How to improve ride quality?

[Scooterman]

My chair has a effing harsh ride on the narrow undulating UK pavements dug up to install cable tv, tree roots, etc, At anything above 3 leds on the r-net it's a jolting ride. Roads are fine at 5 leds as they're smoother.

I can't do anything about the front wheels which are 9" mobility scooter pneumatic tyres. 9" is the largest dia that will fit in forks, plus 10" wheels would mean having to find 10" forks and moving the seat forward which I don't want to do.

So I've only got the rear end to play with.

About 18 months ago I removed about 50kg from the top half of the chair. Recently I've been looking on eBay for a used pair of shocks with lower spring poundage rating. Front mobility scooter shocks look to most promising.

But whatever I find the shock units are short with little travel so I can't imagine are ever going to be that good at cushioning out the jolts?

It's the jolts that are the killer and make using the chair at speed or for any length of time outdoors fatiguing.

So I was thinking of balloon rear tyres on new rims? Do balloon tyres improve the ride much?

Any suggestions/experience of what works?

[Burgerman]

Realistically theres little you can do. Low pressure tyres with large section helps. But not massively.

[Scooterman]

Realistically theres little you can do. Low pressure tyres with large section helps. But not massively.

Mmmm that's does help, I like honest advice . The set-up of the chair is perfect for me at the moment so I wouldn't want to go to the expense and hassle of messing around with it for not much gain.

I wonder partly because me and the chair are so lightweight that the chair gets jolted around, and powerchairs have a short wheelbase?

I measured the wheelbase of the salsa and compared it to my scooter (which has a better ride quality), and the powerchair WB is exactly half the WB of the scooter.

Perhaps I'll just have to live with it. It's okay as long as I don't go everywhere at 6mph.

[steves1977uk]

Have you tried lowering tyre pressure SM? Say 5-10 psi for the casters and 10-15 psi for the rear wheels. That will give a softer ride but use more power. I use 20 psi all round but the seat on my chair is sprung, so that absorbs any nasty bumps.

Steve

[shirley_hkg]

I'd definitely try 3.50-8 tyres first @25 psi or lower.

This is the easiest and foolproof, at the lowest cost as well.

[rickystyx]

Just wondering if something could be rigged up between the frame and the seat plate as secondary suspension. When I was able to use my bike I had a suspension unit between the frame and the saddle - it made a massive difference on rough tracks - so I was thinking that perhaps one mounted either side between the frame and the seat plate may work but the front of the seat plate would have to be hinged in some way.
Just a thought

[wheelie junkie]

I use a chin control so you can imagine how difficult steering is on UK pavement. Went to Tate Liverpool a few weeks ago in the Albert Dock, miles of cobbled pavement and felt like I had been in a boxing ring for 10 rounds. That was with 120/70 tubeless rear tyres and air filled casters plus 4 wheel suspension with soft springs. They all help make a difference but you still get battered. Soft springs can help but ride becomes choppy, brake hard and front compresses then squats back as you accelerate and has side to side movement. I wouldn't revert the changes I made but don't expect miracles.

[Scooterman]

Have you tried lowering tyre pressure SM? Say 5-10 psi for the casters and 10-15 psi for the rear wheels. That will give a softer ride but use more power. I use 20 psi all round but the seat on my chair is sprung, so that absorbs any nasty bumps.

Steve

I will give that a go first Steve, I'm not sure what PSI I'm running. I use a hand pump and just pump them till feel firm

I'd definitely try 3.50-8 tyres first @25 psi or lower.

This is the easiest and foolproof, at the lowest cost as well.

I think I'll definitely end up going down the road of the tyre size you suggest. The rubber on the existing tyres seems quite stiff with not a lot of flex?

Just wondering if something could be rigged up between the frame and the seat plate as secondary suspension. When I was able to use my bike I had a suspension unit between the frame and the saddle - it made a massive difference on rough tracks - so I was thinking that perhaps one mounted either side between the frame and the seat plate may work but the front of the seat plate would have to be hinged in some way.
Just a thought

I've seen lots of MTBs with seat suspension. I was always dubious whether it helped or was just gimicky and adding weight. But your experience says otherwise
But fitting suspension between the seat and frame of a powerchair is way beyond my DIY abilities, plus I think it would raise the seat too high

A mob dealer has these scooter shocks in stocks which are 100 lb/in less than my chair's shocks. But I need to check the dimensions

Screenshot 2019-10-18 at 11.43.12.png (152.84 KiB) Viewed 8790 times

Also I've found this spring supplier which is a cheaper option. But whether I can find a coil spring to match the existing spring dimensions???
https://www.ashfield-springs.com/shop/c ... ngs-3-10mm

I think 7 n/mm equals 40 lb/in

Btw does anyone know how manufacturers of WCs, mob scooters, cars, vans, etc, calculate what lb/in of spring rating to fit?

[Scooterman]

I use a chin control so you can imagine how difficult steering is on UK pavement. Went to Tate Liverpool a few weeks ago in the Albert Dock, miles of cobbled pavement and felt like I had been in a boxing ring for 10 rounds. That was with 120/70 tubeless rear tyres and air filled casters plus 4 wheel suspension with soft springs. They all help make a difference but you still get battered. Soft springs can help but ride becomes choppy, brake hard and front compresses then squats back as you accelerate and has side to side movement. I wouldn't revert the changes I made but don't expect miracles.

