New Tyres on my Puma 40

Power wheelchair board for REAL info!

POWERCHAIR MENU! www.wheelchairdriver.com/powerchair-stuff.htm

Re: New Tyres on my Puma 40

Postby elryko1992 » 29 Dec 2017, 23:31

Yes, for me is perfect 2,5. Here in Romania measure is in Bar, sorry i don’t know the PSI.
User avatar
elryko1992
 
Posts: 385
Joined: 05 Aug 2016, 21:08
Location: Romania

Re: New Tyres on my Puma 40

Postby Burgerman » 30 Dec 2017, 01:11

36... IS 2.5 Bar.

2.5 Bar IS 36psi...
And yes too high.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: New Tyres on my Puma 40

Postby hobie1dog » 01 Jan 2018, 04:14

Thanks for sharing this with us, and the pictures
Earth: The Insane Asylum of the Universe-nowhere else could things be more screwed up.

Invacare M61
Quickie S636- 3.00-4 tires, Chevy seat
User avatar
hobie1dog
 
Posts: 599
Joined: 17 May 2016, 15:53
Location: Cornelius, NC, USA

Re: New Tyres on my Puma 40

Postby inglegrump » 03 Jan 2018, 15:11

Hi. I'm about to change the solid tyres (big mistake) to tubed on my Puma 40. I was intending on puting some gunge in but am no sure about a couple of things. Can anyone help me with: how much to put in and how do you judge this ?, does too much compromise the effect of a reduced pressure of a tubed tyre. I'm asuming the tyre/tube needs to spun in order to distribut the gunge. Is it practical to put the gunge into the tube before fitting the tyre ?. Any advice would be appreciated. Thanks.
inglegrump
 
Posts: 31
Joined: 13 Mar 2014, 02:08

Re: New Tyres on my Puma 40

Postby expresso » 03 Jan 2018, 17:02

inglegrump wrote:Hi. I'm about to change the solid tyres (big mistake) to tubed on my Puma 40. I was intending on puting some gunge in but am no sure about a couple of things. Can anyone help me with: how much to put in and how do you judge this ?, does too much compromise the effect of a reduced pressure of a tubed tyre. I'm asuming the tyre/tube needs to spun in order to distribut the gunge. Is it practical to put the gunge into the tube before fitting the tyre ?. Any advice would be appreciated. Thanks.



I had the same thing done to my tires - first time on tubes - i had the bike shop install them and add the Slime - - i can say this - so far - on the front small caster tires - i wont add it again next time or when i change the tubes - on one chair - they are clogged i believe - not able to add Air - you can remove the valve stem and clean it - unclog them and they may work after - i havnt tried it yet - since its winter here and cold - not using it much and i can use the chair fine with low PSI on the front caster tires anyway -

with the rears - its better - but can still be problematic i think - - i wouldnt overdo it too much - depending on tire size - tube etc, - what ever your going to use - read the instructions - i would think a 16 oz size - use about 1/4 for one rear tire - half a bottle for both rears and leave the fronts alone - or just very little in the fronts smaller tires -

this is my experience so far with tubes the slime - slime is what its called here in the States US - there are many other names etc, - to be honest i think having a Real street Tire on the rears - strong heavy duty Tire - most likely would even be all you need with out adding anything - but like you - i felt it cant hurt and added some anyway - - i think having a good tire would be all thats needed - as long as you dont wear it down to the bone before changing tires - so far i used my chairs with tires and tubes one summer and seem fine - hardly no wear that i can easily notice - i think they may last a good 3 to 5 years - the front tires different story - wont last as long and i rather change them sooner rather than later -
Quickie 636 - 230ah LifePo4
expresso
 
Posts: 11916
Joined: 10 May 2010, 03:17

Re: New Tyres on my Puma 40

Postby shirley_hkg » 04 Jan 2018, 03:02

THINK CAREFULLY , for those who want to use SLIME on tubes !

I used to be able to cripple home with a flat tyre with no sealant .

That time I got one tyre pinched , and SLIME leaked into the tyre with the escaped air .

That formed a very slippery surface between the tyre /tube /rims , thus taking away all the traction . My rim just spin freely . The other wheel rolled , and my chair wasn't moving but spinning in circles .

SLIME doesn't work on tubes . It simply makes it worse .

