Rear Mudflap - Any Use?

[robgul]

Here's my suggestion :

http://www.beewee.org.uk/generaldocs/briefings/robsbriefings-9.pdf

Rob

That's pretty, but what does it do? It won't interrupt much of the water from the tyre to the rider behind, it'd need to be a lot longer for that.
Mine are about twice as long and still too short, the works bike stands destroy anything longer. Ideally they should be almost touching the ground.

You'd be surprised how effective it is - I'm not sure why ... possibly as it gets very soggy and the water doesn't bounce off it in the way it does with hard plastic/Fairy Liquid bottle flaps. I have experimented with a longer leather flap and it makes no real difference.

Rob

[PH]

Here's my suggestion :

http://www.beewee.org.uk/generaldocs/briefings/robsbriefings-9.pdf

Rob

That's pretty, but what does it do? It won't interrupt much of the water from the tyre to the rider behind, it'd need to be a lot longer for that.
Mine are about twice as long and still too short, the works bike stands destroy anything longer. Ideally they should be almost touching the ground.

You'd be surprised how effective it is - I'm not sure why ... possibly as it gets very soggy and the water doesn't bounce off it in the way it does with hard plastic/Fairy Liquid bottle flaps. I have experimented with a longer leather flap and it makes no real difference.

Rob

I'll take your word for it, though I'd rather take the word of a following cyclist. I've always found it's pretty much line of sight, if I can see the tyre in front it can spray me.

[robgul]

That's pretty, but what does it do? It won't interrupt much of the water from the tyre to the rider behind, it'd need to be a lot longer for that.
Mine are about twice as long and still too short, the works bike stands destroy anything longer. Ideally they should be almost touching the ground.

You'd be surprised how effective it is - I'm not sure why ... possibly as it gets very soggy and the water doesn't bounce off it in the way it does with hard plastic/Fairy Liquid bottle flaps. I have experimented with a longer leather flap and it makes no real difference.

Rob

I'll take your word for it, though I'd rather take the word of a following cyclist. I've always found it's pretty much line of sight, if I can see the tyre in front it can spray me.

Speed (or lack of ?) is undoubtedly a factor - and the tread pattern of the tyre perhaps - my bikes with Marathons seem to throw less water than the one with Gatorskins which are all but slick.

Rob

[Gattonero]

That rear flap is pointless - it's not required to keep you clean, and needs to be at least twice as long if it's to keep spray off a following rider.

Not really pointeless.
Giles gave a good reason here:

...However if I had a rear mudflap, let alone one that long, it would very quickly be disasterous. I need to be able to easily wheel the bike on its rear wheel so that I can traverse places like narrow bridges etc. ...

Surely, it has to be longer for being really effective, but that means to make it somewhat heavier at the end (otherwise would simply go horizontal at speed).

Note that this is the Mk1, there's always room for improvement.
Will defintely do another pair, and this time with the fabric pattern matching both front and rear note that I've spend £0 as all the materials are recycled (old brompton front flaps, fabric odd cuts), although there's a coupe of pennies of poly thread.

[CREPELLO]

Surely, it has to be longer for being really effective, but that means to make it somewhat heavier at the end (otherwise would simply go horizontal at speed).

If you curve the mudflap to the profile of the mudguard, that will help give it rigidity.

[reohn2]

I think it is very much a "courses your bicycle is going over" question.

The bike I most often use across the hills round here is configured very similarly to Andrew_s's. However if I had a rear mudflap, let alone one that long, it would very quickly be disasterous. I need to be able to easily wheel the bike on its rear wheel so that I can traverse places like narrow bridges etc. the width of my shoulders and hips. Doing that the flap will either get ripped off when I tread on it, very likely wrecking the mudguard and causing me to overbalance or else trapped under the wheel - pretty much same result. The front one got ripped off by a sheepdog a number of months ago, this saved it getting ripped off on a step - like a kerb.

So highly desirable for following riders and to keep your chainset and feet dry, but I find, not really practicable.

Front m/flap made from a piece of old truck or car inner tube just a bit wider than the mudguard and to within 50mm of the ground is extremely practical and durable,and flexible enough not break when descending upto 300mm drop offs,it keeps feet and bike totally clean.
Yesterday out on the MTB(with full m/guards and front flap)I rode through a 75 to 100mm deep stream for over 400m without so much as a drop of water on me both feet totally dry.

