|
Post by amorti on Apr 15, 2009 17:21:34 GMT
Hi all, ever thought the front brake on your single caliper 600 diversion was a bit too firm? Well, you'd be right. That model diversion has 30+33 mm pistons, and a 14mm master cylinder. The master cylinder is too large, giving a "wooden" feeling. You get a very hard, strong lever and lots of initial bite, which is nice. It feels exactly like it's very well bled. But it has little actual power, and so you have to squeeze hard to draw up to a stop*. This has the added problem that there is virtually no lever travel between dragging the pads, through to locking the wheel**. According to this site, which makes good sense: www.vintagebrake.com/mastercylinder.htmThe single caliper 600 with standard 14mm master cylinder has a brake "feel ratio" of: 20.3 with a 1/2" master I would have 24.6 with a 12mm master I would have 27.6 That chap reckons 27 is what he calls "good" where 23 is what he calls "firm levered", with ratios under 23 being simply "wooden". By the same logic I reckon ratios much above 27 will feel "spongey". So it looks like my/your/our gut feeling is right then - the XJ's brakes are indeed wooden. Now, what bikes have a 12mm master cylinder with built-in reservoir? I know the Honda NTV650 has a 1/2" master cylinder which would be better suitable than the original Yamaha part, but I think I would prefer a ratio around 27 if I was to go to the effort to make a change. *because it suffers reduced hydraulic advantage. en.wikipedia.org/wiki/Hydraulic_machinery#Force_and_torque_multiplication To understand this, consider the reason why a brake master cylinder is smaller than the slave cylinder in the first place. It takes a little getting your head around. **again, consider that a larger master piston moves more fluid, but at less hydraulic advantage for the same amount of lever travel as a smaller one)
|
|
|
Post by General Gman on Apr 15, 2009 21:13:01 GMT
All fairly simple stuff - a lot of people with 6 pot tokicos fit a larger bore master cylinder.While the feel of the brakes is much firmer, power is utimately lost because braking force is reduced.The std master cylinder is 16mm, which is a wee bit small to move 12 caliper pistons.I did a few calculations and reckon that a 17 or 18mm cylinder is going to give the best power / feel combination.Best option is a AP racing item, but they're about £350
|
|
|
Post by pilgrim on Apr 15, 2009 21:38:14 GMT
For the maximum ability and potential of the Diversion and the incapability of most of us amateur riders to get even half way to it does this technical 'study' change anything? For me, no.
It's a cheap and cheerful biking commodity with particular characteristics that I find pleasing to ride, including stopping! ;D
|
|
|
Post by amorti on Apr 15, 2009 21:40:49 GMT
Gman, out of interest, what are the piston sizes on those calipers? My neighbour is on the verge of giving up on his ZX-7R as he can't get the brakes bled to where he is happy with them, I wonder if it's simply that the master is too small, making it feel like it's not bled properly.
|
|
|
Post by amorti on Apr 15, 2009 21:47:07 GMT
For the maximum ability and potential of the Diversion and the incapability of most of us amateur riders to get even half way to it does this technical 'study' change anything? For me, no. It's a cheap and cheerful biking commodity with particular characteristics that I find pleasing to ride, including stopping! ;D You have a point... but there's a but. My other bike is a fireblade. The idea is/was that I ride the diversion in the week back and forth to work, using tyres at 10k intervals and fuel at @56mpg. The fireblade should be kept for weekends, where tyres last about 5k and it returns about 42mpg. Thing is, that's not happening. The main reason is the diversion is just not nice to ride. I would even say with the unpredictable nature of the wooden brakes, and the boingy forks, it's verging on dangerous. So I simply don't often walk past the fireblade to the divvy in the morning. If I make the brakes work a bit nicer (I already just did the pads and caliper seals and it has a braided line) and change the fork springs for something a little less pogo-like (it had new for oil when I got it, and that didn't make much odds - if cheap enough I would also do the bushes while they were open) then perhaps I'll be more likely to use it. The master cylinder swap, once I have resold a perfectly good divvy master with straight lever, shouldn't cost me more than £10 or £15, and the forks about £70 I think - which I would get most of back on ebay when the bike is eventually sold without them. If it means I take the diversion more often, that's good for my wallet in the end. [/waffle] edit: besides, the divvy may have limited potential, but it's not even nearly at where it could be. You try braking up to a corner, releasing the brakes, then turning in. The suspension gets all confused and I have come pretty close to being launched at the scenery. If a few pennies can stop it doing that, I'd like it
|
|
|
Post by metalforever on Apr 16, 2009 8:03:21 GMT
amorti, pennies may very well be the solution to your problems. or atleast the suspension. Try putting 10-20pence of 2pences under the fork cap of each leg. it'll compress the spring nicely give you a firmer ride. and for 40pence is one of the cheapest 'mods' you'll do to make it handle better!
