GB2622182A - Lightweight bicycle seat post - Google Patents
Lightweight bicycle seat post Download PDFInfo
- Publication number
- GB2622182A GB2622182A GB2112063.9A GB202112063A GB2622182A GB 2622182 A GB2622182 A GB 2622182A GB 202112063 A GB202112063 A GB 202112063A GB 2622182 A GB2622182 A GB 2622182A
- Authority
- GB
- United Kingdom
- Prior art keywords
- seat post
- fibre reinforced
- reinforced composite
- metal tube
- bicycle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000835 fiber Substances 0.000 claims abstract description 129
- 239000002131 composite material Substances 0.000 claims abstract description 128
- 229910052751 metal Inorganic materials 0.000 claims abstract description 106
- 239000002184 metal Substances 0.000 claims abstract description 106
- 238000000034 method Methods 0.000 claims description 21
- 238000004519 manufacturing process Methods 0.000 claims description 15
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 10
- 229910052799 carbon Inorganic materials 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 9
- 229910000831 Steel Inorganic materials 0.000 claims description 8
- 239000010959 steel Substances 0.000 claims description 8
- 229920001730 Moisture cure polyurethane Polymers 0.000 claims description 6
- 239000003292 glue Substances 0.000 claims description 6
- 229920000642 polymer Polymers 0.000 claims description 6
- 239000003822 epoxy resin Substances 0.000 claims description 5
- 229920000647 polyepoxide Polymers 0.000 claims description 5
- 238000005520 cutting process Methods 0.000 claims description 3
- 238000006748 scratching Methods 0.000 description 4
- 230000002393 scratching effect Effects 0.000 description 4
- 239000004411 aluminium Substances 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229920001971 elastomer Polymers 0.000 description 3
- 239000004033 plastic Substances 0.000 description 3
- 229920003023 plastic Polymers 0.000 description 3
- 229920000271 Kevlar® Polymers 0.000 description 2
- 239000004760 aramid Substances 0.000 description 2
- 229920003235 aromatic polyamide Polymers 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000004761 kevlar Substances 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 238000007605 air drying Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229920006335 epoxy glue Polymers 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62J—CYCLE SADDLES OR SEATS; AUXILIARY DEVICES OR ACCESSORIES SPECIALLY ADAPTED TO CYCLES AND NOT OTHERWISE PROVIDED FOR, e.g. ARTICLE CARRIERS OR CYCLE PROTECTORS
- B62J1/00—Saddles or other seats for cycles; Arrangement thereof; Component parts
- B62J1/08—Frames for saddles; Connections between saddle frames and seat pillars; Seat pillars
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
- B29C70/28—Shaping operations therefor
- B29C70/40—Shaping or impregnating by compression not applied
- B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
- B29C70/44—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
- B29C70/446—Moulding structures having an axis of symmetry or at least one channel, e.g. tubular structures, frames
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
- B29C70/86—Incorporated in coherent impregnated reinforcing layers, e.g. by winding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62K—CYCLES; CYCLE FRAMES; CYCLE STEERING DEVICES; RIDER-OPERATED TERMINAL CONTROLS SPECIALLY ADAPTED FOR CYCLES; CYCLE AXLE SUSPENSIONS; CYCLE SIDE-CARS, FORECARS, OR THE LIKE
- B62K15/00—Collapsible or foldable cycles
- B62K15/006—Collapsible or foldable cycles the frame being foldable
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/30—Vehicles, e.g. ships or aircraft, or body parts thereof
- B29L2031/3091—Bicycles
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Laminated Bodies (AREA)
Abstract
A seat post 20 for a bicycle comprising a metal tube 31 and a fibre reinforced composite layer 32 arranged on a radially-inner surface of the metal tube 31. A saddle attachment structure 21 and/or stopper (22, fig. 4) may be bonded into either end of the seat post 20. The seat post may be manufactured by inflating a balloon internally during curing of the composite.
Description
LIGHTWEIGHT BICYCLE SEAT POST FIELD
[0001] The present invention relates particularly, but not exclusively, to a lightweight seat post for a bicycle and a method of manufacturing the seat post.
BACKGROUND
[0002] In a bicycle, a saddle is attached to a seat post. The bicycle rider sits on the saddle when riding the bicycle. The seat post is therefore required to support the rider safely and comfortably whilst riding the bicycle.
