Rattling front mudguard Sprint 7

HarryB

Esteemed Pedelecer
Jan 22, 2007
1,317
3
London
I swapped over to the Magura HS11 hydraulic rim brakes - cost £35 and takes 30-40 minutes to install and set up (and they fit straight out of the box). I am amazed at them and it is definitely the best upgrade so far. I can now stand the bicycle on its nose they are so powerful and they are very easy to modulate. Brake judder is now almost none existent - I cannot say gone completely as the front forks always feel like they are flexing. I would highly recommended these brakes to anybody who commutes into a city and they do give you that little more confidence.
 

flecc

Member
Oct 25, 2006
53,304
30,670
To someone who has use of a lathe (Thats both of us :) ), the only difficulty in making new posts would be the external thread which, if it's the same as the unused rear posts, is an unusual very course thread.
Further to my previous post on this, you could turn one from a bolt Ian. The frame thread is 10mm x 1.25mm, so a bolt that size could be the start point, though you'd probably have to buy that size online. The internal thread is 6mm x 1mm, so easily tapped.
.
 

Ian

Esteemed Pedelecer
Apr 1, 2007
1,333
0
Leicester LE4, UK.
Might I be right in thinking that there is something in the design (set-up) of the Torq and Sprint (and maybe the other eZee models) where this factor is responsible for our perceived troubles? There is not much 'rake' on any of the eZee models front forks.
You may well be right about the geometry contributing to our problems Peter, the almost vertical forks may also contribute to the Torqs rough ride by taking road bumps directly in line with the axis, the direction they least have the ability to absorb shocks by flexing.

Funnily enough, I don't have the rattling mudguards on either my Torq or Sprint.


I swapped over to the Magura HS11 hydraulic rim brakes
I did consider the Magura Harry, however I chose the Shimano as a cheaper and simpler option (It didn't occur to me that the posts would be different), not knowing whether either was going to cure the judder.


Further to my previous post on this, you could turn one from a bolt Ian. The frame thread is 10mm x 1.25mm, so a bolt that size could be the start point
.
Brilliant idea Flecc. The simple solutions are always the best :)
 

flecc

Member
Oct 25, 2006
53,304
30,670
I swapped over to the Magura HS11 hydraulic rim brakes - cost £35 and takes 30-40 minutes to install and set up (and they fit straight out of the box).
Unfortunately the Magura HS11 has been discontinued according to some dealers. Alternatives more like double the price now. I notice that the HS11 front brake is part of the eZee Forza spec, and interestingly I've heard of a Forza supplied in another European country with a cable front brake.
 

ITSPETEINIT

Esteemed Pedelecer
Dec 11, 2006
492
0
Mere, Wilts
Rattling and Juddering

Hello all:
I've been busy today:
Job 1 - Fit the new brake blocks to the Sprint and road test.
The blocks I got were PB4100 Aztec V-Brake System Dual - £ 12-95. Yeh! I thoughts so too!!
They were no trouble to fit being a little slimmer than those fitted to the Sprint as standard. They are not made of hard black composition stuff. They are a soft sort of sticky material and they grip the rims like...........
After a short spin (1.9 miles) they did not judder at all. But there is something going on down there like the brake being applied then slightly slackened, then applied again, and so on. An embryo judder? Time will tell.

Job 2 - Fit new Schwalbe M.+ tyres to my Torq (Still for sale with even more extras). It is good practice for when I go to France on a touring holiday in case they are not absolutely puncture proof.
I inflated them to 45 psi in the front and 50 psi on the back. They really are much quieter and slicker than the standard Kenda 'Knobblies'.
Did they eliminate mudguard chatter? Well the stays do not hit the tyre at all. But to eliminate shaking and rattling 90+% it's simple. Keep both hands on the bars.

I discovered in the course of all this road testing and paying rivetting attention to the front wheel assembly, something co-incidental. When the Torq motor (restricted) is accelerating from 0 to 8 mph the motor emits a noise not unlike a mudguard vibrating. I also noticed when refitting the front wheel, when I turned the front wheel backwards there was a faint grating noise coming from the motor (not unlike a tyre rubbing).
It is not a death rattle I hope.
Peter
 

HarryB

Esteemed Pedelecer
Jan 22, 2007
1,317
3
London
Unfortunately the Magura HS11 has been discontinued according to some dealers. Alternatives more like double the price now. I notice that the HS11 front brake is part of the eZee Forza spec, and interestingly I've heard of a Forza supplied in another European country with a cable front brake.
There seems to be a new model the HS11 evo II http://www.chainreactioncycles.com/Models.aspx?ModelID=9441 and it costs an extra £5. According to this website it has a new mounting system but I would assume it is as easy to fit as the standard HS11 (which is still listed).
 

flecc

Member
Oct 25, 2006
53,304
30,670
I also noticed when refitting the front wheel, when I turned the front wheel backwards there was a faint grating noise coming from the motor (not unlike a tyre rubbing).
It is not a death rattle I hope.
Peter
Turning it backwards turns the rotor which does cause a little drag and noise, and if done very slowly each magnet pulse can be felt, but the wheel should flick free between those pulses. The slight grating will matter if the wheel starts to lock up when turned backwards as that's a sign of more trouble developing.
.
 

