DT Shifters-number of sprockets etc

[bikes4two]

I've not had downtube shifters since I was a lad and my grandad looked after my bike

I've been considering fitting them as a temporary replacement for my bar end shifters (to reduce the risk of damage when the packed bike does some airport trips this year )

Looking on eBay there are those marked up as 9sp indexed (friction on FD of course) but a lot are marked 5/6/7/8sp too.

Question: I don't mind friction shifting on the RD (my setup is a touring triple/9sp by the way) but would say a shifter marked up for 6sp work on my 9sp block? i.e. does it have enough cable pull?

Thanks.

PS - anyone got a pair of braze-on shifters going spare (for a price of course)?

[reohn2]

Your existing bar end levers will fit onto the downtube bosses and can be used as d/tube levers retaining your indexing on the right without problem,you just unscrew them from the b/end bosses and use the same screw to attach to d/tube.
TBH in use there's not a lot of difference in hand/arm movement between the two positions,lots of people like b/ends,I've only ever experienced downsides with them compared to d/t levers unless you ride on the drops a lot.

[1942alexander]

Hi,
I use bar ends on all my retro restorations (three so far) but the only one I have taken abroad had modern levers. Thinking about it though, would it not be possible to just unscrew the levers, slacken the bar fitting slightly and turn it ninety degrees inwards thereby getting the vulnerable levers out of harms way?
Cheers... Alex

[bikes4two]

Hi,
...... Thinking about it though, would it not be possible to just unscrew the levers, slacken the bar fitting slightly and turn it ninety degrees inwards thereby getting the vulnerable levers out of harms way?
Cheers... Alex

Now why didn't I think of that - nice and simple! Thanks for the suggestion

Your existing bar end levers will fit onto the down tube bosses and can be used as d/tube levers retaining your indexing on the right without problem,you just unscrew them from the b/end bosses and use the same screw to attach to d/tube.
.....

Ah, didn't think of trying that one either - something to have a go at the next time I have the inner cables out. Thanks for that suggestion too.

[markfh]

This won't help with determining whether a particular set of shifters will work but I have a bike that uses downtube friction shifters that originally had 5 gears at the rear. It currently has 8 gears at the rear (Shimano rear derailleur) and the original friction shifters still work fine. The shifter levers move through 110 - 120 degrees whilst going from the smallest cog to the biggest so there is still some "unused" range left. The critical factors determining the amount that the cable moves is a combination of the inner diameter of the groove in the shifter that the gear cable runs in and the diameter of the gear cable itself. In my case the diameter of the groove is 21.0 mm and the diameter of the gear cable is 1.2 mm,therefore to a first approximation 120 degrees of shift lever movement should correspond to 23 mm of cable pull. For an 8 speed Shimano rear dérailleur each gear requires 2.8 mm of cable pull (from the CTC Shimergo page http://www.ctc.org.uk/cyclists-library/components/transmission-gears/derailleur-gears/shimergo) and 23/2.8 = 8 which is consistent with my experience. If you are using a Campagnolo or SRAM rear derailleur, which require more cable pull per gear, you will probably need a gear shift lever with a large diameter for the groove in order to not run out of shift lever range.

[GavinC]

If you are using a Campagnolo or SRAM rear derailleur, which require more cable pull per gear, you will probably need a gear shift lever with a large diameter for the groove in order to not run out of shift lever range.

Very true. I once briefly used a pair of old Simplex retrofriction levers (which have a small diameter barrel for the cable) with a Campagnolo 9 speed setup, and the lever travel was 180 degrees, so in low gear the lever was pointing to the bottom bracket. It was a bit inconvenient but it worked fine.

[bikes4two]

> As usual, a well informed set of response from forum members and thanks very much to all.
> I've often wondered as to whether to carry a single DT clamp-on shifter when on longer european trips in case of damage to the normal index shifters (bar end or STI)
> Now I'm better informed on the subject