Slim hydraulic brake for front hub motor

fendale2000

Finding my (electric) wheels
Jan 12, 2017
5
0
43
N Ireland
I am just assembling my 250W front wheel kit I got from electricBikeConversions.co.uk - all seems to be working, but I have one problem.

I have shimano BR-M395 Hydraulic brakes on the bike and I switched to a 180mm rotor, but the spokes on the wheel are just clipping the edge of the calliper. I have another bike with M595 brakes on it, and they are basically the same profile and have the same issue.

I'm wondering if anyone knows of reasonably priced callipers that are slimmer on the spokes side? There is only a few mm in it ...

If I went up to a 200mm rotor the existing brake may fit, but I am not sure if putting such a large rotor on the front is a great idea?

Thanks in advance for any suggestions!
 

D8ve

Esteemed Pedelecer
Jan 30, 2013
2,142
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Bristol
Better brakes at the front end? Sounds like a great idea to me.
 

fendale2000

Finding my (electric) wheels
Jan 12, 2017
5
0
43
N Ireland
Might be worth giving it a go then to save replacing the brake. I was a bit worried there would be too much brake with such a big rotor. Its quite frustrating as its only a tiny amount of extra clearance needed.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
Easiest option is to place the AR washer in board or add an extra washer or two in board to get the clearance and then just adjust the caliper.
If that doesn't work go the 203 rotor route, I use a 203 rotor on my front bpm so no problem just gives awesome braking.
 

D C

Esteemed Pedelecer
Apr 25, 2013
1,140
575
203 on mine as well, just needs a delicate touch but no problem at all.
Dave.
 
D

Deleted member 4366

Guest
180mm rotor and caliper adaptor is normally enough. No need to change the caliper.
 

fendale2000

Finding my (electric) wheels
Jan 12, 2017
5
0
43
N Ireland
Easiest option is to place the AR washer in board or add an extra washer or two in board to get the clearance and then just adjust the caliper.
If that doesn't work go the 203 rotor route, I use a 203 rotor on my front bpm so no problem just gives awesome braking.
Nealh- could you explain what you mean by AR washer and 'in board'? Are you suggesting you can nudge the wheel over slightly away from the calliper?

I switched it to a 203mm rotor today and just 3 spokes clip it ever so slightly. I wondering if I tightened them a nip would it pull them straighter, but the spokes are thicker than normal ones so of course my spoke key doesn't fit!!
 

D8ve

Esteemed Pedelecer
Jan 30, 2013
2,142
1,294
Bristol
AR anti rotation, inboard means inside the fork not outside
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,991
8,173
60
West Sx RH
Yes. By placing the AR washer inside the fork you will have added 5mm extra space on the inside. So theoretically should alleviate the spoke/caliper issue as you are moving the fork/caliper 5mm away.
Tightening spokes needs to be done carefully and usually all the ones on the same side and the same turn amount unless those few are just loose, otherwise the wheel may go out of true. If the wheel isn't central in the forks then it could be dished a few mm away from the brake side.
 

fendale2000

Finding my (electric) wheels
Jan 12, 2017
5
0
43
N Ireland
Ok, so I had a spare c washer which I was able to get in against the hub and then the AR washer also inboard. Was a snug fit between the forks but I didn't have to force the wheel in. That shifted the wheel over about 2mm which gives me all the clearance I need - no spokes clip the caliper now. If only I had bought the front post mount instead of the rear one I'd be all done now, but I'll get that swapped on Monday

Took the bike out on its first test run about 10 miles and the kit seems to work well so far! I'll try and post a review in another thread after I've given it a few goes.