Messages

361

The Bike Shop / odyssey quik slic cable

« on: August 06, 2012, 03:18:20 PM »

Do you have cable sticking out of the back hole? You should aim to have the cable flush with the outer face of the clamp on the otherside.

The distance from the edge of the cable hole to the closed end of the clamp body should be a touch under 3mm and this should be compatible with all levers (especially our own obviously).


G.

362

The Bike Shop / definitive freecoaster thread

« on: July 31, 2012, 06:23:59 AM »

I just realized I said Ratchet when I meant G-Coaster. Will I be able to crankflip on the G-Coaster?

Not really. I mean it might go round if you kick really hard, but there will always be an inherent conflict with how all freecoasters work.
When you back pedal there HAS to be some drag to the axle to retract the engagement parts, so in the KHE style ones this would be the ball springs dragging on the clutch. In the G-Coaster (if we ever get it out) it would be the axial spring on the cams.

Dont hold your breath though.


G.

363

The Bike Shop / 22 inches

« on: June 21, 2012, 02:52:57 PM »

I fucking hate how people make these bigger bikes, and put smaller bars on them. Like they should be the same height as a 20" for some bizarre reason. Make that shit HUGE, 12 inch bars and it'd be a giant BMX instead of some shit that's impossible to bunnyhop like a 20incher.

It would be better to use a longer head and steerer tube. We are already pushing what is sensible having 9 and 10 inch bars clamped on a 7/8" tube. Seriously think about the leverage involved. 10" is nearly 23 to 1 ratio, by the time you get enough pressure on the clamp tube to take typical riding forces you are getting very close to crushing the clamp tube and the loads in the tube itself are getting very big...


G.

364

The Bike Shop / 22 inches

« on: June 20, 2012, 08:35:55 AM »

Charlie (from bmxmuseum) built up a sweet STANDARD 22". His has +1.5" bb rise (12.5"bb) and 21" top tube.  Killer!


http://bmxmuseum.com/forums/viewtopic.php?pid=3534258#p3534258

Nice.
Good to see that they didn't dimple/ruin the chainstays on that. Any idea on Chainstay length?


G.

365

The Bike Shop / 22 inches

« on: April 07, 2012, 03:11:53 PM »

I like to run as close to 55 gear inches as possible.. on my 20" I run 36x13 on my model c I run 30x13.  When I rode Taj's proto wave c and then later Jim C's wave c the main reason I didn't upgrade from the model c to the wave c is the lack of chainwheel clearance.  

I like big chainwheels and big cogs not tall gearing.  I don't like wearing out my drivetrain quickly and also deal with massive tight/loose spots.

You cant have everything. We worked very hard to get good tyre and sprocket clearance and still have a nice strong back end that wouldn't twist or bend. Hence the wishbone and rectangular to round tapered (and dent resistant) chainstays. Seriously a lot of work went into them. If you are happy with the longer chainstay then stick with the frame you have, but personally I love the slightly shorter stays and 22/10 works great for me. The difference between a 9 tooth and a 10 is fairly substantial (in terms of chordal action etc) however the difference between a 10 and a 13 is pretty small.
http://chain-guide.com/basics/2-2-1-chordal-action.html (the difference between 9 and 8 is obviously enormous).


G.

366

The Bike Shop / 22 inches

« on: April 06, 2012, 06:55:36 PM »

that's not uncommon with bigger wheeled bikes that also have short chainstays. (they have to bow out to accept the wheel that close to the bottom bracket).  the Liquid Feedback 24" is the same.  the Sunday Wave C 24" as well if I'm not mistaken.

The WaveC will take a 28tooth no problem.

It is obviously important to allow for wheel size, so the 26t on a 22" is equivalent to a 28.6 tooth on a 20".


And the 28tooth on the 24" Sunday is equivalent to 30.5 on a 22" or 33.6 on a 20" ... which should be plenty for anyone.  
I have a 22tooth on mine but its pretty hilly here.


G.

367

The Bike Shop / 22 inches

« on: April 02, 2012, 03:12:45 PM »

But even using the brake your pivot point is still around the axle?

The bushing in a driver shouldn't have an effect whilst manualling, only the spring/pawl set up?

Tha hang 5 thing, maybe cause there is marginally more weight further away from the rider than a smaller wheel?

Actually thinking about it maybe a bigger size wheel of similar weight has more angular momentum (gyroscope)?

I kinda like the look of 22" bikes

Imagine locking up the back wheel, the bike will then be like a solid lump and roll around the tyre.

