OP
UTC

Hooked
1980 Bajaj
Joined: UTC
Posts: 407
Location: Chicago
 
Hooked
1980 Bajaj
Joined: UTC
Posts: 407
Location: Chicago
UTC quote
1980 Bajaj.

The front brake is really bad. I don't know if that's completely normal, or sign of bad front suspension, but the first thing that happens after pulling the brake lever is the wheel sinking into the frame and then basically never locking.

Some may bring this up - I know you don't want the brake to lock the wheel, but for testing purposes, it should! At this point, it's impossible to get it to lock.

I've serviced the wheel and brake - cleaned everything, lubricated moving things and scuffed the brake pads with sand paper. Adjusted the cable wire to my liking (where my grip and squeeze work best in terms of power)

Short of replacing the pads, I don't know what else I can do.
@chandlerman avatar
UTC

Lucky
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 79 P200E, 66 Lammy S3
Joined: UTC
Posts: 9834
Location: Nashville

46 Days Since Last Explosion
 
Lucky
@chandlerman avatar
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 79 P200E, 66 Lammy S3
Joined: UTC
Posts: 9834
Location: Nashville

46 Days Since Last Explosion
UTC quote
I have front drums on my VBB, Sprint and GL and they all work well, though the 8"s on the VBB handicap it a little bit.

Replacing the pads with some good quality new pads, combined with everything else you did, is your best bet.

Also, make sure that there's no flex/slack in the cable and that both ends are solidly seated in the housings.

For the dive, you're looking at a front shock upgrade. Get a quality front shock and that'll make a big difference. It'll still dive, but not nearly as much as what's on there now, I'm guessing, which is probably more-or-less dead if it's what was on the bike when you got it.

Everything past that is probably more work than you're really interested in, i.e. fork swaps, disc brakes, etc.

If you want to, you can radius the pads to the drum to increase the contact area, but that's its own topic.
@hibbert avatar
UTC

Molto Verboso
Vespa
Joined: UTC
Posts: 1713
Location: California
 
Molto Verboso
@hibbert avatar
Vespa
Joined: UTC
Posts: 1713
Location: California
UTC quote
When I changed the cable and housing with a Teflon lined it made an improvement.
OP
UTC

Hooked
1980 Bajaj
Joined: UTC
Posts: 407
Location: Chicago
 
Hooked
1980 Bajaj
Joined: UTC
Posts: 407
Location: Chicago
UTC quote
Upgrading the pads and the cable seems like a must. Suspension service if I find time in the winter, I'll fiddle with it without possibly upgrading it too.

With my most motorcycles in the past I'd be able to stop with only front brake. Not with this guy, so it takes some getting used to
@subetherbass avatar
UTC

Ossessionato
1997 Italjet Formula 125, 2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: UTC
Posts: 4814
Location: Australa, Mate
 
Ossessionato
@subetherbass avatar
1997 Italjet Formula 125, 2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: UTC
Posts: 4814
Location: Australa, Mate
UTC quote
Go on... give us a few PHOTOS so we can assess it better
@happy_wanderer avatar
UTC

Hooked
LML 125 4t & LML 200 4t
Joined: UTC
Posts: 132
Location: Durham, England, U.K
 
Hooked
@happy_wanderer avatar
LML 125 4t & LML 200 4t
Joined: UTC
Posts: 132
Location: Durham, England, U.K
UTC quote
I wonder, are you still using the original Indian tyres? If so, you will never stop the bike even with the wheels locked! The 'never-wear-out-compound' of the rubber does exactly that, and simply slides along the road - remember this is India!

Great on dirt roads, and from my experience, snow but useless elsewhere.

Incidentally, unless you've now fitted a disc brake, it is brake shoes not pads.
@chandlerman avatar
UTC

Lucky
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 79 P200E, 66 Lammy S3
Joined: UTC
Posts: 9834
Location: Nashville

46 Days Since Last Explosion
 
Lucky
@chandlerman avatar
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 79 P200E, 66 Lammy S3
Joined: UTC
Posts: 9834
Location: Nashville

46 Days Since Last Explosion
UTC quote
SubEtherBASS wrote:
Go on... give us a few PHOTOS so we can assess it better
It's this one. He also has a rebuild thread, 1980 Bajaj Barnfind.
OP
UTC

Hooked
1980 Bajaj
Joined: UTC
Posts: 407
Location: Chicago
 
Hooked
1980 Bajaj
Joined: UTC
Posts: 407
Location: Chicago
UTC quote
Well here's a shot of the brake shoes. I could've taken more pictures I guess. Note that bajaj logo on everything. Amazing!

Yes it's the original set of tires. I'll have to replace them soon I'm sure.
Forum member supplied image with no explanatory text
@sdjohn avatar
UTC

Johnny Two Tone
'15 GTS300, '86 PX125EFL, '66 VBB, '01 ET4
Joined: UTC
Posts: 8508
Location: San Diego, CA
 
Johnny Two Tone
@sdjohn avatar
'15 GTS300, '86 PX125EFL, '66 VBB, '01 ET4
Joined: UTC
Posts: 8508
Location: San Diego, CA
UTC quote
Probably should show the west surface, the brake drum inside, the backing plate condition, etc.
UTC

Hooked
PX150E
Joined: UTC
Posts: 253
Location: Florida, USA
 
Hooked
PX150E
Joined: UTC
Posts: 253
Location: Florida, USA
UTC quote
With the banning of asbestos as brake lining material several years ago, the material used today is much harder and has less friction.
Assuming the brake cable and guide are in good condition, and the cable slides easily, and the brake shoes pivot axle and pins are lubed, these will help:

1. Roughen the drum contact surfaces and the new brake shoes linings with coarse sand paper. Reassemble the brake and adjust for some play at the lever.

2. Go ride at slow speed around the neighborhood with the brake lightly applied and feel the friction; make short hard stops several times. This will help get the shoes set for the arc of the drum and ensure the full surface of the linings contact the drum. This may need to be repeated several times.

Eventually, the brake lever should become easier to apply and the brake action improve quite a bit. I tried several brands of brake shoes, and initially, braking was poor until I did the steps above.
If still not completely satisfied, a pulley modification will drastically improve braking even more. I did that to mine, and now the front brake works way better.
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