[0003] In folding bicycles such as three-point folding bicycles such as Brompton bicycles, the seat post is required to serve additional functions. Firstly, the seat post must be of an appropriate length to provide correct geometry for riding when the bicycle is unfolded despite the otherwise low frame of the bicycle which allows the bicycle to be compact when folded. This can mean that the seat post of a folding bicycle may be longer than the seat post of a bicycle that is not designed to be folded. Secondly, the seat post of such a bicycle is raised and lowered frequently as part of the folding or unfolding process. It must therefore be of sufficient structural integrity to withstand this frequent folding and unfolding without becoming damaged or dented. Finally, when the bicycle is folded, the seat post of a three-point folding bicycle such as a Brompton bicycle acts as part of the locking and braking mechanism of the bicycle. The seat post's structural integrity must therefore be sufficient to allow it to be used as part of the locking and braking mechanism of the bicycle when it is folded.
[0004] It is generally desirable for bicycle components to be as lightweight as is compatible with providing sufficient structural integrity. Lightweight bicycle components can improve the ease with which those bicycles can be ridden and transported. The additional length requirement and requirements of structural integrity imposed on the seat posts of folding bicycles, discussed above, have conventionally made it difficult to reduce the weight of these seat posts.
SUMMARY
[0005] The invention is defined in the claims.
[0006] According to a first aspect of the invention, there is provided a seat post for a bicycle, the seat post comprising: a metal tube; and a fibre reinforced composite layer arranged on a radially-inner surface of the metal tube.
[0007] To provide strong, lightweight bicycle components, layered fibre reinforced composite can be used to make the components. However, fibre reinforced composite components can be susceptible to failure when scratched or indented. As discussed above, the seat post of a folding bicycle is raised and lowered frequently as part of the folding or unfolding process and can also act as part of the locking and braking mechanism of the bicycle. Using the seat post in this way makes it susceptible to being scratched and indented. For example, scratching is frequently seen on the seat posts of folding bicycles when dirt that gets onto the seat post during riding is trapped between the seat post and seat sleeve when raising and lowering.
[0008] On the other hand, while metal bicycle components are less susceptible to failure than fibre reinforced composite components when scratched or indented, metal components are significantly heavier and less stiff than comparable fibre reinforced composite components.
[0009] By providing a metal tube and a fibre reinforced composite layer arranged on a radially-inner surface of the metal tube, the invention combines the properties of fibre reinforced composite components of being lightweight and stiff with the properties of metal components of being resistant to scratching and denting. In other words, the seat post of the first aspect provides the advantages of a fibre reinforced composite seat post with protection from damage provided by the metal outer tube. This metal tube can increase the longevity and robustness of the seat post as compared to a seat post manufactured from fibre reinforced composite only.
[0010] The metal tube may have a radial thickness of between 0.2mm and 0.9mm. The metal tube may have a radial thickness of 0.3mm. The metal tube may have a substantially uniform thickness axially. By making the metal tube as thin as is compatible with manufacturing capabilities, the weight of the metal tube may be reduced as far as possible, while still providing protection to the fibre reinforced composite layer beneath.
[0011] The metal tube may be made of steel. The metal tube may be made of titanium. The metal tube may be plated. This can improve the resistance of the metal surface to corrosion.
[0012] The fibre reinforced composite layer may be arranged on substantially all of the radially-inner surface of the metal tube. In other words, the fibre reinforced composite layer may be as long as the metal tube. The fibre reinforced composite layer may have a radial thickness of between 0.2mm and 10mm. The fibre reinforced composite layer may be formed of a plurality of sheets of fibre reinforced composite. The fibre reinforced composite layer may be formed of six sheets of fibre reinforced composite. The fibre reinforced composite layer may have a substantially uniform thickness axially. These thicknesses and numbers of sheets can provide sufficient stiffness for the seat post while ensuring that it remains lightweight. In being arranged on the radially-inner surface of the metal tube, the fibre reinforced composite layer may be bonded to the radially-inner surface of the metal tube.
[0013] The fibre reinforced composite layer may be a composite of carbon fibre and at least one polymer or pre-polymer. The at least one fibre reinforced composite sheet may a composite of carbon fibre and epoxy resin. The at least one fibre reinforced composite sheet may be an aramid, such as Kevlar or another fibre reinforced composite.
