3 x 8 transmission woes - what to do?

[LittleSkink]

Been refurbishing a 10yo tandem, miles are pretty low but it hasn't been cared for. So far things had been going okay, even the disc brakes work really well now.

- until I started on the transmission this evening . . . There is okay (but sluggish) shifting of the rear 8 speed, my suspicion is shifter and rear mech are ok but cable/casing is shot. The 3 x front shifting, however, is a mess. The bottom pull 31.8 mech cage is bent and the grip shift changer appears non functional - unsure why until I pull it apart. Chains and chainsets have cleaned up fine, not much wear under the filth

So - do I go s/h 3 x 8 rapidfire style shifters (dont like RevoShift anyhow) and front mech - if so how to get some decent parts and what to budget? (never been forced to s/h market for parts before, thanks Shimano)

Or is there still some new 8 speed stuff worth buying out there?

Or do I get up to date and look out for a decent deal on a bunch of 3 x 9 stuff new, dumping the old rear cassette and chain - is that going to be way more costly?

I am sure others will have had similar dilemmas so do please share your wisdom (FWIW I did investigate SRAM 3 x 8 which is available new but it doesnt seem to last and the cheaper rear mechs seem to lack spring strength)

 

[catf]

if you want new and youre happy with low end shimano you shouldnt have any probs finding NOS stuff, i guess the sram you looked at was x4, main problem is you are locked into the 1:1 ratio, less point going with 8 speed then. other option would be sunrace but i wouldnt recommend that.

http://www.ebay.co.uk/itm/Brand-New-a-p ... SwU8hY5npv
http://www.ebay.co.uk/itm/SHIMANO-STX-B ... SwB-1YuStU

that would get you going. depends how much you wanna spend but id say that was rock bottom. used triggers are a bit hit and miss, often can be sticky, and a bit of a nightmare to fix. not likely you will find a pair under a tenner even on ebay auctions, so probably not worth the risk? front mech is no problem though. nothing much to go wrong, someone here would probably karma you one.

or you could go for some thumbies? this is retrobike after all

 

[LittleSkink]

thanks catf - liking the look of STX for £9

the current mech attaches really low down, virtually at the botttom bracket - the old STX is much higher - it that a problem?

 

[mattr]

As long as it's a straight seat tube, and there are no braze ones or bottle bosses in the way a high clamp front mech should fit fine.

I've swapped between the two fairly regularly and never had an issue.

 

[hamster]

The problem with tandems is the long cable run: stickiness is much more of a problem.
For that reason I would definitely select a SRAM 1:1 system as it is much less tetchy on cable stick due to its long pull design.

I run thumbies on my tandem as it's simpler and if we get an indexing problem I simply switch out the indexing.

 

[mattr]

Good point, do you have open cable routing or full length outers? My tandem had (very) open routing. Long enough runs on the top tube that it'd buzz at higher speeds due to the breeze. (took me two years to realise what the noise was!)

 

[hamster]

Re:

Dawes Kickback two: three bare runs - two on the top tube plus one down the seatstay. I also run a rollamajig for the cable bend down to the rear mech. If I was determined to go with clicky shifters, I'd go SRAM. It simply never seems to need adjustment on my kids' bikes, regardless of dirt and abuse.

I don't get the buzzing, but run tubing over all the exposed runs to keep things as clean as possible.

As it is I am a grumpy old sod and still run thumbies (and it's 7 speed anyway).

 

[mattr]

Yeah, i had the original 653 double edge, lots of open run on that. Unfortunately someone at dawes specced it with SRT 800 crystal shifters for some unfathomable reason.

Swapped for STis after about 3 weeks.

 

[02gf74]

I d recommend 3x9, 8 spd components are less common. My preference is sti as opposed to gripe shift.

 

[LittleSkink]

thanks folks, ordered the STX front mech as I need one which ever way I go here (hadn't found it myself on ebay as I had been searching for "8 speed" items

Alas the cabling is very open and not so well routed, I have a 30m roll of gear outer so could cable it through with a single run of outer if I took a Dremel to the lugs . . .

intrigued by thumbies, but I know nothing about them - please elucidate. I went from a down tube change un-indexed 12 speed Carlton to an indexed 21 speed MTB when that was "the latest thing" and missed out thumbies