Author Topic: Mudguard skills  (Read 2387 times)

Mudguard skills
« on: January 14, 2019, 05:35:56 pm »
Would like to increase skills in mudguard maintenance/fitting.

My rear SKS bluemels cracked in two places. Shop has agreed to replace so will only cost a couple of quid in postage to replace.
One crack was midway between the (plastic, non-riveted) brake bridge mount, and went right through (but the tape used to fasten the light wire on held it together) and the other was just below the upper (riveted) stay mount, and hadn't quite gone right through.

I would ideally like to acquire the ability to (a) prevent them cracking in future, but also (b) scope out if there is any better semi-permanent way of attaching the dynamo light.
I guess as far (a) goes, make sure the stays aren't bending it / holding it under tension, but anything else?
I previously thought rivets were a source of cracks, but here, one crack has occurred near the rivet but another one away from it. I guess it could be that the one near the rivet occurred first, and that put increased pressure on the rest of the guard that caused the other one. Hmm...

As far as (b_ goes, previously I used this tape: https://www.amazon.co.uk/gp/product/B00940IEU0/ref=oh_aui_search_asin_title?ie=UTF8&psc=1 which has stuck, very well - in that it has remained completely in place and has actually held the guard together when it cracked - but slightly too well - in that it has peeled off little patches of the lacquer of the mudguard, leaving the silver inside showing.#
I would like to be able to remove and re-fit the guard ideally with minimal damage in order to be able to fly with the bike. I guess it's better than tape that comes off when it's wet, as if it peels any lacquer off in future I can just stick new tape over it, but if anybody knows any that doesn't do this, but still sticks well, would like to know. Does the lacquer contribute to the robustness of the mudguard or is it just for looks?
It is what it is. It's not what it's not, so it must be what it is.

BrianI

  • Is it a bird? Is it a plane? No, it's Lepidopterist Man!
Re: Mudguard skills
« Reply #1 on: January 14, 2019, 06:03:05 pm »
Pics of the mudguard fitting would be helpful. Can't ever say I've had any SKS mudguards snap in half. My rear dyno light is on the rear of my pannier rack...

Re: Mudguard skills
« Reply #2 on: January 14, 2019, 06:15:29 pm »
IME the #1 cause of cracked chromoplastic mudguards is that they were not fitted correctly. Some top tips;


1) make sure the stays are secure and that they are not strained sideways when fitted; in other words they should be 'set' so that they sit in the correct place naturally, even when not attached to the mudguard

2) avoid straining the mudguard curvature esp near the brake bridge.  If necessary space the mudguard away from the chainstay bridge so that there isn't permanent strain on the mudguard.

3) chamfer/trim the mudguard if necessary so that it fits between the chainstays without being strained.

4)  if some strain is unavoidable, you can locally heat the mudguard (eg using a hairdryer) so that it takes a 'set'. It is less likely to crack vs being strained when fitted.

5) fit the (stainless steel, the plastic ones are crap) brake bridge mount so that the bottom of the slot is not exposed, if necessary by using washers either side of it, 

6) crimp the bridge support so that the mudguard doesn't rattle there

7) avoid having the stays differently bent one side of the bike to the other; this is commonly the case on disc brake bikes but it encourages the mudguard to flap from side to side more than it should.

8) make absolutely sure that your bike is in track; if it is slightly lopsided (eg a pannier on one side is enough) then again the mudguard will vibrate from side to side more and this (other than massive strain) is what destroys them most quickly.

9) use nylocks etc so that the mudguards are not likely to work loose

Basically if you slacken any one mounting bolt and the mudguard immediately moves under its own steam, there is some strain in it somewhere, and probably this can be reduced or eliminated, thus giving the mudguard an easier time of it.

I agree that the rear light is best put somewhere else; a lightweight reflector is much less likely to strain the mudguard.  Having broken a couple of mudguards with the light on (they seem to crack at the middle stay mounts when the light is attached, and strain all the other mountings more too ) I have my light on the seat stays.