[0014] The seat post may be for a folding bicycle. The seat post may have a total length of between 250mm and 750mm. As discussed above, structural resistance to scratching and denting may be particularly important in a folding bicycle, in which a seat post may be frequently raised and lowered as part of the folding and unfolding process, and in which a seat post may also act as part of a locking and braking mechanism when the bicycle is folded. Also as discussed above, the seat post of the first aspect can provide such structural resistance without excessive weight. It may be particularly important for a seat post for a folding bicycle to be lightweight not only since the folding bicycle may sometimes be carried as well as wheeled, but also because the seat post of a folding bicycle may be longer than the seat post of a bicycle that is not arranged to be folded. In particular, the seat post may be between 400mm and 750mm in length. Despite its relatively long length, the fibre reinforced composite layer can help to ensure that the seat post is lightweight, as well as providing stiffness or resistance to bending, which becomes increasingly important with increased length.
[0015] The seat post may further comprise a saddle attachment in the form of a metal part bonded into an end of the fibre reinforced composite layer. This can allow for a saddle to be attached to the seat post.
[0016] The seat post may further comprise a stopper. The stopper may be a single part bonded into an end of the fibre reinforced composite layer. Alternatively, the stopper may comprise a first part bonded into an end of the fibre reinforced composite layer and a second part fitted into or onto the first part. When the seat post comprises both a saddle attachment and a stopper, the stopper, or the first part of the stopper, is bonded into an axially distal end of the fibre reinforced composite layer. When the stopper is a single part, the stopper may be of a material that is softer than the metal tube, for example rubber or a plastic material. When the stopper comprises first and second parts, the second part may be of a material that is softer than the metal tube, for example rubber or a plastic material. The second part may be axially distal the fibre reinforced composite layer. In other words, the second part may be at an end of the seat post. In a folding bicycle, the stopper can prevent the end of the metal tube from hitting the ground, protecting the floor and dampening the sound. It can also act as a brake to stop the bicycle from rolling away when in its folded state. Finally, it can act as a positive stop to prevent the seat post from being removed by being drawn upwards out of the bicycle frame.
[0017] According to a second aspect of the invention, there is provided a bicycle comprising a seat post, the seat post comprising: a metal tube; and a composite fibre reinforced layer arranged on a radially-inner surface of the metal tube. The bicycle may be a folding bicycle.
[0018] Optional features of the seat post of the first aspect are also optional features of the seat post of the bicycle of the second aspect.
[0019] According to a third aspect of the invention, there is provided a method of manufacturing a seat post for a bicycle according to the first aspect, the method comprising: providing a metal tube; applying at least one sheet of fibre reinforced composite to an at least partially deflated balloon; inserting the balloon and the at least one sheet of fibre reinforced composite into the metal tube; inflating the balloon so that the at least one sheet of fibre reinforced composite is in contact with the metal tube; curing the at least one sheet of fibre reinforced composite; and deflating the balloon.
[0020] In this way, the metal tube which is used to mould the at least one sheet of fibre reinforced composite forms part of the final seat post. By curing the at least one sheet of fibre reinforced composite inside the metal tube, better adhesion between the at least one sheet of fibre reinforced composite and the metal tube can be ensured than if a fibre reinforced composite structure were made and cured before being inserted into the metal tube. The use of a balloon inflated within the metal tube can also ensure good contact or adhesion between the at least one sheet of fibre reinforced composite and the metal tube. By reducing the incidence of any gaps between the fibre reinforced composite and metal, failures can be reduced.
[0021] The at least one fibre reinforced composite sheet may be a composite of carbon fibre and at least one polymer or pre-polymer. The at least one fibre reinforced composite sheet may a composite of carbon fibre and epoxy resin. The step of curing the at least one sheet of fibre reinforced composite may comprise heating the at least one sheet of fibre reinforced composite. The method may comprise, before inserting the balloon and the at least one sheet of fibre reinforced composite into the metal tube, applying glue, for example epoxy glue, to the at least one sheet of fibre reinforced composite. By using either a composite of carbon fibre and at least one polymer or pre-polymer, such as epoxy resin, or by applying glue to the at least one sheet of fibre reinforced, good adhesion between the at least one sheet of fibre reinforced and the metal tube is ensured. The at least one fibre reinforced composite sheet may be an aramid, such as Kevlar. or another fibre reinforced composite.
[0022] The method may comprise, after the step of curing the at least one sheet of fibre reinforced composite, cutting the metal tube and fibre reinforced composite to a predetermined length. This can allow for the production of a seat post of an appropriate length for the bicycle with which it is to be used.
