Bicycle Mechanics - converting 7spd cluster to 9spd cassette

http://www.trademe.co.nz/Sports/Cycling/Parts-accessories/auction-11303253.htm

These are some old trispokes going cheap.
Is it possible to convert them to 9spd? or to get the 7spd to work on a full 9spd Shimano 105 bike?

Or are these wheels worth it, full stop?

TIA
Brendon

7 speeds have 126mm spacing, while 8/9/10 speeds are 130mm spacing. There is also a matter of wheel dishing, but that can't be fixed with trispokes like these, or any other comppsite wheel.

Is there anyway to make the wheel fit into my frame, then use a 7spd bar end shifter on the aerobar? would the deraileur be compatible? would the 9spd chain be ok with the 7spd cogs?

Also would these wheels be worth it for this sorta price? ($150NZD)

Brendon

http://www.trademe.co.nz/Sports/Cycling/Parts-accessories/auction-11303253.htm

These are some old trispokes going cheap.
Is it possible to convert them to 9spd? or to get the 7spd to work on a full 9spd Shimano 105 bike?

Or are these wheels worth it, full stop?

TIA
Brendon

What's the freehub body on the tri-spokes look like? If they use a Shimano freehub body, I suspect that you could retro fit a 9-speed freehub body and a 9-speed axle set onto them and be good to go. You might have to do a bit of fudgeing with axle spacers to get the rim centered.

If they don't use a Shinmano freehub body? While there are some good non-Shimano or Campy freehub bodies (King and Hugi come to mind) there is a lot of pure junk out there too. I wouldn't touch them.

What's the freehub body on the tri-spokes look like? If they use a Shimano freehub body, I suspect that you could retro fit a 9-speed freehub body and a 9-speed axle set onto them and be good to go. You might have to do a bit of fudgeing with axle spacers to get the rim centered.

If they don't use a Shinmano freehub body? While there are some good non-Shimano or Campy freehub bodies (King and Hugi come to mind) there is a lot of pure junk out there too. I wouldn't touch them.

Retro grouch is on the right wavelength - if the freehub is not Shimano - maintenance will be a nightmare. Shimano freehubs last relatively well (unless they are early 9s Deore). If they are not, you may just not be able to get them. This is an increasing problem with the new pre-built wheels that seems to be on every bike you buy. The only way you'll be able to tell though is to dissassemble and look (unless you can find details on the web).

Think carefully about whether you really need tri-spokes as well. You really need to be able to sustain a killer speed for a long time for the weight/cost/aero benefit to make sense.

I believe the threshold for aero benefit from trispokes can be as low as 30kmh, but you only start to really get good advantage at 40kmh. I am entering an U19 TT tomorrow that I thought was 20km and I was hoping for 40-43kmh average. It is actually 40km so I shall see what I do. This is with a Cervelo Road bike, with clip on bars and stamdard 30mm clincher rims.

Brendon

If its Shimano the 7spd hub body just comes off and the 9spd just screws right on no problem. Should be redished, but playing with the axle spacing can help make up for it some.

You can also make it 8 speed by putting 8 cogs of a 9 speed cassette on the 7 speed hub. Just disassemble the cassette and remove the top cog. It should shift with 9 speed components and chain just fine. Just remember to set the top limit screw of the rear derailler so you don't overshift into the wheel. I've been running this for a couple months on one of my bikes and it works fine.