New here - 1991 GT Team Avalanche

Been lurking and reading for a while but finally signed up the other day and broke the bike out as I was planning to today. Have been away from the scene for I guess 20 years now, was an avid reader of MBUK and others back in the day but haven't kept up with whats what these days though have read a fair bit on line etc recently - always rode every now and then during that time and commuted on it for a while too.

As per the title a 1991 GT Team Avalanche bought new by me in early 1992 IIRC - was with a whole load of parts upgraded/changed already so I have never ridden it in factory condition - here's everything I can recall that was changed.

Flite Titanium in place of std GT seat
XT thumbshifter to replace XT rapid fire
Dia-compe SS5 to replace XT brake levers
Dia Compe 986 to replace XT canti's front
XT short cage rear mech in lace of long cage XT
SPD 520's I think in place of XT pedals
Ritchey ZMAX WCS 2.35" front 2.1 rear - don't recall the std tire
Zoom brahama bars with black cork tape in place of GT bars

Within the first year or so;
Zoom stem to replace the GT flip flop one
USE alloy seat post in place of std one
Sachs Silver chain - I kept breaking the crumbie XT ones, never had a problem once I changed.
Road a variety of tires back then, Zmax in WRCand std compound and Smokelites stand out, plu had a pair of 25mm Specialized Turbo'S' (I think thats what they were) for road work including a couple of time trials.

Since then
The Zoom brahma bars snapped one day so I replaced them with a none branded similar shape bar and of course the tires have worn and it's currently on some nondescript stuff I got from my nephew when I was commuting to work on it and just wanted something round and black.

Have a NOS set of Brahma bars winging their way to me courtesy of ebay but I'd like to bolt them up to a shorter higher rise stem in keeping with the rest of the bike as I'd like a more upright position these days - suggestions?

Before I took it out today I spent a while nipping up bearings, truing wheels, setting brakes and shifting up etc and mostly it all still works as it should. However it's desperately in need of a new cassette and I assume chain and may as well do the rings whilst I'm at it and have a set all wearing together but I'd like to keep it approximately period even if not factory correct so whats my best option? cassette is 12-28 and with the short cage I can't go above 28 but an 11 wouldn't harm - forget the chain ring sizes but a slight drop would perhaps be a good idea these days especially if I can get an 11T cassette. May need a bottom bracket too - but am going to try stripping, cleaning and rebuilding with new balls first.

- orforfull size - https://lh6.googleusercontent.com/-QPor ... 15%2B-%2B1

Welcome sptb,

Good to see you getting involved and all nostalgic! And a cracking bike

Looking at the bike, cassette would be 7 speed? 12-28 would be fine to replace, not sure there is much choice for that. Short cage limit would be about 28t

Chainrings may be ok, clean them up and have a further look.

Chain, that's straight forward, any 7 or 8 speed will work.

Hi - yes its a 7 speed - I don't think 8 speed was available in 1991 except on Dura-ace.

Which reminds me back then someone did aftermarket an add on 8th cog that incorporated a screw on gear in the place of the cassette lock ring - are these still available? I know I could do the various 8/9 of 9/10 on 7 methods but that involves new shifters etc and I like my XT thumbies.

So for a cassette I guess I'm looking for NOS or a modern lower groupset.

Yes 28T is the recommended max but having played with it the practical one too, any bigger and there's either two little or too much chain (if I were to add a few links) to use all gears.

Chainwise are the shimano chains any better than back in 92 or should I get something else - I see Sachs bought sedis who were in turn bought by SRAM, are theirs any good?

Santa is bringing me a set of Specialized Fatboys for road work, it always used to feel so alive when on road tyres, looking forward to it.

sptb":1xn9dkv7 said:

..a 1991 GT Team Avalanche bought new by me in early 1992..

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Love these Rigs.. Restored and Built one myself a coupla years ago..

Lovely looking bike, I have sent you a pm regarding the original stem.

sptb":2ic6akoz said:

Which reminds me back then someone did aftermarket an add on 8th cog that incorporated a screw on gear in the place of the cassette lock ring - are these still available? I know I could do the various 8/9 of 9/10 on 7 methods but that involves new shifters etc and I like my XT thumbies.

So for a cassette I guess I'm looking for NOS or a modern lower groupset.

Chainwise are the shimano chains any better than back in 92 or should I get something else - I see Sachs bought sedis who were in turn bought by SRAM, are theirs any good?

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Can anyone help with above questions. Am now leaning more to doing the 8 of 9 conversion with the alternative deraileur cable routing as detailed by Sheldon Brown, so I can use the "hidden" 8th gear on the thumbshifters, which as well as giving me an extra cog would also open up the range of cassettes to choose from to some higher groupsets. Anyone done this? How well does it work?

're the chain I used to break xt ones like they were made of strawberry laces hence the swap to sedis - are modern chains more reliable? Happy to live without hyperglide in favour of reliability.

Change the freehub body to an 8 speed one (buy a cheap 8/9 speed hub on ebay) , fiddle the axle spacers, redish wheel slightly and bolt an 8 speed cassette on.

sptb":2ifr6shb said:

Chainwise are the shimano chains any better than back in 92 or should I get something else - I see Sachs bought sedis who were in turn bought by SRAM, are theirs any good?

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In my experience, no, Shimano chains still aren't great. I've got SRAM ones on a few bikes and they seem much better to me and I also have a few KMC ones that seem good quality too. Clarks seem on a level with Shimano in terms of quality but don't seem to shift as well.

That's just my encounters, I'm sure other people can add further opinions.

shogun":26bwbakx said:

Change the freehub body to an 8 speed one (buy a cheap 8/9 speed hub on ebay) , fiddle the axle spacers, redish wheel slightly and bolt an 8 speed cassette on.

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Is there any advantage to doing it this way? Just seems to be additional cost and work over the 8 of 9 option, will one or other index better with the alternative cable routing or can I get away with out that for an 8spd cassette as the spacing is closer so kind off within tolerances?

8speed cass. cogs distances are closer to the indexing of you thumbies, that a 8of9 would be. 7speed and 8speed chains are the same these days. 9speed are a bit more narrow and therefore less durable. Plus you might run into troubles changing the gears up front with those 9speed chains. (Although I am not sure about that last part it might be worth thinking about it)