[0023] Optional features of the first aspect are also optional features of the third aspect.
For example, the dimensions referred to in relation to the steel tube of the seat post of the first aspect may also be dimensions of the steel tube of the method of manufacturing a seat post of the third aspect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Examples of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which: [0025] Figure 1 shows a side view of a folding bicycle including the seat post of the first aspect; [0026] Figure 2 shows a side view of the seat post; [0027] Figure 3 shows a side view of an upper end of the seat post with a partial cut-away; [0028] Figures 4A and 4B show, respectively, a side view and perspective view of the seat post, with a saddle attachment and stopper; and [0029] Figure 5 shows a flow diagram of a method of manufacture of the seat post.
DETAILED DESCRIPTION
[0030] Figure 1 shows a bicycle 10 including the seat post 11 of the first aspect. The seat post 11 supports a seat 12, also called a saddle. In this embodiment, the bicycle 10 is a folding bicycle. In other embodiments, the seat post 11 may be for a bicycle that is not arranged to fold. In these embodiments, the seat post 11 may have different dimensions. For example, a seat post 11 for a bicycle that is not arranged to fold will generally be shorter than a seat post 11 for a folding bicycle since the remainder of the bicycle frame will contribute more to supporting a rider at the required elevation.
[0031] Figure 2 shows the seat post 11 when not mounted in the bicycle 10. The seat post 11 is generally tubular in shape. The seat post 11 has a main body 20, made up of a metal tube and fibre reinforced composite layer, discussed in further detail below with reference to Figure 3. In this embodiment, the seat post 11 also includes a saddle attachment 21 and a stopper 22. These are also discussed in further detail below, with reference to Figures 4A and 48.
[0032] Turning now to Figure 3, the main body 20 of the seat post 11 will now be described. The main body 20 is made of a metal tube 31 and a fibre reinforced composite layer 32 arranged on the inside surface of the metal tube 31. Broadly speaking, the fibre reinforced composite layer 32 provides lightweight stiffness, while the metal tube 31 provides protection of the fibre reinforced composite layer 32 from scratching and denting.
[0033] In this embodiment, the metal of the metal tube 31 is steel. Alternative metals to steel may be used. The metal tube 31 has a radial thickness of 0.3mm. In other words, the wall of the metal tube 31 is 0.3mm thick. In other embodiments, the metal tube 31 may be as thin as is compatible with manufacturing capabilities, for example 0.2mm. In still other embodiments, the metal tube may be thicker, for example up to 0.9mm. A thicker metal tube 31, while potentially providing increased protection for the fibre reinforced composite layer 32, will increase the weight of the seat post 11. In this embodiment, the metal tube 31 is -plated to improve the resistance of the metal tube 31 to corrosion. In this embodiment, the metal tube 31 is chrome-plated.
[0034] By virtue of being arranged on the inside of the metal tube 31, the fibre reinforced composite layer 32 is, like the metal tube 31, also tubular in shape. The fibre reinforced composite layer 32 is, in this embodiment, made up of six sheets of fibre reinforced composite, although in other embodiments, more or fewer sheets may be used. The manufacture of the composite layer 32, and its composition, are described in more detail below with reference to Figure 5.
[0035] Although the main body 20 of the seat post 11 is, in this embodiment, a metal tube 31 having an inner fibre reinforced composite layer 32, it is envisaged that in alternative embodiments, the seat post 11 may be telescopic. In such embodiments, main body 20 would, therefore, be made up of two or more tubes, arranged to telescope relative to one another.
[0036] Retuming now to the discussion of the present embodiment, and with reference now to Figures 4A to 4B, the saddle attachment 21 and stopper 22 will now be described. As noted above, with reference to Figure 2, the seat post 11 of this embodiment has, in addition to the main body 20, a saddle attachment 21 and stopper 22. The saddle attachment 21 is a metal part bonded into an end of the fibre reinforced composite layer 32. In this embodiment, the saddle attachment 21 is an metal part bonded into an end of the fibre reinforced composite layer. For example, the saddle attachment 21 may be made of aluminium. In other examples, the saddle attachment 21 may be made of an alternative material to aluminium. In this embodiment, the saddle attachment 21 is a single part with a seat post attachment end 21a and a saddle attachment end 21b. The seat post attachment end 21a is dimensioned to fit within the main body 20 of the seat post 11 in order to be secured into the main body 20, for example using glue. In the embodiment shown in Figures 4A and 4B, the seat post attachment end 21a has channels around its outer surface to improve the strength of the bond between the seat post attachment 21 and the main body 20 of the seat post 11.