I think that these mudguards are polycarbonate and therefore eventually embrittle and become likely to crack. Some solvents and UV light will speed this process up.  But I have had a set of chromoplastic mudguards last about 30 years (mostly outdoors) before I broke them; however when they broke they were as brittle as glass.

I'd also note that skinny mudguards and skinny high pressure tyres are a bit of a double-whammy; the mudguards see a lot more vibration damage with this kind of setup.

cheers

Re: Mudguard skills
« Reply #3 on: January 14, 2019, 06:35:34 pm »
Thanks for the pointers on making sure they're not strained.

Agree the seat stay is better maintenance wise for the rear light, but can you counter my suspicion that there is a "blind point" where a road user (e.g. a car) could be in a position such that they can't see my rear light due to the mudguard or wheel being between them and the light source?

Is it worth bothering moving the light to the left seat stay when riding abroad?
It is what it is. It's not what it's not, so it must be what it is.

Re: Mudguard skills
« Reply #4 on: January 14, 2019, 07:01:21 pm »
I use lights mounted on the seatstays but above the wheel. They might be obscured by flappy clothing and/or might be obscured side-on by your legs as you pedal. In the latter case the light becomes a flashing one, so no big deal. [the extent to which this happens depends on frame design; an old fashioned frame with a horizontal top tube and long seat stays is better here without doubt]. The seat stays are not far apart and the light is offset anyway; I wouldn't bother to move it when I'm riding on the other side of the road but I might angle it differently.

FWIW I think rear lights are of most use at long distance when vehicles are coming up behind; you might well be outside of their (dipped beam) headlight range.  From other angles/distances the driver of  any vehicle with working headlights is more likely to see you because of reflectors etc rather than lights.  Many modern rear lights don't cast a lot of light sideways anyway, but a few do.

cheers

Re: Mudguard skills
« Reply #5 on: January 21, 2019, 04:17:29 pm »
Also consider multiple lights. My main dynamo light is on one seat stay, there is a second cheap flashing light on the other and a third clipped on the carradice bag. In the event one stops working or the battery dies then I have back up as well as being visible from different angles.

The seat stays and mudguard also have a strip of in 3M red reflective tape running vertically down each.
Duct tape is magic and should be worshipped

Re: Mudguard skills
« Reply #6 on: January 22, 2019, 05:12:03 pm »
Agree the seat stay is better maintenance wise for the rear light, but can you counter my suspicion that there is a "blind point" where a road user (e.g. a car) could be in a position such that they can't see my rear light due to the mudguard or wheel being between them and the light source?
IMNSHO there isn't a simple counter. The lighting regs say simply "Visible to the rear". That's pretty vague, so there would need to be case history to provide a definitive interpretation. IANAL, but I cannot imagine that "only totally obscured in a small region" would be accepted as a defence in court. Obviously, if the light is wide enough that a reasonable amount of it is visble despite the wheel/mudguard you'd have a better defence. However it would be rather vulnerable.

I'm currently engaged in upgrading the lights on youngest daughter's bike, which has a Shimano alternator to power primary lights. I believe that 2 rear lights are esssential for utility cycling. Failures happen, so a backup is needed. Also, flashing lights are probably better at attracting attention, but steady lights help following road users judge distance, apart from being almost a legal reqiurement. My personal opinion is that the 2 lights need to be separated by a significant distance to work effectively. That is based on the problem I have with some modern cars, where rear indicators become overwhelmed by brake lights until too close for anticipatory riding.

The OE rear light is mounted on the rear of the pannier rack & has now been replaced by a better one. The only alternative mounting point which will never be obscured by bags or other cargo on the rack is the mudguard. Even there it's hard to find a place which is reasonably separated, has adequate support to avoid plastic fractures & isn't vulnerable to damage. My own bikes have a light in each location, but even then there are compomises; mudguard mounted dynamo lights have inefficient optics, but flashing lights are heavier & bigger, so are more vulnerable & more likely to cause fatigue failures.
Quote
Is it worth bothering moving the light to the left seat stay when riding abroad?
I don't know. UK lighting regs specify "On the centre-line or off side of the vehicle". I don't think that an alternative that complies with EU regs is allowed, so I'd guess it'is country-specific when you're abroad.

