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Wheels
Jul 12, 2013 4:21:18 GMT
Post by sportsracer on Jul 12, 2013 4:21:18 GMT
I've noticed some carts are running 20" BMX wheels. Are these strong enough or should I stick to 16" bicycle wheels? Are there any tricks to making spoked wheels stronger apart from double or triple lacing them and soldering a piece of wire wherever the spokes cross?
I have wheelchair hubs that have 16mm axles and I want to build up some good wheels using these hubs. They have 32 spokes and I can get double wall 16" rims and 115 psi tyres to suit but they are expensive. 20" rims and tyres are cheaper but are they strong enough?
Cheers
Paul
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Wheels
Jul 13, 2013 21:51:29 GMT
Post by caisse433 on Jul 13, 2013 21:51:29 GMT
hi, there some year, I have see this wheels, in germany: and a belgium driver have made that:
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Wheels
Jul 13, 2013 23:56:19 GMT
Post by sportsracer on Jul 13, 2013 23:56:19 GMT
When I win Lotto I'm going to have someone make up wheels like these. Fantastic looking but how well do they perform?
Another question I have is, with BMX wheels do you use alloy rims or steel? Steel would be stronger but weigh more and therefore more inertia when you start rolling. It would also require more time to slow down for corners and take longer to speed up. Alloy would bend easier in cornering or are alloy wheels as good as steel wheels?
Cheers
Paul
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Wheels
Jul 14, 2013 0:08:08 GMT
Post by sportsracer on Jul 14, 2013 0:08:08 GMT
Here's a few pictures of a BMX wheel that looks like it is twisting under load or the suspension is bending. Does anyone know if the wheel was useable after the spin and was it a steel rim or alloy? Strange that the back wheel didn't deform as well. I would have thought there was more weight at the back of a cart. Cheers Paul
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Wheels
Jul 14, 2013 0:41:47 GMT
Post by caisse433 on Jul 14, 2013 0:41:47 GMT
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Wheels
Jul 15, 2013 0:18:51 GMT
Post by Scottish Cartie Association on Jul 15, 2013 0:18:51 GMT
20" BMX wheels tend to be more common in the UK because they are easier to get hold of and there is a better choice of high pressure tyres. They are slightly heavier and bigger than 16" wheel, so accelerate slower and have lower drag, although the weight advantages are marginal and one courses with lower incline or uphill sections they might even be a disadvantage.
As for steel or alloy rims - most people don't get to choose. They just use whatever they can get their hands on. 20" BMX wheels with 48 spokes are usually ok for even the hardest use, although they can sometimes be mangled in a crash. As for the pictures you found - I don't know what the rims are, but if I recall correctly the were fine after the incident. I don't know anyone who is double lacing, soldering spokes or anything like that. Usually people just get 48 spoke BMX wheels and leave it at that. The bigger challenge is trying to find 20" wheels with disk hubs.
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Wheels
Jul 15, 2013 7:08:02 GMT
Post by sportsracer on Jul 15, 2013 7:08:02 GMT
I've got lots of 16" and 20" wheels and bicycles from the local tip - you'd be amazed what a small town can throw out. Building a cart from these parts should be easy but building a real racer is going to take some money.
prowheelbuilder.com sell a disk brake BMX hub in axle sizes that go up to 24mm. Problem is they want $213 per hub. Add another $64 for a 16" alloy velocity rim and $66 for a 115 psi tyre to suit. That's over $340 per corner and I haven't even bought the disks or calipers yet. Luckily there are very few organised races in Australia so I can build up my cart for fun.
I've been looking at the performance of C12 at Cairngorm on youtube and I'm very impressed, especially where it pulls away from other carts at the start line and the speed it goes through the esses. It has 16" wheels doesn't it?
Cheers
Paul
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Wheels
Jul 15, 2013 8:46:48 GMT
Post by Scottish Cartie Association on Jul 15, 2013 8:46:48 GMT
Well as I said before - most people don't get to choose what wheels the get - they just use what they have lying around or can scrounge. Sometimes you'll get some bargains on ebay. When you get into custom built wheels then costs add up pretty quickly. (If money is no object, though check these out...) C12 does run on 16" wheels, but they are custom made carbon disks.
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Wheels
Jul 15, 2013 15:09:37 GMT
Post by sportsracer on Jul 15, 2013 15:09:37 GMT
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