Ian

Esteemed Pedelecer
Apr 1, 2007
1,333
0
Leicester LE4, UK.
When the Torq motor (restricted) is accelerating from 0 to 8 mph the motor emits a noise not unlike a mudguard vibrating. I also noticed when refitting the front wheel, when I turned the front wheel backwards there was a faint grating noise coming from the motor (not unlike a tyre rubbing).
It is not a death rattle I hope.
Peter
Mine does both of those things, always has. I'm sure both are normal noises, the Torq/Quando motor is noted for sounding rough in low speed, high load situations.

The noise when the wheel is turned backwards is the motor being turned through the gears by the wheel, it doesn't happen in the forward direction as the motor has a freewheel mechanism to prevent drag from the motor when coasting. On mine a distinct vibration can be felt if the bike is pushed backwards.
 

Ian

Esteemed Pedelecer
Apr 1, 2007
1,333
0
Leicester LE4, UK.
Of course Flecc may be right!! after all he's seen inside a motor which I haven't. It's allways dificult trying to explain a noise in words, the reader usually ends up imagining something totally different to what the writer is trying to describe.
 

flecc

Member
Oct 25, 2006
53,304
30,670
I'm just going by my first motor which started doing this and gradually started destroying itself. As long as it doesn't start locking up in reverse you'll be ok Peter. I understand it's a rare fault though.
.
 

ITSPETEINIT

Esteemed Pedelecer
Dec 11, 2006
492
0
Mere, Wilts
Sprint motor self-destruct.

I'm just going by my first motor which started doing this and gradually started destroying itself. As long as it doesn't start locking up in reverse you'll be ok Peter. I understand it's a rare fault though.
.
Hello Flecc:
How old was your motor when you first noticed this and how long before it became unserviceable?
My Sprint is less than 1 month old, has done (about) 120 miles). Inspite of the aggravation I would not want this motor to die just out of the guarantee.
This lock-up that you refer to: does it happen when going forwards or just when the wheel is turned backwards (as in manoeuvrng)?
Peter
 

flecc

Member
Oct 25, 2006
53,304
30,670
In just two weeks and 200 miles Peter, when I took it back to 50cycles as it had become so bad. A new motor wheel fixed it.

It was an early example, and the Quando/Torq motor is very different from the Sprint unit anyway. Also I the the Sprint unit as fundamentally more robust, so the chance of you suffering this is very small.
.
 

ITSPETEINIT

Esteemed Pedelecer
Dec 11, 2006
492
0
Mere, Wilts
Other Forums

My Torq brakes have always juddered, I don't regard it as a serious problem but I am something of a perfectionist and would like to solve it. I have tried swapping all brake components, including a Tektro lever from my Sprint (which has never juddered) however the cure was only temporary, the judder returned when the new parts bedded in. I have now ordered a Shimano Deore XT V-brake with parallel linkage, I will keep you posted on the results.

There are many posts on other cycling forums about front brake judder affecting rim braked bicycles in all price ranges, it seems the problem is not limited to electric bikes with a front hub motor, and as is our experience, it affects different users to different degrees.
Hello Ian:
I wonder if I could ask you to give me the web addresses of some of the other Forums that deal with cycling and brake judder.
Thanks
Peter
 

ITSPETEINIT

Esteemed Pedelecer
Dec 11, 2006
492
0
Mere, Wilts
Judder will wear brake pads

Wow thanks for all the responses and suggestions.

Obviously it's a common problem!

I'll try the simple things suggested and if they don't work - it would appear that the symptom is just annoying rather than dangerous so I'll accept it as a characteristic of the bike (and other bikes in general).

I imagine it will wear my brake pads out quicker - at which point I'll take advice on the best ones to fit as replacements.

I think the mudguards vary - my own Sprint 7 and my husband's Sprint 7 (both delivered at the same time = as replacements for the product recall earlier this year) have different fittings on the mudguards, both rattle tho!

Thanks again
Jeanette
Hello Jeanette:
I am not so sure that is the only problem that might arise from this juddering. On my Torq and new Sprint the juddering over the few yards before the cycle comes to rest is quite violent. The harder one brakes, the worse it is.
There are other more expensive components that could be at risk.
Fork failure may be lurking to manifest itself in the future.
Head bearings must take some additional strain because of it.
The suspension in front forks may degrade sooner.
Brake arms (on V brakes) may fail.
The truth of wheels may suffer and rims may wear out prematurely
That these things may not happen in the short time allotted to the guarantee period is all the more worrying.
It is certainly distracting at a time when the rider's concentration is need elsewhere on a more important matter (like the reason the brakes were applied so hard in the first place).

