Monday, August 15, 2005

Hope Mono M4's

With the purchase of my new steed I looked around at all the hydraulic disc brakes available and at the time the Mono M4's were one of the top options. Not only did early reports indicate that they worked well but they also had some nice engineering features such as different sized pistons to aid modulation. They also look the dogs...

I'd spent three happy years with Hope C2's and they never gave me any trouble. However, brake techonology had evolved since then and I also wanted to try a larger diameter disk in exchange for more power for less effort. On some of the longer decents in Wales, I found that the C2's could give me Popeye like forearm "pump" as I squeezed the hell out of 'em.

The M4's were duly purchase and fitted to my 5Spot which was a fair hassle as the IS mounts mean that aligning the calliper against the disc requires re-shimming a whole bunch of washers. I also hoped that the first few rides would free up the odd lazy piston but in the end I had to remove the pads, hold 3 pistons back and pump the lever to free 'em up. Repeat until all pistons move equally(ish).

I eventually chose 180mm rotor's front and rear which seems more than adequate to haul up my mass. However, I would be interested to see if a smaller 160mm rear disc would be a better match as I have to be slightly more careful with the rear brake. It's not a problem as you soon get used to it, but then I do like to ponder and tinker...

Ensuring that the disc tab's are straight 'n' true is highly recommended as any misalignment seems to result in noisy, squealin' brakes.

The levers fit snuggly next to my SRAM shifters and have a reasonable feel, not grabby and nor are they vague.

The complete brakeset (front & rear) incl'g the 180mm rotors, etc weighs in at around 2.1lbs. Which compares favourably with C2's that had smaller 160mm disc's fitted to my ol'Marin, coming in at 2.7lbs all in.

After being thoroughly bedded in on our local trails, we headed over to Afan for some proper testing. I found that full stop braking was easily achieved with single digits and that I was now riding much smoother as I had such a powerful reserve of speed shedding ability. I was also pleased to find that my forearm's weren't aching anymore.

More miles were put on the brakes and they've performed reliably, in both the wet or the dry. They did have a few weeks where they squealed throughout entire rides but I've since put this down to pad contamination, possibly after using car wash 'n' wax. This was soon cured after blasting the pads and disc's with Isopropyl Alcohol, as found in Maplins for cleaning circuit boards. They occassionally howl after standing for a day a two but they soon scrub up and shut up after a couple of stops.

By the end of the summer, I'd managed to put something like 900 miles on them with the original pads still having around 3/4's left. However, one wet, 18 mile around Cannock Chase soon saw the pads disintigrate and braking was limited throughout which has been the only hiccup in thier performance. I wasn't alone tho, 'cos by the end of the ride our pal uphilla (with his Shimano XT 4-pots) were also down to their backing plates.

If I have one gripe it has to be that the pads don't retract into the callipers very well which causes a little brake rub every now and again. Provided the discs/pads are cleaned with Isopropyl then I haven't found squeal to be a regularly annoying problem like many reviewers sugguest.

After the wet ride around Cannock, I've had a pair of Galfer pads in the rear which appear to be quieter, have the same feel / bite and don't seem to wear as quickly as some would suggest. Although our "alpine" stlye Bedfordshire trails aren't that demanding...

Overall, I must say that I'm impressed with their performance and if the long term niggle of dragging pads could be resolved then they'd get 10/10.


Farqui said...

After wet rides around Cannock and more recently in Woburn woods, the M4's have consistently had reduced braking. I think I'm still running resin pads so perhaps it's time to look at sintered ?

Farqui said...

After a full years use/abuse, you'll find a bleedin' update here.

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