeration of the problem - Doh!)
Did you put your headset cups in the freezer before bashing them in? I have found it makes the job much easier.

A threaded BB tool is less readily available and more expensive than a piece of threaded rod. In order to remove a BB screwed in by my LBS I had to buy a socket since the cheap stamped out tool ripped up the alloy. Alligator grips would have been useless. But you could always try them firstly - there's nothing to lose.

[jb]

Bodging means using what's available at the time (Derived from rural chair making). It does not mean 'to do a sloppy and or bad job', as it is often wrongfully employed to do.

[Mick F]

I've not worn out the 10t on a 10-42 1x11 cassette in over 4 years (since Feb 2017 & should pass 10,000 miles this week). But then I only use it when doing around 30mph or faster & wanting to keep pedalling.

Exactly the way lots of people think.

I'm of the opinion that there's no point in having gear ratio you rarely need.
All it needs, is the correct choice of chainset and cassette.

On Mercian for instance, my top gear is 53/12 = 116" which means at 30mph I'm turning the pedals at 85rpm.
35mph would be 101rpm.

I don't need, or want, anything smaller than 12t.

[thirdcrank]

Before I changed the chainset, 52 x 12 on my Cannondale was 117".

I thought one of the reasons for the smaller sprockets made feasible with freehubs was to use more of the OLD without fouling the RH chainstay.

[Mick F]

Before I changed the chainset, 52 x 12 on my Cannondale was 117".

Point of order here.

If my Mercian has a 53/12 and a top gear of 116" .......... how can a bike with 52/12 have a higher gear?
It must be that you have bigger tyres.

700c with 23mm tyres on Mercian has a rolling diameter of 26.2inches with me sitting on it with 120psi in the rear tyre.
To get 117 gear inches from 52/12, the rolling diameter must be 27".

What size tyres have you, and at what pressure?

[thirdcrank]

52 x 27 ÷ 12 = 117

ie. I use the normal gear table.

[Mick F]

Normal?
What's normal?
Nothing, IMHO.

Gear tables that assume a "standard" will never be correct.

[thirdcrank]

I can'r remember how many places of pi you use. Was it 99 or 100?

[RickH]

I'm of the opinion that there's no point in having gear ratio you rarely need.

I wouldn't say rarely, I probably use it most weeks just not frequently. I used it yesterday going for a train at Wigan on the drop down from Aspull - 30mph speed limit & a fair bit of traffic so I wanted to keep up when it was moving. The same applies if I go into Bolton - down Chorley Old Road into town. Bits you can coast at 30, or more, but other bits need pedalling to keep up with the speed of the traffic. On the open road downhill I'll generally pedal until I run out of gears around 35mph. Faster than that, & having had bikes with higher gears, it tends to be debatable whether pedalling or a decent aero tuck is quicker.

Fast downhills don't tend to last long so the 10 will only be used for a few minutes at a time & not on every ride.

[Mick F]

I can'r remember how many places of pi you use. Was it 99 or 100?

Sit on the bike and roll forwards having marked the start with the valve at the bottom. Do as many wheel revs as you can, stopping with the valve at the bottom.
Measure the distance in inches and divide by the number of revs.
That figure is the wheel circumference of course.
Use a calculator to work out the diameter.

Simple.
You only ever need to that once.