A Level Cycle trailer Project

2tired2ride

Hi

I used your advise and comments last year for my AS project, however I am now in my final year of A Levels and now need your comments again.

My project is a cycle trailer for commuting and touring. But not a boring coloured cycle trailer to carry your kid's around but something you would be proud to cycle around. I know the idea of commuting with a trailer attached sounds dangerous, and it might not be the best option for London. But for commuters who travel on cycle path it would be great.

The picture below show my model of the trailer and is one of the marketing posters.



The frame would be made from Aluminium and the cargo body would be made from ABS. The white wheel covers are ment to repersent a hubless wheel, which is more of a concept idea than what would probally end up on there in real life (but it is only an A level project at the end of the day).

The low attachment to the wheel creates a low centre of gravity that really helps with the handling. The pivot point coming off the pannier rack means you can still use panniers if you want to and puts pivot behind the rear wheel which also helps with the handling.



This is only a very quick explaination of it and feel free to ask questions and find problems with it.

I look forward to all feedback both bad and good.

Thanks

FeynmanC

Nice idea.

How would it cope with being parked up, does it have a stand at all or would it need to be leaned against a wall.

Also, what about locking it up outside the shop or work? Any built in security?

I want one that I can use for shopping and to put my old dog in when he's tired out on long runs down cyclepaths.

2tired2ride

FeynmanC wrote:

Nice idea.

How would it cope with being parked up, does it have a stand at all or would it need to be leaned against a wall.

Also, what about locking it up outside the shop or work? Any built in security?

I want one that I can use for shopping and to put my old dog in when he's tired out on long runs down cyclepaths.

It can stand on its own by angling the bike and trailer like below.



You can obviously still learn it against a wall as well. I did intend to design and make it with a built in locking system, however in the end I ran out of time in the end.

I forgot to say that it has a modular system, so you can unclip the waterproof cargo body and clip in other modular parts such as the specific child seat. If anyone has any other modular parts that would be a good idea that would be great. So yes it could alos have a dog basket and storage system that could clip in.

thanks

coopster_the_1st

First, it needs somewhere to attach a light, preferably two.

I know this is an A level project but I think you are trying to solve a problem that has been created(if that makes sense).

I can see the use for shopping but if you need to commute with that much stuff, are you really going to want to cycle. Surely, in this case the problem you are trying to solve is how to carry less stuff. (i.e. spare laptop at home).

I like the design but do wonder what handling would be like if it was filled with books, etc. Would it be trying to throw you off the bike around corners?

2tired2ride

Coopster the 1st wrote:

First, it needs somewhere to attach a light, preferably two.

I know this is an A level project but I think you are trying to solve a problem that has been created(if that makes sense).

I can see the use for shopping but if you need to commute with that much stuff, are you really going to want to cycle. Surely, in this case the problem you are trying to solve is how to carry less stuff. (i.e. spare laptop at home).

I like the design but do wonder what handling would be like if it was filled with books, etc. Would it be trying to throw you off the bike around corners?

Thanks, yes I can't belive I fogot to add a light on my model (it was on my designs). Ilike the idea of more than one light. Maybe have side lights or reflectors and a rear light or two.

I can see what you are saying about carrying that much stuff, but it is also designed to be used in cycle touring as well as commuting.

I have tested the trailer weighted round corners, turning quickly, over bumps and up and down curbs and it handles very well and does not affect the handling in anyway close to throw you off the bike.

Thanks

deptfordmarmoset

NIce project and it looks very well modelled.

Coopster the 1st makes a good point about lights - and possibly you'd need something that would signal to a car intending to overtake that it's more than simply a bike and, being longer, will need more space to pass safely.

Some possible problems - first, is there enough road clearance at the rear of the trailer body? You're going to have to haul it up kerbs from time to time.

Secondly, loads might end up getting compacted towards the rear - vibration will be constantly impelling loads backwards.

The length of frame between rear of the trailer and the wheel looks like it's going to be fairly stressed too, it's carrying the full weight laterally to a point that's going to be subject to all the road ups and downs that the highways authorities can throw at it.

