Search found 283 matches

by OnYourRight
13 Sep 2014, 1:17pm
Forum: Bikes & Bits – Technical section
Topic: Rolling resistance?
Replies: 167
Views: 10724

Re: Rolling resistance?

Interesting test, NetworkMan. If you’re interested in the comfort and speed of your tyres, consider swapping the the Gatorskins for something plusher.

Rmurphy195: your hill illustration is muddied by rider weight and aerodynamics; at 20 miles per hour the latter is significant. If your road bike (or clothes) puts you in a more aerodynamic position than the mountain bikers, you may roll faster even if your tyres have greater resistance.

Probably it was some combination of tyres, weight, and aerodynamics.
by OnYourRight
11 Sep 2014, 5:44pm
Forum: Bikes & Bits – Technical section
Topic: Rolling resistance?
Replies: 167
Views: 10724

Re: Rolling resistance?

If I had just discovered bicycles and someone told me tyres with supple sidewalls would improve comfort, I would be incredulous. It intuitively seems that no sidewall could be so stiff as to significantly affect the suspension of 80-odd kilograms. And yet it is so, and the difference in comfort between various tyres of the same size and pressure can be quite astonishing and often more noticeable than the difference in rolling resistance.
by OnYourRight
3 Sep 2014, 9:46am
Forum: Does anyone know … ?
Topic: Why are bikes so expensive…
Replies: 211
Views: 12013

Re: Why are bikes so expensive…

Postboxer wrote:I don't think that is what he is arguing. Assuming the average car driver earns more than the average non-driver, then they are paying proportionally more income tax, VAT and so on.

But even if that were true, what has it got to do with the topic under discussion? It’s a perfect non sequitur.

Driving has significant uncosted externalities that have long been ignored. Cars are as popular as they are because they’re much cheaper than they would be if their full costs were borne directly by their owners.

The situation reminds me of air travel. Did you know that aviation fuel is not charged excise duty? It’s not taxed! This bizarre anomaly exists for some historic reasons and for some pragmatic reasons (e.g. if the UK or the EU taxed jet fuel but other countries didn’t, airliners would fill up outside their jurisdiction and burn even more fuel hauling massive quantities of cheap fuel around Europe).

Needless to say, the massive growth in low-cost airline travel depends heavily on jet fuel being untaxed while land-based competitors are taxed. So even though flying is many times less fuel-efficient than travelling by land (train, coach, etc.), and even though fuel is a huge cost of flying, in many cases it’s cheaper to fly across the country than to hop on a train.
by OnYourRight
3 Sep 2014, 1:03am
Forum: Bikes & Bits – Technical section
Topic: Rear rack advice & Carradice Bagman problem
Replies: 29
Views: 5550

Re: Rear rack advice & Carradice Bagman problem

niggle wrote:… the very solid chromed steel struts do not lend themselves to being bent

Are they really steel? The stay for my otherwise steel Tubus Fly is some kind of light alloy. This is how I bent mine (with a protective covering of handlebar tape, though the spanner bit through the tape so I’m not sure how much use it was):

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It required a very hard squeeze. I was surprised at the force required. I also had to bend it repeatedly in small increments to get the angle just right without risking an overshoot.

I’m not suggesting this method is good for the ring spanner or the strut, but it worked for me and it may work for others without access to proper tools.

And here are pics of my Tubus Fly installation as promised. Pretty!

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by OnYourRight
2 Sep 2014, 10:46am
Forum: Does anyone know … ?
Topic: Why are bikes so expensive…
Replies: 211
Views: 12013

Re: Why are bikes so expensive…

Roads have taken more and more traffic over the last few decades for the simple reason that their use is not fully costed. They’re effectively subsidised by all of society and indeed the whole planet, regardless of whom benefits from their use.

Taking a big-picture perspective, it’s obviously far from efficient to have a huge fleet of low-capacity vehicles, each with a driver doing nothing economically or socially productive beyond driving, consuming simply stunning amounts of energy, killing thousands and seriously injuring ~80,000 people per year (in the UK alone), causing untold health damage by supporting a culture of driving 200 yards to the post office, turning our city centres into Dickensian nightmares overrun by diesel fumes and noise, etc., etc.

This is only efficient in the narrow market sense of being thought to be profitable for each of those individual actors because the true costs are borne by someone else.
by OnYourRight
1 Sep 2014, 8:41pm
Forum: Bikes & Bits – Technical section
Topic: Track pumps
Replies: 73
Views: 4619

Re: Track pumps

Brucey wrote:I am more interested in the prospect of being able to still buy spares for my older Silca pumps, and also fitting silca chucks onto other pumps; that should be a more economic exercise.

Agreed. And this puts me in a mind to acquire a new Silca Pista or Super Pista while I still have the chance. But I’ve used a Rennkompressor and liked it, whereas I haven’t used a Silca. Another imponderable choice …
by OnYourRight
1 Sep 2014, 8:08pm
Forum: Bikes & Bits – Technical section
Topic: Track pumps
Replies: 73
Views: 4619

Re: Track pumps


The new super-pump mentioned in that article is presumably this one. I can appreciate fine things as well as the next guy, but ultimately I enjoy economic engineering more. In any case, $450 is a fantastic price for a pump.
by OnYourRight
1 Sep 2014, 7:06pm
Forum: Bikes & Bits – Technical section
Topic: Track pumps
Replies: 73
Views: 4619

Re: Track pumps

But do you want your pump to double as a bike stand, Mick?
by OnYourRight
1 Sep 2014, 1:35pm
Forum: Bikes & Bits – Technical section
Topic: Track pumps
Replies: 73
Views: 4619

Re: Track pumps

So are all these connectors more or less interchangeable? I could buy an SKS Rennkompressor (for example) and just attach one of those if the SKS connector turns out to be rubbish?
by OnYourRight
31 Aug 2014, 11:26pm
Forum: Touring & Expedition
Topic: Best Ortlieb Rear Panniers for touring?
Replies: 92
Views: 7484

Re: Best Ortlieb Rear Panniers for touring?

