3.5" tubeless tires

[expresso]

https://www.quickie-wheelchairs.com/rep ... caster-rim


item number 9 - goes in the middle and the bearing should have a nice snug fit - instead the bearings i got with this package were too large the ID - so item number 9 was loose - and i never checked it - i just checked that i had the parts but never tried to fit them -

i took the items with my tires and tire liners to the bike shop to do all the work - if i didnt have that extra new spare set of casters - rims with the correct bearings - i would have been screwed today - and not able to install the tires -

goes to show - always have to double and triple check everything - same as with the lithium packs - even when i swore i had everything - - been sitting here for weeks all that time - i would have gotten the bearings -

[Burgerman]

Mine is out of production but similar to these https://www.starrett.co.uk/shop/precisi ... _id=DM6172

Waterproof because I use it with a lathe and cutting fluid etc. Well made and extremely repeatable. And an extra digit. All helps!

[expresso]

When you search for bearing add RS or look for it. It means Rubber Sealed. And 2RS mans each side.

The ones you link to are zz so have a metal oil splash shield and are not sealed.

Ok - i will just go to home depot and bring the inner part that has to slide inside the bearing to be sure - or have to use amazon and then return if not correct




this one 10 pack at least - -


https://smile.amazon.com/dp/B01GLQXYVS/ ... RBQ2LAUELL

[expresso]

https://www.amazon.co.uk/J-Bonest-Stainless-Electronic-Measuring-Resistant/dp/B01N7CW7LQ/ref=pd_vtph_328_tr_t_2?_encoding=UTF8&psc=1&refRID=MQZXQYHTJVWTTDMJ0YK4

I may be tempted to spend a little extra after reading reviews of super cheap ones. Like this?

yes i would if i do get one - - i dont see the need enough right now -

[Burgerman]

https://www.amazon.com/6002-2RS-Ceramic ... +stainless

In the UK you can get stainless bearings as used in marine and food industry for the same price, literally a couple of dollars each. In the US stainless bearing are ridiculously priced! As above.

When a bearing in a powerchair caster or fork dies its almost always because water has gotten in, mixed with the grease and corroded the bearings running surfaces from the inside. Often because of carpet or other fibers getting wrapped around and into the rubber seal. And stopping it being water tight. Stainless ones dont care. They dont corrode! So they dont die.

You could sell stainless ones on amazon bought from here and make a small fortune!

[expresso]

i seen that one - i wouldnt buy it - the reg. ones are fine and last long enough - easy enough change also - i didnt notice any bearings on my Rear tire rim

dont think they are there

[Burgerman]

http://www.ebay.co.uk/itm/BL-Radial-Bal ... Sw~rpZOTLC

Cheaper on ebay... Above high quality. Or cheaper ones from 3 dollars!

You wont find any in a rear wheel, the shaft turns! The bearings are inside the gearbox.

[expresso]

half the cost there -

i cant tell for sure the correct size from pictures alone and the markings i have to double check that i didnt make a mistake and take a picture of the one that dosnt work instead - being how i missed a few things - i wouldnt be surprised

i will check the bearings i have which are too large tomorrow - if they are different markings - then i got the correct pic.

even at half price - its not cheap - 4 would cost around 50 dollars - when you can get a dozen for $15 and maybe never even change them once -

i never had to change them ever so far - on my chairs - Just once before on my very first chair - not sure what it was - since i didnt know much about chairs then i just remember hearing grinding noise - bearings i think -

i know they took the chair for about 6 months - and i got it back with new tires rims all around - noise was gone - i didnt know or care then what it was -

but i didnt leave that vendor after the next time i needed forks or something done to it - they said they had to take the chair - i said - you take care - good bye -
not taking it anymore - worse vendor - i had it out with there tech. and salseman a few times different occasions -

[expresso]

First ride with new tires - New issues now - Fender removed - i dont mind - but now it gets very dirty compared to before - i may see if i can add it again

thats the easy part - if i can - i will - if not - no big deal - i have to watch out for water - -

the more important issue - is both front casters wobble - flutter - what ever the correct term for it is - i had to cut my ride short today - i still did 21 miles

but had to slow down when it happens - had to be more careful on downhills - bumps etc, - so now i have to figure out how to fix this if i can -

i have to get the tech over to check everything again - i will change the caster position on the fork to lower it down more - - maybe will make better contact on the ground - and last lower the PSI a bit - it didnt feel bad but a few less should be better -


Can lowering the PSI and the wheel to the lower hole on the fork help the wheel wooble issue ? or make no difference ?