I am interested to know what is it that some bikes have, that don't have the judder. Flecc says that its always been around since alloy rims were first introduced. I did not experience it on my Tourers but I did get some 'brake squeal' that was cure by re-establishing the correct amount of toe-in of the brake blocks.
So is the answer just a 'Gallic Shrug'?

Something constructive on the subject from the Sole Distributors and the Manufacturer would be welcome.
Peter
 

Ian

Esteemed Pedelecer
Apr 1, 2007
1,333
0
Leicester LE4, UK.
Hello Ian:
I wonder if I could ask you to give me the web addresses of some of the other Forums that deal with cycling and brake judder.
Thanks
Peter
Hello Peter,

a Google search for "bicycle brake judder forum" will give you the forums you are seeking, you will even find disc brake users complaining of it.

Ian.
 

ITSPETEINIT

Esteemed Pedelecer
Dec 11, 2006
492
0
Mere, Wilts
More on my brake judder.

Hello again everybody:

The road test:

The brake were Judder free for about 1.5 miles and many applications. When I braked before entering my drive I just perceived a slight grabbing on/off.
I think that the brake blocks are leaving deposits on the rim and that causes the juddering where the deposit is not applied evenly.

The mudguards vibrated with every significant bump in the road and more so if I rode one-handed. But the stays did not touch the tyre. Narrower tyres (Schwalbe M.+ 35 or 38) will help in the event that they could.

Hope that helps.
Peter
I regret that the improvement was short lived.
The new Aztec blocks on the Sprint made no difference. After 15 miles it was back with a vengeance.
I shall ride the Torq today after having cleaned and abraded the rims and the blocks (the standard ones fitted).
We now need to have the application of some science from the experts like the manufacturers. I have insufficient knowledge and no equipment to pursue a likely cure or establish a likely cause.
Peter
 

ITSPETEINIT

Esteemed Pedelecer
Dec 11, 2006
492
0
Mere, Wilts
Lighter Guage Spokes a cure?

As I mentioned earlier I have a Sprint which doesn't suffer Brake judder or mudguard rattle despite having the usual play in the brake arms and a small amount of play in the suspension, the only parts not original are the front rim and spokes. I purchased the bike secondhand with a rim that had failed due to excessive wear on the brake surfaces. I rebuilt the wheel using a cheap secondhand rim I already had, and slightly lighter 14g spokes as as was unable to obtain 13g. I dished the wheel as centrally in the forks as my limited wheel building skills would allow and managed to true the wheel to about 1.5mm, I then went on to use the bike and thought no more of the wheel until reading this thread. I'm now wondering whether something I did has alleviated these problems, perhaps the lighter spokes allow more flexibility in the wheel or perhaps the inexpensive rim is more or less flexible or a different alloy. Unfortunately I'll probably never know as it's doubtful anyone will rebuild a wheel over a relatively minor problem with no guarantee of a fix.
I wonder?
What pattern did you use in the rebuild?
I see from my Sprint, having had the benefit of close aquaintance for some time changing the brake blocks and adjusting the toe-in, that the Front Wheel is built "1 cross" (sorry to contradict you Flecc: unless yours is different to my Sprint).
If it was not such a "wind up" disconnecting those vital wires to the front hub I'd have a go at rebuilding them "3 cross". I have built and rebuilt a few wheels in my 'pure' cycling days: mainly to practice the art in case of wheel failure when touring with those massive loads that now astound me.
(And I've got the book) :D
I doubt whether my Truing Jig (now given to another builder) would have the width across lock nuts to accommodate a motor hub, unless by coincidence it is 126/130 mm, the same as a back wheel in a standard bike of the 1980's.

It's a bit late to speculate why there was "excessive wear on the brake surfaces". Might it have been attributable to brake judder?
Peter
 

ITSPETEINIT

Esteemed Pedelecer
Dec 11, 2006
492
0
Mere, Wilts
Regular Rim Cleaning!

And I thought I was a perfectionist! ;) . Seriously though, the spoke tensions on my Torq (Which does judder) do vary, but the wheel is very true. As I'm very much an amateur when it comes to wheel-building I'm reluctant to touch what appears to be a perfectly good wheel, so I'll try different brakes and resign myself to regular rim cleaning, which does effect a temporary cure.
I must remember to put "Rim Cleaning" on the 'pre-flight' checks every time I've done 15 miles or so. :rolleyes:
Peter
 

Ian

Esteemed Pedelecer
Apr 1, 2007
1,333
0
Leicester LE4, UK.
I used a one cross spoke pattern Peter, an exact copy of the original. I don't have a proper truing jig, I used the inverted bike, that also saves the hassle of disconnecting the motor.

I don't think the original rim failure was caused by judder, just normal wear which had gone beyond the wear limit indicators on the rim. I think e-bike brakes work a lot harder than those on conventional cycles due to the extra weight and generally higher speeds involved.
 
Last edited: