Joes Polo Bike Build

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Voidcore
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these are my forks, lite guys
http://www.rocknrollbikes.com/trials/bikes-frames/forks/onza-lite-guy-fo...

smart guys are the suspension corrected ones so there higher

Joe
Joe's picture

Ok, I'll grab the lite guy forks instead of the smart guy ones, thanks!

Voidcore
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Sweet youl get there! It will be worth the effort when you get it and its awesome

Neil
Neil's picture

Stepping back from the committee/research bike build for a moment, are you prioritising your polo skills/development through the new bike or do you enjoy the tinkering aspect of bike polo as much or more than playing the game itself?

At an early stage of playing experience you WILL be chasing your tail by building an advanced/out-of-leftfield bike and you will never really know whether your experimentation has paid off.

Now you've paid your dues on a stable (read: long wheelbase) bike, whatever contemporary change you make will immediately give tighter and more responsive turning capability and I'd expect weight will be saved giving a greater sense of acceleration.

If you analyse your current game and where you want to be then you can decide the next level priorities for the bike: are you aiming to be fast; big shot maker (stability/acceleration); agile; intricate skills (instability/short wheelbase) etc. Where is your weight balance - mostly forward/mostly midships/mostly back?

The bigger decisions I'd be thinking about would therefore be cockpit length and 700c v 26". I wanted core stability for my tall build so chose a 'big' frame that would also give me the space to move my trunk from side-to-side. I offset this by choosing 26" wheels to shorten the overall wheelbase to make sure I can access mobility without toe-overlap, which I find a big distraction and limits confidence. 26" wheels also feel quicker in acceleration but are a handicap in goal.

FWIW I'd also not countenance permanent removal of the rear brake until you know for sure you are capable of/want to be playing a 'front-end' game.

If you want to make more/quicker progress on court this year then that would suggest you take a look at the top 5 or so players of your build and who play in a style that you aspire to and average out the specifications of their bikes as a template. A sum of great parts may not be the holy grail for you.

Whatever first proper polo bike you get it won't be your last, fo sho... :)

Neil
Neil's picture

... forgot to mention THE critical question - colour!

snottyotter
snottyotter's picture

Does it barspinz?

Joe
Joe's picture

I'll probably buy the forks later today (even if I can't use them for a long while!) as it seems to be the least controvertial item.

So! Regarding the controversial 150mm crank arm lengths:

To achieve 15mph (what I estimate to be roughly high speed at polo) at ~44.8 gear inches:
A 175mm goes at ~112 rpm.
At the same gain (37.8 gear inches) A 150mm crank goes at ~134 rpm.

Looking at track bikes and their acceleration :
https://docs.google.com/viewer?url=http%3A%2F%2Fwww.flavelo.org%2Fflyers...

They typically use gearing that's effectively just over double the gear inches (they use 165 cranks, so 90"-92" is more like 95"-97") but typically sustain ~120-130rpm peaking at ~150rpm for sprinting, Supposedly any "roadie" can hit 140rpm.

Now...Track bikes run fixed so I think (please someone correct me) that you could temporarily get slightly higher spins on a freewheel, but... I'm making the assumption that ~140-145ish is somewhat around the max/peak/optimum rpm to ride at in a short sprint and according to the article, achieving it is easier/faster for acceleration with shorter cranks (though they mention why they don't go below 165 cranks)

Regardless...at the planned gear inch/gain ratio we have a rough max speed (140-145rpm) of:
~15.7-16.3mph for 150mm cranks
or at 175mm cranks the equivalent would be ~18.6-19.3mph (though with theoretically slightly slower acceleration).

Also technically due to the reduced movement a higher rpm is theoretically possible on smaller cranks...but I'm not even going to think about that right now...

What I really don't know is how fast you can get in a few metres from a standing start though...it's kinda more like the equivalent of riding up a hill (where longer cranks are preferable) so longer cranks are probably better from standing/slow starts to accelerate to point X, after that shorter cranks will overtake the guy on the longer cranks.

So the big question is:
Does a guy on shorter cranks on the same gain charge to the centre/ ~1/4 court / ~1/3 court faster than a guy on longer cranks.

If long crank man is faster to centre and ~1/4/~1/3 of the court, longer cranks are basically always better in polo. If short cranks are faster to the centre , then crank length is pretty much a compromise. If short cranks are faster to ~1/4/~1/3 mark as well as centre then short cranks are probably generally better than long cranks.

andytk
andytk's picture

I'm confused.

Voidcore
Voidcore's picture

Are you still going for it then? (The 150 cranks)

Emyr
Emyr's picture
Joe wrote:

What I really don't know is how fast you can get in a few metres from a standing start though...it's kinda more like the equivalent of riding up a hill (where longer cranks are preferable) so longer cranks are probably better from standing/slow starts to accelerate to point X, after that shorter cranks will overtake the guy on the longer cranks.

So the big question is:
Does a guy on shorter cranks on the same gain charge to the centre/ ~1/4 court / ~1/3 court faster than a guy on longer cranks.

I'd say that the start of a polo game is halfway between a BMX start and a Gate-start on the Track, so having longer cranks will help you when you're doing that initial effort before anything's really started moving. It's a greater set of muscles.

