2 replies to this topic

[gsp23]

Ok this is probably going to be an easy question for some of you who have been using wheelchairs longer but I have a bit of a mystery of the wheels on one of my chairs...

I have two chairs
1) Folding chair with standard 24" wheels which I hate but took the advice of the wheelchair store without knowing any better. I will some day be changing them out but not sure of what size till I figure out the current size of my rigid chair wheels.

2) Rigid chair with unknown size I am trying to figure out.

My rigid chair came with what Quickie says are 24" Heat Treated (559)

Ok, well 559 is 25" tires so I just figured that since they are heat treated then they have a bigger tire size. I know the hand rim is definatly larger (diameter) than the folding chair wheels and it is much nicer with the larger size. Ok so I basically thought I have the equivalant of 25" wheels. The tires that came on it were 20x559.

Well, I recently had to replace my tires and I ordered up some 25x559 which fit just fine. On the side of the tires it says "25x559 - 26x1". Now I just kinda blew that off as the bicycle tire equivalent size, of 26x1 but maybe that was incorrect assumption. When I pulled the tires off the tube said 26x1 on it as well but figured again that that was bicycle tire equivalent sizing (maybe wrong assuption again). Then I got the tube pulled to the side and I saw on the inside of the rim it says "20-26". So now I am completely confused. Do I have 24", 25" or 26" wheels". If I can use 590 for the tires next time that makes more options available for tires as the 559s are pretty limited (althought I do like the ones I have now). Also, I am looking at maybe ordering some Spinergys. If I order them what size would I want if I want equivalent to the ones I have now? I know Spinergy even lists the 20-26 as 590 which is what I always assumed to be correct, but I wouldnt want wheels larger than what I have now so maybe the 20-25 Spinergys are the correct ones?

Anyone that can help to clarify my wheel size mystery, I would really appreciate it.

[russ1]

Ok firstly you definately have 25" wheelchair wheels - 559 is the bead seat diameter of the tyre - the inner diameter of the tyre and is the only important figure there.

However you have bike tyres on there which is why they're marked as 26x1 (a wheelchair tyre marked as 26x1 has a bead seat diameter of 590) this is because 559 is the bead seat diameter of mountain bike tyres that are usually fatter and thus create a outside diameter or 26" whereas with the skinny tyres the actual outside diameter is about 25"

I think the figure on the rim 20-26 refers to the recommended width of the tyre in mm - the 20 or the 25 in the 20x559 or 25x559.

The good news is you can now stop looking at the limited list of wheelchair tyres and start looking at bike tyres - I have a set of Hutchinson 25x559 bike tryes on my chair that are superior to wheelchair tyres in just about every way imaginable.

The inch marking on a tyre is highly variable - if you buy by bead seat diameter you won't go wrong so you want 25" spinergies. 26" wheelchair wheels are markedly bigger and unlikely to suit you if you like the 25" you already have.

If you want the whole story on tyre sizes it's here http://sheldonbrown....ire-sizing.html

Hope that clears it up but if not ask away

[gsp23]

Great, thanks for the info. I had a feeling it was just a difference between bike and wheelchair tires. Since the tires I have on their now are primos and are sold through wheelchair suppliers like Sportaid, local wheelchair store, Edmunds, etc. I thought that they were marketed wheelchair tires. Then when I saw the markings on the rim I really got confused. I absolutely hate the 24" wheels on my other chair they are way too small. That one inch makes an amazing amount of difference. I know that I dont intend to get new wheels from a wheelchair store cause they are way too expensive and for some reason I feel guilty going in wasting their time to try things out only to know in my head I have no intentions of buying from them. I am glad you cleared this up. I used to be a cyclist so I worked with lots of different tires before but apparently still learning some things about the wheelchair tire sizing.

Thats great to know that I can use bicycle tires though because there sure arent a lot of options out there for 25" tires... lots of them in the 37x540 though, which I dont like. So far I like the primos I just bought but I have only been using them for abuot a week so we will have to see how they hold up as I use them more.

Thanks for clearing this up, I had a feeling it wasnt as confusing as I was making it out to be!