[0037] With continued reference to Figures 4A and 4B, the stopper 22 will now be described.
The stopper 22 serves to close the lower end of the main body 20. In this embodiment, the stopper is made up of a first part 22a bonded into the lower end of the main body 20 of the seat post 11 and a second part 22b fitted into the bottom of the first part 22a. In other embodiments, however, a single-part stopper can be provided. In this embodiment, the first part 22a has a lower aperture, and the second part 22b is dimensioned so as to be fitted into this aperture. In other embodiments, the second part 22b can be attached to the first part 22a by alternative means, such as by using glue, or fitting the second part around an outer edge of the first part 22a. In this embodiment, the first part 22a is made of aluminium. The second part 22b is made of a material that is softer than the metal tube 31. In this embodiment, the second part 22b is made of rubber, although in other embodiments it may be made of a plastic material.
[0038] When the seat post 11 is a seat post used in a folding bicycle 10, the stopper 22 prevents the lower end of the main body 20 from touching the ground when the bicycle 10 is folded. The second part 22b can help to protect the ground surface and dampen any noise. It can also act as a brake on a folding bicycle 10 when the bicycle 10 is folded. The first part 22a can act as a positive stop to prevent the seat post from being removed by being drawn upwards out of the bicycle frame.
[0039] With reference now to Figure 5, a method 50 of manufacturing a seat post will now be described. The method has the following steps: providing 51 a metal tube; applying 52 at least one sheet of fibre reinforced composite to an at least partially deflated balloon; inserting 53 the balloon and the at least one sheet of fibre reinforced composite into the metal tube; inflating 54 the balloon so that the at least one sheet of fibre reinforced composite is in contact with the metal tube; curing 55 the at least one sheet of fibre reinforced composite; and deflating 56 the balloon. In this embodiment, the method 50 is a method of manufacturing the main body 20 of the seat post 11 described above.
[0040] The metal tube of this embodiment is the metal tube 31 described above with reference to Figure 3. Thus, in this embodiment, the metal tube 31 is made of steel. The skilled person would understand how such a steel tube 31 can be manufactured. The at least one sheet of fibre reinforced composite forms the fibre reinforced composite layer 32 described above with reference to Figure 3. To form the fibre reinforced composite layer 32, at least one sheet of fibre reinforced composite is applied to a balloon. The balloon is dimensioned to fit within the metal tube 31 when deflated and to fill the metal tube 31 when inflated. The at least one fibre reinforced composite sheet is, in this embodiment, a composite of carbon fibre and epoxy resin. Thus, when cured, they will harden to the inside of the metal tube 31. In other embodiments, the at least one fibre reinforced composite sheet is a composite of carbon fibre and an alternative polymer or pre-polymer. The skilled person would be able to select an appropriate composite based on the principle that the at least one fibre reinforced composite sheet must set within the metal tube 31 to join to the inner surface of the metal tube. Alternatively or in addition, the at least on fibre reinforced composite sheet can be attached to the inner surface of the metal tube by applying glue to the at least one sheet of fibre reinforced composite before it is inserted 53 into the metal tube 31.
[0041] In this embodiment, applying 52 at least one sheet of fibre reinforced composite to the balloon is performed by laying up six fibre reinforced composite sheets onto the balloon, at angles selected to provide a strong fibre reinforced composite layer 32 within the seat post 11. The skilled person would be able to select an appropriate orientation for the fibre reinforced composite sheets using fatigue and stiffness testing to validate.
[0042] After the at least one sheet of fibre reinforced composite has been applied to the balloon, the balloon is inserted into the metal tube 31. The balloon is then inflated 54 so that the at least one sheet of fibre reinforced composite is in contact with the inner surface of the metal tube 31. The at least one sheet of fibre reinforced composite is cured 55, either by air-drying or heating. Once the at least one sheet of fibre reinforced composite has been cured 55, the balloon is deflated 56. This allows the balloon to be removed from the seat post 11 once the fibre reinforced composite layer 32 has cured in place.
[0043] By curing the at least one sheet of fibre reinforced composite inside the metal tube, better adhesion between the at least one sheet of fibre reinforced composite and the metal tube can be ensured than if a fibre reinforced composite structure were made and cured before being inserted into the metal tube. The use of a balloon inflated within the metal tube can also ensure good contact or adhesion between the at least one sheet of fibre reinforced composite and the metal tube. By reducing the incidence of any gaps between the fibre reinforced composite and metal, failures can be reduced.