You don't see cars with tube now, do you ? Honesty , try your best to go tubeless , if you want pneumatic wheels . :bravo cheers
Attachments
IMG-20180104-WA0000.jpg
shirley_hkg
 
Posts: 3918
Joined: 31 Dec 2010, 13:42

Re: New Tyres on my Puma 40

Postby expresso » 04 Jan 2018, 03:18

good idea - i might not add any the next time around - its a done deal for me already - i have two chairs with slime - and my new chair will have it added from the factory -

you must have had a bad hole - big enough to leak out and not work - i have to keep an eye out on my tire trend as it wears out - i was just starting to feel safe and now you have to scare me again :D

tubeless is much more involved for some of us - me being one - easier said than done - but can keep it an option for who knows when - with tubeless - you still have to add or want to add some sort of off road sealant also - if not slime - something else - all do the same more or less
Quickie 636 - 230ah LifePo4
expresso
 
Posts: 11916
Joined: 10 May 2010, 03:17

Re: New Tyres on my Puma 40

Postby snaker » 04 Jan 2018, 03:37

shirley_hkg wrote:Honesty , try your best to go tubeless , if you want pneumatic wheels . :bravo cheers

Links please shirley, I cannot afford UK style :mrgreen:
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: New Tyres on my Puma 40

Postby shirley_hkg » 04 Jan 2018, 08:30



1£ → CNY ¥8.7968
Attachments
IMG-20180104-WA0011.jpg
shirley_hkg
 
Posts: 3918
Joined: 31 Dec 2010, 13:42

Re: New Tyres on my Puma 40

Postby Burgerman » 04 Jan 2018, 11:12

Too small.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom


Re: New Tyres on my Puma 40

Postby Burgerman » 04 Jan 2018, 13:27

User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: New Tyres on my Puma 40

Postby ex-Gooserider » 12 Jan 2018, 06:05

Interesting - at least the pictures... Unfortunately I don't read Chinese, so can't get much of the details.... However from the pictures, it looks like there might be something that would be a bolt-on tubeless conversion for my Ranger X...

Shirley - does this seem possible, and would you mind looking through the listings to see if there is anything that might work? (It would help to have at least a guess about US $ prices and shipping costs as well...) I'd probably want to get 4 wheels in order to have a spare set.

The stock wheels have 3.00-8 Primo Powertrax solids on them. Pretty standard 'hospital grey' squarish cross section with knobby tread. They bolt onto hubs that are attached to the motor shaft, just like a car so if I could get the right bolt circle, and the appropriate depth, a tubeless wheel should swap on easily...

Doing some quick measurements (eyeball caliper center-center on the nuts) I get a 2.5" bolt circle - it seems unlikely that it would be much different from that, if it's inch, which I'd expect....

Not sure about the depth, but the ends of the nuts are just a bit past the edge of the rim, but inside the bulge of the tire - I can pull the wheel and try to get a more precise measurement if needed. If I don't use the fenders, it looks like about 3/4" of clearance between the inside of the tire and the chair frame, motor or other obstructions

I'd like to stick to a tire about the same OD, and keep the width close to what it is now... Tread pattern / profile is not real critical, but it seems to me like a flattish contact patch would be best for tire wear and traction... Obviously it is more important that the wheel fits the hub than what tire is on it - assuming it's a standard size that can be changed...

ex-Gooserider
T-5, ASIA-B
Jazzy 1100
Jazzy Select 6
Quickie Q-7
Invacare Mariner
Want to make / get a better chair, ideally one that stands.
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: New Tyres on my Puma 40

Postby shirley_hkg » 12 Jan 2018, 08:30

It will work on brushed motors only .

For GB , you need 10" rims like me .
shirley_hkg
 
Posts: 3918
Joined: 31 Dec 2010, 13:42

Re: New Tyres on my Puma 40

Postby ex-Gooserider » 13 Jan 2018, 04:36

I know that, but I have two of the H-frame chairs, one with brush motors, one with the old MKIV series brushless... As I have concerns about the future parts availability, and the clunkiness of the MKIV controller hardware, I have been working mostly on the brush motor chair....

I am interested in getting the wheels for the brush motor chair.

ex-Gooserider
T-5, ASIA-B
Jazzy 1100
Jazzy Select 6
Quickie Q-7
Invacare Mariner
Want to make / get a better chair, ideally one that stands.
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: New Tyres on my Puma 40

Postby shirley_hkg » 13 Jan 2018, 05:57

BM has the wheels already and may have more specification to share ..

