Bicycle frame with passive seat tube pivot joint

Patent metadata

Field	Value
Publication number	US-9789925-B2
Application number	US-201514878658-A
Country	US
Kind code	B2
Filing date	Oct 8, 2015
Priority date	Jan 5, 2011
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A bicycle frame assembly that includes an upper frame member and a lower frame member that each extend between a head tube and a dropout. A seat tube extends between the upper frame member and the lower frame member. The seat tube is preferably connected to a bottom bracket of the lower frame member and is connected by a pivot to the upper frame member so that the seat tube can deflect from a rest position without altering an orientation of a top tube to a bottom tube of the upper and lower frame members, respectively.

First claim

What is claimed is:

1. A bicycle frame assembly comprising:
a forward frame triangle comprising:
a top tube having a first end connected to a head tube and a second end;
a bottom tube having a first end connected to the head tube and a second end;
a bottom bracket connected to the second end of the bottom tube; and
a flexible, unitary seat tube extending in an upward direction from the bottom bracket;
a pair of seat stays connected to the top tube and extending in a rearward direction beyond the forward frame triangle; and
a rotable coupling connecting the seat tube to the forward frame triangle proximate the top tube at a location nearer a bicycle seat than the bottom bracket.

2. The bicycle frame assembly of claim 1 , further comprising a passage formed proximate an intersection of the seat stays and the top tube and shaped to accommodate the seat tube passing therethrough.

3. The bicycle frame assembly of claim 2 , wherein an axis of the rotable coupling is oriented normal to an axis of the passage.

4. The bicycle frame assembly of claim 1 , wherein the flexible, unitary seat tube is made of a fiber reinforced plastic.

5. The bicycle frame assembly of claim 1 , wherein the seat tube can rotate at least 7 degrees about the rotable coupling allowing the seat tube to deflect from an at rest shape.

6. The bicycle frame assembly of claim 1 , wherein a longitudinal axis of the rotable coupling is one of positioned forward of a longitudinal axis of the seat tube, aligned with the longitudinal axis of the seat tube, or positioned rearward the longitudinal axis of the seat tube.

7. A bicycle frame assembly comprising:
an upper frame member that includes a top tube and a pair of seat stays and that extends between a dropout and a head tube;
an opening formed in the upper frame member;
a lower frame member that includes a bottom tube, a bottom bracket, and a chain stay, and that extends between the dropout and the head tube;
a flexible, unitary seat tube extending from the lower frame member toward the upper frame member and passing through the opening in the upper frame member; and
a rotable coupling connecting the seat tube to the upper frame member proximate the opening so that more of the seat tube is located between the rotable coupling and the bottom bracket than extends beyond the upper frame member.

8. The bicycle frame assembly of claim 7 , wherein the rotable coupling is oriented either forward or rearward relative to a longitudinal center-line of seat tube.

9. The bicycle frame assembly of claim 7 , further comprising a bridge that extends between the pair of seat stays and defines a rear wall of the opening.

10. The bicycle frame assembly of claim 7 , wherein the flexible, unitary seat tube is made of a fiber reinforced plastic.

11. The bicycle frame assembly of claim 7 , wherein the rotable coupling includes a first portion and a second portion that threadably cooperate with one another.

12. The bicycle frame assembly of claim 11 , wherein each of the first portion and the second portion of the rotable coupling include a head portion and a shank portion wherein only the shank portion passes through the upper frame member.

13. A method of allowing deflection of a seat tube, comprising:
connecting a flexible, unitary seat tube to a bottom bracket;
connecting the seat tube to an upper frame member with a rotable coupling located at an overlapping intersection of a seat tube and the upper frame member so that the seat tube can deflect from alignment along an line between the bottom bracket and the rotable coupling; and
forming the upper frame member with a pair of seat stays and a top tube.

14. The method of claim 13 , further comprising defining an opening through the upper frame member that is shaped to allow the seat tube to pass therethrough.

15. The method of claim 14 , further comprising closing a forward facing, a rearward facing, and opposite lateral facing sides of the opening.

16. The method of claim 13 , further comprising connecting the pair of seat stays to one another at a location rearward of the seat tube that is offset from a rear wheel.

17. The method of claim 13 , wherein the flexible, unitary seat tube is made of a fiber reinforced plastic.

18. The method of claim 13 , further comprising providing a gasket that cooperates with at least one longitudinal end of the rotable coupling.

19. The method of claim 13 , further comprising forming the rotable coupling as a first part and a second part that removably cooperate with the seat tube and engage the upper frame member from opposite lateral directions relative to a longitudinal direction of the upper frame member.

Assignees

• Trek Bicycle Corp

Inventors

• Lund Reggie
• Pomering Christopher

Classifications

• B62J1/04

  Saddles capable of swinging about a horizontal pivot · CPC title

• B62K3/02

  Frames (tandem frames B62K3/14) · CPC title

• B62K25/04

  for mounting axles resiliently on cycle frame or fork (for sidecars, forecars or the like B62K27/06) · CPC title

• B62K2025/041

  the cycle frame being made of a flexible material · CPC title

• Y10T29/4984

  Retaining clearance for motion between assembled parts · CPC title