Hello

I wonder if anyone can shed any light on my latest (and hopefully last) TY problem.

The front brake was very poor and had run out of adjustment - moving the brake arm around the splined shaft didn't work either.

I've now fitted a new genuine Yamaha cable, new (quality) shoes and new lever/perch of the type designed to lighten the clutch.

What i've ended up with is a brake that i can adjust to the point just before the shoes make contact with the drum, then as i squeeze the lever to the bars it feels increasingly spongey until fully home. At this point i can still push the bike forward without it locking the front wheel !!

I did notice a bit of scoring inside the hub, have i got to bed the shoes in quite a bit before the doing the final adjustment?

Thanks

Can you post pictures of the brake hub? Can it be turned and smoothed?

Hi

I will try to post an image of the inside of the hub (computer skills no better than my mechanical ones!!)

If the scoring of the hub is likley to be the problem and skimming it would be the only cure, would it mean removing the hub from the wheel and respokeing it to get this done?

I don't really fancy this idea as iv'e just fitted eletronic ignition to give a reliable spark, new clutch plates and cable to cure a grabby/slipping clutch and now this! What next i wonder?

I have to ask myself if it's time to admit defeat on nostalga and stick to modern bikes?

Cheers

The problems you are having could be that the drum is so worn that when the brake shoes expand to the max by the cam they are only just touching the drum,is the cam a nice fit in the brake housing?..Have you tried to lock up the brake just by levering on the brake arm?

PS the new shoes will take a while to bed in.

Edited February 12, 200818 yr by Andy.T

Hi Andy

To answer both of your questions.

Yes, the splined shaft is a good fit in the hub, and yes i do seem to be able to lock the wheel when operating the brake arm by hand.

The inside of the hub is only slightly groved when you run your finger across it.

Ta

Hi,it just sounds like the shoes need a little time to bed in then,if you think about it there probably isnt much of the shoes touching the drum at the moment, this could be evident if you remove the drum and look at where the points of contact are,the grooves probably dont help.I would give it a good run and give the front brake some stick.

turning the wheel by hand only puts a few pounds force on it, braking the entiner machine is msuch more load.

Is the cam oriented properly inside so it doesn't go full out and sort of past center, if there is too much clearnace shoe to drum the oval part gets up on the very tip. that makes no sense, but you'll see it.

cleaning and sanding and sanding shoes mayhelp. What shoes? OEM yamaha I got changed to SBS and they were way too hard. Vesrah japanese were pretty good. still lot of maintenance. Why I switched th TY350 to GasGas front disc and 4 piston AJP. but for TY175 assume you want to stay vintage stock.

just lots of cleaning and roughing up.

kcj

Shoes are Vesrah grooved ones. The cam is set in both the correct logical position and as per the Haynes manual.

I think I'll try the sanding of both the new shoes and drum, then plenty of miles to try and bed them in well before tackling any steep downhills.

Last time i tried a steep decent quickly was when i discovered just how rubbish the front brake was!!

Thanks for all advice

Not only do the new shoes have to be bedded into the grooves, but also to be the same radius of curvature as the drum. New shoes in a drum that is even slightly oversize will only touch at one point on each lining until they bed in. To work properly, the whole surface of both linings has to touch the drum.

By the sound of yours, it will probably take a long time to get to that point by just riding the bike and you will have the cam angle working against you by then.

If you want reasonable brakes, get some oversize linings fitted to your old shoes and machine them to the size of your drum.

If you want great brakes, machine the grooves out of the drum before you machine the linings.

Yes it may seem like a big deal to you now, but you will have killer brakes if you do it properly.

If you don't have much time and are made of money, the quickest might be to just buy a new hub and get the wheel respoked or get a SH wheel with a good drum.

And yes, if you want a bike to be good to ride, you have to get it into good condition whether it is 5 or 35 years old. I've seen under-maintained 5 year old bikes with brakes probably as bad as yours.

Hello feetupfun

Blimey i can't believe someone in Oz is trying to help me with my crappy old TY!

Whilst i realize you've got to fettle old bikes a bit more than new ones I still want things to work.

Whilst i don't expect the braking ability of my modern bikes i'm surprized that myBSA B25 has much better ones!!

I also realize thatc some of you fanatics will put more cash and effort into solving a problem than me!!

Cheers

2shock,

I also realize thatc some of you fanatics will put more cash and effort into solving a problem than me!!

Cheers

did you not spend about

Edited February 15, 200818 yr by Andy.T

Hi Andy

Ok, so i admit it's probabaly the thought of the thought of faffing about getting special shoes made up and than finding someone to machine 'em to the right size that put's me off more than anything.

I prefer the 'quick fix' approach to solving problems (like fitting the eletronic ignition) even if it costs a few quid as at least i can ride it when time allows rather than fiddling with it!

Incidently the ignition works just like i was told. Easy to fit, starts first time every time and ticks over evenly indefinatly.

I can't really comment on what it's done for the power delivery as it never ran for long enough to find out before i fitted it, and my memory doesn't go back the 15yrs to when i last had a TY, but it feels nice and 'unstallable' to me.

Next dilema is solving the bottoming out rear shocks so.......

Hello feetupfun

Blimey i can't believe someone in Oz is trying to help me with my crappy old TY!

Whilst i realize you've got to fettle old bikes a bit more than new ones I still want things to work.

Whilst i don't expect the braking ability of my modern bikes i'm surprized that myBSA B25 has much better ones!!

I also realize thatc some of you fanatics will put more cash and effort into solving a problem than me!!

Cheers

Yes I admit I do spend many hours getting my Twinshock bikes to work well. That is what I like to do. Some bikes take years to get just right. Here is an example of a recent little project.

I just did a front wheel up for my Majesty 250. The wheel on it was OK but the brakes were not as good as some of my other TY twinshocks mainly because of drum scoring.

Labour involved despoking the wheel, machining the drum, changing the bearings, polishing the rim, painting the hub and backing plate and respoking the wheel. Probably about 10 hours labour in total.

Purchases were new spokes ($80), bearings ($15) and the oversize brake linings ($50).

Total cost for amazing front brakes $AU145 or 60 UK pounds. I reckon that is a fantastic bang/buck ratio.