My Bafang Ultra Mountain Bike! Frey AM1000

[Balmorhea]

My chain is worn out: +-75%, what chain do i need to buy? I know it is a KMC X11 chain, but there are different versions (EPT, ..) and what is the chain length? How many links do i need?

Thanks for all the help guys!

Any 11 speed chain will do. Unless your bike is strange, one box of chain will be more than enough, and you will shorten it to suit your gearing. Here’s a guide.

If the fresh new chain skips under load, then you’ve worn out the cassette, and you have to replace that too. That’s when it’s really cool to be using 7 or 8 speed.

 

[Tom]

Anyone else lose power randomly for a split second when going over bumps? I have a Frey CC with gear shift sensor and suspect that is the culprit. I am not shifting when this happens but suspect with the movement of the suspension it creates slack and tension on the derailleur which might be enough to fool the shift sensor. Any way to fix this other than disabling the sensor? Or could it be something else causing this?

 

[Hardcore]

Hi, could be the power cut off from the levers. I don't have a gear sensor and still, this occurs, so I disconnected them to test.

 

[Tom]

Thanks, sounds like it's somewhat normal. It's mostly just annoying.

Another thing, my rear MT5 brakes sounds like a rolling drum when I come to a stop, not super loud but you can hear it. This has been from day 1. I'm in week 2 and was hoping they just needed to break in but it's not going away. I thought perhaps I didn't bed them in properly so checked the pads. They don't seem glazed or look different from the front pads. I wiped down the rotors with a household degreaser, rinsed them off with alcohol and then water, let things dry, then tried to bed them in again before riding but didn't really help. Any thoughts on how to fix? I've seen videos that suggest taking off the rotors, fully degreasing, roughing the pads and rotors up with some sandpaper, but seems a bit extreme. I'm wondering if something else is going on?

 

[Animalector]

have you tried re-aligning them?

1. Loosen the caliper bolts so the caliper is 'just' free
2. Squeeze brake lever hard
3. Tighten caliper bolts while squeezing brake lever
4. release lever and test.

Good luck
Andy

 

[jeron]

Thanks, sounds like it's somewhat normal. It's mostly just annoying.

Another thing, my rear MT5 brakes sounds like a rolling drum when I come to a stop, not super loud but you can hear it. This has been from day 1. I'm in week 2 and was hoping they just needed to break in but it's not going away. I thought perhaps I didn't bed them in properly so checked the pads. They don't seem glazed or look different from the front pads. I wiped down the rotors with a household degreaser, rinsed them off with alcohol and then water, let things dry, then tried to bed them in again before riding but didn't really help. Any thoughts on how to fix? I've seen videos that suggest taking off the rotors, fully degreasing, roughing the pads and rotors up with some sandpaper, but seems a bit extreme. I'm wondering if something else is going on?

Hi Tom,

It is definitely your gear sensor. I had a big crash because the motor assist stopped at a big hill. You need to open the plastic cover from the right side of the motor and unplug the sensor. Its a lot better without it anyway.

I also unplugged the back brake cutoff. When i need to shift i just tap the front brake lever.

Regarding your musical experience, my front brake is making the same noises. I tried new pads but didn't work. Alignment did work a little, but it's still there. I just ordered a new disc as last resort.

Maybe i try to sand it a little first. Let me know if you find a solution, ill do too.

Greets

 

[Tom]

Thanks, so you eventually replaced the rotor to fix? The bike came like this so maybe I'll take it up with Frey to diagnose and send a replacement rotor if it comes to that. So far I'm kind of underwhelmed by the brakes, the front brakes don't bite well but at least don't make noise or vibrate like the rear brakes after heavy braking, just figured it was the weight of the bike.

FWIW, I adjusted the brakes before riding and after cleaning the rotors to make sure they were spinning smoothly, loosening the 2 bolts, clamping the brake, then tightening up. Also made sure the rotor bolts were torqued properly. Front brake needed a few iterations to fine tune the alignment as the rotor has a slight warp. Rear wheel is harder to listen for pad rub with the hub and motor noise, but I'm 99.9% sure the pads are aligned properly.