|
|
|
Post by General Gman on Apr 16, 2009 8:08:56 GMT
Gman, out of interest, what are the piston sizes on those calipers? My neighbour is on the verge of giving up on his ZX-7R as he can't get the brakes bled to where he is happy with them, I wonder if it's simply that the master is too small, making it feel like it's not bled properly. Tell him to fit a pair of 4 pot Nissins from a 90s GSXR750/1100 or 4 pot Tokicos from a SRAD.As long as the mountings have 90mm spacing, they'll fit. I had a set of Nissins on my ZX9, but went back to 6 pots because I was determined to make them work.They do, but they should be so much better.Will have to have a look for the piston sizes - but there are two different sorts of 6 pots with different piston sizing.. I'm going to be getting some adaptors and fitting radial calipers from a ZX-10R as soon as I can afford it
|
|
|
Post by Deleted on Apr 16, 2009 9:09:42 GMT
Surely you understand the divvy is not a blade and, no matter how much you play with it, it never will be. If you feel it's going to punt you over the nearest hedge perhaps you need to tailor your riding style. Pre-loading your front suspension will help a little as will setting your rear shock to a suitable height.
I would go so far as to suggest that if the Divvy is too much bike for you perhaps you should get the bus.
|
|
|
Post by CD on Apr 16, 2009 9:14:09 GMT
For the maximum ability and potential of the Diversion and the incapability of most of us amateur riders to get even half way to it does this technical 'study' change anything? For me, no. It's a cheap and cheerful biking commodity with particular characteristics that I find pleasing to ride, including stopping! ;D Not arguing at all with the point of view, but if the brake can be improved for minimal costs we get an even better bike for minimal money. Of course if we like the brakes as they are there's no point. But on my 900... while powerful enough to lock the wheel at 30mph the brakes had poor control - on or off. I hated the pogo effect they so often caused. I came a cross a full front brake system from an R6 for £80 - needed new pads anyway and wanted some braided hoses - so went for it. The bike is much much better to use. etc etc, looks good, blah, blah. However, if simply fitting a different master cylinder would have had a similar effect I could have saved my self quite a wedge. We can consider different master cyl designs. I put a long bolt into the throttle grip top screw and fitted the R6 reservoir with a spacer tube. I also used the original D9 handlebar clamp so the mirror would be usable.
|
|
|
Post by teejayexc on Apr 16, 2009 9:15:30 GMT
Surely you understand the divvy is not a blade and, no matter how much you play with it, it never will be. If you feel it's going to punt you over the nearest hedge perhaps you need to tailor your riding style. Pre-loading your front suspension will help a little as will setting your rear shock to a suitable height. I would go so far as to suggest that if the Divvy is too much bike for you perhaps you should get the bus. ;D Or perhaps you could become an FB to stabilise it? Dunc, suggesting he get's an FJR is overstepping the mark imho
|
|
|
Post by Deleted on Apr 16, 2009 9:19:36 GMT
;D Or perhaps you could become an FB to stabilise it? Dunc, suggesting he get's an FJR is overstepping the mark imho The FB route certainly works for me Nothing wrong with an FJR, it's the pensioners showing you their bus pass everytime you stop at the lights that would piss me off. ;D
|
|
|
Post by CD on Apr 16, 2009 9:24:04 GMT
Saw a very nice blue FJR in town the other day. OH said, "horrid bike much prefer yours". And, everyone knows the green ones are faster ;D
|
|
|
Post by teejayexc on Apr 16, 2009 9:27:48 GMT
Saw a very nice blue FJR in town the other day. OH said, "horrid bike much prefer yours". And, everyone knows the green ones are faster ;D OH ? You found another bone shifter with a thirst for motorcycle forum posting then CD?