Price US $35.00 rim + tyre

Shipping US $100.00 for 4 at my estimation of a 8kg parcel .
shirley_hkg
 
Posts: 3918
Joined: 31 Dec 2010, 13:42

Re: New Tyres on my Puma 40

Postby Burgerman » 13 Jan 2018, 10:46

Mine are 3.5 wide for 120/70 - 8 tyres.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: New Tyres on my Puma 40

Postby shirley_hkg » 13 Jan 2018, 12:10

More . Diameters of centre hole and the 4 bolts .
shirley_hkg
 
Posts: 3918
Joined: 31 Dec 2010, 13:42

Re: New Tyres on my Puma 40

Postby ex-Gooserider » 14 Jan 2018, 07:17

I can't find a good comparison chart for the size tires we use - all I could find was stuff on car tires...

So my current tires are 3.00 x 8

Several of the wheels you had links to above had 3.50-8 tires in the pictures, with tread patterns / profiles not that different from my current tires...
https://item.taobao.com/item.htm?spm=a2 ... t=8#detail
https://item.taobao.com/item.htm?spm=a2 ... t=8#detail
https://item.taobao.com/item.htm?spm=a2 ... t=8#detail
https://item.taobao.com/item.htm?spm=a2 ... t=8#detail
https://item.taobao.com/item.htm?spm=a2 ... t=8#detail
https://item.taobao.com/item.htm?spm=a2 ... t=8#detail

I'm guessing from the photos that these are complete wheel / tire assemblies?

I'm not certain of the difference between a 3.00 x 8 and a 3.50 x 8, but if I'm remembering BM's discussions elsewhere, the 3.5 would be 1/2" wider and 1/2" taller, which I think would not be a big problem...

I haven't pulled a wheel to get more detailed measurements, but it looks from where the valve stem hole is on the stock split rim tire vs. where it looks like it is on the wheel's in Shirley's links (which look like they are all the same wheel, just from different vendors?) that if I turned the valve 180* it would line up about right....

One of the links shows the valve hole being about in the center of the inside of the rim, while others show the valve stem is offset from the mounting surface to the outside. On my chair, it looks like the hole is offset to the inside of the mounting surface a similar amount... If so, and the hole bolt circle is OK, then it might be a straight bolt on... Even if the circle isn't right, if the diameter of the inside hole is small enough, I have access to a CNC mill that even has a program for doing bolt circles...

ex-Gooserider
T-5, ASIA-B
Jazzy 1100
Jazzy Select 6
Quickie Q-7
Invacare Mariner
Want to make / get a better chair, ideally one that stands.
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: New Tyres on my Puma 40

Postby ex-Gooserider » 15 Jan 2018, 06:15

OK, I have pulled one of the wheels off, and gotten some better measurements - with photos, so several posts...

The wheel as seen from the outside -
wheel-outside.JPG


And the inside -
wheel-inside.JPG


The tire width is 2.7" and has an OD of about 13.5"

tire-width.JPG
T-5, ASIA-B
Jazzy 1100
Jazzy Select 6
Quickie Q-7
Invacare Mariner
Want to make / get a better chair, ideally one that stands.
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: New Tyres on my Puma 40

Postby ex-Gooserider » 15 Jan 2018, 06:47

It bolts onto this hub....

close up -
hub-close.JPG


a bit further back -
hub-side.JPG
(those little "Lab-Jacks" are very handy for lifting...)

and from the side -
hub-side view.JPG


There is about 2.3" between the mounting face of the flange and the motor gear-box. It appears from checking with a straight edge that the gear box is just about even with the chair frame - so presumably I could have about 2.25" of wheel and tire width on the inside of the mounting surface before hitting the frame, though I'd be more comfortable with 2".

It might be possible (but difficult) to pull the hub and shorten its shaft to move it in, obviously not a big deal to add spacers if needed...

The bolt circle is a bit more interesting perhaps? Averaging the distances I got with my caliper between the insides and outsides of the opposite studs, I got 2.424", not the 2.5" I'd guessed at previously. Comparing to metric, 62mm = 2.44" is that a common size? Setting the caliper to 2.4" and eyeballing it for fit on the stud centers looked closer than it did when set to 2.5"...