Re: Mudguard skills
« Reply #7 on: January 22, 2019, 06:07:17 pm »
I'm not bothered about the law (as much), I'm mainly bothered about safety.
It is what it is. It's not what it's not, so it must be what it is.

Kim

  • Timelord
Re: Mudguard skills
« Reply #8 on: January 22, 2019, 08:08:35 pm »
I don't think there's any evidence that rear bicycle lights contribute towards safety, is there?
Careful, Kim. Your sarcasm's showing...

Re: Mudguard skills
« Reply #9 on: January 22, 2019, 09:44:49 pm »
Not sure about evidence, I certainly think they do.
It is what it is. It's not what it's not, so it must be what it is.

Re: Mudguard skills
« Reply #10 on: January 23, 2019, 11:31:40 am »
Basically, the "unbreakable" SKS guards are a bit shit for anything other than German roads, and the vibration kills them.  The best tip is to avoid the narrowest P35 ones and buy at least P45.  These are stiffer so they take a lot longer to shake themselves to death.  I used to get through P35s in less than a year.
Never tell me the odds.

Re: Mudguard skills
« Reply #11 on: January 23, 2019, 11:35:22 am »
I don't think there's any evidence that rear bicycle lights contribute towards safety, is there?
Are there any CTC types still alive who resisted rear lights when they were first made legal?  The theory was that drivers should be able to stop within the range of their headlights* and a reflector should be enough...which seems logical, but I wouldn't want to test it with my life.

*if you flick from main to dipped beam at 60mph, your visibility goes from half a mile to 100 yards, just like that
Never tell me the odds.

Re: Mudguard skills
« Reply #12 on: January 23, 2019, 12:27:50 pm »
rear lights have always been 'legal', presumably you mean 'compulsory' which is different.  There is plenty of documented discussion on this point and the other major CTC issue of the time, that of dedicated cycle paths, which the CTC were also against for various reasons.

Pedestrians walking on country roads are obliged to carry no lights or reflectors and occupy about the same road space as a bicycle.  However a pedestrian is able to jump into the verge if they have to.

 When riding country roads at night I have always taken note of the way my shadow is cast from car headlights behind. If the shadow is still cast directly forwards as a vehicle draws close that might be the last thing you ever see; just once or twice I have taken evasive action.

cheers

FifeingEejit

  • Not Small
Re: Mudguard skills
« Reply #13 on: January 23, 2019, 01:43:09 pm »
I don't think there's any evidence that rear bicycle lights contribute towards safety, is there?
Are there any CTC types still alive who resisted rear lights when they were first made legal?  The theory was that drivers should be able to stop within the range of their headlights* and a reflector should be enough...which seems logical, but I wouldn't want to test it with my life.

*if you flick from main to dipped beam at 60mph, your visibility goes from half a mile to 100 yards, just like that

Assuming the highway yard of 1m
75m is the highway code stopping distance for 60mph
at 60mph you travel 100m in 3.7 seconds on a dry clean road

So in theory it's sufficient...

However, if you're on an open road and on dipped beams, then chances are you're on dipped beam because there is an oncoming vehicle.
If there's an oncoming vehicle then there is a pair of bright white lights reducing your light sensitivity and just like that other great big bright light that reduces light sensitivity the sun, means there's contrast issues that are going to make it near impossible to see the dim return of light from a reflector.

For all the stealth ninja's I've come across in town while cycling or riding the existence of street lighting has helped make them at least distinct, but the worse I've come across was a dark coloured car on the dual carriageway between Dundee and Perth with no working rear lights and a closing speed around 20mph.

It wasn't the reflectors that gave me a chance of seeing them when I did, it was the light spill from the street lights in Glencarse seen through their rear window giving me the outline of the car.

quixoticgeek

  • Mostly Harmless
Re: Mudguard skills
« Reply #14 on: January 24, 2019, 10:21:30 am »
Pedestrians walking on country roads are obliged to carry no lights or reflectors and occupy about the same road space as a bicycle.  However a pedestrian is able to jump into the verge if they have to.