it feels as if its lighter on the front end - Can that be possiable from just changing out the tires - i would think having a larger rear tire would lean forward more on the casters - instead it seems the other way around -

unless if i change the caster postion on the fork - should drop the front end down a bit -

unless i get this resolved - will be short lived - and would have to go back to suspension forks with 8x2 tires and grey is all i have now - not good -

this chair does come with the larger fronts - fixed forks which i have - so really the only change is the rear tire - being larger overall -

cant use the chair this way - i can if i need to use - but cant leave it this way -

any ideas - suggestions would be welcome -

thanks

[Burgerman]

You have raised the whole chair. That makes caster shake more likely, as you get weight transferred all over the place on uneven ground. But it sounds like all your tyre pressures are very high.

Can lowering the PSI and the wheel to the lower hole on the fork help the wheel wooble issue ? or make no difference ?

It can make a big difference. Also lowering REAR pressures can stop shake too. As can tyre profile, seat position, and 101 other things. Air filled tyres are normally less likely to shake. And also new tyres do it more. Once they are worn in a week, then it will likely go away anyway. Similar to lowering pressures.

[expresso]

thats not good news to me - i have to get this resolved one way or another or else this will be a total waste -

i will try to lower the PSI all around - and put the caster on the other hole on the fork which will lower the front down a bit - i figured i put it on the bottom hole to keep it more level front and rear tires -

i hope that small adjustment along with PSI does the trick - if not not sure what else can be done - Homedepot didnt have bearings - only online ordering

i couldnt find a washer for the fork stem - or the stem bolt or Nut - i did manage to get a 15/16 socket - for the Nut on the fork
my tech had the correct size but his Sockets where thick walled - hard time getting it in -

My other chair has more room in that dept. 646se dosnt have room i hope the Socket i got is thin wall enough -

cant seem to find the correct Nuts - fork Stems i need anywhere other than ordering from Sunrise which they charge 5X more for each item -

[Burgerman]

Well if you stop messing about with all that imperial stuff and fractions you will likely find its meteric. So it will just be 12 or 14mm and about 10 cents.

[expresso]

i was told it was 24mm - from the Tech- unless he made a mistake or i didnt hear well on the phone - with noise in the background in his end

either way - i had the Nut with me and a 22mm didnt fit was too small - turned out a 15/16 did fit - so i took it - - i will never fully learn all these sizes - either standard or Metric -

i rather just have the Nut with me and test fit it - now i hope i had the correct Nut with me today - i believe it was one of the stem bolts that fitted correctly -

i had a few other stem bolts for the same fork - and those didnt fit my chair - again Ebay at its best -

worse case - i have to get what ever Nuts or stem bolts i may need from sunrise - i would hate to do that since they take time to get here - over a week before they process and ship etc, -

i am hoping to get this fixed with the current hardware i have - bearings i have to order on amazon now and hope those are correct

[expresso]

Test wheelies on grass. Its just as embarrassing as you tip over the rear, but its less painful! Ask me how I know!

chair feels great with the wheelies - dont think it will tip over - havnt done a big hill yet - not till i get my caster issue fixed first

[shirley_hkg]

Long forks + big caster raised your front MORE than that of your rear wheel did . The geometry of the chair is deformed .

Lower the front and move the caster axle rearwards as much as possible , by drilling another hole .

[shirley_hkg]

[expresso]

Long forks + big caster raised your front MORE than that of your rear wheel did . The geometry of the chair is deformed .

Lower the front and move the caster axle rearwards as much as possible , by drilling another hole .

yes thanks for the Tip - but thats a problem for me to start trying to drill new holes - etc, - - its either going to work or its not - which i then go to plan B - which is back to original setup - i can get black tires the same way and everything will just work then -

i cant do the work and there is no one who is going to start drilling holes - they have to be perfect - they have to work - which there is no way of knowing till you do it like i did and then find out - it dosnt for one reason or another -

isnt worth the hassle to be honest - i will move it to the next slot on the fork - lower the PSI all around and have the tech double check everything - - if i had the help with me all the time with me - who can do this for me - then i can try a few more things - but i have to call the tech everytime - and its not free - so in the end - really isnt worth the hassle and the cost - i gave it a shot - and its not over just yet - hopefully i can get it resolved enough that it wont be a problem

i like the tires - and feels great - but unless i can get rid of that wobble - dosnt matter how cool the chair looks when it will just sit there in the living room for looks only summer is here - i want to be out there - dont mind drilling a few holes - -just not those holes -

i hope to have the tech over this Sunday - or early next week - will know then after another try which way i will be going - either it works or i scrap it and move on to what will work for sure -

i can either try those other tires 300-8 - https://smile.amazon.com/dp/B005J8WMYU/ ... RBQ2LAUELL


with a tire liner in the rear - or just the same original tire in black with Air also - i rather use the above tire in the link which the other users just installed also - Sourstraw i think -

either way - not looking to waste my summer drilling holes - unless of course it the right hole