I take your point about rear m/flaps they can get in the way as you say when wheeling the bike on the rear wheel.they do protect riders behind though and if I were riding in a group regularly I'd fit one but as I don't have small deflector fitted to the rear to stop muddy wet spray getting all over me and the bike.On the Vaya the rear deflector sticks out from the rear m/g about 50cm and all it needs,on the mtb it's a purpose made one that sticks out 10cm

Some upthread mentions m/guard not being long enough,SKS Longboards address the issue,though they're only available in 35 and 45 mm widths and the range needs a 52mm width adding for wider tyres

[dragonrider]

I have found that tandems are the worst bikes, particularly for spraying the stoker's feet. The air flow from the front tyre seems to drag the spray back in after it gets splashed outwards. John at JD Tandems suggested a few years ago making large mud flaps from builders damp proof membrane. It works a treat, stiff enough not to flap about, and stable enough to stay in place at speed. All our bikes with mudguards, sadly now all solos, have these mud flaps front and back. Why all solos you ask? Well I find the inertia of firing up a tandem from low speeds makes my dodgy knee flare up - but that is another problem.

[andrew_s]

Not really pointeless.
Giles gave a good reason here:

Entirely pointless.
You can wheel the bike on the back wheel* even more easily if you don't have the mudflap at all, and having one that short doesn't keep a following rider (or you) any cleaner than if you don't have it.
I'll agree that it may stop spray going clean over the top of the rider behind and hitting the rider behind him.

* my extremely limited experience of wheeling a bike on the back wheel leads me to believe that easy wheeling is best served by not having a proper mudguard at all, regardless of flaps (where "proper" means full length, not raceblades, crudguards, or MTB style).

[peetee]

Somewhere I have a roll of damp proof course for brickwork. It's thick but flexible plastic and perfect for the job - although a whole roll is a bit over the top and not too economical! If I find it i will let you know and you can have a bit.

[reohn2]

I used to use builders DPC but went over to truck or car inner tube material(old ones are free from a tyre fitting garage) for front m/flaps,as it's more flexible and more durable,it's also heavier and hangs lower at speed than DPC.
IME a rear mud flap has to be stiff and long to work well for protecting riders behind,which isn't too good if the bike has to be wheeled stood up on the rear wheel.

[Gattonero]

Surely, it has to be longer for being really effective, but that means to make it somewhat heavier at the end (otherwise would simply go horizontal at speed).

If you curve the mudflap to the profile of the mudguard, that will help give it rigidity.

Good idea in fact the Brompton flap is shaped to follow the mudguard profile

[Giles Pargiter]

If I persevere a little reon2, I could probably devise a front mudflap that was effective without risking the mudguard (sheepdogs are not often a problem – and it was one that I knew well!). In my experience they don’t actually need to be that close to the ground to keep one’s feet and chain wheels fairly dry.

The rear mudflaps I really do have problems with though. Even quite short extensions to the mudguard do certainly help protect people behind, a fair bit. However I find that even on my “road” bike if the mudguard comes even as far round as the spindle, I break them in short order at some point.

As for the MTB, well it is just not even a consideration – it goes to muddy places, I get muddy. Just keep clear! I do use mudguards on it but they are quite short and a long way from the wheels. They keep most of the mud out of my face and a great deal from my back. Even these sometimes cause problems. Only a few days back, on top of a hill in wet sticky snow the amount of ice going round caused my wheels to jam. That is pretty rare though.

[Giles Pargiter]

Just thinking about that. I suppose the thing to do is have a rear mudflap that one can clip on and remove easily?

[NorwichVelo]

Hi Simon

They work if youre riding in a group. If not a mudgard should suffice for the back. But a front one could help keep you bike cleaner. If you want i can send you some high tech roofing membrane thats easy to cut and will hold in place with nylocks and bolts. Just pm me your address.

[simonhill]

Hi Norwich, thanks very much for the offer. I won't take you up on it at the moment as I am off to Sri Lanka in a few days and don't want it sitting on my doorstep while I am away. I'll bear it in mind when I return.

I'll see how I get on without one, although if it rains there I will probably get very wet regardless of any protection.