Thank you Wheelie, you make some really good points. Your experience is much appreciated

[steves1977uk]

I use one of these... https://www.airman-uk.com/product/airgun-compressor/ Soon inflates tyres to the specified PSI you set.

Steve

[shirley_hkg]

I use this naked parts @£1.25 , with 50psi gauge.

[hank]

Gas air shocks would work better if could fit some in.

[shirley_hkg]

All these can do away cracks and holes of pavement only , but Not the back and forth rocking .

Scooterman himself has pointed out the reason already , short wheelbase and seat high.

Articulated caster arm with suspension like Storm 4 Xplore / Willchair 123 etc , may help.

[wheelie junkie]

Most mountain bikes don't have suspension seatposts what is common is a hydraulic dropper seatpost not suspension. Air shocks have a downside in the amount of friction caused by the seal and relatively big diameter shaft. I work in mountain bike industry and have access to both coil and air shocks, fitted air to my off road chair and because of the suspension design with a low leverage ratio the shock pressure was low and difficult to overcome initial seal stiction. You really need to understand leverage ratio and progression before trying to design a suspension system.

It is easy to adjust air rather than having to find the right coil spring but also easy to be outside the optimum operating pressure.

[White Lightnin']

Use spoked wheels with multiple cross lacing to soften the ride.

[farmer]

get a 1/2in. or whatever mm that is equal to the size of your cushion and put a scooters tube with a little air in it between the board and base put your cushion on and have at it , to soft add more air to hard take some out

[Scooterman]

Use spoked wheels with multiple cross lacing to soften the ride.

Do spoked wheels temporarily deform when they hit a bump and give a cushioning effect?

My manual wheelchair has 24" spoked wheels and thin slick HP tyres that I pump up to 120psi, although they probably sit around 90-100psi most of the time. Even though you'd think that would give a hard ride they're actually quite cushioning. And the thin plywood seat base flexes a bit as well.

The solid 4" front castors are a different matter though, and are lethal outdoors if you don't keep your eyes peeled for debris, especially in the autumn.

[Burgerman]

Spoked wheels dont change anything. Unless the spokes are loose! And then it will destroy itself.

[Scooterman]

Spoked wheels dont change anything. Unless the spokes are loose! And then it will destroy itself.

I thought they might flex a bit, boing!

[shirley_hkg]

Hasn't heard from him for quite a while. Whatsapp messages unread too.

Kind of worry.

[Irving]

Hasn't heard from him for quite a while. Whatsapp messages unread too.

Kind of worry.

last post Dec 21, 2019

[Burgerman]

Last visit 5th jan.

[White Lightnin']

Changes in spoke configuration will affect ride quality. I’ve ridden enough different types of bicycles far enough to know.

[Burgerman]

There could be some tiny suspension like flexing happening I agree. I would be surprised if that was signigicant enough to remove any actual bumps in the road. It can only be a tiny proportion of what the tyres absorbs for e.g.
It would depend on the spokes being loose enough to allow the rim to bend at the point of road contact and deform the rim too and so deforming the wheel. Because any suspension like behavior depends on knocking the wheel out of round when hitting a bump. Its one reason motorcycles started using solid alloy/magnesium rims.

You would get a similar change in feel by using thinner spokes instead of a different pattern of construction. With similar problems. Or by adding 100lb of extra load to a wheel.

[Irving]

Changes in spoke configuration will affect ride quality. I’ve ridden enough different types of bicycles far enough to know.

True, but there's very little 'suspension' give in properly tensioned wheel spokes, most of it is in the tyre and the forks/rear stays. The difference between my steel/carbon tourer and my full-carbon race bike was very noticeable even with the same wheels/tyres fitted to both. The next biggest difference was going to the more flexible 28 or 32mm tyres from 23/25mm on the tourer. A 100km/3h ride on the race bike was significantly more punishing to my skin than an 180km/8h ride on the tourer all other things being similar (inc same Brookes B17 saddle on both)..

[flagman1776]

I know TravelScoot has an optional spring on it's central pedestal seat mount. I wonder if a seat, hinged at the front like old touring motorcycles (and bicycles) with springs at the rear, might be successful. Hell, even tractors and lawn mowers have them. The trick would be calibrating to the load. As part of the system...

[charlie ford]

always looking for smoother ride,2 quickie chairs have seat suspension, p222 fibreglass type leaf springs,525s torsion rubber arms,have both and they help a little,may be retrofitted maybe?and was wondering what other chairs have seat suspension?

[Burgerman]

Cant think of any. Probably because unsprung mass shouldbe as light as possible for the best ride. So suspension at the wheel is the best way to do things. Although anything helps.

[ex-Gooserider]

Hopefully pointing out the obvious, but remember that it is important that any sort of spring suspension also needs a compatible level of damping or the bumps will just turn into bouncy bounces - Then if you find the right frequency of bumps it can actually amplify the bouncing and make it worse...

I've driven farm tractors with the spring seats and they did take up the worst of the bumps on rough ground, but tended to always have a certain amount of up and down bouncing even on smooth ground... (Not to mention the disconcerting habit of the seat going up when stepping on the brake / clutch pedals before the pedal would go down...)

ex-Gooserider