[LROBBINS]

Expresso,

Caster shimmy is an ever present risk and very hard to predict. Every caster will start to shimmy at some speed - hopefully at a speed higher than you can or will go. The tricky bit is that even tiny changes can have a big effect. Tire pressure is surely one of them - for the casters themselves, lower pressure means more "scrubbing" friction to change direction and that can greatly reduce shimmy. For drive tire pressure, it's more indirect but the effect is still there. Same for amount of trail (sometimes more helps, sometimes less - go figure). On many casters there's a wave washer (aka Bellville washer, spring washer) to create a "known" amount of friction - if it's missing, or not actually partly compressed - you will have trouble. Other casters just depend on adjusting the tightness of the top bolt to get the right amount of pre-load friction. As rule of thumb, with the caster raised off the ground you want that nut loose enough that a caster turned to the side will swing back to center, but tight enough that it's a slow return to center or even needs a light touch from a hand to help it. If it's too loose, you'll get shimmy. If it's too tight, you shorten bearing life and if a lot too tight it becomes hard to turn the chair.

So, first step I'd suggest is lowering the pressure in the caster tires, even going quite low, but a bit, say 5psi, at a time, same if needed for the drive tires, but while the tech is there also check the stem bearing pre-load. Unless the geometry is really bad, at the speeds we go these changes will usually do the trick, but it may take some trial and error.

If you look at light aircraft, which touch down at speeds considerably higher than we go with a chair, you'll see various damping strategies to control shimmy - hydraulic or pneumatic shimmy dampers, a viscous grease in a fiber packing between a fixed and rotating cylinder. During WWII the Brits even experimented (successfully) with a tire that had two tread areas separate by a deep groove. That caused a major increase in turning friction because one tread would be moving faster then the other when turning, but the tires were expensive to make and sure didn't last long scrubbing across cement.

If you search this forum you can probably find multiple older threads dealing with shimmy problems and how people solved them.

[expresso]

thanks Lenny - i will try all of those tweaks and hopefully one of them will work - i will put the caster in the other hole on the fork , lower the PSI all around anyway - - i happen to find this site

https://www.whiteheadindustrial.com/p-1 ... oC8EHw_wcB

in order to try to build or add an extra washer to put a bit more contact on the ground - i needed a larger fork stem - so i purchased the same ones in 4 1/2 inch long and 5 inches long - the original is 4 inches -

i am guessing the 4 1/2 should work with an extra washer over the top part of the top fork giving it a bit more pressure down - for some reason both my chairs - seem to have similar issues - and its always the left side which needs extra attention -

i ordered the bolts both sizes - extra washers - and the nut on top in two different sizes - standard and slim - just in case - i got the correct socket 15/16 - i think after this - it should work fine - i am hoping this will be all thats needed

if after all this and it dosnt work still - i would just leave the front alone since the front end is original parts really - the only change i made which affected it are the rear tires -

theres a chance the tech didnt tighten it enough on the forks either - i recall that from the other chair - same thing - once he did it over - it worked much better - it can still be tweaked but its fine if i left it - this is the other chair -

if this works - i may have him change the bolt on that chair also - just the left side with the longer stem - add extra washer and then it would be perfect i think on the P222se chair


this caster issue is with the 646se chair which i just changed the tires on -

[Burgerman]

Why do you think longer bolts will add "pressure"? Confused here...

Pressure to bearings? Weight on casters?

If you reduce all 4 tyre pressures substantially, it will drive nicer and stop the shimmy. By as much as it takes!

Also, if the RIGHT front caster shakes, reduce pressure in the right REAR tyre by 10 or 15 percent. These chairs are not built accurately. The caster that shakes is usually the one with the least weight.

Its all I did to cure this:
http://www.wheelchairdriver.com/BM3-con ... -shake.mp4 This shakes at 12 or 14 mph here only going up hill as here. Lowering all 4 tyre pressures, and esp the rear left more cured it completely. Now I go 16mph and no problems.