 

[Tom]

It was raining today and figured I would take a video clip of the noise. It's not usually this loud, the wetness amplifies the sound. At speed I don't hear the noise, mostly noticable as I approach a stop.

https://www.youtube.com/watch?v=Sj_YnlTUNU8

I took a few pictures of the front and rear rotors to compare wear pattern. Rear pads seem to bite a little lower, but I don't think that's the issue. I noticed when degreasing the rotors last week the rear rotors have a weird burn color, as if they might have been subjected to a lot of heat. But I haven't ridden enough to cause this.

 

[Hardcore]

Hi, can you take a picture of how your brake pads look?
Furthermore, did you check if the bolts on the discs are tightly secured? Is there any chance some oily substance could have gotten on the pads? Maybe using a spray chain lubricant or other way?

If it's related to the discs, what you could try is swapping the front and rear disc brake and see if it relocated/changed. Or one more thing you can try is changing the left and right brake pads around, so they're oppositely placed.

The burning like look i've also got on my brakes, but this sound reminds me of winters. See my vid at about 20 sec in: https://youtu.be/DByknT084LU?t=20
But also in dry conditions i've had it squeak:
https://youtu.be/wzE0brCcoQk?t=135

They really sounds exactly the same when it gets cold or wet here, or even misaligned caliper/disc. Don't know if this helps in any way.

 

[Tom]

Good point, I'll try swapping the pads. The rotor bolts were all tight, at least my 6 nm wrench said so. Good to hear your rotors look as burned as mine, ha. I was careful to not touch the rotors but possible they got contaminated somehow. I suppose swapping front and rear pads would tell me.

 

[Hardcore]

Well, I know for certain my disc brakes look like that due to actual burning. I've seen smoke come off on some extreme downhill segments. But even under these circumstances the braking power was more than adequate, even for such a heavy bike.

 

[barbarossa]

It was raining today and figured I would take a video clip of the noise. It's not usually this loud, the wetness amplifies the sound. At speed I don't hear the noise, mostly noticable as I approach a stop.

https://www.youtube.com/watch?v=Sj_YnlTUNU8

I took a few pictures of the front and rear rotors to compare wear pattern. Rear pads seem to bite a little lower, but I don't think that's the issue. I noticed when degreasing the rotors last week the rear rotors have a weird burn color, as if they might have been subjected to a lot of heat. But I haven't ridden enough to cause this.

normally a typical problem that can occur with Magura Storm HC and black Magura MT5/7 pads. have a close look at your pictures : brake pads are larger than brake surface. it brakes not equal during one rotation so you have a pulsating noise. some guys even report that their front fork would be damaged by that pulse but i wouldnt go that far. you can improve it a little with perfect alignment and some different brake PM adapters but the reason will still be there. Btw this might also explain the dark color where it rubbs more.

short and cheap solution : try blue Magura MT5/7 pads - as a quick&dirty solution. based on their different bite they dont have that "rubber effect".

but to honest : i knew that problem before (and the terrible sound in wet conditions) so a few years ago when i bought my own Frey AM1000 the very first thing was : Replacing the brake discs.
now it is a little easier : Magura has new discs with larger brake surface (MDR - series). it seems like Magura finally recognized the need for a larger surface.
in the end not Freys fault but a real disappointment of the quality of Magura brake systems.

 

[Tom]

Thanks, I'm not sure I understand what you did to fix your problem. You replaced the rotors? And the pads? I can try some blue pads. I'm just really surprised as I had always heard good things about Magura brakes but so far I've been a little underwhelmed. My 2 piston shimano brakes with smaller rortors seem to do a better job, but on a 50 pound bike.

 

[barbarossa]

Hi,
me, I replaced the rotors that solved the fundamental problem caused by the smaller "bridges" (smaller than the disc pad ) of the Storm HC rotor. Giving me the ability to use black or blue disc pads - it does not matter anymore in that case.

but if you wanna keep your Storm HC rotors and save some money you can just use the blue pads.(I also tested this combination for a short time period and it worked for me) More silent and way more smoother. you will be surprised, at least i was...