[0044] In this embodiment, after the step of curing 55 the at least one sheet of fibre reinforced composite, the method 50 includes the step of cutting 57 the metal tube and fibre reinforced composite to a predetermined length. This can allow for the production of a seat post of an appropriate length for the bicycle with which it is to be used. In alternative embodiments, the metal tube 31 into which the at least one sheet of fibre reinforced composite is inserted and cured can be pre-cut to an appropriate length.
[0045] As mentioned above, in this embodiment, the method 50 is a method of manufacturing the main body 20 of the seat post 11 described above with reference to Figures 1 to 4B. Accordingly, to make the finished seat post 11, the method also includes the steps (not shown) of gluing the seat post attachment 21 and stopper 22 into opposite ends of the main body 20.
[0046] Accordingly, there has now been described a seat post for a bicycle, the seat post comprising: a metal tube; and a fibre reinforced composite layer arranged on a radially-inner surface of the metal tube, as well as a bicycle comprising such a seat post. There has also been described a method of manufacturing a seat post for a bicycle, the method comprising: providing a metal tube; applying at least one sheet of fibre reinforced composite to an at least partially deflated balloon; inserting the balloon and the at least one sheet of fibre reinforced composite into the metal tube; inflating the balloon so that the at least one sheet of fibre reinforced composite is in contact with the metal tube; curing the at least one sheet of fibre reinforced composite; and deflating the balloon.
Claims (2)
- CLAIMS: 1 A seat post for a bicycle, the seat post comprising: a metal tube; and a fibre reinforced composite layer arranged on a radially-inner surface of the metal tube.
- 2 The seat post of claim 1, wherein the seat post is for a folding bicycle 3 The seat post of claim 1 or claim 2, wherein the metal tube is made of steel.4 The seat post of any preceding claim, wherein the fibre reinforced composite layer is a composite of carbon fibre and epoxy resin, or wherein the fibre reinforced composite layer is a composite of carbon fibre and a polymer or pre polymer The seat post of any preceding claim, wherein the fibre reinforced composite layer is as long as the metal tube.6 The seat post of any preceding claim, wherein the fibre reinforced composite layer is bonded to the radially-inner surface of the metal tube.7. The seat post of any preceding claim, wherein the metal tube is of substantially uniform thickness and has a radial thickness of between 0.2mm and 0.9mm.8. The seat post of claim 7, wherein the metal tube has a radial thickness of 0.3mm.9. The seat post of any preceding claim, wherein the fibre reinforced composite layer is formed of a plurality of sheets of fibre reinforced composite.The seat post of any preceding claim, wherein the seat post further comprises a saddle attachment in the form of a part bonded into an end of the fibre reinforced composite layer.11 The seat post of any preceding claim, wherein the seat post further comprises a stopper bonded into an end of the fibre reinforced composite layer and wherein the stopper comprises a first part bonded into an end of the fibre reinforced layer and a second part fitted into or onto the first part, or wherein the stopper comprises a single part bonded into an end of the fibre reinforced layer.12. The seat post of claim 11, wherein the single-part stopper is of a material that is softer than the metal tube, or wherein the second part is of a material that is softer than the metal tube.13. A bicycle comprising the seat post of any preceding claim.14. The bicycle of claim 13, wherein the bicycle is a folding bicycle.15. A method of manufacturing the seat post for a bicycle of any of claims 1 to 12, the method comprising: providing a metal tube; applying at least one sheet of fibre reinforced composite to an at least partially deflated balloon; inserting the balloon and the at least one sheet of fibre reinforced composite into the metal tube; inflating the balloon so that the at least one sheet of fibre reinforced composite is in contact with the metal tube; curing the at least one sheet of fibre reinforced composite; and deflating the balloon.16 The method of claim 15, wherein the at least one sheet of fibre reinforced composite is a composite of carbon fibre and at least one polymer or pre-polymer.17 The method of claim 15 or claim 16, wherein the method comprises, before inserting the balloon and the at least one sheet of fibre reinforced composite into the metal tube, applying glue to the at least one sheet of fibre reinforced composite 18 The method of any of claims 15 to 17, further comprising, after the step of curing the at least one sheet of fibre reinforced composite, cutting the metal tube and fibre reinforced composite to a predetermined length.19 The method of any of claims 15 to 18, wherein the method is a method of manufacturing the seat post of any of claims 1 to 12.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2112063.9A GB2622182A (en) | 2021-08-23 | 2021-08-23 | Lightweight bicycle seat post |
