Switching from Racing Shifters to Thumb Shifters!

[JusFoolin]

(06-28-2015, 10:57 AM)nfmisso Wrote:  

(06-28-2015, 09:49 AM)JusFoolin Wrote:  Could I use these and then just 'ignore' the 8th gear on the right shifter?? Or would this cause the chain to fall off / other problems?
http://www.chainreactioncycles.com/shimano-claris-r240-8sp-brake-gear-shifter/rp-prod106887?gs=1&gclid=CjwKEAjwtr6sBRDv7uzB492H9XISJADj6aqbQWRqxXfL-8fLr0wqYV723SOPwP5cUwzv6GsVRG7VSRoC1N_w_wcB&gclsrc=aw.ds
Thanks!

No.  7 speed and 8 speed spacing is different, at best, you'll be able to set it up so that one gear works.

The limit screws on the derailleurs control their travel, not the shifter.  Indexed shifters move a certain amount of cable (not adjustable); which has to match the spacing of the cogs times a factor.  The factor varies: 
* rear: 
*** Shimano standard (all Shimano road up to 10 speed and mountain up to 9 speed)
*** Shimano 10 & 11 speed mountain
*** Shimano 11 speed road
*** SRAM
*** Campagnolo

* front:
*** Shimano road (includes SRAM)
*** Shimano mountain (includes SRAM)


I would suggest Sunrace Friction Thumb shifters   see: http://fcdn.mtbr.com/attachments/one/579134d1289529232-one-inbred-build-img_0112.jpg for an example
http://www.niagaracycle.com/categories/sunrace-slm10-friction-shifter-set?gclid=CjwKEAjwtr6sBRDv7uzB492H9XISJADj6aqbFbLKZXyg9EmcWT44HeR8YwHulo1Unu5whh​mpwMQdghoCA6Dw_wcB

and Tektro MT2.1 levers: http://www.amazon.com/Tektro-Eclipse-Universal-Brake-Silver/dp/B00288JJQS/ref=sr_1_25?s=outdoor-recreation&ie=UTF8&qid=1435503795&sr=1-25&keywords=tektro+brake+levers
The MT2.1 levers will work with any kind of bicycle cable operated brakes, there is a two position adjustment inside.

Forgive me if I'm being a bit slow and stupid
I have been searching for UK sites selling gear shifters which match the number of gears on the bike.
Even though they are not a matching pair, would these work?
(a 7 speed shimano altus on the right, 2 speed sram x5 on the left)
http://www.tredz.co.uk/.Shimano-Altus-7-speed-Rapidfire-Pod-Right-Hand-Shifter-SLM310_45153.htm
http://www.tredz.co.uk/.SRAM-X5-MTB-Trigger-Shifter-Lever_60289.htm