Two quotes for a curved stairlift can differ by thousands of dollars and the reason is frequently the rail, which almost nobody explains.
There are three designs in the market. They ride differently, they carry different weights, and one of them produces a noticeably worse result. Here is each one.
Tube rail
A round or dual-round steel tube, bent to the shape of your staircase at the factory. The carriage runs along the outside of the tube, and the gear rack the drive engages with is on the surface of the rail.
Who uses it: Harmar, Handicare, Savaria and Stannah among others.
Lead time: Harmar publishes 2 to 4 weeks from measurement to installation for a custom curved rail.
The trade-offs. Tube rail is generally less expensive than a custom flat rail and gets in faster. It tends to carry a lower rated capacity. And the gear rack is exposed rather than shielded, which matters for debris and for anything that gets near it.
Custom flat rail
A flat or T-shaped track, curved to your staircase at the factory from a survey. The gear rack sits behind a flange on the track rather than on the outside.
Who uses it: Bruno, whose curved rail is bent in the factory from measurements taken with a photographic survey system.
The trade-offs. Generally stronger and higher capacity than tube. The shielded gear rack is the practical safety difference. It costs more and takes longer to manufacture.
Modular flat rail, and why it is different
This is the one to understand before signing anything.
Modular flat rail is not custom bent for your staircase. It is a set of standard track segments, straights and pre-formed curve pieces, assembled on site to approximate the shape of your stairs.
The appeal is speed and price: no factory fabrication, so a much shorter lead time and a lower number. The cost is precision. An approximated curve means more joints and a fit that follows your staircase roughly rather than exactly, and a carriage crossing many joints produces a ride that is bumpier and less even than either custom option.
It is not unsafe and it is not what most people picture when they are told they are buying a custom curved stairlift.
The question to ask
“Is this rail custom manufactured for my staircase, or assembled on site from modular sections?”
Ask it exactly that way. A custom rail, tube or flat, takes weeks to fabricate. If a supplier is offering a curved stairlift in days, you are almost certainly being quoted modular track, and the quote should say so.
A short lead time on a curved job is the tell. Our curved staircase guide covers why the manufacturing window is real.
How the survey differs by rail type
Custom rails need precise geometry, and the method varies. Photographic survey systems build a digital model of the staircase; hand surveys take a defined set of dimensions the factory specifies.
Either produces a rail cut once, which is why a quarter inch of error at the first turn matters. Modular track needs less precision at survey, because the fit is approximated on the day, and that is exactly the difference you feel riding it.
What each means for capacity
Rated capacity varies by model rather than by rail type alone, and rail design is one of the constraints. Custom flat rail generally supports higher capacities than tube.
If the person is near the upper end of any rating, ask for the figure for the exact model and rail configuration being quoted, not for the manufacturer’s range. Our capacity guide covers why specifying to the limit is the wrong approach.
Where we would be careful
Most of what is published comparing these is written by dealers who sell one of them. The clearest comparison online is by a Bruno dealer and it concludes Bruno’s rail is best, which may well be true and is not a neutral source.
Our position: tube rail and custom flat rail are both proper products from serious manufacturers, and the choice between them is usually decided by capacity, lead time and what your supplier is authorized to fit. Modular flat rail is the one we would want named explicitly in a quote rather than discovered on install day.
Folding rails on a curve
A related question that comes up on the same quotes. A hinged section at the bottom is straightforward on a straight rail and much harder on a curved one, and only some manufacturers offer it.
If your curved staircase has a door at the foot, raise it at survey. It narrows the choice of manufacturer, and it has to be specified with the order. Our folding rail guide covers the options.
What should be on the quote
- Manufacturer and model.
- Rail type, named: tube, custom flat, or modular.
- Whether the rail is factory manufactured for this staircase.
- Survey method.
- Rated capacity for this configuration.
- Lead time from survey to installation.
- Hinged or folding section, if needed.
- What happens if the rail does not fit on delivery.
Eight lines. A curved stairlift quote without them is a number rather than a specification, and our buying checklist covers the rest.
If you are comparing two quotes
Look at the lead times first. A four-week quote and a four-day quote for the same staircase are not the same product, whatever both are called.
Then look at capacity, then at who services it afterward. Both Bruno and Harmar sell through authorized dealers, which affects parts and warranty either way.
All consultations, estimates and scopes of work are free of charge with no pressure or obligation, and smaller equipment ships free from our online shop.
What you actually feel on each
Worth describing, because this is the part a specification cannot convey and a test ride can.
A custom rail, tube or flat, is continuous. The carriage travels the whole flight at a consistent speed, slowing through the turns deliberately, with no change in sound or feel except where sections join, and on a well-set rail those joints are imperceptible.
Modular track has more joints and an approximated curve, so the ride has more transitions in it. Nobody is thrown about; it is the difference between a smooth road and a patched one.
If a supplier has a showroom, ask to ride a curved lift rather than a straight one. Riding a straight lift tells you nothing about how a curve feels, and our guide to trying equipment covers what else to test.
Parking on a curve
A custom rail can be run past the top or bottom of the stairs and around a corner, so the lift parks off the staircase entirely rather than at the foot of it. That is called a parking curve and it solves the problem a hinged rail solves on a straight flight.
It is one of the genuine advantages of a custom rail and it has to be designed in at survey. If the bottom of your stairs opens into a hallway, ask about it specifically.
Service considerations
An exposed gear rack needs the rail kept clear of debris, which matters in a house with pets or in a dusty hallway. A shielded rack is more tolerant.
Either way the rail gets wiped and inspected at the annual service, and neither is lubricated: Harmar’s drive uses a nylon polymer gear rack that requires no grease, and adding some attracts grit. Our maintenance guide covers the rest.
If the rail is wrong on delivery
Rare on a custom rail and worth asking about before ordering, because the answer reveals how the supplier operates. A rail manufactured from an incorrect survey cannot be adjusted meaningfully on site: it goes back, and the lead time runs again.
Ask who carries that cost and that delay. A supplier confident in their survey will say plainly that it is theirs.