Brake Lever Travel – Stock vs Smaller Master Cylinder

Wow, thank you all for the feedback. You've given me a lot to consider!

gggGary – I like your idea of one step at a time. It would be a really interesting learning process. If I were working with a more complete/functional brake system, I'd likely take the same approach. Thanks for the tip about the Yamaha dirt bike m/c too.

retiredgentleman – I was under the impression that all xs650 calipers were the same from 1977 onward... Measured my caliper piston again this evening and it is a hair over 38mm... very strange!

Paul Sutton – Your experience with the stock m/c and stainless lines perfectly illustrates my concern about that combination. Are you thinking of switching to a smaller m/c as well?
Oops, my apology to eyewinder. You are correct. The stock piston 1977 onward, is 38 mm. I incorrectly measured the outer end of the piston, instead of the inner part, which is the true diameter of the piston.
 
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Ok. Brake lever travel. The first pic is a 1980 special mc, rebiult with rebiult caliper , rubber lines, the second pic is a 1980 mc 11mm from mikesxs, rebiult caliper, ss one peice line
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I tried to employ the same pressure with my thumb while taking the pic, as evidenced by my red thumb. Of all the evolutions, you'd think we would have a third hand by now.
I like the feel if the 11mm better than the 14, but the 14 is fine
 
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Paul – Makes sense to give the new stainless lines a chance before deciding... Sounds like your previous ones were really bad! My lines aren't quite that rough, but they do have a chunky precipitate stuck in them. The bike had been sitting for about 28 years when I got it, and at some point the front m/c ruptured, creating quite a mess. Definitely past the best before date!

aldo5468 – Thank you for the tip about the parts fiches. That's really helpful, since I'd like to get a new m/c assembly rather than cleaning & rebuilding another used one.

5twins – Do you know which bike the m/c in your pic is from? Is it the same part number that aldo5468 mentioned? Thanks for highlighting the caliper and m/c sizes. I didn't know that early models used such a large caliper piston!

retiredgentleman – No worries, it happens to the best of us!
 
The one in my pic is the one Aldo mentioned. Do eBay searches for XT225, TW200, TTR225 and TR250 master cylinders. It's not easy to find a pristine one since these are dirt bikes. Many of them are kinda beat up, lol.
 
angus67 – Thank you for posting the pics. They are extremely helpful. I was expecting the 11mm to travel much further, but that appears to be a very reasonable point of resistance.

5twins – Thanks for the confirmation, it looks like a good option
 
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Since we've stumbled on Banggood and their cheap stainless lines, there's absolutely no reason for anyone to still have an old rubber line. Note that the hose mounts on the front of that 11mm unit. The stock MC has it attached to the end. That means each needs a line with the fittings oriented differently to one another. For the stock unit, you want a line that has fittings 90° to one another. For the 11mm unit, you want fittings in the same plane. One of these will do for the 11mm unit. 90cm (35.4") works well for most normal to low bars .....

http://www.banggood.com/50cm-200cm-...10mm-Banjo-Silver-p-1122628.html?rmmds=search

For the stock unit, 90° offset ends work best .....

http://www.banggood.com/90cm-Braide...bike-ATV-Pit-Bike-p-1048321.html?rmmds=search
 
XS650SH - Here are my current brake lever positions for two short stainless steel brake-lines arranged as per the original setup:

Brake Lever at Rest
BrakeRest.jpg


Brake Lever Fully Applied
BrakeHard.jpg


I would prefer to have the lever, when fully applied, perhaps half an inch closer to the hand-grip but there is no more adjustment available.
 
Thanks Paul – Interesting, it looks like there's a bit of variation when compared to Angus' stock m/c setup. I assume this is likely due to different lever adjustment screw positions?
 
XS650SH - Here are my current brake lever positions for two short stainless steel brake-lines arranged as per the original setup:

I would prefer to have the lever, when fully applied, perhaps half an inch closer to the hand-grip but there is no more adjustment available.

Paul, you either have extraordinarily long fingers or I have short ones. Methinks a span adjustable lever would be a good investment?
 
Max Midnight - average fingers, so the girls tell me!

Some 40 years ago I cut the tendons in my right-hand and it is now weakened. The lever is a long way out in the resting position but that is not an issue to me. The best control and strength comes when my hand is closed more. I would prefer to have the lever closer to the hand-grip when fully applied for this reason. With a bit of magic I now have the end of the lever 2 inches from the hand-grip when fully applied. I hope to test this for comfort on a ride tomorrow. I may even file a bit off the lever to bring it even closer.

I will investigate the span adjustable levers as you suggest - Thank you for that Max Midnight.
 
Good luck with the testing Paul. Interested to see how it goes!

I haven't figured out exactly what I'm going to do here yet... Will probably give one of the smaller Yamaha master cylinders a try. I'll post an update once everything is reassembled. Thanks again everyone
 
Lever can be bent in out a bit with little drama, clamp in a vice short piece of pipe over the end, don't stress the MC or bracket. Doesn't hurt to get it good and warm with a propane torch.
 
Lever can be bent in out a bit with little drama, clamp in a vice short piece of pipe over the end, don't stress the MC or bracket. Doesn't hurt to get it good and warm with a propane torch.
Hi Gary,
my experience in trying that method to return collision damaged levers to their proper shape is that with extreme care they'll go back to almost where you want them.
Then you give it that final cautious tweak to make it perfect and the bastard snaps off like a carrot.
 
Yeah I used to break them too. but with some propane heat I've been doing pretty well recently. No big grunts either, slow and steady, it gives the aluminum a chance to "flow" to the new shape instead of the crack, snap, schmidt result.

This (not my video) shows it pretty well. Never tried the soap trick, I put a bit of pressure on the lever with the pipe, you will feel it start to yield when the lever's warm enough. Round the pipe end with a file so it doesn't mar the lever.

 
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gggGary, thank you for the video. I see where I was going wrong! I used heat, but far too little, and went too fast. The secret seems to be a ton of heat and that other thing, what was it? Oh patience! Should take about 12 minutes to do a good job based on the video.
 
To be clear that's not me, just a random you tube video, turns out there are quite a few how to straighten lever videos, wonder why? LOL. Yes aluminum is GREAT at dissipating heat quickly. The good news is that you can easily control exactly where you want the lever to (un)bend by moving the torch and pipe.
 
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