PH: you say 30 litres, but the Ortlieb website says the Front-Roller Classic panniers have a capacity of 25 litres per pair. Are yours a little bigger?

What saddlebag do you use? I’m interested in this idea – small front panniers at the back combined (only when needed) with my Carradice Lowsaddle Longflap saddlebag – but I wonder how they’d work together. I’d probably favour the Front-Roller City panniers, since they’re cheaper and simpler, but I’m wondering if 25 litres is really enough. It seems to me like it would be, but nearly everyone uses something bigger.
by OnYourRight
31 Aug 2014, 10:03pm
Forum: Bikes & Bits – Technical section
Topic: Rear rack advice & Carradice Bagman problem
Replies: 29
Views: 5550

Re: Rear rack advice & Carradice Bagman problem

thirdcrank wrote:PS I'm not saying that a pipe bender is necessary or suitable for making the 90deg bend that would be needed to fit the end of the strut vertically to the seat stay bridge.

Mine didn’t require a 90-degree bend either, since Tubus supplies a little metal tab which accommodates much of the bending needed. I think your pipe-bender idea is much better than my method with a 13 mm ring spanner, but I didn’t have a pipe bender either!

NetworkMan wrote:I wonder if using the inside of the braze-ons reduces stability?

I’m certain it does, but it seems to be stiff enough for a lightly loaded Bagman, based on three months of use. Most of the force is in the vertical direction, of course – and using the inside of the braze-ons doesn’t reduce strength in that direction.

It doesn’t surprise me to hear that Dawes bikes have had this interference problem for years. A few details on this bike don’t seem brilliantly thought out, though the overall quality seems good – the paint, for example, is very tough and hard-wearing (and pretty!).

I will put up photos of my Tubus Fly installation as soon as I take them. When researching these topics I read a lot of threads that just petered out with no follow-up from the original poster. This one won’t be like that!
by OnYourRight
31 Aug 2014, 9:53am
Forum: Bikes & Bits – Technical section
Topic: Replacing a crankset on 90s bike
Replies: 7
Views: 1109

Re: Replacing a crankset on 90s bike

Ask the place you bought it what length of bottom bracket is required for the new chainset, then order the cheapest available relevant part (should be under a tenner). However, you probably don’t have the bottom bracket removal tool needed to change this part, so you may need to get that or have the work done. It all adds up.

The new gears will be higher, since there are more teeth on the new chainset. Not necessarily a good thing but I realise you don’t want to spend a fortune here.
by OnYourRight
31 Aug 2014, 9:36am
Forum: Bikes & Bits – Technical section
Topic: Track pumps
Replies: 73
Views: 4619

Re: Track pumps

Is there any chance of that Lezyne ABS hose fitting to an SKS Rennkompressor?
by OnYourRight
30 Aug 2014, 11:12pm
Forum: Bikes & Bits – Technical section
Topic: Rear rack advice & Carradice Bagman problem
Replies: 29
Views: 5550

Re: Rear rack advice & Carradice Bagman problem

(Old thread alert!)

I’m pleased to report the Bagman arrangement suggested by Norman H has worked perfectly for the last three months. Thanks Norman!

As for lightweight racks/carriers, in the end I opted for the Tubus Fly classic in stainless steel. Its design and construction are beautiful. I honestly don’t think it detracts at all from the appearance of my bicycle. It’s wonderfully neat and elegant. What’s more, it’s impressively stiff, resisting lateral forces far better than you’d expect from its feather-light weight.

Speaking of weight, there are claims on the web that Tubus weights are very optimistic, but thankfully not so for my example:

Carrier itself
Tubus claim: 369 g / my example: 366.8 g

Mounting parts
Tubus claim: 67 g / my example: 72.3 g (including the supplied spacers, since my bike (130 mm OLN) needed them)

Total installed weight
Tubus claim: 436 g / my example: 439.1 g

Installing it was tricky because I don’t have a vice. After a few failed attempts at bending the central stay by hand and between bits of wood (no chance!), I managed to give it a fairly neat bend by wrapping it in a bit of leftover handlebar tape, inserting it into a 13 mm ring spanner, and applying quite a bit of force. This method should work for anyone without access to a vice.

The little metal tab for mounting behind the brake calliper was easily bent by fixing it to the bike, fixing it to the stay, and moving the stay itself. The stay is much stiffer than the tab, so only the tab bends when you do this.

I mounted the mudguard stays to the secondary holes on the feet of the Fly classic (these holes no longer exist on the new “evo” models) with M5 bolts (and nyloc nuts) and a few washers between carrier and stays to keep them apart to avoid noise.

I’ll put photos up soon, hopefully tomorrow.
by OnYourRight
30 Aug 2014, 9:47pm
Forum: On the road
Topic: 3rd time unlucky
Replies: 16
Views: 2182

Re: 3rd time unlucky

Tonyf33 wrote:I've just had two punctures in quick sucession..loads of tread on the tyre but the carcass had split in a couple of places near the cosmetic channels..not impressed.

What tyre model?