Extra gears & EBBs

rjsterry

Two questions:

1. My 13yr old Giant has 7-speed Shimano RSX STIs, which thanks to a recent tune-up at Pearson's are still running nicely. However, only having 7-speeds at the back limits me to (so the chap in Pearson's said) one of two reasonably priced cassettes:

11-27, which I have, and is very gappy, but workable

13-25, which means I don't get eyeballs-out 52x11 (for descending in the North Downs or Embankment/tailwind madness) or get-out-of-jail 42x27 (for going up said hills or Embankment headwind with luggage madness).

My rear hub will take up to 9-speed I think, but I would settle for even 8. Is there any way that the RSX shifters will accommodate 8 speeds?

2. Anyone any experience of fitting the newer style external BBs as opposed to a standard square taper (Shimano UN54 or similar) into an older frame? Is it possible without mucking up the chain line/front mech position, and does it actually make any significant difference?

nicklouse

rsx shifters 7spd only.

are you really sure the rear hub is 8/9 compatible?


yes they can be fine just get the BB shell faced first.

rjsterry

nicklouse wrote:

rsx shifters 7spd only.

are you really sure the rear hub is 8/9 compatible?


yes they can be fine just get the BB shell faced first.

Thanks for that. Had a feeling that was the case, but had a vague recollection of seeing an 8-speed version on ebay (pretty much my only bet for spares now - a pity as they have served me well and seem to be more robustly built than newer Sora and Tiagra versions). Might have been RX100. Much newer wheels than shifters - R550s at the moment - just checked and they can apparently take 8, 9 or 10-speed according to an old RCUK review. I do have a couple of spacers behind the cassette.

Good to know about the EBB. Not needed at the moment, but when this one dies, the chainset will probably be due for replacement as well (13yr old unbranded heavy lump of alloy and scratched to buggery).

whyamihere

The highest gear on my Cannondale is 53/13. I've seen 50mph on it. Don't worry about the high gearing, the 13/25 will be fine, and feel a whole, whole lot nicer under most riding conditions.

wgwarburton

whyamihere wrote:

The highest gear on my Cannondale is 53/13. I've seen 50mph on it. Don't worry about the high gearing, the 13/25 will be fine, and feel a whole, whole lot nicer under most riding conditions.

+1 - you'll use the middle gears more than the extremes, especially the highest.

I wouldn't worry about parts availability, either, TBH. The whole drivetrain on my tourer is officially obsolete (Suntour friction-shifters, Stronglight chainset, "compact" 6-speed freewheel, Cyclone mechs) but I've been able to replace parts as they wear by judicius eBaying....
Keep an eye on the bits that wear out and look for spares in advance.
Cheers,
W.

rjsterry

I should mention that my chainrings are 52T/42T (compact schmompact!); a bit bigger than standard for the small ring, so the granny cog is quite useful on the likes of Leith Hill, etc., but not in London. Mind you, as it's the same bike, it will need to do both.

7 speed cassettes are a bit thin on the ground these days, but a quick search has revealed this

http://www.chainreactioncycles.com/Mode ... elID=47962

At 16-24T I think this really is limited at the top end 16T is about my current middle sprocket.

And this

http://www.chainreactioncycles.com/Mode ... elID=38302

The 12-28T is virtually what I already have, but the 12-21T is a possibility. Any idea what the difference between HG30 and HG50 is (I have HG30 at the moment. As this is only £11, I'm thinking I might get this for commuting and swap back to the 11-28T when off in the hills.