GT750 4ls brake on a T125?

[Fisch]

Sorry for such a silly question, but I am working on my first bike ever. Is there such a thing as too much brake up front? I love the design of the GT750 4LS front drum brake, but would it be too much for my T125? I don't want to flip over the bars, LOL.

I was thinking of a T250 or T500 set-up, and I realize the GT750 brake isn't light, but it is also about the sexiest drum I've seen. Could I run the entire front end, with forks, from the GT750? I know it is a 19" rather than my stock 18, but hopefully aluminum rims are in my future too, so I can remedy that.

[GT750Battleship]

The phrase "over engineered" springs to mind !!!
Cheers,
Roger

[jabcb]

The T250/T350 have an 18" rim.
The T500 has a larger brake & 19" rim.

The GT550/GT750 4LS front brake is used by vintage racers & tends to be quite pricey.

Ride quality is a function of ratio of sprung to unsprung weight.
A GT550/GT750 4LS front end would result in a lot of unsprung weight for the T125.
I wouldn't expect a very good ride with all of that weight.

[Fisch]

The T250/T350 have an 18" rim.
The T500 has a larger brake & 19" rim.

The GT550/GT750 4LS front brake is used by vintage racers & tends to be quite pricey.

Ride quality is a function of ratio of sprung to unsprung weight.
A GT550/GT750 4LS front end would result in a lot of unsprung weight for the T125.
I wouldn't expect a very good ride with all of that weight.

Thanks jabcb, I was hoping for that sort of answer. I ran across a GT750 brake for possibly a good deal. So it started me thinking about it for my T125 as I think it is a beautiful brake. Adrian Baker mentions using a GT750 4ls on his race T20, and suggests it isn't the best solution, but doesn't mention why exactly. He does mention the weight though and that he had to lighten them quite a bit by cutting holes.

On a light bike like the T125 I was worried the 4ls might lock up too easy. Though I assume it would have a lot to do with how hard you hit the lever.

Originally I was looking for one from a t20 or t250, which probably makes more sense for a bike this light. And they are a 2ls at least, so I imagine they'd be better than the single on the t125. (Which I believe I read was a little under braked from the factory.)

The reality is I have a lot to do to even get my bike running, let alone stopping, so brakes aren't the highest priority yet. But when a 4ls crosses your path you have to think about it!

[Alan H]

Set up correctly, the original brake should be fine, but if you really want to change, why not look at the front end setup on a GT125/185? The early ones had a twin leading shoe brake and I would imagineit would be easier to fit something from a similar sized bike.
Don't get me wrong, I love the 4LS brake, but it's too much for a 125 (it's bloody heavy and much wider than your current wheel hub) and it would look daft anyway. My 2penn'orth.

[Fisch]

Set up correctly, the original brake should be fine, but if you really want to change, why not look at the front end setup on a GT125/185? The early ones had a twin leading shoe brake and I would imagineit would be easier to fit something from a similar sized bike.
Don't get me wrong, I love the 4LS brake, but it's too much for a 125 (it's bloody heavy and much wider than your current wheel hub) and it would look daft anyway. My 2penn'orth.

Thanks Alan, I apprciate the 2penn. Idon't think I have ever seen a gt750 in person, so I wasn't sure just how big that brake was visually. Again it is just that the 4ls happened to cross my path that I was really thinking about it.

My T125 looks like it was pulled from the bottom of a river, and though I am pretty sure I can bring the stock brakes back to life, a bike this bad gives me license to go full custom with it without feeling bad. Thus the thoughts of new brakes, etc. Heck maybe even a mono shock conversion. I,d like to make it as light as possible, which the GT750 4ls is clearly not. Battling in my head with how modern I want to go. Inverted forks? Discs? Maybe an older Ninja 250 mono shock and front end. Or more classic. Probably whatever crosses my path for a good deal.Lol.

[Alan H]

Just think that if you put on forks (or rear suspension) from a much bigger and heavier bike, they will be grotesquely over sprung and over damped so it will handle like a bag of spanners.
Of course if you weigh over about 300 pounds it won't handle too good anyway!!
If you can get the 4LS for a good price, they clean up nice and sell well.

[Coyote]

Everything you are 'imagining' is waaaaaaaay overkill for this little bike. K.I.S.S.

[Fisch]

Everything you are 'imagining' is waaaaaaaay overkill for this little bike. K.I.S.S.

Thanks Coyote, you know how it is, having dreams of a fully custom little cafe racer right now. Dreams of making a tank and seat. Just bought the nose from an airplane to turn into a fairing up front. LOL. I am an artist by trade and would love to go nuts with this thing. I want it to be rolling art. But back in the real world, I need pistons, oil lines, a new wireing harness. The list goes on and on.

Heh it is like my cat is telling me, "Dude, what is this? Aren't you putting the cart before the horse a bit!!!"

[titan performance]

Lovely cat Fisch.....that's a Kaliko cat,....usually have some attitude.

[tz375]

4LS brake and matching forks will weigh more than the complete bike does now. OK, so technically that may not be exact, but it's far too heavy for that sexy little bike. If you want an upgrade, try a Titan/Cobra front brake or even better a brake from a smaller bike - say a CB160 or T200 - then lighten teh brake and paint it gold to make it look like a Ceriani or Fontana drum.

Or if money is no object, get a replica 180mm Fontana and a set of 30mm Ceriani forks but that's still more brake than you need. Look for a T20/T200 front end.

[Fisch]

You guys rock, thanks so much for the thoughts. The gt750 parts bike with the 4ls near me sold, so the temptation is gone! Phew.

But now you have me dreaming of Fontana and Ceriani tz375. Time to start googling! LOL!

I will change K.I.S.S. to K.I.L.L. or 'Keep it lighter, leaner'.

[jabcb]

WOW.

new Fontana 180mm 4LS front brake for £1,350.00 or $2,270US
http://www.tga.co.uk/catalog/product_in ... cts_id=117

[Alan H]

Long, long time since I saw a 8LS brake.
They were sold by Dave Degans at Dresda here in the UK and IIRC they were used in the very late 60s/early 70s but I had to cheat to find more details.

One for sale last year HERE (clicky linky)

Have a good read at the specification - and weight!!

Now people complain about setting up twin leading shoe brakes, but they are actually quite straightforward to do - likewise the 4LS on the Suzukis, after all it's only 2 twin leaders on one wheel. The 8LS would have taken a bit more time though. Remember this was in the day before discs were used on bikes (or anything else really!)

Here's a couple elsewhere I've linked to, pretty ain't they;
https://www.flickr.com/photos/53591907@ ... 6146/?rb=1" onclick="window.open(this.href);return false;
https://www.flickr.com/photos/53591907@ ... 1367/?rb=1" onclick="window.open(this.href);return false;

Saves on long spokes anyway........

[Coyote]

WOW! That hub is enormous. Betcha can't find spokes. Looks like a lacing nightmare