The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Minto on 04.07. 2021 19:42
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My A10 plunger has had a noisy front end (and p155 poor 7" front brake) since I bought it 2 years ago
Today, as it was lashing down, I decided to drain the fork oil and replace. Dropped out the drain plugs and nothing... So I pumped the forks a few times and about 100ml of what can only described as diarrhoea splurged out of the left leg, while about 4 drops of water dripped out of the right leg. I flushed both legs with some clean 5 30 engine oil, then refilled each leg with 113cl of oil. Thing is the level in the right leg was visibly a lot higher than the left. I removed the rh plug again and pumped the forks again, this time a load of sludge came out followed by what I'd just put in. Left to drain and refilled . I'll replace this oil with proper fork oil when I can get to the shop.
While at it, I dropped the front wheel out and noticed that a) the spindle wasn't fully tight and b) the brake plate was really loose and flapping about. So that taken care of the rain conveniently stopped for 15 minutes. Anyway, the really loud clanking has gone, and though the brake sill isn't Brembo good, it is markedly better.
So happy days.
Jase
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G'day Minto
Time for new fork seals if your lucky and/or stanchions if your not.
The problem with the design is water/road grime enters over the fork seal holders and sits on top of the seal. Chewing the seal out, rusting the stanchion and wearing the bushes.
Next time the front wheel comes out it is time to rebuild the forks.
Cheers
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Hey Musky
Yeah, planning on rebuilding the forks after this riding season, gonna look into upgrading the internals.
The bike currently feels ok and handles pretty good, but with what came to it of them, I want to at least check it all.
Jase
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G'day Minto.
In 40 years with the 51 A7 I've replaced the stanchions 3 times. The last time with hard chrome and don't wash her as much *ex*
Cheers
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Jase If you're running a 7" brake I'd persevere with that for now. To upgrade the front end as well as changing the front wheel, the fork ends may also require replacement, depending on what mix'n match bits the previous owner fitted. The good news is that bushes and seals are common across the range, the downside is that incorrect model parts will fit. Provided the internals are nice and clean, even worn bushes perform reasonably as most of the time the upper and lower bushes are under load and furthest apart. Time to change them is when there is a distinct harshness under braking, rather than the distinct metallic clank as the forks bottom from inadequate oil as you have already found. The difference between a new pattern bush and a worn original is marginal, having changed them over the years with no appreciable benefit in my examples. I've also cheated by turning the stanchions and top bush "front to back" to present a relatively unworn portion of the stanchion to the previously lightly loaded and less worn side of the top bush.
At the end of the day it all depends on what horrors you find within, but for now a planned strip and clean will probably do.
Cheapskate Swarfy.
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I've also cheated by turning the stanchions and top bush "front to back"...
Ah yes, the technique for making one's underpants last for a month. Don't forget the inside out step.
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Cheers Swarfy
I'm going to leave it all alone for the time being, as it's much improved from how it's been since I bought it, and really I just want to ride the thing.
The thing that grates really is that I'd paid, what I think was "top dollar" for the bike from a shop, and though I was prepared for some work to be required ( replacing half the engine components!!!) I did expect that basic, and essential safety aspects of the bike would have received attention prior to the bike being delivered, especially as I'd been assured it would undergo a thorough inspection before delivery. I suppose I should have realised early on after being told the oil would be changed etc, then doing it myself and realising it hadn't been for a long time judging by the sludge in the tank. Oh well, buyer beware!!
If I knew then what I know now, I'd probably still bought it, but haggled a couple of grand off the price.
It is however now, after 2 engine strips, a barrow load of cash, and a lot of help from yourself and others here, a joy to ride.
Jase
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I've also cheated by turning the stanchions and top bush "front to back"...
Ah yes, the technique for making one's underpants last for a month. Don't forget the inside out step.
Chuck em at the wall, if they don't stick they're good for another week.
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Jase. No shame there. You can bet your boots we've all bought bikes and other vehicles that have had their faults, never noticed or pointed out at the time of purchase decision. Buying a complete bike, runner or not, costs more in one lump but with a bit of luck you don't waste time and money chasing the odd missing bits. To build from a basket case is a conundrum, collections of parts and unfinished projects fetch as much as complete bikes on good days, which is a bit weird. You may think you paid too much, but sadly it's the way of the world, the next fella may consider it a bargain. As mentioned on the Forum, some people in the trade are not exactly too good at customer service and in their world a deal's a deal, thanks, now pi55 off.
Buying from a dealer should bring some sort of paperwork ready to put the bike onto the road, saving hassle we can do without. They don't make 'em anymore so fingers crossed we are on a rising market and for now it's better than money in the bank.
Front brake adjustment. A good clean out and removal of any glaze on the shoes, plus maybe some homespun pads on the cam end of the shoes to compensate for lining wear. Some fixed pivots are actually in a slot in the backplate. If this is the case, and you loosen the pivot nut and apply the brake, the pivot will move slightly as the shoes centralise themselves. With the brake still applied, retighten the pivot nut. Your plunger rear brake has the slot and a simple adjustment like this improves matters.
Swarfy.
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Cheers Swarfy, I'll look into the brake adjustment method you described. I've had the back apart last year to replace the old chair geared sprocket/drum, didn't know that it was self centering so that's a job for the weekend (between weddings and gardenings).
I did clean up the shoes and the drum with some abrasive paper yesterday which may have improved things but I think the biggest improvement came from tightening the brake plate up so it doesn't flap about. The shoes were worn quite unevenly, like only half way across them for the first leading inch and half then no wear at all. Obviously as the brake was applied the plate would move off centre and just wear on the one side.
I rely more on engine braking anyway, but for emergencies it's nice to have a back up. Lol.
Jase