T 140 Front Brake - Simple Mods?

I prefer to keep things as stock as possible but I also want them to be effective. The stock disc on my T 140 is just as weak, and wooden, as a stock Commando disc brake.

Is re-sleeving the master cylinder the first step? And then, does anyone offer larger and lighter discs?

I’ve got a complete Suzuki Bandit front end and some of those parts look swappable

How about this ?
https://www.ebay.com/itm/TRIUMPH-T1...831660?hash=item54628f9c2c:g:qbIAAOSwzU1bkpHa

I’d just try different pads first. EBC geeen pads or EBC HH pads work well on cast iron discs.

Some of the aftermarket pads sold today are shockingingly bad!

All depends what you want out of it. I put a bigger disc, braided hose, and 13mm master cylinder on mine which were tremendous improvements. It’s still a tad less than I’d hoped for though.

Yes, Norman Hyde does a lightweight, bigger, floating disc, see here:

https://normanhyde.co.uk/meriden-tr.../single-12in-disc-kit-with-alloy-caliper.html

I fitted one, see pics below. But if I did it again I think I’d got for twin discs, whilst this kit is a big, huge improvement, it doesn’t have the performance of twin discs I’ve used in the past.

I tried some modifications..Stripped the chrome off the rotor and Ferodo street pad and a 14mm master cylinder.. It worked well but I felt it was missing braking "feel". There's more to good brakes than locking up the tire....
I replaced the rotor with a 320mm item from a Ducati and a Goldline Brembo caliper...Yes, the fork assembly was replaced with a 41 mm 95 Honda 750 Interceptor set up that is a whole different story...I am pleased with brakes now, very progressive and easy to modulate at the verge of lock up..

Thank you all.

I already ordered Ferodo Platinum pads so that’s first step.

A couple of sweet front ends there. Thanks for the pics

For the sake of originality and a low key look, I’m tempted to spend money on an alloy AP caliper and make a bracket for it to mate up with a larger disc.

On the other hand, I can do the same with the 4 piston alloy Bandit caliper and disc that I already have. The Hyde set up would save time though

I’m with you Eddie on dual discs. If they are relentlessly light. I hate fork twist and while a big single disc can get the job done, when it does then you have to escalate to a fork brace, or late model transplanted upside down forks

xbacksideslider said:

Thank you all.

I already ordered Ferodo Platinum pads so that’s first step.

A couple of sweet front ends there. Thanks for the pics

For the sake of originality and a low key look, I’m tempted to spend money on an alloy AP caliper and make a bracket for it to mate up with a larger disc.

On the other hand, I can do the same with the 4 piston alloy Bandit caliper and disc that I already have. The Hyde set up would save time though

I’m with you Eddie on dual discs. If they are relentlessly light. I hate fork twist and while a big single disc can get the job done, when it does then you have to escalate to a fork brace, or late model transplanted upside down forks

Click to expand...

When I disassembled the stock front end on my T140 ,the front left fork tube was bent back slightly just below the lower yoke. I have ben told that they bend from the braking forces...Geez...
The 41mm forks on my bike do not flex, part of the issue is the clamping forces of the yokes.Wide alloy yokes really grip the stanchions..Buells have a massive single disc and on the earlier models with a conventional 39 MM fork, brake pull to one side was slightly noticable during the most agressive braking even with the built in fork brace. But they have a 120/60-17 radial front tire I assume has a lot more traction that the 100-19's generally used on Triumphs..

I spent a day on a generous friend’s Buell XB 9 in the mountains above Santa Barbara riding with some fast guys; that Buell was a handling fool, think and it turns, and that big disc was faultless.

Buells are great fun. I’ve only ridden the HD engines X1 and loved it. The trouble with the XBs is they’re just physically too small for my frame.

Me too but then I’ve got tons of time on Ducati singles and RD350s where I was longer, wider, and heavier than the bike I was riding

That XB9 handled a lot like an RD except I could oversteer it with midrange throttle. Fun. Despite. Near hundred horse it lacked a top of rev band rush though

Anyway good single disc brake

Ordered the AP alloy caliper and an EBC alloy centered disc . . .

Where did you get the disc from?

Ebay

Now I’ll be looking for an old 40 hole WM 3 Borrani

It would be well worth talking to VINTAGE BRAKE for ideas. 209 - 533 - 4346. He may recommend a different master cylinder. Good technical info on his website.

Thanks Seattle. I will.

Here’s pics of my new acquisitions; weight reduced about 4 pounds

About $48 per pound saved. All rotating and unsprung weight though

I wonder if the aluminum caliper is as stiff as the iron one and whether the stainless holey disc has the bite of the iron stocker

I’m do not believe the caliper will flex, decades of race use would seem to indicate the design is ok.