Is there any sort of list of likely bolt circle diameters that would show the probable match?
T-5, ASIA-B
Jazzy 1100
Jazzy Select 6
Quickie Q-7
Invacare Mariner
Want to make / get a better chair, ideally one that stands.
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: New Tyres on my Puma 40

Postby ex-Gooserider » 15 Jan 2018, 06:50

I also think I've measured everything of interest on the wheel -

The distance from the outside of the rim to the inner mounting surface - 1.4"
dist-rim-flange-int.JPG


The distance to the outer mounting surface - 0.45"
dst-rim-flange-ext.JPG


I used the depth probe on the caliper to measure the flange thickness - 0.25"

The three numbers totaled 2.1" - which matches tolerably to the 2.105" I got with the caliper through the holes in the wheel....

Measuring the rim to the split rim seam, I got 1.1"
dist-rim-split-inside.JPG
T-5, ASIA-B
Jazzy 1100
Jazzy Select 6
Quickie Q-7
Invacare Mariner
Want to make / get a better chair, ideally one that stands.
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: New Tyres on my Puma 40

Postby ex-Gooserider » 15 Jan 2018, 07:42

The bulge in the center of the wheel that covers the nut in the center of the hub actually sticks out more than the tire...

Measuring the total distance from there to the table -
total-wheel-width.JPG


I got 2.85" total width for the wheel with tire.

Earlier I measured the width of the tire as 2.7", minus 2.1" for the rim width gives me 0.3" of 'tire bulge' on each side, subtracting that from 2.85 gives me a total rim width of 2.55"

The valve hole had a bit of a strange shape, but was basically centered on the split of the rim -
valve-hole.JPG

(the elongated side of the hole is on the outside half of the wheel)

Also possibly of interest, is that among the other stuff on the sidewalls, is a line "Standard rim 2.5" - not sure what that means. IIn addition to the 'Made in China' on the tire itself, I noticed that the wheel still had some stickers on it, presumably manufacturing with Chinese characters - so I suspect the wheel was also China made. Checking the studs on the hub, they are 5/16 - 24 thread, so can't reach any conclusions about inch vs. metric sizing on the bolt circle...

ex-Gooserider
T-5, ASIA-B
Jazzy 1100
Jazzy Select 6
Quickie Q-7
Invacare Mariner
Want to make / get a better chair, ideally one that stands.
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: New Tyres on my Puma 40

Postby shirley_hkg » 15 Jan 2018, 08:57

Long before going tubeless, this was my Bridgestone 3.50-8 tube on an ARROW , A direct fit with original rims and everything , except moving the fender upwards .
Attachments
IMG-20180115-WA0004.jpg
shirley_hkg
 
Posts: 3918
Joined: 31 Dec 2010, 13:42

Re: New Tyres on my Puma 40

Postby Burgerman » 15 Jan 2018, 19:16

Stock 3.00 x 8 tyres fit 1.75 (looks a bit squeezed but common), 2.00, 2.25 inch rims. On some odd chairs that can even be 2.50 inches which is borderline too wide for a 3.00 x 8 tyre.

3.50 x 8 tyres need need 0.5 inch more than above to fit correctly. They are ok on 2.50 rims but would be better on 2.75 or 3.00. On less than these figures, they have the sidewalls pulled in, and the tread is too pointed, as shown in shirleys pic above.

110/80 and 120/70 - 8 tyres need 3.25 and 3.50 inch rims respectively for proper fit, or 3.5 for 110, and 3.75 to 4 max for 120 tyre.

This is how to measure, and the rim on my desk is 3.50 wide inside the lips as shown, but is also available in 2.50.
Attachments
810_1662-1024.jpg
Image1.jpg
Image1.jpg (28.7 KiB) Viewed 12307 times
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: New Tyres on my Puma 40

Postby Burgerman » 15 Jan 2018, 19:21

And...
300 x 8 tyres are 14 diameter. Often a little less however.
350 x 8 tyres are 15 diameter.
110 x 80 - 8 tyres are 15 diameter.
120 x 70 - 8 tyres are 14.5 diameter.

