N+1 Tiddles

[Night Train]

The twistgrip with the leather grips is fantastic. Are you taking orders for the conversion? :-)

Not thought about that but the twist grip is a simple enough DIY job to do. The leather work is fiddly and all you'd get is a bit of leather with some stitch holes and a roll of cotton and a needle.

 

[CopperBrompton]

I think Sir misunderstands ... I mean fitted.

There are actually specific Emergency Orders banning me from attempting anything resembling DIY or mechanics.

 

[Night Train]

Is that a paid job on offer?

 

[CopperBrompton]

Is that a paid job on offer?

It is - how much?

There is the small matter of you being in Manchester, but I do wander up that way from time to time.

 

[Night Train]

I have absolutely no idea how much. We'll have a PM chat about it when you know when you are going to be near here, with the Brom.

 

[CopperBrompton]

Cool

 

[Night Train]

I finally got around to making the trailer hitch.

I cut and carved a lump of aluminium to shape and drilled a 1/4" BSP hole in the centre and drilled and tapped an M6 through hole across it. It is asymmetric so that there is more movement upwards then there is downwards.

I then bent a strap of 1/8" thick aluminium and drilled it with two 6mm holes. and fitted an airline QR fitting.

The hitch fits on the seat post and allows for Yaw and Pitch. The airline fitting allows for Roll.

The trailer end is done but I forgot to take photos.
I turned a bit of steel to 17mm OD with a 1/4" BSP internal thread. The steel was then pressed into a bit of the tent pole tubing which was then riveted to the end of the trailer drawbar. The steel is a tight fit but is also drilled with a 5mm hole to take a M5 bolt that will secure the safety strap fittings, when I get them.

 

[Arch]

Nice! That piece of aluminium looks so nice and tactile too, the sort of thing you could roll round in your hand for ages...

 

[CopperBrompton]

Beautiful!

 

[HovR]

Great thread, thanks for posting! Made a really entertaining read. I may also borrow that trailer hitch idea.

 

[Night Train]

Great thread, thanks for posting! Made a really entertaining read. I may also borrow that trailer hitch idea.

Hmmm, I was thinking of marketing it so I guess I shouldn't have posted it here.
Are you able to make one?

I am going to redesign it better. I can already see a development process from the first one I make for a friend.

The next one will be less rattley on the seat post.

 

[HovR]

Hmmm, I was thinking of marketing it so I guess I shouldn't have posted it here.
Are you able to make one?
.

Yep, I should be able to, although I may have to purchase some metric taps.

This would be going on my Dawes, so do you think a seatpost mount would be suitable, with it being much higher up than on a Brompton? The other option is obviously something which attaches around the QR or stays area, although that would make the design a bit more complicated.

 

[Night Train]

I prefer to keep the hitch point as close to the wheel axle height as possible, relative to the saddle height. It reduces any sideways pushes from the trailer affecting balance.
On the Brompton the bottom of the seat post is so low that it is not much higher then the hitch on any other bike trailer and so any sideways pushing is minimal.

This is the sort of hitch location on a Brompton.

Demonstrating the strength of the trailer.

I tend to avoid seat post hitches on uprights as trailer twitch occurs right where you least want to feel it. Some people are ok with it though.

 

[HovR]

I thought that might be the case.

I have some design ideas formulating for a QR mounting hitch, but I still have a few issues with the design to sort out - So more on that another day!

 

[Night Train]

I am working on a more conventional trailer hitch for QR and non QR axles and suss and non suss frames but it is complicated trying to get a simple 'catch all' design that works.