Magura brakes are not bad. ok they have some problems with some leaky levers (i also had one - always examine your levers carefully of there is some oil) and some not matching rotors. but Magura does not only produce the MT5/7 and for most other Magura brakes with smaller pads there is no problem at all with Storm HC.
(some people tried to buy the old Storm rotors a few years ago -that almost didn't exist to buy anymore- because of their problems with the combination of the new MT5/7 and the new Storm HC).

i was always wondering why not more people with Frey bikes (always using Storm HC) have the same problems. but now i am glad that i am not the only one :lol:

 

[jeron]

Hi,
me, I replaced the rotors that solved the fundamental problem caused by the smaller "bridges" (smaller than the disc pad ) of the Storm HD rotor. Giving me the ability to use black or blue disc pads - it does not matter anymore in that case.

but if you wanna keep your Storm HD rotors and save some money you can just use the blue pads.(I also tested this combination for a short time period and it worked for me) More silent and way more smoother. you will be surprised, at least i was...

Magura brakes are not bad. ok they have some problems with some leaky levers (i also had one - always examine your levers carefully of there is some oil) and some not matching rotors. but Magura does not only produce the MT5/7 and for most other Magura brakes with smaller pads there is no problem at all with Storm HD.
(some people tried to buy the old Storm rotors a few years ago -that almost didn't exist to buy anymore- because of their problems with the combination of the new MT5/7 and the new Storm HD).

i was always wondering why not more people with Frey bikes (always using Storm HD) have the same problems. but now i am glad that i am not the only one :lol:

What do you mean with storm HD rotor? The break disc on my bake are storm HC?

Which disc did you buy? (MDR C or P)

 

[barbarossa]

...uupppssss… my mistake of course i meant "Storm HC" NOT "Storm HD". i will edit my posts and post some photos of my rotors.

 

[barbarossa]

i made 2 short trips and took some photos:

my Frey EX has of course MDR-P 220mm :lol: and the blue pads. a nice combination, the MDR-Ps have an enormous usable braking area:




the AM1000 has Galfer 223mm (only the 223mm version has 2mm thickness) and Shimano Saints with Magura motor-cutoff pressure switches:




you can see where my brake pads touch the rotors - and i think it is a big difference between my rotors and the Magura Storm HC.

problem areas of Storm HC in yellow:


in the end the disc brake has to match the rotor. in my opinion this is not the case for the combination of MT5/7 and Storm HC.

cheers

 

[jeron]

i made 2 short trips and took some photos:

my Frey EX has of course MDR-P 220mm :lol: and the blue pads. a nice combination, the MDR-Ps have an enormous usable braking area:
EX1.JPG

EX2.JPG

the AM1000 has Galfer 223mm (only the 223mm version has 2mm thickness) and Shimano Saints with Magura motor-cutoff pressure switches:
AM1000_1.JPG

AM1000_2.JPG

you can see where my brake pads touch the rotors - and i think it is a big difference between my rotors and the Magura Storm HC.

problem areas of Storm HC in yellow:
storm_HC_problem.JPG

in the end the disc brake has to match the rotor. in my opinion this is not the case for the combination of MT5/7 and Storm HC.

cheers

Great post! Thanks for the info. Ordered the HDR P

 

[Tom]

Thanks for highlighting problem areas but my front brakes are fine (at least they don't make the drum roll noise). My issue is the rear brakes making noise. Not that I don't think you are correct regarding what is causing the noise.

 

[barbarossa]

Thanks for highlighting problem areas but my front brakes are fine (at least they don't make the drum roll noise). My issue is the rear brakes making noise. Not that I don't think you are correct regarding what is causing the noise.

no problem. it can occur at front and/or rear brakes.
but hey it is easy to check:
- take 2x washers (height 2mm for 6mm screws - standard 6mm steel screw washers) or even better: 1mm standardized high precision distance washer
- loosen your 2 brake caliber screws
- put the 2 washers under your brake caliber (it is 2mm higher then)

dont worry. that 2mm at your rear brake (which has only 25% braking power compared to your front brake which has 75%) wont be a problem and the screws are long enough.
with that method you can also check if your brake caliber touches the upper side of your rotor which also can cause a sound like this.

do you still have the noise with a 2mm higher brake caliber ?

 

[smorgasbord]

have you tried re-aligning them?

1. Loosen the caliper bolts so the caliper is 'just' free
2. Squeeze brake lever hard
3. Tighten caliper bolts while squeezing brake lever
4. release lever and test.

I know that's the often-recommended procedure, but it's never worked quite right for me. Tolerances are tight and you need the screws loose enough that applying the brake centers it, but as you tighten it can pull the caliper one way or the other just a mm or so.

