Off road tyres driving me INSANE

[Blade Runner]

I would think that as long as it's not actually touching it should be O.K.
Not knowing how your wheels mount, could you use washers to space it out a little?

Bob

[Burgerman]

He could. But more importantly, those kevlar reinforced fat tyres are really good are they not! And as well as a softer smoother ride, they are almost impossible to deflate without an electric drill as long as you have them without a tube. And being wide they dont sink in sand/snow etc.
Although they are OK on sand they dont grip snow very well.

[alexapc]

If it wasn't for that stupid gearbox clip it would be fine, I don't know if it's touching or the gap is too small to see, it does look like it's pressing against the wall though when I sit on the chair. I had to add spacers to fit them (Martin sent bolts to go in between plates).

Can I add washers to just that one side?

[Burgerman]

CLIP?

What clip?

Yes you could. But mine just fit. Shouldnt yours? Whats different? Is it something to do with suspension? I dont have that.

[Burgerman]

Which motors?
Which hubs?
Do you have suspension?
6 or 8.5 mpg?
100 Amp (pilot plus yes? Because of programmer)
Are we talking about a narrowed F55 here by martin?
Confused as to what you have there.

Just tested my BM3 and it has a 1p coin clearance. But thats no suspension, and uses different hubs, (welded 6 bolt) and alloy Hegar wheels. Needs to be right to start with here:

http://www.wheelchairdriver.com/BM-MK3- ... uction.htm

BM2 uses cheap steel quad bike wheels, and the taperlock solution from years ago with 3 bolts and spacers. Heres a rusty one! Can be moved in/out easily and retightened.

http://www.wheelchairdriver.com/images- ... r-1024.jpg

Not sure what you have or what martin uses here.

[alexapc]

4 pole Sunrise motors
3 bolt hubs like BM2
Yes suspension
mpg? you mean mph? 6.
100A Pilot+
Not as narrow as yours, between 26-27in for now

That pic looks nothing like my plates, and I can't find that clip on any of your motor pics, where the gearbox joins to the motor, there is like a stick out bit that lines up the two sides


(I Edited this, by mistake so tried to repair it! BURGERMAN)

[Burgerman]

>>>4 pole Sunrise motors

But groove or F55?

>>>3 bolt hubs like BM2

You mean 3 bolt wheels, but how are they fitted to the motor shaft? Mine has the machined taperlock pulleys. That means you wouldnt need washers, just move position and tighten up.

>>> Yes suspension

F55?

>>> mpg? you mean mph? 6.

Yes next key along!!! So F55 motors. So I have no idea how your wheels are fitted, or what clip we are talking about. Mine has no clip, so maybe just remove it.

>>> 100A Pilot+

Then you really need those strengthened motor couplings. But likely matin did that already as he saw what I did, and did the same for Nandol. I think.

>>> Not as narrow as yours, between 26-27in for now

Because of martins different centre section design/suspension etc.

>>>That pic looks nothing like my plates, and I can't find that clip on any of your motor pics, where the gearbox joins to the motor, there is like a stick out bit that lines up the two sides

Picture?

[alexapc]

>>>4 pole Sunrise motors

But groove or F55?

F55

>>>3 bolt hubs like BM2

You mean 3 bolt wheels, but how are they fitted to the motor shaft? Mine has the machined taperlock pulleys. That means you wouldnt need washers, just move position and tighten up.

My plate looks exactly the same as these http://www.wheelchairdriver.com/images- ... s-1200.jpg

Martin sent 4 nuts to put between the original shaft and the new plate that extends it by about 1.5cm.

>>> Yes suspension

F55?

Yes I think so, HAGON?

>>> mpg? you mean mph? 6.

Yes next key along!!! So F55 motors. So I have no idea how your wheels are fitted, or what clip we are talking about. Mine has no clip, so maybe just remove it.

Lol so it is! I'll try and get a picture tomorrow, like I said the other side is fine, no clip.

>>> 100A Pilot+

Then you really need those strengthened motor couplings. But likely matin did that already as he saw what I did, and did the same for Nandol. I think.

>>> Not as narrow as yours, between 26-27in for now

Because of martins different centre section design/suspension etc.

>>>That pic looks nothing like my plates, and I can't find that clip on any of your motor pics, where the gearbox joins to the motor, there is like a stick out bit that lines up the two sides

Picture?

Will get pics tomorrow!

[Burgerman]

Mmm. Those plates were designed for the Groove motors, to fit the 145 tyre very close to the groove motor gearbox with steel wheels. And they bolt to a groove steel hub, in turn bolted to the motor shaft. Not the f55 motor.

The F55 motor has no taper so I used the taperlocks/pulleys.

So not sure if the steel hubs are martins own, or the ones that come with the newest f55 wheels. So still no idea how they fit.

[alexapc]

Will get pics, I don't think they're F55 supplied as they bolt on to the original wheel hub..I said shaft before I meant hub, shaft has 2 small alan keys are they adjustable?

It goes

Kenda tyre/rim

3 bolts

Plate in above pic

4 screws/bolts and spacers

Original hub

Shaft

[Burgerman]

I think the hubs on your motors shafts, are martin made, so no idea of dimensions. But if they are then they may be adjustable in/out as needed. But I thought his hubs had 3 allen keys. Actually allen bolts that tighten on to the shaft. Which I dont think is wise... Maybe not, they could be the F55 ones as supplied with a set of wheels. In which case they are like the groove ones and not adjustable but stronger.

[alexapc]

Well 2-3mm washers will fix it, pics tomorrow.

Those tyres are amazing though! Literally feels like I'm floating, never had such a comfy smooth wheelchair, and SILENT!

[alexapc]

Ah yes the 2 little allen screws on the shaft, can you adjust length with them?

[ex-Gooserider]

The idea is that if the motor shaft is NOT tapered, and you are not doing something like bolting the hub into the end of the shaft, then it should be possible to loosen the allen screws that lock the wheel hub onto the shaft, and slide it out just enough to get the needed clearance, then tighten the screws back down... (The clearance problem might even be from not having the hub located perfectly in the first place!)

Obviously if the motor shaft is tapered, or the hub is partly secured by a bolt into the end of the shaft, that locks the hub into one position and makes it effectively impossible to relocate - so you'd need a spacer between the hub and the wheel, or a different hub...

Also note that those screws locking the hub in place need to be TIGHT, and it would not be a bad idea to put some Locktite or equivalent on the threads to make sure they stay that way. (Checking that they are still tight should also be part of the maintenance drill any time the wheels are off as well...

ex-Gooserider

[Burgerman]

If that is what you have, and I thought martin was changing it, there was some discussion about durability and coming loose. As its not a good setup. And why I use taperlocks on these shafts.

So expect martin to have locktited them and tightened them up like a gorilla!

[alexapc]

Ok so it's not tapered or with taperlocks.

Hmm one of the screws was finger tight..

Can you adjust the shaft with these 2 screws?

[Burgerman]

Hmm one of the screws was finger tight..

Thats because in my opinion, that trying to lock that to the shaft with grub screws, will never work. It will always be working loose. This is what the earlier discussion was about. Even a tight fitting hard steel flat key as used on an F55 with masses of contact area works loose and eventually causes problems with backlash on the alloy wheels.

Thats why they made a newer wheel, with a bolt on setup like the Groove. And also why the groove has a taper. The key on that chair doesent take drive/reversing loads - the taper does.

Martin says it will be fine. I said it will come loose and wear... We will see. The solution is the new wheel adapter as used on the latest F55 chairs. But its not available without a wheel. Hence my taperlock/pulley re machined in the pictures above somewhere that cant move or fret. Did this from BM1 onwards, years before sunrise ever admitted they had a problem.

[redandwhite]

Hi Alex
I have followed this thread with interest as I am in similar situation to you.
I got a BM2 from Martin a few weeks ago but unfortunately. due to health problems I have not been able to try it yet. The wheels and tyres look very similar to yours, quad bike tyres on 3 stud steel wheels. As ride comfort is important to me it sounds like I have got the wrong tyres.
Martin is also building me a second chair to the same spec which will be my everyday chair. this also has the same wheels and tyres but I am thinking it will be worth getting a couple of Kevlar tyres for this one.
The questions I have are;
1) Did you put these tyres on your current wheels or did you buy new ones?
2) Did you get the tyres fitted by a normal tyre fitting co. such as Tyreservices or did you have to use a specialist quad bike dealer?
3) To save me time doing the same research that you have just done where did you get them from?
Any help or advice will be greatly appreciated.

Martin,
IF i organise a couple of these tyres will you be able to swap them over for me before delivery or will I need to organise it myself once I have the chair?

Thank you in advance for any replies.

[Burgerman]

You realise that there are better quality tyres than the cheap quad bike tyres? They cost more, but try to get a set of the ones used on the X5 chairs (cant remember the name?) as seagreen says his are massively better. And I had a set here and they are better. Althought the turf tyres are the way to go really unless you need mud/snow in winter. If only because they dont wear and cant really puncture.

I would use the alloy, split rim wheels as on the BM3 though, hugely better, easy to change tyres, and proper tubeless beads. Tyres are a pig to change on the quad bike wheels unless you have a dealer with a tyre changer for them. And if you are not careful the powder coating gets damaged and you lose your shine! Well it matters to me...

http://www.wheelchairdriver.com/BM-MK3- ... uction.htm

bottom of page...

[redandwhite]

Thank you for the reply BM.
While searching for tyres I have seen some 13x5-6 and wondered if they would fit as it would reduce the width of the chair, currently 26" with offroad tyres.
Am I correct in thinking that these will be 13" tall, 5" wide and to fit 6" rim.If this is correct and they will fit it will save 2" which doesn't sound much but it will make a big difference indoors.
The rims I have are steel and 4.5x 6. The plan is to keep the offroad tyres on one pair of wheels for snow and have a pair of turf tyres on the same type rims so that changing is simply a case of swapping the rims over rather than having to keep fitting tyres.