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[jefrs]

The rear brake on any bike should only be used for balancing it up fore and aft. It cannot provide much braking effort, maybe over 80% of the stopping power is done by the front. Whilst the back brake will be capable of locking the wheel (if you pull the clutch in and decouple the 27 horses), the CofG weight shifts forwards which lessens contact friction with the road. Hauling on the front anchor serves to put more weight on that wheel increasing its effectiveness. It's Newtonian physics and, "ye cannae break the laws of physics".



Otoh if it's making grinding noises you may have no linings left. You may need to re-align shoes to drum so both actually make contact.

ric, at 70kg a grown man ought to be able to apply at least 280kg force onto the brake pedal - which seems excessive, it should lock.

I've noticed my brake rod has a small kink in it which means it must act like a spring.

[Rattlebattle]

My new C5 has a 19inch front wheel, 18 inch rear. I find the Roadriders are superb tyres on the C5; they are tubeless but have tubes fitted. Usually 100 miles is enough to get rid of the moulding compound and it isn't much of an issue on such a slow bike anyway. As regards the running in, I found that it was not at all sensible to do less than 40mph in top gear, unless downhill, because it was obvious that the engine was straining. In top gear I cruised at 45mph for the first 300 miles, then 50mph for the next 300. The engine will tell you when it is unhappy either by chronic shuddering if you try to do 35mph in top or bad vibration if you rev it too highly. Both should be avoided. The UCE engine has a roller big end and does not have plain main bearings either, so really it is the piston rings that need to be run in more than anything. If you keep the engine in its sweet spot, neither lugging it to comply with some arbitrary speed nor using wide throttle openings instead of using the gearbox properly you should be ok. FWIW I have only had to tighten the screws holding the exhaust shield on. Nothing else has come loose nor have I yet resorted to lecture. I suspect they only shake to bits if you stick religiously to the ludicrously slow maximum speeds specified. I did my own service; I want to know what's on the magnetic plugs and to see it decrease each service. Just my opinion; as ever others will be available.

[Rattlebattle]

Lecture should read loctite; predictive text, brilliant or PITA, discuss....

[Rattlebattle]

Jefrs, I think he means the rear brake pedal is hitting the deck as he is cranking the bike over so far when cornering.... I find that part of the fun of these old plodders is that on decent tyres they handle really well on the twisties; it's very satisfying to go round B road corners without shutting off, as long as you can stop within the distance you can see to be clear on your side of the road of course. ...

[jefrs]

Oops (blush).

Around here we don't got twisties, we gots tight bends and coming out of one too fast will have you parked up the end of a horse. Locals' idea of an all terrain vehicle is a John Deere. SUVs aren't Chelsea tractors, they get caked in mud, mine does. Latest trick of nice old lady walking dogs is her to move smartly over to one side of the road, whilst her dogs are on the other, on an expanding lead, neat.

The original log of an exhaust got a little scrape but the 50s is tucked right in. The brake pedal can be adjusted up a little, cruiser style.

Does the brake pedal scrape before the foot peg or your toe?

[2cvandy]

Follow Rattleback's advice regarding running in. Just use common sense, if the motor sounds happy, it will be. Don't get bogged down trying to stick to particular speeds, don't thrash it and don't let it labour and it'll be fine. Enjoy!

[2cvandy]

Jefrs - "The rear brake on any bike should only be used for balancing it up fore and aft. It cannot provide much braking effort, maybe over 80% of the stopping power is done by the front. Whilst the back brake will be capable of locking the wheel (if you pull the clutch in and decouple the 27 horses), the CofG weight shifts forwards which lessens contact friction with the road. Hauling on the front anchor serves to put more weight on that wheel increasing its effectiveness." - You've obviously not spent much time on cruisers? I bought my first Harley in 1989, and having traded in a Guzzi California with the excellent linked brakes, I admit I was in the habit of just using the pedal most of the time. But I quickly found this technique worked well on the Harley. Because the weight is carried so far back and so low there's very little weight transference if you grab a handful of front brake, and with the dumper truck sized pedal fitted to many Harleys you can get a fair bit of pressure onto the rear brake. On mine the rear disc and caliper are exactly the same size as the front one and you rarely need to use both. Over the last 25 years with Harleys I've found that I generally wear out two sets of rear pads to one set of front. I wouldn't recommend the technique for most bikes, particularly if you've got a disc front and a drum rear but it's horses for courses I guess?

[Beezabryan]

All tractors have rear wheel brakes

[ric]

Just to clarify, the underside of the rear brake pedal does make contact with the road surface on some right hand bends, despite raising the resting position of the pedal annoyingly above footrest height. As a purely preventative measure I've also raised the legs of the centre stand by an inch or so for the left handers. Did I mention how good I thought the Roadriders were?

With regards to the rear brake, I know just how devastatingly effective it can be once set up correctly. Testing the rear brake (post fettling) on anti skid surfacing left me with a flat after rotating the tyre on its rim. I've since rotated the brake arm to reduce mechanical efficiency which still leaves the option of fitting the shorter brake arm if required. I now treat it with the respect it deserves instead of once having to use as much effort as could be mustered in the hope it might make some contribution towards reducing speed.

[jefrs]

I grew up on old british bikes but if you want to practice stoppies I found it best done on your mate's pride and joy Yam RD350 howler heading towards a brick wall. Ah happy days when we was young an' stupid.



I've no desire to do a treatise on Newtonian vector mechanics, I'm a retired physicist-engineer, it's out there if your want it. Essentially the CofG always shifts but the heavier it is the more effort the rear can apply. So a Harley can use it's back but the front is still the most effective for hauling the beast to a halt. My mate N managed to tip his HD over the other week and couldn't lift it back up on his own. One can just about pull a stoppie on the bullet; I've had it pull a surprise wheelie in 2nd when the sticky cable unstuck (fixed). It's why reversing a car down hill is bad news, the rear brakes aren't as beefy so it won't stop and the front tries to lift so you lose the steering, hence give way to vehicles ascending. Contact patch on the road is load weight on wheel divided by tyre pressure, I back of envelope (guesstimate) Bullet C5 as rear 5-sq.in. front 28-sq.in. under full braking.



ric - I'm very interested in your brake lever mods. Please explain some more.