Improve my XS250 disk brake?

[rjh357]

Hi all

I got myself an old XS 250 a couple of months ago and have really enjoyed riding it, it has a nice big bike feel is comfy and has enough performance about town to keep me happy and can cruse at 65 to 70 on longer trips.

I am loving everything about it apart from the front disk brake it works but takes a big handfull to slow it down, it is working perfectly so nothing to improve there, also has a braded hose fitted.

Just wondering if anyone has got an XS 250 or has had an XS 250 brake master cylinder apart and knows the piston Dia.

If i can get one even a mm or 2 smaller i will get more PSI for the same effort, (travel will increase but i have room for that the braded hose limits the travel nicely). There are lots of aftermarket brake and master cylinder kits available and is someone knows the diameter of the piston it save me stripping mine.

Other option is same diameter but the fulcrum further from the piston but no one on the web pages advertising the aftermarket brakes seem to have that in there info.

Of course any other ideas that anyone has tried successfully (or unsuccessfully so i can discount he idea) it would be much appreciated

Many thanks

[blackhat250]

Try sintered pads . more abrasive .. .

[mervin]

Try a modern master cylinder , you will have a either 5/8" or 14 mm master cylinder on the XS i reckon , it will be written underneath, also have you stripped the claiper to make sure everything is free and sliding moving as it should

[drewpy]

i fitted a twin disk on my xs400 as fitted to the xs1100 and 750/850. uses the same caliper design

it did stop on the proverbial dime and could even lock up the front

I suggest a caliper strip down and M/C rebuild as they should be good stoppers!

[rjh357]

Thanks all I am a competent engineer and have checked out the calliper and all is free; I like the idea of the twin callipers from the bigger bike as my forks although oil tight are pitted and will probably eat seals every year or so.

Drewpy can you remember all the parts you had to use, fork yolks as well I guess I imagine there a bigger diameter might as well fit tapered head race as well at same time. Might start looking on EBay gather the bits during the winter and can do the work in May for the MOT.

Thanks for the suggestions will have a look see if the piston Dia is on the master cylinder

[drewpy]

you just use google and You'll find my how to

http://www.xs400.com/forum/showthread.php?t=4730

[dt502001]

Fitting a single larger disc is less work,all you need to make is a bracket to move the caliper out and find a larger disc with the same bolt pattern.Better yet is to fit a newer caliper at the same time a 4 or 6 pot will have you stoping on a dime. with a 290-310mm disc

I guess it comes down to do you wan't to retain the original look or go with a" I mean bussiness" look,drewp's conversion looks so good most would think it was stock.But it adds weight and a 250 needs all the help it can get it the weight department.

Nice to have a engineer on board,can always use someone who can do the caculations,haven't heard someone use the term fulcrum point in a while.

Shortie adjustable levers might just do the trick for you as you can change the engaugment point like these ones http://www.webbikeworld.com/t2/pazzo/adjustable-levers.htm along with some new sintered pads. as Blackhat suggested.

[drewpy]

I fitted a large disk and blue spot caliper off an xjr1300 to the tracker if you wanted to go that route

[rjh357]

Hi again all thanks for the help and suggestions there are some very intelligent and well thought out possibilities here I hadn’t thought about the bigger disk.

I know have a few things to ponder on, the MOT ends in may 2014 so I will take it off road for a month there is an oil leak from a couple of rotary oil seals and I need cut out the rot and plate and paint the back mudguard (unless eBay comes up with something).

The oil leaks are a 2 edge sword they one on the gearbox output shaft keeps the chain perfectly lubricated, does the job as well as any Scot oiler.

It doesn’t drain the oil level at all but I do need to put a drip tray under it when I park at home only 1 or 2 spots but as I use it most days doesn’t take long to mess up the drive.

As someone mentioned though the weight is a real concern the bike is very underpowered it is OK for my style of riding but I am about to add small homemade panniers, nothing fancy just some brackets and a couple of E bay ammo boxes but I suspect even that feeble weight will have an effect, not had it 2 up yet I imagine a moden125 would be as good.

I don’t care about how it looks just how it functions so I think I will look out for a bigger disk and adapt the calliper perhaps with a new master cylinder.

My other thought is I love the feel of the bike, the handling, weight, riding position, all fit me so well I just might look out for a similar age XS 400 that can pull my 15.5 stone and anything else I want to add to it with a little more in reserve.

Then strip the 250 and do the full rat bike deal olive drab paint all over cut out as much weight as possible maybe hard tail and a comfy single seat, (anyone do olive drab frame and swing arm powder coating can you even get a Mat finish of powder coating something I need to research). Also do the brake upgrade and anything else I can think off.

Once again many thanks I shall conceder the options here and plan repairs and upgrades or look to a 400 for the spring.

[drewpy]

the 400 engine will slot straight in, the brakes are the same throughout the range I'm afraid.

just need to make sure that they are either points or electronic ignition engines, although you can convert if you search this forum.