Originally Posted by LukasM
Lot's of discussion about this topic in the 1190 thread already, so in order not to derail it any more I'm starting a new thread.
Many of the "old school" 950/990 owners are claiming that this would be a useless exercise as you would just give up a lot of horsepower for only a couple of lbs of weight loss.
Well, I don't agree.
The weight difference between a 690 and a 990 (non ABS!) is around 140 lbs, with the engines accounting for around 40 lbs of that. Considering the smaller displacement and that manufacturing technologies have improved, a die cast 700-800cc twin engine should be at least 10 lbs lighter than the 990, probably more.
So you've got around 110 lbs difference after the engine, you don't think you can beef up a 690 chassis enough to deal with 80-90 horses and add a fairing and be left over with a significant portion of that? The 450RR rear tank that bolts to the 690 chassis is available already and weighs maybe 1 lb more, and with it's 18 liters of fuel will give you better range than a 990 has.
And don't forget that the 690 already has 48mm forks, 21"/18" wheels with Dirt Star rims, the same brakes as the 950SE and that the 690 rally replicas and even the factory LC4 rally bikes (some sporting a >80HP 730cc engine) run through the desert at up to 200 km/h for two weeks during the Dakar using that same trellis frame and I have never heard of anybody having problems, have you?
I think with some modern and creative engineering a 80-90 HP 700-800cc twin with 360-380lbs (wet no fuel) is a realistic goal, and I'd buy one tomorrow.
What do you guys think?
the 690E has no sub frame, no provision for a luggage rack, not designed for 2 up and single front disc, no nav tower or wind protection.
All of those thing add weight and all of those things are things the market would want to make it compete with the other 800cc bikes... If you design it as a narrowly focused dirt adventure tourer and except people to travel lightly and are willing to trade ruggedness for weight I think it could be done and use more composite and TI construction it could be done.
If the 9x0 is so heavy where's the weight savings to be had? Short of a major cost increase to more exotic materials and AL frames