Pedestrians on roads with no footway are supposed to walk on the opposite side of the road, into the direction of oncoming traffic. This makes it possible for the pedestrian to see the oncoming threat.

J

--
Beer, bikes, and backpacking
http://b.42q.eu/

Re: Mudguard skills
« Reply #15 on: January 24, 2019, 12:16:05 pm »
My rear mudguard snapped just below the bridge of the seat stays. I cut two holes either side
of the split and used zip ties to go through the holes and above the bridge to make a secure
refit.

mattc

  • n.b. have grown beard since photo taken
    • Didcot Audaxes
Re: Mudguard skills
« Reply #16 on: January 24, 2019, 01:34:28 pm »
Agree the seat stay is better maintenance wise for the rear light, but can you counter my suspicion that there is a "blind point" where a road user (e.g. a car) could be in a position such that they can't see my rear light due to the mudguard or wheel being between them and the light source?

Is it worth bothering moving the light to the left seat stay when riding abroad?
I would definitely not ride with just a rear light that is obscured by the wheel. The "blind spot" would be when a driver approaches from behind on a long (fast) LH-bend. Just not worth the gamble IMHO.

Likewise, I tend to move lights over to the left for riding in relevant foreign countries.

(I usually have a bag or a rack that I can mount rear lights to. Mudguards are for reflectors, ideally. And for being nice to other cyclists  O:-)  )
Has never ridden RAAM
---------
No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

Re: Mudguard skills
« Reply #17 on: January 24, 2019, 01:48:08 pm »
The Portland Design Works mudguards are thick enough to be unlikely to snap like chromoplastics inevitably do, and the spacing of the rear mudguard flap holes is perfect for mounting a mudguard rear light, and they can easily take the weight. Nice telescopic adjustment system too.

Pricey though.

(and they insist on calling them "fenders", whatever they are)

Re: Mudguard skills
« Reply #18 on: January 24, 2019, 03:05:34 pm »
I use rubber tap washers when fitting guards, threadlock the screws and don't over tighten, before finally fitting I loosen everything to check there's no straining.  I'm lucky that my bikes have direct fittings and don't use the guard brackets.  Where possible I also use a Tubus bracket to attach the rear on to a rack. I've yet to break one in normal use, two have broke in accidents and another snapped trying to move it between bikes.  I gave up on dynamo mudguard lights, they just don't survive my usage, I don't think I kept one long enough to test the guard.  The SKS range has changed in recent years, I fitted some Blumel Matt 18 months ago mainly because I liked the look of them, they do feel a bit more pliable than the traditional Chromoplastics, still  looking like new on a bike that gets used most days.

Kim

  • Timelord
Re: Mudguard skills
« Reply #19 on: January 24, 2019, 03:12:55 pm »
(and they insist on calling them "fenders", whatever they are)

Perfectly acceptable for a USAnian company to use the USAnian term for things that were invented between the colonial era and their re-invasion of BRITAIN during WW2.  If it bothers you, just picture them wearing their cacky pants with suspenders.
Careful, Kim. Your sarcasm's showing...

quixoticgeek

  • Mostly Harmless
Re: Mudguard skills
« Reply #20 on: January 24, 2019, 03:15:47 pm »
I don't think there's any evidence that rear bicycle lights contribute towards safety, is there?

Depends what you mean by contribute. Round these parts they are a legal requirement, but many riders have the merest hint of a tiny LED light, somewhere on their body, and as many riders again don't even bother with lights...

Before retroreflectors were common place, Dutch law required the bottom part of your rear mudguard be painted white (effectively making a mudguard a legal requirement...). You can occasionally see an older bike with the white mudguard from this time.

