Dammit’s adventures in mountain biking

And my non-Alps wheelset, which looks silly on this bike, but I imagine I'll get used to it.

XTR cranks installed

Cool - will pm you.

Glad to hear the uberbike pads seem to be working - they have been like night and day compared to the stock shimano pads imo.

This arrived today (after I’d set the bikes up with the Uber Bike pads. I’ve spent so much money on Magura parts I sincerely hope I now don’t have to spend a penny for five years.

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This came too late for a customers cargo bike (fitted the one piece brake pads we have in store), want it?

Oddly this claim to have superior durability and less fading.

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May as well! Thanks Ed.

I’ll be riding both bikes (weather permitting) this weekend, hopefully - and what I hope to find is that the brake I bled feels as good (firm, nice crisp bite point) as it did when bedding the brake in. Of course, the lever may go to the bar tomorrow morning, but it’s held pressure since I bled it so fingers crossed there.

If it’s worked then my take on how to bleed a Magura is to take your time. I found that waiting for tiny bubbles to make their way (ever so slowly) to the top of the mineral oil was essential to prevent said cloud of tiny bubbles being sucked back into the lever, for example.

I also spent a long time gently pulling and pushing oil through the system whilst moving the lever from horizontal to around 30 degrees declined, flicking the lever every now and again.

Every once in a while a large bubble would pop out of the lever- often when I was absolutely certain that the system was fully bled.

I left the bike in the stand for hours- started the process, went on a Zoom call, did some more pulling and pushing, next Zoom call- probably around four hours passed.

I doubt any bike shop would be able to afford to tie up a stand for that long, but I was still seeing the clouds of tiny bubbles well into the third hour. Tiny bubbles squished together form a large bubble, of course.

I found holding a powerful torch behind the upper reservoir enabled me to see when the liquid was fully clear of air, and moving the fluid through the system very slowly and carefully seemed to help prevent sucking air in.

Anyway! We shall see, if the rear brake stays feeling this good I’ll bleed the others, and hopefully my Maguras will work as designed (at last).

TL;DR Fuck Maguras.

True facts: I know of a Shimano Europe mechanic that has a vibrator in his toolkit for the sole purpose of helping move trapped air from the caliper to the lever. Swears by it for speeding up the rising bubble wait time.

Did it really need to be a 12” veined girthy number tho?

kind of genius, @cake good use of the wand!

Every once in a while a large bubble would pop out of the lever- often when I was absolutely certain that the system was fully bled.

Biggest fustrastion about hydraulic in general is that they do need time/coaxing to get rid of the bubble or at least minimise it within a short time frames in a bicycle workshop.

I’ll drop off the pads next week, I’m not too far in Catford.

"Bigger the better!"

Ooh, good call, I usually use a hammer on the bike stand to send vibration.

Park Tools VB-12 will soon be a workshop essential

Hunt trail-wide, Hans Dampf front and Nobby Nic rear on the 295 today, it's astonishing how lightweight, faster rolling tyres change the character of the bike.

With the Reserve 30/Minion DHR II's the 295 feels like it has endless grip, but that it's only really happy going down, with the Hunt/Schwalbe wheels it's abruptly very much a lightweight trail bike.

Quite a lot less grip, but that's quite fun. Quite a lot faster on hardpack, which is also fun.

The Magura saga continues.

The rear pads were dragging slightly at the end of yesterday’s ride, I pushed the pads back in this morning to re-centre the calliper and start the self adjustment/self centring again.

Now the bite point is basically adjacent too/inside the grip. I can’t see how to adjust this. Not good.

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Looking at it some more I think the inside pistons are stuck in the calliper body.

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I want to suggest xtr (I'm sure people probably already have) but enjoying your persistence with the Magura

Took everything apart, cleaned everything, got the inner pistons moving- but not self adjusting, so bite point very close to the bar. Fuck it, I’ll ride it like this and see. Plenty of power, just not where I want it.

If you lube the outer edge of the inner pistons then do a few cycles of push out push in they should come back to life.

With mineral oil I assume?

Yeah the brake fluid. Wet a bud with it and paint it on.

Funny thing about those brakes is that it can accept a different pads;

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Halfway round summer lightning but I have no rear brake at all, going to bail. Bollocks.

Ok, I bled the rear brake on the 4th of March, the lever was (fnar) rock hard at that point, and each day thereafter when I pulled the lever to test it (the bike was in the spare bedroom whilst I waited for the suspension bolt that I broke to arrive).

Yesterday I went to Swinley with Fenella, one hour forty eight moving time and the lever feel was great, nice and firm, bite point came in smoothly and powerfully.

However, I did notice that toward the end of the ride the outside two pistons were fully extended, the inner's not so much, and the pads were rubbing on the disc lightly - enough to make an embarrassing noise.

This morning I wanted to resolve the issue before heading out as the noise was not one that I wanted to accompany me around the Surrey Hills.

Bike in the stand, wheel out, pads pushed back, retaining pins out, pads out, loosened calliper, gave it a clean, wheel back in, centred it, pads back in, pin in, span the wheel and pulled the lever.

Outer side pistons moved in, to what looked to be the maximum extent that they'd comfortably move, inner pistons moved when the lever was operated but didn't auto-adjust and stayed in place.

The brake stopped the wheel, but the lever was travelling fully to the bar.

This didn't make any sense to me, so I took everything apart, grabbed the isopropyl and some clean towel and cleaned everything, worked the pistons in and out, but could not get the inner pistons to come out evenly with the external ones.

If I pushed all the pistons in, no pads, pulled the lever then the upper external piston moved but the other three stayed put.

Time was passing so I put everything back together, wheel in, and then rode the bike up and down before pulling the lever - success! Or something like it, bike point was very close to the bars, but it was there. Bike on roof, drove to Holmbury St Mary.

Bike off roof, set off - absolutely no brake. Fucksticks.

If I pumped the lever maybe 20 times I could get a little bite, but that vanished as soon as I stopped working the lever.

I rode for a while and then decided to call it as whilst I was fast I was unhappy with the balance when setting up for corners using only the front brake, which was leading to some interesting lines. I got seven PR's, Strava told me when I got home. I think that's tyres with lower rolling resistance rather than my "can't stop/won't stop" approach courtesy of Magura.

So! Place your bets:

1. The fluid has leaked away and there's practically nothing in there
   
2. Huge air bubble
   
3. Inner pistons stuck in their bores
   
4. Evil goblins
   
   

And if either 1 or 2 is your choice, where has the fluid gone/air got in?

I'll pick something nice from my parts bin as the prize for the person who comes up with the correct answer.