My engineering genes stopped evolving when chimpanzees started using sticks as tools so you're welcome to pour scorn on me, but did you consider using the frame to hang the trailer (on a lip around the frame) rather than support it underneath? I guess I'm thinking of it like a kind of bucket - and the most stable way of carrying a laden bucked is not by supporting it from underneath but by letting it hang as you carry it by the handle. That way you might(?) be able to reduce the stress on the rear part of the frame (because it would be more vertical) and deal with the clearance question at the same time.

2tired2ride

deptfordmarmoset wrote:

NIce project and it looks very well modelled.

Coopster the 1st makes a good point about lights - and possibly you'd need something that would signal to a car intending to overtake that it's more than simply a bike and, being longer, will need more space to pass safely.

Some possible problems - first, is there enough road clearance at the rear of the trailer body? You're going to have to haul it up kerbs from time to time.

Secondly, loads might end up getting compacted towards the rear - vibration will be constantly impelling loads backwards.

The length of frame between rear of the trailer and the wheel looks like it's going to be fairly stressed too, it's carrying the full weight laterally to a point that's going to be subject to all the road ups and downs that the highways authorities can throw at it.

My engineering genes stopped evolving when chimpanzees started using sticks as tools so you're welcome to pour scorn on me, but did you consider using the frame to hang the trailer (on a lip around the frame) rather than support it underneath? I guess I'm thinking of it like a kind of bucket - and the most stable way of carrying a laden bucked is not by supporting it from underneath but by letting it hang as you carry it by the handle. That way you might(?) be able to reduce the stress on the rear part of the frame (because it would be more vertical) and deal with the clearance question at the same time.

Thank you

You are definatlly correct about the lights which is very important and I will add them into my design. I think I might postion a light either side of the trailer and one on the back and maybe on off the pannier rack?

I built two frames before I came up with this one so that I could test the geometery, to get the correct geometry for my final model. In the test i got the correct clearance needed to clear curbes and speed bumps. So the clearance is not a problem.

You are right about the the cargo moving all to the rear, I was thinking on modular slide in dividers with many options, so you create the space you need.

As for the frame being stresses, I again agree with you. I intended for the frame to have either limited up and down movement or some type of suspension around the pivot piont. However because of limited time I did not get further than research on that matter. But was interessed in doing something with Hydroelastic (like the moultons have, and old mini's) suspension.

With the idea of having the frame hang off the pannier rack. I tested it with it in that postion, but it caught on the pannier rack and stopped it from being able to turn so quickly, so I moved it to the top of the pannier.

Many thanks and I will definatly take your feedback on board and use it in my project.

2tired2ride

Another picture, this one shows the hubless wheel.

FeynmanC

You could put a kiddy saddle on top of the luggage compartment. shopping inside, kid on top.

2tired2ride

FeynmanC wrote:

You could put a kiddy saddle on top of the luggage compartment. shopping inside, kid on top.

On one of my design sheets (below) for the modular system I had the child seat in front and the cargo space behind.

lost_in_thought

*disclaimer* this may be an idiotic idea *disclaimer*

Would it be possible to put rixen kaul style pannier mountings on the box, so you could expand it? Make it a bit more adaptable, so you could, say, have children and shopping on it, or something?

Not a well-formulated idea, just thinking out loud.

Also, don't build in lights, put in mountings for them so people can choose their own and replace them easily/cheaply.

Also, and this is a minor concern, white is super-impractical. How about day-glo? Or make use of the reflective tape that looks black when it's not reflecting?

How is it in a side wind?

nicklouse

My only thoughts are the main change from the drawings to the model.

the trailer "floor" is not like the drawings. IE Flat to the ground? Also with both the top and bottom planes being so angled you are losing a lot of storage space.

maybe have a variable hitching system to cover a 26/28" wheeled bike option. Different rack heights.

something that i have not seen on any trailer project yet is a brake.

which should not be too hard to work out. you could even have it regulated by load.

Aidy

How does having such a high pivot point affect the handling?

solsurf

you've done a great job there, well done, and it is always brave to ask for feedback.

I think the design of trailers has long needed some attention. I can only say that I would want a trailer that can be broken down easily so it can be put on a train so rather than have a solid construction have a waterproof bag. Also in a side wind a solid contruction would act like a sail.

Anyway hope you get a great grade. Well done.

