cassette onto a hub gearing?

[kravmonsta]

Hi all. another newbie who has come across. will be ordering my kit in a few weeks and this forum is great for ideas, build etc.
2 qeustions.
being a big unit at 6' and 125kgs any recommendations on frame size? i see the common thead is 26 inch from ground cross bar. does this still apply?

also my mate years ago had a greenspeed trike and he had a 7sp cassette onto a 8sp hub gear. combine this with his crank he had like 63 gears and when he put the hammer down he was gone.

how hard is this to do? i will ask the bike shop to do it but need to know 1st if this is expensive?

there are some very creative people on here and very inspiring.

 

[JonB]

kravmonsta wrote: Hi all. another newbie who has come across. will be ordering my kit in a few weeks and this forum is great for ideas, build etc.
2 qeustions.
being a big unit at 6' and 125kgs any recommendations on frame size? i see the common thead is 26 inch from ground cross bar. does this still apply?

also my mate years ago had a greenspeed trike and he had a 7sp cassette onto a 8sp hub gear. combine this with his crank he had like 63 gears and when he put the hammer down he was gone.

how hard is this to do? i will ask the bike shop to do it but need to know 1st if this is expensive?

i have never heard about combining a 7 speed cassette with a 8 speed hub, unless a middrive was used. Using a middrive on a cruzbike is impossible.

You can get a DualDrive from SRAM that combines a 3 speed hub with up to a 9 speed cassette. You could take any kind of rear gear, hub, pure derailleurs and DualDrive and combine it with a front derailleur. You can get a schlumpf or hammerschmidt front hub with 2 gears which can be combine with any kind of rear gearing.

I am just 10 kilo lower weight than you, and i have a used Rohloff that works fine. Rohloff alone is sufficient gearing

 

[kravmonsta]

thanks for that. ironically i found the dualdrive on the greenspeed site. yeah i think i got the numbers wrong but you got the idea.

looking forward to the build.

 

[currystomper]

I think it would be a great idea for a 451 quest as it is an over drive in high gear and will give you gears for higher speeds.....

CS

 

[Doug Burton]

The SRAM 3x9 hub is geared equivalently to a 54/42/26 crankset. You can tailor the range by the number of teeth on the chainring you select; stump-pulling lows and ridiculous highs are available. The middle range is dircet drive, the upper and lower ranges run through a planetary gearset in the hub.

Using a 53t ring can give 20" bikes gearing equivalent to 26" big wheelers. A 44t ring works very well for 26" bikes.

The hub internal gears are controlled by a "clickbox", which you'll need to accommodate size-wise on the fork dropout, but with clever cable routing this is not an issue.

The only hubs available in the US are 36 hole hubs; SRAM makes a 32 hole hub, but no one seems to supply it in the US. If you convert a Cruzbike-manufactured recumbent, you'll need to replace our 32-hole rims with a 36 hole rim for the drive wheel.

A single shifter is availble to control both the rear derailleur and the hub, or SRAM dual shifters will work (you'll need to get the recommended left shifter model from SRAM). The Dual Drive derailleur is actually an SRAM X5 mid-length cage derailleur, so no need to hunt down a dual-drive derailleur. Any SRAM 1:1 derailleur will work; the mid-length cage will keep the shifting snappy, since the additional cage length to accommodate the chain uptake from a front triple crank is not needed.

The Silvio is unable to accommodate the hub because of the axle configuration and the dropout design on the Silvio fork.

You'll probably have a little over $700 US in the drivetrain when you're done, not counting brakes. Disk brakes won't fit on a kit-converted bike without LOTS of customizing (i.e., custom-built fork).

This hub is a good option for Cruzbikes if you're not put off by the cost. I was critical of this system earlier, but after extensive research I have warmed to it. It doesn't appear to suffer the large power losses folks associate with internal gear hubs. and it's essentially maintenance-free.

Best,

Doug

 

[defjack]

A seat hight of 26 in is max. lower is better around 22-24in. Jack

 

[JonB]

Doug Burton wrote: The only hubs available in the US are 36 hole hubs; SRAM makes a 32 hole hub, but no one seems to supply it in the US. If you convert a Cruzbike-manufactured recumbent, you'll need to replace our 32-hole rims with a 36 hole rim for the drive wheel.

I would not recommend reusing the cruzbike wheel because, why destroy a wheel that actually works? Besides the price of a new rim is nothing next to the price of the hub+shifter and making the wheel. You can reuse the Cruzbike tire, tube and cassette.

Doug Burton wrote: You'll probably have a little over $700 US in the drivetrain when you're done, not counting brakes. Disk brakes won't fit on a kit-converted bike without LOTS of customizing (i.e., custom-built fork).

That much? is dualdrive really that expensive? Then you might as well fork out the extra cash and get a Rohloff.

 

[JonB]

Doug Burton wrote: A single shifter is availble to control both the rear derailleur and the hub, or SRAM dual shifters will work (you'll need to get the recommended left shifter model from SRAM). The Dual Drive derailleur is actually an SRAM X5 mid-length cage derailleur, so no need to hunt down a dual-drive derailleur. Any SRAM 1:1 derailleur will work; the mid-length cage will keep the shifting snappy, since the additional cage length to accommodate the chain uptake from a front triple crank is not needed.

I can not see why reusing the existing cruzbike rear derailleur, shifter and cassette wouldnt work. Are cassettes not a standard? And the rear derailleur and cruzbike shifter are made for each other, i think it should work, which further lowers the price.

 

[kravmonsta]

great advise. one thing is i'm in Australia. maybe i need to get one thats upside down... :lol:
still looking for ideas which is half the fun of finally designing my own toy rocket.
unfortunately my car engine blew up so the funds just got seriously depleted. a few more weeks it will be spring so it's worth it!