I have 3 rear lights, plus all the reflectivor tape gubbins RATN required last year. On xmas day on my festive 500 attempt, I ended up on a 70kph main road in Germany, in conditions where motorists would not expect a cyclist, after 100m, I stopped and put on a hivi which I had because of France. I object to Hivi's in general, but on that road, in those conditions, I chose to opt for one, along with 3 rear lights, and reflectors... I had a couple of motorists (one BMW, one Audi), beep at me, as they passed fast and close, obviously feeling I shouldn't be there...

Ultimately the lighting I have on the rear is as much for the avoidance of doubt in the event of an accident than anything else. "You couldn't see me? I'm like a bloody xmas tree here!", but I can tailor the amount of it I actually turn on. On Dutch roads, it tends to just be the seat stay mounted dynamo light.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Kim

  • Timelord
Re: Mudguard skills
« Reply #21 on: January 24, 2019, 03:36:20 pm »
I don't think there's any evidence that rear bicycle lights contribute towards safety, is there?

Depends what you mean by contribute.

I meant actually preventing collisions with other road users, rather than being a legal requirement or avoiding accusations of contributory negligence.  AIUI what data there is (at least in the UK) is inconclusive, with the rate of KSIs being independent of darkness.

Of course, most cycling collisions happen in urban areas, so perhaps lighting is more beneficial on unlit roads.  There's also the argument that sufficiently obnoxious lights might reduce the looked-but-failed-to-see rate, as per other Theory Of Big factors.

The way I see it, irrespective of any safety benefit, front lights are beneficial for helping you to go faster without crashing into things (which may be subject to risk compensation and therefore not appear in the stats).  On the basis I've got lighting at the front I'm happy to comply with the legal requirement for a rear light too, if only for the contributory negligence angle, and in doing so I might as well make an effort to have a decent one.  Reflectors are like rear lights but lighter and lower maintenance - so you might as well have them - and drifting back on topic - rear mudguards are a good place to put one.


Quote
On xmas day on my festive 500 attempt, I ended up on a 70kph main road in Germany, in conditions where motorists would not expect a cyclist, after 100m, I stopped and put on a hivi which I had because of France. I object to Hivi's in general, but on that road, in those conditions, I chose to opt for one

I'm not a fan of it either (I'm happy to dress the bike up like something from Tron, but I don't want to look like a railway worker just to ride a bike).  I have donned a yellow Altura-alike for its hi-vis (rather than weather-protective) properties on a couple of occasions, chiefly during dense fog in daylight, and when directing traffic at the scene of an accident.


Quote
Ultimately the lighting I have on the rear is as much for the avoidance of doubt in the event of an accident than anything else. "You couldn't see me? I'm like a bloody xmas tree here!", but I can tailor the amount of it I actually turn on. On Dutch roads, it tends to just be the seat stay mounted dynamo light.

Agreed.  I've got the B&M dynamo light for normal riding (particularly in groups) and the obnoxious blinky for scary roads and really foul weather.  I have been known to adorn my bicycle with actual christmas lights, but that didn't stop an impatient Brummie trying to drive their car at me.
Careful, Kim. Your sarcasm's showing...

Re: Mudguard skills
« Reply #22 on: January 24, 2019, 03:44:45 pm »
,,,,, I ended up on a 70kph main road in Germany, in conditions where motorists would not expect a cyclist,

Apart from autobahns, what other roads in Germany would motorists not expect to see a cyclist?

,,, I had a couple of motorists (one BMW, one Audi), beep at me,

Audis and BMWs in Germany?

Re: Mudguard skills
« Reply #23 on: January 24, 2019, 03:55:52 pm »
IIRC in Germany (as in NL) it's compulsory to use a cycleway if there is one alongside the main road (subject to certain caveats, which the motons tend to be unaware of, so if you ride in the road they'll beep at you regardless...)

Re: Mudguard skills
« Reply #24 on: January 24, 2019, 04:10:15 pm »
IIRC in Germany (as in NL) it's compulsory to use a cycleway if there is one alongside the main road (subject to certain caveats, which the motons tend to be unaware of, so if you ride in the road they'll beep at you regardless...)
Is there an exemption for professional cyclists (if they're not training abroad)?