keiron curtis said:
I have a Venture GT 27speed touring bike,which I want to convert to an internal hub geared version,or failing that,even to a fixed wheel system.Can it be done and would it be expensive?
Is your bike's frame alloy or steel? If the frame is steel, re-spacing the frame's rear to fit the "new" rear wheel will be a simple matter.
An internally geared hub will probably not have as wide a range as an externally geared drivetrain can have ... and, while maintaining the adjustment on an internally geared hub is not difficult, adjusting the indexing on an externally geared drivetrain is probably, actually easier.
Essentially, the cost of conversion will the the cost of a new rear hub ... you may need new spokes (i.e., different length), or not ... plus/(or, not) the cost of relacing the wheel ... OR, of course, you could buy a ready-to-ride rear wheel.
If your bike's frame has horizontal dropouts, you won't need anything specal to adjust the chan tension, otherwise you will need a chain tensioner (you can simply use almost any rear derailleur if you want).
Why do you want to convert your current bike's gearing so drastically?