|
|
|
Post by Deleted on Apr 16, 2009 10:02:43 GMT
OH ? Other half ? that explains a lot there's 2 of them ;D
|
|
|
Post by amorti on Apr 16, 2009 10:05:33 GMT
amorti, pennies may very well be the solution to your problems. or atleast the suspension. Try putting 10-20pence of 2pences under the fork cap of each leg. it'll compress the spring nicely give you a firmer ride. and for 40pence is one of the cheapest 'mods' you'll do to make it handle better! I got as far as jacking the bike up, removing the handlebars and taking the first cap off before I realised a 2p piece falls straight in as the diameter is too small. Also, it's not (just) preload that's missing, the spring rate is too light. I actually suspect that at near 60k, my springs are just worn out.
|
|
|
Post by amorti on Apr 16, 2009 10:06:13 GMT
Tell him to fit a pair of 4 pot Nissins from a 90s GSXR750/1100 or 4 pot Tokicos from a SRAD... Thanks
|
|
|
Post by amorti on Apr 16, 2009 10:08:46 GMT
Surely you understand the divvy is not a blade and, no matter how much you play with it, it never will be. If you feel it's going to punt you over the nearest hedge perhaps you need to tailor your riding style. Pre-loading your front suspension will help a little as will setting your rear shock to a suitable height. I would go so far as to suggest that if the Divvy is too much bike for you perhaps you should get the bus. Politely and with all due respect, get bent. You don't know me, and you don't know my riding ability or style. The divvy is not enough bike for me, that is why it is dangerous. It won't ever be a blade, but it can at least maybe be setup such that it works properly. If you want to suggest the divvy is too much bike for me, try and keep up with me and the guys I ride with one weekend on a rideout, I will gladly invite you. But I'll be riding the blade. That is too much bike for me, which means I am unable to ride beyond its limits. It's much safer that way than what happens on the divvy.
|
|
|
Post by amorti on Apr 16, 2009 10:12:04 GMT
[Interesting post about blue spots...] What I would rather do is keep the 14mm master cylinder and fit a blue spot caliper. Unfortunately on my single caliper model D6 that means milling off the fork leg and/or caliper mounting face, and mounting the disc out on washers. That's because otherwise the caliper will clout the wheel spokes. I also don't fancy taking my disc off as the bolts don't look like they'll work! Even then I might end up with it not working, and given all that and the fact i only just rebuilt my caliper... Anyway, your solution looks good! Nice job
|
|
|
Post by Deleted on Apr 16, 2009 10:23:28 GMT
Politely and with all due respect, get bent. You don't know me, and you don't know my riding ability or style. The divvy is not enough bike for me, that is why it is dangerous. It won't ever be a blade, but it can at least maybe be setup such that it works properly. If you want to suggest the divvy is too much bike for me, try and keep up with me and the guys I ride with one weekend on a rideout, I will gladly invite you. But I'll be riding the blade. That is too much bike for me, which means I am unable to ride beyond its limits. It's much safer that way than what happens on the divvy. With all due respect to you I'm not the one struggling to get to grips with a bog standard D6. If there is something fundamentally wrong with your bike then fair enough but if it's standard then I'd suggest that the problem lies with your style or abilities. Incidentally, being able to ride fast on a Blade has me really impressed.