You are absolutely right, the boshing wont matter, just the pawl drag as you say... dont know what I was thinking...

When you make a correction in either a hang 5 or a manual you do so because your centre of gravity is no longer over the contact point. When you correct you shove your weight back towards the contact patch, but you also pull the bike back under you. So weight and momentum will be "felt", however until you brake or add drag I dont think that the specific radius is important except as so far as it effects rolling and momentum.

I do love my 24"


G.

368

The Bike Shop / 22 inches

« on: April 02, 2012, 09:54:33 AM »

IF you had a perfectly smooth rolling hub, then the bike would only really pivot around the hub axle as long as you stay off the brake, but as soon as you start touching the brake it will start to roll around the tyre as well. So any friction in the hub (hubs are very smooth but not perfect, and when you are balancing you may notice this, especially if there is significant drag in your driver say if it is a bushing one rather than one with proper rolling element bearings and you run a tight chain) will be a similar effect.


G.

369

The Lounge / Steven Hamilton

« on: March 26, 2012, 01:48:37 PM »

Fuck the controversy that was a great bit of video...


G.

370

The Bike Shop / 22 inches

« on: March 12, 2012, 07:45:48 AM »

Inner tubes have a lot of stretch and forgiveness, I would guess that in a pinch you can use 20" tubes with no problems.


G.

371

The Bike Shop / 22 inches

« on: March 09, 2012, 06:13:29 AM »

Can we go back to the basic machines and £11.50 tires please?

Not unless you can get oil back down to $60 a barrel and all other raw materials to follow suit...

How much is a loaf of bread now compared to then? Price increase is about the same...

The better machines are quicker and produce less rejects, so the extra cost of buying them is about balanced by the savings, we just get better tyres..


G.

372

The Bike Shop / 22 inches

« on: March 06, 2012, 06:21:06 PM »

Haha, that article is awesome.... Shows how far BMX has come... at least we dont have to worry about what race category it fits into...

The article also mentions having different sized front and rear wheels, something that motorbikes often do (did?) been tried on MTB's too... slightly smaller back wheel would allow shorter stays and front would still monster truck over stuff.... ah the possibilities are endless...

Right I am off to design a mountainbike with a 29" front wheel and 22" rear...


G.

373

The Bike Shop / 22 inches

« on: March 06, 2012, 03:07:18 PM »

I'm far from a pro. Just some guy who is testing a bicycle.....

I do have HUGE respect for G/Odyssey however, the way G was talking he was all but shutting this thing down. Sure it's a niche market but if one company is making the tires, they'd be getting all the sales. Looks like those sales will be going to Fit/Revenge....

This really was not my intention, please re-read what I wrote and try to see where I am really coming from.

As I already stated many times, I would LIKE to see this size develop and have a chance to prove itself. I then went on to try to have a mature conversation about whether I thought it was likely and I (stupidly it turns out) thought that people might be interested in what I see as the manufacturing pitfalls and also the potential performance pitfall. 22" could be better than 20" but the difference between a good tyre and a bad one could easily be enough to hide a lot of benefits...

I have been to tyre factories. I have seen the equipment used. I have had senior staff at the factory slag off their own "basic" assembly machines and then 2 minutes later asked them which machines make our 20" tyres and have them look sheepish and explain that it WAS the "basic" machines he just slagged off. (thankfully this has changed now and there are 20" versions of the "super duper" machines and it is these that have made OUR tyres for the last several years (3 or 4) and the quality has gone up and the QC rejection rate down as a result).

I think of this as "interesting information about how tyres are made", you somehow see it as an attack on the 22" size.

I KNOW that if WE walked into the factory and said we wanted to do a 22" tyre that we would have them try to talk us out of it for some considerable time. I realise that you may think that Odyssey is a big company, but to these tyre makers we are "small potatoes", we make a few thousand tyres a year in their factory that makes MILLIONS of other tyres, they do not want to make investments in new machines if they even VAGUELY think that it is not going to become HUGE. They would NOT be stoked on it and as a project it would probably not go well for us.... However I think that S&M/Fit ordered some improbably huge number of tyres last year so they may have got a better reception than I imagine... If so then that is great. If the tyre makers are cool with doing the size and either already have or set-up good machines for the assembly then I will have been proved totally wrong and I will be more than happy to say so... and yes we might even "jump on the bandwagon" and make parts for the size.

My point has always been that rims, frames, forks, spokes, tubes etc are all easy, it all hinges on the tyres, so if that is sorted then there is no reason it cant become super popular and maybe even take over from 20" as 29" is being predicted to do from 26" in MTB (though personally I will be sticking with 26" for a while yet).