On correct sized rims.
The 3.50 tyre is 1/4 inch taller and narrower if the rims are narrow.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: New Tyres on my Puma 40

Postby inglegrump » 06 Feb 2018, 20:19

I have finally got the solid tyres on my Puma 40 replaced with some pnumatics. I now realise that solid tyres should be banned as a health hazard. Went down the road and bounced through the potholes instead of hitting them like a brick. When I say bounced even the suspension was working like I have never felt it before. Fabulous. :dance
One thought about wheels and tyres. Back in my rallying days from 1968 into the 70's was a time when everyone started using wider wheels and tyres, everyone except the Scandinavians. They used narrow wheels on the theory that in snow and loose surfaces putting the weight onto a smaller footprinnt and displacing less mush actually gave them better traction and more speed. They were winning just about everything so a good theory ??
inglegrump
 
Posts: 31
Joined: 13 Mar 2014, 02:08

Re: New Tyres on my Puma 40

Postby Burgerman » 06 Feb 2018, 23:03

If you want to sit on top of mush and snow, wide tyres are great. If you want rubber on road, and want to sink through the snow or surface crap for better grip then thinner is better.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: New Tyres on my Puma 40

Postby ex-Gooserider » 05 Jan 2019, 06:22

Dragging this thread back up since it has some good pictures of my existing wheels and hubs on the Ranger-X... I figured while I'm waiting for the next set of tires for the casters to arrive, I'd get back to working on making the rear wheels I got from Shirley fit...

According to other discussion, the Shirley wheels have a 90.5mm bolt circle diameter and the center hole is 75mm.

As best I can tell, the existing wheels have a 62mm bolt circle, and the hub flange OD is about 82mm / 3.25" - or bigger than the center hole in the new wheel :problem:

There is about 1/2" (13mm) of space between the stock tire, and the fender bracket that is the tightest clearance point - if I moved that, might be another 1/4" or so to the motor... The stock wheel is a 3.0 - 8 tire, the new wheels use a 3.5 - 8 tire, so nominally 1/2" wider... (measured - stock is about 2.75" wide, new wheel is about 3.75" :thumbdown: - so much for nominal sizes....)

I definitely want to keep the chair as narrow as I can, so if I can use that space and pull the new wheels in as far as I can, then the end result will be nicer wheels without making the chair much wider :thumbup:

To make things even more annoying, the mounting flange on the new wheel is more towards the inside of the wheel than the old one, so just pushing the new wheel up against the hub flange gives me 0.625" 15mm of space, plus the added wheel width would make the chair a LOT wider - so BM's approach of cutting an adapter plate to bolt to the outside of the hub seems out.... banghead

So I'm wondering what I should do? :eh:

For reference, I'm attaching a closeup photo of the hub that I've added some rough dimensions to show what I'm talking about
hub-side view_w-dims.jpg
hub closeup with dimensions

The hub is keyed onto the shaft, and sandwiched between a step on the motor shaft and the nut on the end (Yes I know that is not an ideal design!) so it's length seems pretty fixed. The material looks like cast / forged steel.

I have two or three ideas at this point - I am interested in feedback...

1. Turn the flange down to <75mm so the new wheel can go past it, and then make an adapter plate that is bolted or welded to the BACK of the flange... I would likely need to remove the existing studs out, and make different bolt holes... Given the 41mm diameter (which likely could be turned down?) I don't know if there would be enough 'meat' for a good mount...

2. Press the studs out, and put the hub on 'backwards' which would effectively move the flange face in about 35mm.... Then make an adapter disk that bolted into the existing holes in the flange (possibly press the studs back in from the other direction?) Rough math says I'd have more than enough room - 35mm -15mm = 20mm which means an awfully thick adapter plate, or possibly some interesting turning - but that's a solvable problem....

ex-Gooserider
T-5, ASIA-B
Jazzy 1100
Jazzy Select 6
Quickie Q-7
Invacare Mariner
Want to make / get a better chair, ideally one that stands.
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: New Tyres on my Puma 40

Postby Burgerman » 05 Jan 2019, 07:08

Not sure. But I figured out that the thinner rims and 3.50 tyres would be a pig to fit long ago. However you do it you end up with a not very elegant solution. Its why I used the taper-lock hubs on the old BM1 chairs. And the 3.5j rims and 120/70 tyres on the salsa. Because the motor shaft is too long for aftermarket skinny wheels. They have zero offset. You end up with the wheel having a nut or flange poking through.

You can do it with a set of these with the correct taperlock size for the shaft.

https://shop.eriks.be/en/mechanical-pow ... aper-bush/

Its what holds these on... http://www.wheelchairdriver.com/images- ... re-450.jpg
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

PreviousNext

Return to Everything Powerchair

Who is online

Users browsing this forum: No registered users and 321 guests

cron

 

  eXTReMe Tracker