260mmHow big was the Yamaha TD/TZ front drum brake? They were huge and heavy and were used for years. Replaced by RD350 disks, but that's not the point.
This is not an ad, I and my friends modified with a motorcycle. I am in China, send pictures just want to communicate with everyone.Judging by the number of vent plates I guess you are going to produce a good number of these? And that your post is some sort of low key advertisement? Well lets hope your well insured or perhaps you are too far away to care..........
290mm for a drum brake is far too big, there's a very good reason why Ceriani, Oldani, CMA, Seeley, Robinson never made a brake bigger that 230 (9") only Fontana built a 250. Its not the brake efficiency that the issue its the brakes internal stress, the movement / flexing of the brake plates and worse of all its the gyroscopic forces generated by a brake / wheel that size - Those forces will fight the rider when they try to turn the bike and if they are unlucky and get the front end airborne it will not want to come down again and can pull the bike one or the other.
Photo - Imola, Rivazza a fast corner following a 700mtrs decent of straight ish track on which a good twin can top 125mph. Would you trust your life on the brake above? Or on cast Magnesium 250 Fontana that will still stand a bike on its nose after 3 laps of the Isle of Man and fitted to the bike pictured? Rivazza has about 40mtrs of run off, a little kitty litter then mostly grass or rather just enough time to kiss your arse goodbye.
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