I thought long and hard after typing this before posting it. I really dont want to further enrage you, I have better things to do, but at the same time I feel like there is an interesting conversation to be had here and I think it is worth one last crack at having it. I hope this makes sense and seems reasonable...


G.

374

The Bike Shop / 22 inches

« on: December 09, 2011, 06:04:20 PM »

I think you are missing what I am trying to say. Let me rephrase it.

Tyres are a real pain. PERIOD.

Doing any tyre is hard. 20" 24" 26" etc. It isnt something that you can set up to do in small volume in your garage like most other bike parts.

If someone asked us to do 22" rims or forks or frames or spokes it really wouldnt be a huge problem. We might lose money on it but we could do it.

When it comes to tyres there are practicalities of dealing with the factories that make them. They have huge production lines set up and they have machines set to each size of tyre that they like to leave set to those sizes so that they are consistant.

There are two basic tyre assembly machines/jigs and the basic ones make basic tyres and the fancy ones make fancy tyres.
It was hard getting the fancy machine for 20" and cheaper tyres are still made on the basic machine.

My opinion... is that getting the tyre manufacturers to set up fancy machines for 22" is going to be very hard. They will reason that people will either buy 20" or 22" and that there will be no net change to their sales volume, and these people dont listen to Fugazi.

I keep harping back to it, but the 29" situation is a good guide. 29" tyres can be assembled (this is prior to moulding the shape) on the same machine as a 700c road tyre. So they already have everything set up for the beads and assembly. All you need is a new mold and boom, done. MTB is also a massive market and there is way more competition between tyre making factories. Yet it still took a long time to get going...

I mention doing all the other sizes because I am a big believer in experimentation. I wasnt putting it up as an extreme example, I would genuinely like to do it. But if the 20" tyres are beautifully made then they will seem better than the 21" prototypes and that would skew the results. Much in engineering is how it is for stupid reasons and it irks me. Road bikes use 700c wheels because the UCI makes it mandatory. Can you imagine how much bikes would have advanced in the last 100 years if riders had been free to ride anything? Would we now be seeing fully suspended 20" wheeled recumbents competing against Graham Obree inspired uprights and fully faired Lotus bikes by Mike Burrows in the Tour de France? Might make for a much more interesting tour when one bike excels on the flat and another is better uphill and yet another downhill.

As I say, I love my 24" and I would love to do more 24" tyres, and I would love to try 22", but I am afraid that the deck is stacked against 22" in a way that it isn't against 24" and until I actually ride one (and more than a couple of older legends try it), I also worry that 22" is equally as likely to be the worst of both worlds as it is to be the Goldilocks zone...


G.

375

The Bike Shop / 22 inches

« on: December 09, 2011, 06:01:39 AM »

I'm sure the people who rode those tires in the video are fearing for their lives that their tires are going to explode any second. I'm sure they just didn't show how the tires rolled off the rims every other minute when they filmed the video.

Hey, I have never tried them myself, just going off the feedback we got from legendary bike riders who tried the size and liked it but couldn't get the performance they wanted from the tyres so asked us if we were planning on doing them.
I thought my input might be constructive but I guess not...
I am open to new sizes etc, I love my 24" and would happily try this size too, but when we look at the practicalities of it, the tyres are a major hurdle, much more so than doing 29" was for MTBers. If there was a common bead the tyres could share with road or mtbs or something then it would be a lot easier... The 24" tyres we do now are already a bit of a headache from our point of view.
Stuff like this needs to be top down. Top riders try it and like it, so it trickles down and THEN you get cheap bikes using it. This is what 29" has done. Hard to see how it could work the other way.
Local shredder sees beginner kid with department store bike on 22" and thinks, hey I will give that a go, local shredder goes to bigger comp and pro riders see it... Seems unlikely..
Thread is nearly 3 years old now and has reached 4 pages in that time on a super nerdy site like this... not exactly a huge response... Sorry to be negative, as I say, I would love to try it, and I would ideally love to be able to build half a dozen bikes up with 19", 20", 21", 22", 23" and 24" wheels (or even more intermediate sizes) and try them all, but the reality of the industry is that BMX is small and relatively unprofitable branch (compared to "adult" bikes) and this is a small segment of that small market, its hard to see how we could ever get the tyre manufacturers (who need huge numbers) excited about it... "hey on a few years we might get 10% of 5% of your sales, so that is half a percent of what you make?!?!?!"

G.