Neon
Member
I tried searching the forums for this but came up with nothing. I was wondering if this would be the ultimate setup for gearing or would it be just a waste of time and $300.
Has anyone tried the SRAM Dual Drive alongside The SBP Shift Kit?
- Thread starter Neon
- Start date
Hawaii_Ed
Member
It seems really nice, my understanding is it goes higher and lower than a standard casette does? I can say with my 8 speed rear, I rarely hit 8th gear unless I am down hill and flying. IMHO the DD SRAM is more gear than you'd need, a simple 8 speed works great.
Neon
Member
Thanks for your reply Hawaii_Ed. Your feedback means a lot. I kinda figured it might be a little bit of overkill. But it might be fun to get the feel of driving a Transport again with low, mid-range, and high. Now if they just made a small diesel that was light enough i'd be in heaven.
Hawaii_Ed
Member
Are you a military driver? LOL. Running a veggie-diesel bike would be great!
Realistically, 45 MPH is my cruise speed, that is a decent rpm in 7th gear. If I hit 8th, I lose speed unless I am behind a truck, tail wind, or down hill. The power band in these engines is pretty high and narrow!
If you have the cash, why not
More is always better!
Realistically, 45 MPH is my cruise speed, that is a decent rpm in 7th gear. If I hit 8th, I lose speed unless I am behind a truck, tail wind, or down hill. The power band in these engines is pretty high and narrow!
If you have the cash, why not
More is always better!
Neon
Member
Not a military driver just an ex transport mechanic that had to rescue a few rigs. One of the nice things about a diesel is as long as it is oily it will burn it. Not so sure that the common fuel rail system will take anything other than pump diesel though. Never had the nerve to try it. Anyway I have the cash but wasn't sure if it would be worth the effort or if i should give the nuvinci hub a shot like everyone else seems to be doing.
Hawaii_Ed
Member
I'd say build it with normal gears, and then upgrade once you get it dialed in. Obviously, I am a fan on the shift-kit. I'd like to try a nuvinci, but I am fine as is.
I had a dream of building a veggie-mercedes at one point, but I have too many cars!
Ed
I had a dream of building a veggie-mercedes at one point, but I have too many cars!
Ed
Neon
Member
Not hard to get the veggie Mercedes. Dump in vegetable oil in your tank and advance the timing a hair. Not that i'm trying to convince you to do it or anything but it really is that easy. Actually you don't even have to advance the timing any but it never hurts. And i know what it's like to have too many cars.
Fabian
Well-Known Member
Hi Neon,
I have thought about the SRAM Dual Drive before, actually i really want to fit one to my motored bike because i never have a 1st gear that's low enough for the hills i need to climb and never have a gear high enough when selecting a front chainwheel that's low enough for hill climbing.
A SRAM Dual Drive is exactly the solution i want, save for a proper Rohloff hub that's awfully expensive.
My concern (and it may be unfounded concern) is that the planetary gear drive would blow itself to pieces with the torque put through it from a 9T to 44T Jackshaft ratio and a 30T to 36T chainwheel to cassette ratio.
If i could be reassured that the Dual Drive hub was sufficiently strong enough to cope with the torque applied to it, my bike would have one fitted tomorrow.
Fabian
I have thought about the SRAM Dual Drive before, actually i really want to fit one to my motored bike because i never have a 1st gear that's low enough for the hills i need to climb and never have a gear high enough when selecting a front chainwheel that's low enough for hill climbing.
A SRAM Dual Drive is exactly the solution i want, save for a proper Rohloff hub that's awfully expensive.
My concern (and it may be unfounded concern) is that the planetary gear drive would blow itself to pieces with the torque put through it from a 9T to 44T Jackshaft ratio and a 30T to 36T chainwheel to cassette ratio.
If i could be reassured that the Dual Drive hub was sufficiently strong enough to cope with the torque applied to it, my bike would have one fitted tomorrow.
Fabian
Neon
Member
From pictures i've seen of the hub torn apart it looks like it will take a lot of grief. The teardown pictures can be seen at Endless Sphere. I guess the early versions of the hub were not very tough and might last a month. But have since been made tougher. I don't like the idea of being a guinea pig either.
Happy Valley
Active Member
Just a comment on this..........
Fill in the blank above but I see this question come up a lot in relation to MAB engines and components being able to handle the requisite torque from them. These small engines generate almost nothing in the way of torque compared to a 200 lb. cyclist standing up on the pedals cranking up a hill. The point being if bicycle components stand up to heavy duty torquing in cycling tasks they should withstand the few ft. lbs. of torque supplied by a MAB engine.
I think a more representative question in fitting out components is if they are designed to hold up under the wear and tear of consistant higher ground speeds that motorizing a bicycle usually allows, IE: sufficient access to frequent lubing, etc.
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