Watch the 2nd half, see how soft my tyres are! And why! Admittedly easier on 3.00 x 4 tyres.
http://www.wheelchairdriver.com/gopro/soft.mp4

[expresso]

well one side - usually the left - on both chairs - is worse - so adding extra washer to build it up gave a tighter fit - on the P222se chair - and that helped
since the bolt is 4 inches long - couldnt do much more because then the bolt is too short to screw on the nut enough - this chair has same issue but also was loose - when they built it - its not perfect and the reason to try to build it up inside with extra washer - didnt use a washer since the bolt was too short - we used tuberware plastic cut it to size - thin sheet used - but with a longer bolt on this chair - i can add a washer there and fix it better - its ok now - but still has a bit of play and fork off the ground more than the right - a bit -

sort of when you see a Dragster car take off and lift the front end - you notice one side on the front end is always higher or lower than the other sometimes
flex in the chassis

and my chair it seems its the left front which is always first to go up

so on most surfaces - just sitting there - all my chairs have a slight difference - to one side - can be the floor also which may not be perfectly flat also -


you may be right - it may not do what i though i was looking to do - we see - my vision was to add an extra washer to try to make the left side fork longer than the right - thinking it will even out on the ground - level since i feel the left side sits a bit higher -

but maybe i wont achieve what i was thinking - either way its shipped and once i get them - will call the tech to set up the date to give it a shot -

i decided i will try to add the Fender again - but i forgot to order the longer screw for that - so have to either order it or try to find one at home depot Again -

i will lower the PSI for sure -

[expresso]

Why do you think longer bolts will add "pressure"? Confused here...

Pressure to bearings? Weight on casters?

If you reduce all 4 tyre pressures substantially, it will drive nicer and stop the shimmy. By as much as it takes!

Also, if the RIGHT front caster shakes, reduce pressure in the right REAR tyre by 10 or 15 percent. These chairs are not built accurately. The caster that shakes is usually the one with the least weight.

Its all I did to cure this:
http://www.wheelchairdriver.com/BM3-con ... -shake.mp4 This shakes at 12 or 14 mph here only going up hill as here. Lowering all 4 tyre pressures, and esp the rear left more cured it completely. Now I go 16mph and no problems.

Watch the 2nd half, see how soft my tyres are! And why! Admittedly easier on 3.00 x 4 tyres.
http://www.wheelchairdriver.com/gopro/soft.mp4

i will do it - but too low - then its harder to move and more force needed - battery etc, i feel its harder than it should be now - even if it feels better as it is now than before - it can be lower for sure - how low is the question - needs to be stable enough to stay on the rim and not force it to roll - that would feel slower etc - making the chair work harder to move ?

i will try to check the PSI with the new pump - i am suppose to be able to monitor it - not sure what that means - i am guessing i can check the pressure with out adding or taking away just to see what the current PSI is - i wait to do that with the tech - on rush - i can use both chairs - i went 21 miles with the bad caster chair so - it didnt do it all the time but more than enough and if only once - thats too much for me

[Burgerman]

If its slight and only at full speed it will go away on its own as the tyres wear in. Probably.

[expresso]

If its slight and only at full speed it will go away on its own as the tyres wear in. Probably.

dont think this will go away on its own - it can happen even during slower speeds - depends if i hit a bump or a crack - it can trigger it to start - left side is the worse side - but even the right side did it a few times - sometimes together - downhills are much more dangerous -

i can use the chair - but this is my Long distance chair - and cant have it happening at all - i travel too far and hills etc, - there is hardly ever a flat even street or sidewalk - always a dip - cracks - bumps - and the chair has a soft bounce to it - which can then trigger it to start -

there were moments where it didnt happen for some time during the ride - but even those times - i felt it as its on the edge of about to happen -

i feel the front end a bit lighter - - could be the caster on the lower position - i am hoping thats would fix it - along with lower PSI - when i checked my other chair - the caster is on the higher position -

i just let out some air in that chair also - - now i noticed with that chair - one caster wheel - the value may be clogged from the slime etc, - because i cant let the air out as easy with that tire - so i left it alone - as long as it holds the Air - i leave it alone -

only on that tire it feels that way - the others feel fine - air comes out using a pen just one quick shot - i am curious will check the PSI on that chair when my tech is here just to know -

now i think maybe the new air pump i got - hope it can read the PSI correctly - i feel the slime inside will make it work correctly

[Burgerman]

You fuss a lot. Take charge! Air wont come out? Remove valve core. Re-inflate to lower pressure. Start too low on all 4, so they look a little flat. Like a cars tyre. Test. Add more as needed. When it behaves as you want, stop!

