Author Topic: 4 leading shoe issue  (Read 1815 times)

Offline Denis

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4 leading shoe issue
« on: August 02, 2015, 04:36:56 PM »
I have broken the third brake return spring in a couple of years on my Eldorado 4LS. It's on the left side this time and if I remember correctly the last time was on the right side. I have no idea what is going on with them. at first I thought the shoe was poorly cast and finished and perhaps some flash was left in the hole, causing all the brake pressure to focus on a small area on the spring itself but the hole seems pretty clean with no high spots.

Vintage Brake set it up a few years ago and it works like an absolute charm.

Has anyone else has had an issue with breaking these springs?

Also, I have come to absolutely detest replacing these things. Hasn't gotten any easier or faster even with all the practice!
Show me a Le Mans IV and I'll show you a Le Mans 1000.
'87 SPII, '74 Eldorado, '85 LeMans, '91 California, '71 Ducati 450 RT, '41 Indian 841, '40 Indian Model 640-B ex-Canadian Army

Online guzzista

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Re: 4 leading shoe issue
« Reply #1 on: August 02, 2015, 08:19:42 PM »
I have never owned a 4LS Eldo ( wish I did!) but I own a 4 shoe Brake Benelli and have owned a Grimeca  4SLS  equipped bike. If the springs are as old as the bike  it could be just metal fatigue and nothing else.  Did they just break while braking or while installing? I have had best braking when setting up shoes at approx 6 mm max  lever travel on each side.  Setting the brake springs on the shoes when the shoes are off the bike, then sliding on the pivot bolts and then sliding the whole thing on the backing plate has worked best for me.  Perhaps Michael Morse @ Vintage Brake has some better springs available. Good  Luck
1975 750S Tribute bike, 1994 Cali 1100, 2007 Ducati GT1000, 1983 SP1000


Offline Idontwantapickle

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Re: 4 leading shoe issue
« Reply #2 on: August 02, 2015, 11:02:37 PM »
You must use it too much.
 :bike-037:
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Offline leafman60

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Re: 4 leading shoe issue
« Reply #3 on: August 03, 2015, 05:23:19 AM »
I never had spring breakage problems with my 4LS brakes. Breaking brakes, I guess.

I will, however, take this chance to say again that the Guzzi 4LS brakes have been some of the best brakes I've had on a bike.

No, they are no match for the modern multi-piston Brembo disc brakes but I've preferred the 4LS, when properly adjusted, to the early disc brakes fitted on the Guzzi bikes. The self-servo effect of the 4LS make for a seriously powerful brake.
« Last Edit: August 03, 2015, 05:28:31 AM by leafman60 »

Offline canuck750

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Re: 4 leading shoe issue
« Reply #4 on: August 03, 2015, 09:32:38 AM »
After a few attempts I finally got the 4LS on my V7 Sport set up to where I like it and most importantly where it STOPS with confidence. These are a pretty darn good brake system, not equal to the modern EBC floating pair of discs I installed on my Eldorado but the 4LS is way ahead of the 2LS on the big Loops.

My only recommendation is to get a professional shop to arc the shoes and install new springs. I had the hub on my 4LS turned ever so lightly on a big old lathe to true it, needed next to nothing. The same shop made new linings and arced the shoes. I trust the V7 Sport brake in any conditions.
1949 Guzzi Airone
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1973 Benelli 650S
1974 Guzzi 750S
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Offline Antietam Classic Cycle

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Re: 4 leading shoe issue
« Reply #5 on: August 03, 2015, 09:55:12 AM »
My only recommendation is to get a professional shop to arc the shoes and install new springs. I had the hub on my 4LS turned ever so lightly on a big old lathe to true it, needed next to nothing. The same shop made new linings and arced the shoes. I trust the V7 Sport brake in any conditions.

He's already done that: "Vintage Brake set it up a few years ago and it works like an absolute charm." He's just having trouble with springs breaking.

Are these new springs that are breaking or used originals? I haven't had any problems with breaking springs, but then I only reuse the originals if they "ring" when dropped onto the floor. Perhaps Harper's has some new-old-stock? Might be worth checking. 

FWIW, with Mark's shoes, "Barney's" 2LS front drum stops just as well as any 4LS drum, but with less effort (no extra cable, levers, linkage, pivots and springs). 
« Last Edit: August 03, 2015, 09:59:02 AM by Antietam Classic Cycle »
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Offline Denis

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Re: 4 leading shoe issue
« Reply #6 on: August 04, 2015, 07:51:02 PM »
Are these new springs that are breaking or used originals? I haven't had any problems with breaking springs, but then I only reuse the originals if they "ring" when dropped onto the floor. Perhaps Harper's has some new-old-stock? Might be worth checking. 

Hmm, that is a good question, thinking about it. I am pretty sure I ordered new springs at the same time as shoes (which would have made sense). Vintage Brake set everything up and shipped it back and so all I had to do was mount them back on the bike.
I ordered four new springs the last time because they were difficult to get for a while.
I'll see if I have the paperwork from the wheel rebuild, which couldn't have been more than 6-7 years ago. In any case, at least two of the four are only 2-3 years old.
Show me a Le Mans IV and I'll show you a Le Mans 1000.
'87 SPII, '74 Eldorado, '85 LeMans, '91 California, '71 Ducati 450 RT, '41 Indian 841, '40 Indian Model 640-B ex-Canadian Army

Offline Denis

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Re: 4 leading shoe issue
« Reply #7 on: August 29, 2015, 08:54:07 PM »
No more hassle of using a vice grips and other half-assed tools to remove and install the brake shoes, at least. Made this spreader tool the other night.

Show me a Le Mans IV and I'll show you a Le Mans 1000.
'87 SPII, '74 Eldorado, '85 LeMans, '91 California, '71 Ducati 450 RT, '41 Indian 841, '40 Indian Model 640-B ex-Canadian Army

Offline leafman60

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Re: 4 leading shoe issue
« Reply #8 on: August 29, 2015, 09:22:11 PM »
No more hassle of using a vice grips and other half-assed tools to remove and install the brake shoes, at least. Made this spreader tool the other night.



I made a similar device a few years back. Helps tremendously.

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