2tired2ride

lost_in_thought wrote:

*disclaimer* this may be an idiotic idea *disclaimer*

Would it be possible to put rixen kaul style pannier mountings on the box, so you could expand it? Make it a bit more adaptable, so you could, say, have children and shopping on it, or something?

Not a well-formulated idea, just thinking out loud.

Also, don't build in lights, put in mountings for them so people can choose their own and replace them easily/cheaply.

Also, and this is a minor concern, white is super-impractical. How about day-glo? Or make use of the reflective tape that looks black when it's not reflecting?

How is it in a side wind?

I like your expandible idea, it would be good for a different modular cargo carrier for the trailer. I will look into it.

I agree with you that it would be best for the user to use there own lights.

I did research the use of Scotchlite 680 (the black night glow), however I didn't design the trailer to use it in the end, mostley down to time constrents.

Thanks for you comments

2tired2ride

nicklouse wrote:

My only thoughts are the main change from the drawings to the model.

the trailer "floor" is not like the drawings. IE Flat to the ground? Also with both the top and bottom planes being so angled you are losing a lot of storage space.

maybe have a variable hitching system to cover a 26/28" wheeled bike option. Different rack heights.

something that i have not seen on any trailer project yet is a brake.

which should not be too hard to work out. you could even have it regulated by load.

The reason it changed angle was that it need to be raised so it can clear high curbs when going up them. The storage space is already large and I don't think anymore is needed.

The pannier rack is adjustible so that it will fit bot 26" wheel and 700c wheels with mudgaurds on. (It also fits bikes with disc brakes as well.)

I'm interessed on your idea of a brake, and if I had more time I would of liked to look into that further. (My hand in is tomorro)

2tired2ride

solsurf wrote:

you've done a great job there, well done, and it is always brave to ask for feedback.

I think the design of trailers has long needed some attention. I can only say that I would want a trailer that can be broken down easily so it can be put on a train so rather than have a solid construction have a waterproof bag. Also in a side wind a solid contruction would act like a sail.

Anyway hope you get a great grade. Well done.

Thanks

Once the cargo body is removed (uncliped) the frame can be taken apart into two. Just by using a 5mm allen key to undo two bolts, so although it won't be quck enough to do for taking on the train, is does store smaller.

I never tested my trailer in very strong winds, but with the cargo in it, it should stay weighted down, if I had more time I would of tested stronge winds.

thanks

deptfordmarmoset

Just out of curiosity, how does it handle with a full load when braking heavily? As body weight is transferred to the front wheel, is there also a risk of it jack-knifing, either sideways or vertically?

And did you come across problems fixing the trailer to the bike itself, i.e. the seatpost? Because, if that were possible it would mean not having to also have a pannier rack and you could possibly lower the attachment point, thereby ''horizontalising'' the whole thing. And possibly improving stability.

And, forgive me for being a little irreverent, but it struck me that you have come up with something that the ancient Greeks might have recognised. Google ''hyperteria monokyklou''

(This is not in any way a criticism - it's just the way I look at things. Besides, I think it's an excellent project that I'm sure will get you the grades it merits!!)

2tired2ride

deptfordmarmoset wrote:

Just out of curiosity, how does it handle with a full load when braking heavily? As body weight is transferred to the front wheel, is there also a risk of it jack-knifing, either sideways or vertically?

And did you come across problems fixing the trailer to the bike itself, i.e. the seatpost? Because, if that were possible it would mean not having to also have a pannier rack and you could possibly lower the attachment point, thereby ''horizontalising'' the whole thing. And possibly improving stability.

And, forgive me for being a little irreverent, but it struck me that you have come up with something that the ancient Greeks might have recognised. Google ''hyperteria monokyklou''

(This is not in any way a criticism - it's just the way I look at things. Besides, I think it's an excellent project that I'm sure will get you the grades it merits!!)

It handles well when braking unless you start to let the back wheel up (endo), when it then puts stress on the pivot and frame.

I agree it would probally handle better if it had a lower attachment point, and I did do a few sketches of that type of thing, but in the end I decided to go down this route and otherwise it would of pretty much of been a "BOB Yak" trailer.

The greek wheel barrow is good asurence that my design is tried and tested

Thanks