| PCT/GB2022/052170 WO2023026038A1 (en) | 2021-08-23 | 2022-08-23 | Lightweight bicycle seat post |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2112063.9A GB2622182A (en) | 2021-08-23 | 2021-08-23 | Lightweight bicycle seat post |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB202112063D0 GB202112063D0 (en) | 2021-10-06 |
| GB2622182A true GB2622182A (en) | 2024-03-13 |
Family
ID=77913911
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2112063.9A Pending GB2622182A (en) | 2021-08-23 | 2021-08-23 | Lightweight bicycle seat post |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB2622182A (en) |
| WO (1) | WO2023026038A1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5364095A (en) * | 1989-03-08 | 1994-11-15 | Easton Aluminum, Inc. | Tubular metal ball bat internally reinforced with fiber composite |
| US6213488B1 (en) * | 1997-12-16 | 2001-04-10 | Jas. D. Easton, Inc. | Exposed carbon core bicycle seat post and method of manufacture thereof |
| US20060172101A1 (en) * | 2005-02-03 | 2006-08-03 | A.P. Lin | Method for bonding composite material to alloy pipe and resultant product |
-
2021
- 2021-08-23 GB GB2112063.9A patent/GB2622182A/en active Pending
-
2022
- 2022-08-23 WO PCT/GB2022/052170 patent/WO2023026038A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5364095A (en) * | 1989-03-08 | 1994-11-15 | Easton Aluminum, Inc. | Tubular metal ball bat internally reinforced with fiber composite |
| US6213488B1 (en) * | 1997-12-16 | 2001-04-10 | Jas. D. Easton, Inc. | Exposed carbon core bicycle seat post and method of manufacture thereof |
| US20060172101A1 (en) * | 2005-02-03 | 2006-08-03 | A.P. Lin | Method for bonding composite material to alloy pipe and resultant product |
Also Published As
| Publication number | Publication date |
|---|---|
| GB202112063D0 (en) | 2021-10-06 |
| WO2023026038A1 (en) | 2023-03-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5215322A (en) | Dual and single seat composite bicycle frames and fabrication methods therefore | |
| US4900048A (en) | Integral seamless composite bicycle frame | |
| ES2665010T3 (en) | Composite stile and manufacturing method | |
| US6109638A (en) | Honeycomb reinforced composite fiber bicycle frame | |
| US5557982A (en) | Composite bicycle handlebar | |
| US7475705B2 (en) | Manufacturing method for multi-material tube structures | |
| US5078417A (en) | All terrain cycle fork with fiber reinforced resin blades and crown and method of making same | |
| EP0498797B1 (en) | Cycle fork with fiber reinforced resin blades and crown and method of making same | |
| US20030205882A1 (en) | Living hinge member and suspension | |
| JP2007161239A (en) | Wheel having multiple tube frame structure | |
| JP5236487B2 (en) | Ultralight saddle structure, in particular an ultralight saddle structure for pedal-driven vehicles, and a method of manufacturing a support frame thereof | |
| JP4362788B2 (en) | Manufacturing method of tubular body made of fiber reinforced resin and golf club shaft manufactured by the method | |
| US9387884B2 (en) | Vehicle body | |
| ES2685274T3 (en) | Distribution of point loads in honeycomb panels | |
| US20080118303A1 (en) | Composite Structural Member And Method For Producing The Same | |
| US20130101762A1 (en) | Ultralight composite structures | |
| US6213488B1 (en) | Exposed carbon core bicycle seat post and method of manufacture thereof | |
| GB2622182A (en) | Lightweight bicycle seat post | |
| JP5457231B2 (en) | Golf club shaft manufacturing method | |
| US9463840B1 (en) | Bicycle component with reinforced structure and manufacturing method thereof | |
| TWI430897B (en) | Bicycle rim | |
| TWI374814B (en) | Reinforcement element for a bicycle rim | |
| ES2339581T3 (en) | SEAT SADDLE FOR A BICYCLE. | |
| US5676780A (en) | Method of making a single rear fork bicycle frame | |
| EP0685386A1 (en) | Adapter fitting for the selective connection of a radiator to a one- or a two pipe system |