serotta

[Rita green]

help hi I am restoring my old serotta t max which I am trying to make into a gravel bike im having issues with getting the front gears I have installed ultrega shifters 2 speed but can only get them to work with the middle chain ring . I have kept the old front gears on but shifter does not move chain over enough any ideas ?

 

[Woz]

Can you spec. the part numbers and supply some pictures?

Otherwise, we are like a blind mole in a dark hole.

 

[Rita green]

Can you spec. the part numbers and supply some pictures?

Otherwise, we are like a blind mole in a dark hole.

 

[Rita green]

I can not find any numbers I believe the shifters are st6700 if that helps

 

[Woz]

Road STI front shifters pull less cable than a MTB front shifter. Hence, the problem. Solutions are:

- update your ancient MTB mech with a suitable road mech. Sounds simple, and may work fine but it
will depend on how far your cranks are outboard and if there is enough throw of a road front mech -
you are already in a lucky position because it's a downpull cable routing like about 99.9% of road mechs.

https://productinfo.shimano.com/download?path=pdfs/archive/2010_Compatibility_en.pdf

You are lucky too that the ST-6700 appears compatible with older front mechs (page 8 of the above, so any 8, 9 or 10
speed road front mech should work of a sort, even with your smaller MTB chain ring sizes.

- try the alternative cable route for the MTB front mech. You put the cable the otherside of the pinch
bolt, resulting in different pivot and leverage point similar to a road front mech.

I frequently do the 2nd option, it's fiddly, trial and error to get the cable length right (especially with
a triple) and with the help of the trimming function of the more modern road STI it will normally work one
way or another.

At this point, I would recommend you first try with an older 9 speed road front mech (FD-5503 for example), if that
doesn't work, then attempt the 2nd option which is considerably more involved.

Basically, it is a big ask to try and mate parts with a 20 year innovation spread from different discipline group sets; you
have definietly strayed away from any sort of plug and play!

 

[Rita green]

that's amazing thank you for the advice I have been looking for a fd 5503 mech but can not seem to find ons any ideas of other models that would work ? a bit worried that the cable is under so much tension when at mo I put in large chain ring not that its does work at present and when set to middle chain ring if I change down the chain is like a washing line

 

[Woz]

Right, from memory: FD-6703, FD-6603, FD-5703, FD-5603, FD-4603 (all 10 speed) but could equally work, so may be worth a try, but
the cage may be too narrow for your chain and could result in chain rub in one / two gears.

FD-6503, FD-5503, FD-5403, FD-4503, FD-4403 are other reasonable options. Really though, if you get your hands on any older
triple road front mech it should work. Even something like from an old RSX groupset could work.

Stay absolutely clear of anything later. You really are in the realm of trial and error here. Another obscure option is to try the FD-CX70
which is intended for a double, and could work with a triple; I noticed your big ring must be about 46T too so it could work well.

There is a thread here for hackers like you, and worth going over. It will soon become apparent that mating modern road STIs and
old MTB tat is really in the minority for good reason.

https://www.retrobike.co.uk/threads/the-unofficially-cool-mtb-drop-bar-thread.94356/

 

[KermitGKona88]

Hi

Might also be worth looking at a company called Jtek they make rollers to adjust the cable pull, they definately make a front derailleur one.

 

[Rita green]

that's great thank you Im a bit new to restoring but I've had the bike for 31 years but didn't realise it would be this difficult !! thank you so much for the advice

 

[Rita green]

Hi

Might also be worth looking at a company called Jtek they make rollers to adjust the cable pull, they definately make a front derailleur one.

ok thank you I shall take a look