You could argue that there is no reason for track cyclists to use long cranks but the greater range of movement allows for more efficient use of muscle power.

tl;dr:

Get 170mm or 175mm cranks, MTB ones with a 104mm BCD if you go for a 135mm rear axle. External BB (e.g. Hollowtech2) systems are great.

Get 5-arm 110mm bcd (marketed as road compact or cyclocross typically) if you're using a 120mm rear end.

Joe
Joe's picture

I'm thinking at least 70% Orange :D

Joe
Joe's picture

Ok, 170mm sounds like a good compromise with 36/22 gearing. Phew!

Is your rear wheel 120 or 135mm Emyr?

Joe
Joe's picture

I'd say I'm prioritising polo skills/development rather than tinkering.. I havn't had much experience with dual brake, not sure how much advantage they give you.

Emyr
Emyr's picture

My rear wheel is 135mm, 10mm axle with 15mm nuts. Proper.

Emyr
Emyr's picture

Just checked your updated list, might be able to help you with the chainring (got a golden eThirteen 35T "guide ring"), bars and front brake (Avid Juicy 3, you might prefer cable though).

Joe
Joe's picture

All of those things sound very good, what kind of bars are they?

snottyotter
snottyotter's picture

Those ethirteen rings are meant to be good.

Emyr
Emyr's picture
Joe wrote:

All of those things sound very good, what kind of bars are they?

Pics later.

Neil
Neil's picture
Joe wrote:

I'd say I'm prioritising polo skills/development rather than tinkering.. I havn't had much experience with dual brake, not sure how much advantage they give you.

It's 2013 and no-one is going to get a clear bike advantage other another bike/rider combination in polo these days - what we are all striving for is a personal tool we can use, that we can trust in, that we can forget about and focus on the game. No one bike will have universal properties and most experienced players inch their way towards their current set up rather than making huge changes.

Hence dual brakes offer no universal player advantage per se - however if you tend to position you weight midships or to the rear then you will almost certainly benefit from a rear brake in many situations. Until you know for sure it'd be naive to build a bike without the capability IMHO.

It's a personal reflection - but we do seem to find it so much easier to talk about the tools and not about the game. I can't remember many threads about how to perfect backhand shots/passes or the art of the block/screen....

snottyotter
snottyotter's picture

Perfect backhand shots come from having the correct amount of spokes, blocking is all about tyre tread compound.

Rincewind
Rincewind's picture

smart guys arnt suspension corrected, infact they're lower than the lite guys,which arnt in stock anyway and havnt been for ages.

according to rocknroll bikes:

Gentle curve for good shock absorption and approx. 30 mm rake with 400mm length and good tyre clearance.

http://www.ebay.co.uk/itm/Onza-smart-guy-rigid-lightweight-alluminium-tr...

can you not say stuff that you dont know is true to stop confusion please? I already spent time researching the smart guy forks and knew the lite guys wernt in stock.

Voidcore
Voidcore's picture

Are you front brake only at the moment? I would be tempted to get removable mounts and disk brake tab anyway, better for future proofing and selling on

Joe
Joe's picture

I am front break only atm yeh. A 400mm length gives me 68mm clearance I think- would less clearance be better?

Rincewind
Rincewind's picture

clearance from what? 400mm is axle to crown. NOT length for the wheel to fit. It will fit any size 26" wheel and tyre you'd use for polo though so no need to worry about 'clearance'.

However its really debatable on whether you want that number higher or lower, based on geo. 60-65 trail is what I think you should aim for. Shorter forks and longer HT make for generally stronger front end though, I wouldnt really regard that much though.

Joe
Joe's picture

Quite hard to find anything with less clearance generally, so 400mm seems good now, random shot in the dark - are these forks good/bad?

http://www.ebay.co.uk/itm/Martyn-Ashton-Alloy-Trials-Forks-26-Red-/22119...

http://www.ebay.co.uk/itm/ECHO-FORKS-PURE-DISC-TRIALS-/230956621811?pt=U...

Rincewind
Rincewind's picture

2 fork measuremnts to consider. rake / offset and axle to crown.

any fork would do, but you have to correct the frame to suit them. lower rake means you can make the head tube steeper and keep higher trail.

if you have more rake you need slacker head angle to get higher trail.

e.g. if the head angle is 74 with 30mm rake then trail is 60 (about right)

if the head angle stays the same and the same fork but with 40mm rake is used then trail would be 40. (real twitchy)

If you wanted to continue using that fork at 40mm rake then to get back to 60 trail you slacken the head angle to 73.

However I think that less rake steeper head angle provides better handling, as opposed to slacker head angle and more rake.

woops better get to polo, inabizzle.

Emyr
Emyr's picture

When you turn the steering to 90 degrees the trail approaches zero and the front end drops. For the same trail, a slacker head angle gives you more drop. This is one of the emergent properties which causes jack-knifing.

Voidcore
Voidcore's picture

Oh sorry Scott those ones, I thought it was fly guy like emyrs, I used to have them there are too many onza forks! They look ok but ugly, the Ashton ones look good

snottyotter
snottyotter's picture

I love bear guys.

snottyotter
snottyotter's picture

#sohomo

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