However, I also don’t believe those calipers offer any actual performance advantage over the stock iron ones.

I do not believe stainless gives the same grab as cast iron (although that’s a bit of a sweeping statement and I imagine there are different grades and specs for brake disc use, so it depends what you’ve got).

Pad choice is crucial to performance. EBC Green or HH pads on cast discs transform the performance. But they can chew up some stainless discs quickly. I would strongly suggest talking to your disc supplier re pad choice.

I had one of those calipers with a Hyde stainless disc (post #4 above). With the stock master cylinder set up the lever travel was too small, and too sudden / hard, kinda like squeezing a brick! I tried a 13mm master cylinder body and that was too far in the opposite direction with too much lever travel. I went through 3 or 4 sets of pads to trying to best performance, I didn’t really succeed though.

Sorry do be a party pooper, but although your kit is nice and the weight saving is great, you haven’t improved your braking performance yet. If you want to do that, you need to research the pad options carefully.

Also, those AP copies use all metric threads, so be careful when ordering brake lines etc. Off the shelf braided kits for Triumphs aren’t metric.

Thanks Eddie, good info.
I already got improvement with switch to Ferodo Platinum pads but they’re with existing stock iron disc.

I see that Vintage Brake has a recommended slave/master ratio chart.

I could look it up but you probably know - What’s stock MC’s piston diameter ? What diameter does your experience indicate?

On my Tiger 750 I have fitted a 1/2" Nissin master cylinder as fitted to lots of different small Hondas. With the stock caliper it works really well, giving just the right amount of travel & feel with Earls type hoses.

Martyn.

Standard master cylinder is 5/8” or 0.625” which is equivalent to 15.875mm.

You can buy 13mm cylinder bodies that fit into the stock lever assembly and many folk swear by them.

If you’re prepared to lose the right hand switchgear you can fit a modern 13mm master cylinder assembly like Brembo or Magura which have nice dog leg levers which help with feel and lever travel.

There’s no shortage of options !

I vastly improved the front brake on my T140D (6 hole disc) with about four related changes, that will leave you with a basically stock-looking motorcycle and an extremely strong and predictable brake.

I got a de-chromed and drilled stock cast iron disc. This gives much more braking feel. There is also a full floating stock diameter disc on eBay https://www.ebay.com/itm/TRIUMPH-BR...264087277471?_trksid=p2385738.m4383.l4275.c10

I replaced all the rubber brake hoses with braided stainless steel lines from Britain. Mine are HEL brand. This change takes out a lot of the flexy feeling rubber lines introduce. You will need to replace your lines anyway, for safety and function, so go to the industry standard stainless braided lines.

I got good Ferodo pads. Lots more bite

And most important, I simply removed the stock master cylinder from the switch gear, and replaced it with an 11 mm master cylinder from a modern YZ Yamaha, which slides in conveniently behind the T140D/E switchgear, with the lever properly located. It is easy to know you have the right one, because the "11 mm" size is cast right into it. You can get these used on eBay for a reasonable price, or buy new Chinese re-pop, also on eBay--if you get used, make sure it comes with the banjo bolt and a good straight uncrashed lever. Along with the stock Lockheed caliper (or the aluminum replica) this is the size combination (11 mm and dual 41mm pistons) that Vintage Brake recommends--giving you a hydraulic ratio of 27:1. See Michael Morse's advice about this at http://www.vintagebrake.com/mastercylinder.htm This combination feels a bit soft while sitting still on the bike, but underway it gives you very, very superior brake feel, and it is the one I always used on my AHRMA race bikes.

If you do these things, then it is not functionally necessary to go to a twin disc, or even larger single disc setup, for street because you can pick the bike up onto the front wheel without a huge effort (you might want to do this for stylistic reasons though, and there may be a small advantage to dual discs, but truthfully on the street it has to be minimal over what you get if you make all these mods). I raced with this identical setup on my Triumph in AHRMA 750 Sportsman for years, using a 12 inch disc, and it was entirely adequate at hard braking locations like, say, at Daytona coming into the International Horseshoe, or into the backstretch chicane, or into Miller turn 1, where you may actually be lifting the bike onto the front wheel. Very controllable and confidence inspiring.

On the subject of aluminum calipers, I always used Grimeca 1055 Lockheed replicas but they are not available anymore--but there are others out there now. I will pass along what plain-spoken Neil Keen once told me: the iron stock calipers are actually better because they do not flex like the aluminum ones do, and you will never lose a race because the caliper weighed a bit more.