|
|
|
Post by beeblemaster on Apr 16, 2009 10:36:44 GMT
Incidentally, being able to ride fast on a Blade has me really impressed. And me.. they usually get in the way ;D The brakes for me are fine now that I've changed to stainless lines and sintered pads, yep I agree they feel wooden. The problem is the front suspension, it really is pathetically soft. But to be honest I've no plans to spend money on getting it right, if I can get some Hagon springs cheap I'll be chuffed. But the Divvy does the job it's supposed to perfectly. It's a commuter and a tourer - and it tours remarkably well.
|
|
|
Post by amorti on Apr 16, 2009 10:46:17 GMT
With all due respect to you I'm not the one struggling to get to grips with a bog standard D6. If there is something fundamentally wrong with your bike then fair enough but if it's standard then I'd suggest that the problem lies with your style or abilities. Incidentally, being able to ride fast on a Blade has me really impressed. We'll just have to agree to (dis)agree You reckon the diversion's brakes are good enough, but I reckon they're wooden and can be improved (potentially a lot) very cheaply. You reckon the suspension is OK for a commuter, but I reckon (as above, probably because my front springs are shagged) that mine is so boingy it's verging on dangerous, and can be improved cheaply, for a very recoupable outlay. Seriously, I'm not Rossi, but I am quick enough to ride in a group with some more experienced fast riders (I've [only] been riding 8 years now), on eg. a few BMW GS's, Moto morini's new adventure thingy, TDM's, a new tenere on road tyres and such kit, on roads far more suited to adventure bikes! So I will accept your compliment
|
|
|
Post by amorti on Apr 16, 2009 10:52:54 GMT
The brakes for me are fine now that I've changed to stainless lines and sintered pads, yep I agree they feel wooden. The problem is the front suspension, it really is pathetically soft. But to be honest I've no plans to spend money on getting it right, if I can get some Hagon springs cheap I'll be chuffed. Agree with you entirely: the brakes work and are good enough to ride to work with, but they're not good. The springs are indeed very soft, but they do work well enough for a no-smiles ride to work and back. But if I want to get a move on, things get hairy.
|
|
|
Post by Deleted on Apr 16, 2009 10:58:42 GMT
We'll just have to agree to (dis)agree You reckon the diversion's brakes are good enough, but I reckon they're wooden and can be improved (potentially a lot) very cheaply. You reckon the suspension is OK for a commuter, but I reckon (as above, probably because my front springs are shagged) that mine is so boingy it's verging on dangerous, and can be improved cheaply, for a very recoupable outlay. Seriously, I'm not Rossi, but I am quick enough to ride in a group with some experienced fast riders, largely on eg. BMW GS's, Moto morini's new adventure thingy, TDMs and such, on roads far more suited to adventure bikes! So I will accept your compliment In truth I reckon the brakes could be better but they do what they're meant to. As I said you'll get better performance by pre-loading the front suspension and possibly going up a weight with the fork oil. Both these changes cost next to nothing, tossing around changing brakes on a D6 is to my mind a waste of money and will only make the suspension problem seem worse. Your Blade is a performance machine your D6 is a commuter/tourer and will never be anything else. Each to their own but I would never expect a D6 to stop on a sixpence and would ride accordingly. As for a compliment, take it as you will, but riding fast is not as impressive as riding safe, for me. There are several on this Forum who combine both exceptionally well but as you said before I don't know you. I guess you are under 25 and still Immortal, long may it continue. The thread is the first interesting one for a while though. If the D6 is so bad why don't you get rid of it ?
|
|
|
Post by amorti on Apr 16, 2009 11:57:33 GMT
Bev - you're wrong. The grabby brakes show up the bad suspension, the improvements I plan will alleviate that to a degree. The bike had fresh oil, it didn't make a big difference. As for preload, over-damped forks even with extra preload can still be under-sprung.
I ride fast enough but safely. I don't speed in 30, 40 or 50 mph zones, I don't overtake unless I know I can do it where I can see, I don't make other road users swerve. I do go out to ride and have fun. Have you forgotten that that is what bikes are really all about? Perhaps you need to sell up and get a nice volvo.*
I am exactly 25, yet I am quite aware or my mortality.
