Mechanics and Fixing Any Questions Answered

But while the numbers might be constant, there’s no arguing that certain lengths and cadences will just feel better for some people and others for others right?

certain lengths and cadences will just feel better for some people

Yes, since there's nothing to be gained by changing within the normal range, there's no harm in going with your personal preference.

All of the above assumes you're only interested in making power in comfort. At some point, we have to consider that it's not a "physics problem" and look at how crank length limits positional options which might be aerodynamically advantageous. Outside the dyno cell, the actual task is to go as fast as possible, not just to generate power.

My 10 speed deore derailleur has stopped shifting into two smallest cogs, even with the cable tension completely backed off

Can you manually push it into the correct position? That eliminates the question of a hard stop (limit screw, frayed cable) and leaves a weak spring as the culprit. It shouldn't happen in the 21st Century, what with metallurgy being so good in general, but we used to avoid storing bikes with the rear dérailleur in the low gear position to avoid the return spring taking a set and getting slow at the top end.

I found 165mm cranks helped my knee pain, but I'm more than happy swapping to different lengths on different bikes if I'm not riding a longish way, 165mm is also better for polo.

I can't think of anything besides a bent derailleur hanger, unless someone has been messing with your limit screws. Or some very specific failure in your shifter.

To check the hanger:

• Shift into a larger sprocket on the cassette.
  
• Stand behind the bike and look at the cage from the rear.
  
• Does it hang straight down or does it point in towards the spokes?
  
  

If you don't have a derailleur alignment gauge then then you can use a long 5mm allen key in the derailleur bolt (where it clamps to the hanger).

Is there a guide for rebuilding/servicing a SR suntor raidon forks.

Looking on line at the you tube videos and these don't relate to my forks.

They're a bit shit so just replace them, or from poor memory they're grease based, so pull them apart, clean and regrease.

Think these ones are air, and have bits missing. Not sure a bit shit covers these.

Off to wiggle to see if the 129 quid 29ers come back up for sale

I'm putting this down in the category of science not understanding why cycles stay up.

But we know how they stay up. I guess maybe you're aware the gyroscopic effect of the wheels has been debunked by that guy who put counter-rotating wheels next to the working wheels? Which leaves a single possibility: the steering geometry makes it so the bike automatically steers into whichever direction it's falling.

Essentially, all bikes get down the road by subtly zigzagging as they continually begin to fall left and right.

I have an oversized headtube and a tapered fork on my mtb. i’d like to try slackening it out by a degree, from 68 to 67 partly because my fork is longer than the frame is designed for. I want a cheap angleset annd would like to know if there’s a chinese option but more importantly i need to work out what fit will work in my frame if at all. Where do i start?

https://www.fastcompany.com/3062239/the-bicycle-is-still-a-scientific-mystery-heres-why

First Google hit.

That article is more than seven years old, and pop-sci journalism generally sucks.

https://academic-accelerator.com/encyclopedia/bicycle-and-motorcycle-dynamics

Which is why it’s so hard for people to adjust to cycling with reverse steering?

If my fork looks like this with a 28c tyre which is true to size, will 25c be too tight too?

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Don't lean.

Once we start discussing biomechanical I'm out. Know very little and the bio bit are wierd ;)

Remember reading about biopace rings, along with crank length and got the more I read the more questions I had.

It was the first Google hit.

@MCamb isn't that learning to counter steer above a certain speed. Then added to the ability to pedal.

is it necessary to use pedal washers on sram cranksets?

I would have washers on every crankset.

Pretty sure every SRAM crankset I've bought has come with them, so they obviously think so

I've never srammed before and I've never used pedal washers on Shimano cranks.
what's the purpose? to prevent steel spindles chewing up the alu cranks?
the sram cranks I've bought are brand new unused but removed from a new bike, so I'm not sure if they'll arrive with washers or not.
I assume they require specific washers rather than generic ones?

have been thinking the same thing today about some truvativ cranks (sram). in the service pdf every iterate of these cranks spec a washer. i’m a bit concerned i won’t be able to find two in my tool box but also pretty sure there weren’t any when i took them off my wife’s bike after ten years use so they’re probably fine

Anyone who's seen what Jobst Brandt had to say about the pedal/crank interface would have to agree that what we have is pretty suboptimal... Washers make it a tiny bit better.

It's a shame more folks didn't see and agree with Jobst's fix - a fat 45 degree chamfer on the pedal hole, and in the absence of pedal spindles to suit, split collets.

I had to pop into town so went into Evans and the friendly mechanic gave me couple of washers.
shhh! don't tell Mr Ashley!

Looking at a second hand frame but it’s got some tyre rub on a seat stay. This look like a nail polish job or to steer clear? Know seat stays aren’t the most load bearing but i’m not the most well versed in carbon.
Cheers

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