Current Projects chat and miscellany

that's my steed and my beefy krypto chain but it's just the bike shed at work.

I lock up on the street these days. too much faff getting the key to put the bike in there.

Another question for the more experienced members, I have been using standard Shimano PD540 SPDs for quite a while, but recently have been having some problems with them releasing on me under hard braking.

Have checked the almost new cleats, and virtually no wear, I've tightened the spring tension on the pedals to the max, and its still doing it.

Is this a problem with the PD540 pedals, SPD pedals in general, or just my bad luck for being a heavy fucker?

Are there other pedals anyone could suggest that are less likely to do this?

It just looks like if you were able to pan the camera there would be a rack or big iron rings on the wall!

So the pink bits, not got anything against pink, but the frame i just bought is painted the same on the rear drops and rear stut, is this a fashion thing i know nothing about?

I do like the taped look though. ;)

Yes, I went from 18/47 to 18/48, but found it easier, not harder to pedal, which is why at first I thought it might have been the crank length.

Yeah, I would expect that to feel slightly easier (except uphill). Easier to go, harder to stop, that is.

perhaps easier as in being able to spin a bit more while maintaining an average speed?

I find 48/20 a little difficult to spin more at an average speed than 48/18 (crank length make no difference whatsoever).

Hmmm, quite possibly Ed.

Have been thinking of going up a gear to 17/46 (I know its a wimpy increase), as I'm finding myself spinning out a bit on the 18/48, so will see if this has similar effect.

Also thinking I should have got 165mm cranks for spinning and not 170mm.

While you guys are talking about crank length, is it just a preference or is there an efficiecy calculation for your instep or something (grasping at straws but you get my point)

Just a preference I reckon, only those who's shorter than the average may find them advantageous.

Some people say its easier to spin with shorter cranks as you're making smaller circles with your legs, but apart from that its down the toe overlap with smaller or tighter frames, and for leaning into corners, it helps to have shorter cranks.

Yeah you know i had forgoten about not being able to stop pedling round corners, i now remember catching a pedal on the floor and spinning out on my first fixie, hmmmm road rash!

Another question for the more experienced members, I have been using standard Shimano PD540 SPDs for quite a while, but recently have been having some problems with them releasing on me under hard braking.

Have checked the almost new cleats, and virtually no wear, I've tightened the spring tension on the pedals to the max, and its still doing it.

Is this a problem with the PD540 pedals, SPD pedals in general, or just my bad luck for being a heavy fucker?

Are there other pedals anyone could suggest that are less likely to do this?

Time atacs. ^ this (and the fact they're bombproof) is the reason atacs get some much fixieluv™

Cheers Miro_o, at least with the Atacs I don't have to buy new shoes as well as pedals.

^^
1 brake fixed > 2 brake fixed

this isn't the place for this discussion.

No.

Do you wear a helmet

While you guys are talking about crank length, is it just a preference or is there an efficiecy calculation for your instep or something (grasping at straws but you get my point)

You get more leverage with longer cranks, but travel less distance in a rotation with smaller ones. It kinda cancels out.

If you are very tall or very short, you may have a big preferance. But most are happy with anything within the standard 170 to 175 range.

Sweet, looks like the one i nicked off my Dad :)

You stole an njs frame with risers.from your Dad!? And all I got was a lousy Hetchins.

TM - You listened to the haters?! Whats wrong with you mate? Mind you, bike still looks fantastic. What rims you lacing to the DA hubs?

I did feel a bit ridiculous pootling about town on twin heds. Considering getting tb14s and taking the badge off as they are a similar shape to the arayas, ideally I'd find a pair of arayas though.

You stole an njs frame with risers.from your Dad!? And all I got was a lousy Hetchins.

I did feel a bit ridiculous pootling about town on twin heds. Considering getting tb14s and taking the badge off as they are a similar shape to the arayas, ideally I'd find a pair of arayas though.

Haha, no i should imagine it wasnt very special, but it was too my as it went like stink.

I don't think it's an arbitrary choice.... In the old days when you purchased cranks in person at a decent LBS they'd tell you what size you need by looking at your legs.
Presumably long-legged and big-footed types need longer cranks than their dinkier counterparts - I don't know if there's an algorithm or even a rule of thumb.
With a proper track frame you should be able to run the same cranks as your road bike without grounding a pedal - if your running a road conversion you probably want the shortest cranks you can get for road-rash related reasons described above...

Time atacs. ^ this (and the fact they're bombproof) is the reason atacs get some much fixieluv™

Time Atac Roc, or XS?

I don't think it's an arbitrary choice.... In the old days when you purchased cranks in person at a decent LBS they'd tell you what size you need by looking at your legs.

They also said the best way to measure the right frame for you is to put your elbow on the saddle and point your hand toward the stem.

Conventional wisdom does not necessary mean it's right.

Time Atac Roc, or XS?

I got some brand new Time Atac Titan Carbon XS pedals off eBay for £68 last year. Keep an eye open on there.

It's not an arbitary choice, this is typical scoble bollocks.

Shorter cranks let you accelerate and spin faster (this has been proven by a number of studies*). However, they have less leverage, so some people find them slightly harder to climb with.

Longer cranks give you longer sustained speed but take longer to spin up. Martin and Spirduso (linked below) concluded that:

Optimal pedaling rate decreased with increasing crank length, whereas optimal pedal speed increased with increasing crank length.

Height doesn't really have anything to do with it, as you can adjust your saddle to change the distance between the saddle and your pedals. Indeed Martin and Spirduso also concluded that:

the use of 170mm cranks would only reduce the power of our shortest and longest-legged subjects by less than 0.5%

• Such as Determinants of maximal cycling power: crank length, pedalling rate and pedal speed by Martin and Spirduso in the European Journal of Applied Physiology (2001).
  
  

Leonard Zinn did two studies himself into crank length ("Tech Report", VeloNews, May 13, 1996 and "More on Cranks", VeloNews, July 1, 1996). He declared the first study invalid as he used the same cadence to test, but the conclusion of his second study was that:

Long cranks excel in steady-state cycling, which our test mimics, but acceleration is slower at their lower cadences

So AngelD, are you a spinner or a grinder? If you're a spinner, shorter is better, if you're a grinder, longer.

Brilliant, just what I wanted to hear! Thanks, I shall keep the Omniums then, aesthetically I prefer the SG75s, but I am not sacrificing performance for aesthetics (at least not the cranks!).

suginos are superior to omniums in every aspect!

Time Atac Roc, or XS?

Alliums have always been the best value. Have a look on the WW forum for some real weights before spending more on the lighter variants, there isn't much in it.

They're all heavy unfortunately.

So AngelD, are you a spinner or a grinder? If you're a spinner, shorter is better, if you're a grinder, longer.

I tend to be more of a grinder as have strong legs, but want to really be more of a spinner as have already got a dodgy knee.
Might see if I can pick up some 165mm Omiums and stay with current gearing for a while, and see how that works.

Alliums have always been the best value. Have a look on the WW forum for some real weights before spending more on the lighter variants, there isn't much in it.

They're all heavy unfortunately.

I was asking more for things like spring strength, ground clearance, and pedal surface area for better power transmission, but guess I should have mentioned that!

I'm a spinner and run 165s and it works for me. Anecdotally, shorter cranks may be better for the knees as you don't need to bend your legs as much, but there's no evidence of that (AFAIK).

I
I was asking more for things like spring strength, ground clearance, and pedal surface area for better power transmission, but guess I should have mentioned that!

Look Arc FTW
(assuming you don't plan to walk anywhere of course!!)

The ATAC Xs have 3 settings for spring tension I think.