I won't sell the divvy just yet because it's very very cheap. And with just a little work and money, maybe it can be a good commuter as well as a cheap one. My insurance renewal just came in at £98. I can't imagine I could get any other bike of 400 or more cc insured for that. Thing is, it can be so much better than what it is.
You clearly don't agree with me, and that's fine. I'm a born tinkerer, and so I will do it anyway.
*see, I can make assumptions about you, too.
|
|
|
Post by teejayexc on Apr 16, 2009 12:17:18 GMT
1) Bev - you're wrong. 2) Perhaps you need to sell up and get a nice volvo. 1) He's a Jock they're never wrong, they want independance, but they'll never vote for it cos they'll not have an excuse to moan about the English then. 2) Do they come with a sidestand? Ps, good thread
|
|
|
Post by CD on Apr 16, 2009 12:42:14 GMT
I went for the new brakes option because I could. Appreciated it not such an option (easily) on the 600. I found the std 900 brakes to be grabby and the 600 (single disc) acceptable, but also needed lots of muscle (and therefore less control) on the limit. If a smaller master cylinder will help then why not and fit one. There is lots of stuff on ebay for minimal cash (sometimes) all it needs some research into the piston sizes. Why are some folk so bad tempered.
|
|
|
Post by Deleted on Apr 16, 2009 12:45:40 GMT
Bev - you're wrong. The grabby brakes show up the bad suspension, the improvements I plan will alleviate that to a degree. The bike had fresh oil, it didn't make a big difference. As for preload, over-damped forks even with extra preload can still be under-sprung. I ride fast enough but safely. I don't speed in 30, 40 or 50 mph zones, I don't overtake unless I know I can do it where I can see, I don't make other road users swerve. I do go out to ride and have fun. Have you forgotten that that is what bikes are really all about? Perhaps you need to sell up and get a nice volvo.* I am exactly 25, yet I am quite aware or my mortality. I won't sell the divvy just yet because it's very very cheap. And with just a little work and money, maybe it can be a good commuter as well as a cheap one. My insurance renewal just came in at £98. I can't imagine I could get any other bike of 400 or more cc insured for that. Thing is, it can be so much better than what it is. You clearly don't agree with me, and that's fine. I'm a born tinkerer, and so I will do it anyway. *see, I can make assumptions about you, too. Good post young man, I have 3 clones of you at home, they also think they know everything there is to know. Upgrading the brakes is not going to fix your worn out springs, fixing the suspension will give you a better ride. Preload and stiffer front will go some way to alleviate the dip and bounce from the front which appears to make you skittish I'm not quite ready for the Volvo thanks, I'll continue to ride my bike at speeds approaching 25mph and damn the consequences, I live for the thrill. As for making assumptions about me feel free, you're way off the mark but I appear to have been spot on. When you alter the brakes you will of course inform your insurance company that you modified the bike, you'll find that not being an old fart like me this will cause the cheap bike insurance to rocket. Far better to go for something that suits your youthful exuberance and get rid of the underperforming D6. You know you want to.
|
|
|
Post by amorti on Apr 16, 2009 13:08:13 GMT
better to go for something that suits your youthful exuberance and get rid of the underperforming D6. You know you want to. I did - a fireblade. But it costs me about £4 more a week in fuel, about £3 more a week in tyres, and I haven't done any more calculations on the other consumables. Plus it only gets 160 to a tank not 200 like my divvy, so needs me to stop and fill up more often. And it wakes the neighbours up. FYI, I keep a spreadsheet of the fuel both my bikes use, and fitted both with scottoilers. Now that's what I call exuberant.
|
|
|
Post by teejayexc on Apr 16, 2009 13:14:47 GMT
FYI, I keep a spreadsheet of the fuel both my bikes use, and fitted both with scottoilers. Now that's what I call exuberant. We call it Billywhizz
|
|
|
Post by neilmud Lord Protector on Apr 16, 2009 13:44:02 GMT
FYI, I keep a spreadsheet of the fuel both my bikes use. Geek Neil
|
|