[expresso]

You fuss a lot. Take charge! Air wont come out? Remove valve core. Re-inflate to lower pressure. Start too low on all 4, so they look a little flat. Like a cars tyre. Test. Add more as needed. When it behaves as you want, stop!

yes - just not as simple as it sounds - with slime inside and i need to make sure - if i do that - i can put it back - will wait for tech to try it - thats on the other chair and thats pretty much ok anyway - i can even leave that one alone -

its the new chair with the new tires i have to get fixed more important -

[expresso]

testing the chair again today with lower PSI - i went out and seemed to be worse if thats possible - either way it didnt fix the issue and i noticed my front tires being shredded -

i went to test the hill where i crashed first time - its a steep hill going up - this was to see i was able to tackle it the same way as before adding the tires

and NO - i cant - i almost flipped back - i was half way up - a bit more and my front end lifted too high and i was stuck up all the way facing the sky for a few moments -

i wasnt able to move the chair or i may have flipped over - lucky for me a biker was around and lowered my front end down - i turned around and went back

so now i have a few more Neg. - so far not looking good - the only PROS so far is that the chair looks cooler - Fat Rear tires look nicer etc, - but thats it

i lifted my chair in the front when i got home - i checked my tires PSI - i put the rears to 20 PSI and the fronts to 10 PSI - as a starting point -

i did feel the forks were a bit loose - which have to be tighten down - maybe just maybe if the forks can be tightned more and caster wheel moved to other postion - - i hope thats all it takes -

if this dosnt work - then this was a lost for me - and may have to go back to the stock front end - and see if i can manage to keep the rear tires at least with the stock suspension forks and 8 x 2 tires instead -

i have the tech coming to me this Wed. - and we see what comes of it - so far not looking great - - -

PROS -

Looks cool- feels nice -

Cons

Front end issues - wobble - cant use this way -

NO fender which looks Ok - but chair gets very dirty -

Front tires are getting shredded unless this is resovled -

cant climb steep hills any more - --

i will put back the 4 inch casters for the anti tippers - i am using 3 inch now - was fine till i added the new tires which raised it up even more -

i can wheelie nicely - its only a problem on some hills - dangerous - not looking to get disabled now

in the end - this may come to nothing but something i tried and didnt work for me- if its more work than its worth - time - money -

so far not looking great - we see after Wed..

[Burgerman]

i was half way up - a bit more and my front end lifted too high and i was stuck up all the way facing the sky for a few moments -

i wasn't able to move the chair or i may have flipped over - lucky for me a biker was around and lowered my front end down - i turned around and went back

Now you are beginning to understand the importance of CG position. Higher causes less stability. (And caster shakes) and other issues on slopes... You need to lower it again. By suspension or whatever it takes. A powerchair is a mobilized tall bar stool. Its high, short, and narrow. Its amazing they work at all.

I keep telling people that my own BM2/3 chairs are super sensitive and you cant just bung a heavy caar seat, or tilt/recline or even a fancy back without causing all of your problems. Its also why I fit lower profile tyres when I go wider. As I mentioned about 100 times! Because you can fit wider rubber, without making the chair higher. You raised yours by half an inch. And look what it did. Powerchairs are finely tuned!

[expresso]

i been unable to find any tire here that was the same size overall and wider for the stock rims i have - the chair sits higher and i felt it right away the first time i sat in it - the front end felt loose lighter - not enough downforce on the the front end -

lesson learned - if this is not fixed after Wed. - theres not much else i can do other than to put it back the way it was - Now - i would hate to loose out on the rear tires - but it may come to that -

if Wed. dosnt fix my issue - then i can put the front end back the way it was stock - and leave the rears alone - try it that way - if that works OK - i can then just get black front front tires and leave it alone -

will also put back the larger anti tipper wheels i removed -

that would be the easy way out - less expensive also - i can then just keep the front tires as spares for the other chair which use the same tire caster rim -

now if Wed. dosnt work out - and changing back to the original front end dosnt do it either - then i am left with no other choice but to remove the rear tires and go back to the stock setup -

if i have to do that - i will and then just work on getting new tires - the same kind - size brand which i can get - in black with Air also -

then everything will be stock - and at least black tires - not as wide but stock size - but i wont have to worry about it and can ride safely again

its summer now - i dont want to waste time tinkering with this or that - besides the fact i have to call a tech to come to my house to do this all the time

not worth the expense unless it works after this Wed. - than i consider it worth it - at least i tried

[shirley_hkg]

It shouldn't make such drastic difference .

How much higher is it , in terms of seat -to -floor height ?


May be 20 psi for the rear wheels is too soft , as heavy chair will sag them real down low , making the chair tilted further back when going up inclines .

I inflated my BRIDGESTONE 3.50-8 @38-40 psi .

Besides , could it be the ADD -ON swinging behind ?