What I do is sight down the open end of the caliper through the pads and rotor. I've even put an linear LED flashlight on the floor shining up to make the gaps obvious. Then I put on a pair of magnifiers, and adust the caliper and tighten the bolts until I've got even gaps and the bolts are fairly tight. Then I torque the bolts. With the bike on a stand and the chain off the rear wheel, both wheels turn and turn and turn with just a slight push, and then I look for the wheel at least do a little bit of rotation back the other way (typically due to the valve being slightly heavier).

 

[Tom]

Thanks, the funny thing is it feels like I have a lot more braking power in my rear brake. My front brake doesn't seem to have much bite.

I tried the spacer suggestion. I couldn't find a washer big enough for the bolt size so improvised with some square brass plates from a door lock kit. I think they are at least 1 mm.

Took the bike out for a quick test and made no difference. Still have drum roll. One thing I noticed when inserting the spacers is the lower plate almost looks like it had been ground down. Not sure. It was shiny and didn't seem completely flat.

I will try swapping the front and rear pads to see if I can get the front to exhibit the same behavior to rule out dirty pads. If not I guess I will try the blue pads although seems I could just upgrade the rotor for $75 which might be cheaper long term.

 

[barbarossa]

Took the bike out for a quick test and made no difference. Still have drum roll. One thing I noticed when inserting the spacers is the lower plate almost looks like it had been ground down. Not sure. It was shiny and didn't seem completely flat.

Hi Tom,
thanks for your checks.

but wow...
you dont have an original Magura PM adapter but even an grounded down PM adapter. normally Magura brake calibers dont like other brand adapters - or lets say are sensitive - resulting in some misalignment or some noise. not always but it can happen (even with an "not grounded down" other brands adapter).

the consequence of that "self made"(=grounded down) adapter might result in exact your problems. alignment is not correct so braking power might be different (as you can see concerning the discoloration of your rotor). (perhaps it was made like that because the frame is not exact aligned concerning the PM attachment but hopefully i am not right.)
i highly recommend to use an (not grounded down ) original Magura QM-42 adapter.

the adapter looks like that:



this could explain your problems.
have a close look at your pictures and just compare your front and read rotor:

distance of the holes to the bridge is different. => your rear caliber is nearer to the center than your front brake => more braking power at rear brake.

 

[Tom]

Thanks, it seems I do not have original Magura adapters on either front or rear brake. Front and rear look identical. I did not check to see if the front adapter was ground as I did not want to re-align the brake. It took me a long time to align it after cleaning the rotors last week. I'm not sure the rear was actually ground, could just be the aftermarket adapter is not finished with paint on that side.

There would be no reason for the front fork to need a custom aftermarket or modified adapter since it is attached to a standard rockshox fork that is independent of frame design. Hopefully the brakes are original Magura MT5 and not counterfeit, lol.

I tried all sorts of variations tonight. I tested with double spacers. I tested with spacers on one side of the adapter but not the other. I flipped the left and right pads. All to no avail. It seems ok at first, I get excited, but after a few brake pulls I eventually get the drumroll. Maybe the pads are dirty. I will wait for Frey to get back to me.

 

[hoojsn]

Thanks, sounds like it's somewhat normal. It's mostly just annoying.

Another thing, my rear MT5 brakes sounds like a rolling drum when I come to a stop, not super loud but you can hear it. This has been from day 1. I'm in week 2 and was hoping they just needed to break in but it's not going away. I thought perhaps I didn't bed them in properly so checked the pads. They don't seem glazed or look different from the front pads. I wiped down the rotors with a household degreaser, rinsed them off with alcohol and then water, let things dry, then tried to bed them in again before riding but didn't really help. Any thoughts on how to fix? I've seen videos that suggest taking off the rotors, fully degreasing, roughing the pads and rotors up with some sandpaper, but seems a bit extreme. I'm wondering if something else is going on?

Previously, I have the same problem. My solution.
1. Clean the Rotor, and find some dirt and oil left over.
But sound still persisted almost wanted to throw the bike away.
2, the Last action loosens the Front Thru Axle, probably too tight
Well, my case resolved and the noise was gone.

Good luck, and hope it works for you too.