Bicycle Mechanics - MTB thumb shifters on drops?

good snowy morning from NY.

Im new here and just posted on the commuting board.

Im retrofitting my 1992 Falcon road bike into a commuter.

Its been suggested to use thumb shifters vs downtubes (saftey reasons) and I do like the idea as I like thumbies.

My bike is at the LBS , I typicaly do all my own work but im swampped with domestic dutys at the moment so the LBS is doing new tires , head set and a tune.

I can get a hold of a brand new set of suntour MTB XC pro thumbies that I know will work on my shimano 7 speed rear as I have a set on my giant ATX 760 with a shimano rear end and the suntour shifters work fine.

the clamp diameter of mountain components is 25.4 my MTB bar measured .985 (25.019 mm)

Cutting to the chase is it possible to Bore out the mounts on an MTB set of shifters to use on a road bike??


I know a road bike clamp is 26 but my bike isnt here for me to Mic it out to see how close it is.

there looks like plenty of metal on the XCs at least on my existing set

I work for an industrial repair company and have a full service machine shop at my disposal, tig welders ...

again I know the shifters will work its a matter of will they fit?

taking a half mill +- off a side on the suntour mount seems like it would be be fine.

many thanks "John"

good snowy morning from NY.

Im new here and just posted on the commuting board.

Im retrofitting my 1992 Falcon road bike into a commuter.

Its been suggested to use thumb shifters vs downtubes (saftey reasons) and I do like the idea as I like thumbies.

My bike is at the LBS , I typicaly do all my own work but im swampped with domestic dutys at the moment so the LBS is doing new tires , head set and a tune.

I can get a hold of a brand new set of suntour MTB XC pro thumbies that I know will work on my shimano 7 speed rear as I have a set on my giant ATX 760 with a shimano rear end and the suntour shifters work fine.

the clamp diameter of mountain components is 25.4 my MTB bar measured .985 (25.019 mm)

Cutting to the chase is it possible to Bore out the mounts on an MTB set of shifters to use on a road bike??


I know a road bike clamp is 26 but my bike isnt here for me to Mic it out to see how close it is.

there looks like plenty of metal on the XCs at least on my existing set

I work for an industrial repair company and have a full service machine shop at my disposal, tig welders ...

again I know the shifters will work its a matter of will they fit?

taking a half mill +- off a side on the suntour mount seems like it would be be fine.

many thanks "John"Why doncha just use barend shifters? I personally don't get this 'safety' business issue with downtube shifers, but that's just me....There is no problem with maching the shifter mounts,assuming there is enough meat to work with.

Why not get these (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=42330&item=7143033121&rd=1&ssPageName=WDVW) for $20? There are all sorts of others on there too. Do a search for thumb shifters.

Why not get these (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=42330&item=7143033121&rd=1&ssPageName=WDVW) for $20? There are all sorts of others on there too. Do a search for thumb shifters.There is the issue of flat bar vs drop bar diameter.

MANY THANKS,

I guess the saftey issue with downube shifter is just one of those little things.

not having to reach very far to shift should be safer but maybe not!

those shimano shifters look interesting but it appears they do not have a friction option which I definatly want or do they have a friction option??

Ive never seen those before.

thanks again "John"

Yes they for sure have a friction option. Also I am about 90% sure there is enough clamp dia when not tightened to get on std sized drop bars. Not oversized bars but on a std bar you will be fine. You might even get these (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=42330&item=7143295217&rd=1&ssPageName=WDVW) cheaper and if you look at the second photo you can see there is a lever you can slide from SIS to F which is how you change them to friction shifting.

Yes they for sure have a friction option. Also I am about 90% sure there is enough clamp dia when not tightened to get on std sized drop bars. Not oversized bars but on a std bar you will be fine. You might even get these (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=42330&item=7143295217&rd=1&ssPageName=WDVW) cheaper and if you look at the second photo you can see there is a lever you can slide from SIS to F which is how you change them to friction shifting.'Oversized bars' are only oversize at the stem clamp.

HI Sydney.

if you were doing athe commuter thing and all things being equal would you go with bar ends or thumbies mouted close to the stem??

I was ALSO toying with kelly Take offs but they just do not sit well with me in the durability dept though they mount inside the bars.

looks like the easiest option would be bar cons.

shimano still offers an 8 speed bar end that I guess works fine with 7 speed rears (one dead click?). it certainly would be the easiest to set up !!

I could always get paul mounts or make mounts later on if I want to mount as thumbies but id rather not stack hardware if I dont have to, and mounting MTB thumbies would be clean so would bar ends.


your thoughts again please.

"John"

... if you were doing athe commuter thing and all things being equal would you go with bar ends or thumbies mouted close to the stem?? ...

I AM doing the commuter/transportation thing, and I really like, and strongly endorse, barcons (the venerable SunTour ratchet units, in my case) for this application. I have a second set of barcons ready to go onto the PKN-10, as well.

HI Sydney.

if you were doing athe commuter thing and all things being equal would you go with bar ends or thumbies mouted close to the stem??

I was ALSO toying with kelly Take offs but they just do not sit well with me in the durability dept though they mount inside the bars.

looks like the easiest option would be bar cons.

shimano still offers an 8 speed bar end that I guess works fine with 7 speed rears (one dead click?). it certainly would be the easiest to set up !!

I could always get paul mounts or make mounts later on if I want to mount as thumbies but id rather not stack hardware if I dont have to, and mounting MTB thumbies would be clean so would bar ends.


your thoughts again please.

"John"I'm for barends,and have had the Kellys and they blow.

Put the shifters wherever you want to shift.

Though I am a roadie primarily, I think the preference for downtube shifters or bar ends is mostly a roadie bias. I admit the the down tube shifters and bar end shifters are more elegant looking than thumb shifters but I can't remember a time I ever made an equipment decision based on anything other than what I ergonomically and functionally wanted. After having put in many miles with all three systems, yes, including thumbies on drops for almost all of 1992-3. Sure people thought it looked weird but I was in traffic all the time, avenues crammed with rude and sometimes hostile drivers.
I think thumbies right next to the stem is fine.

I remembered this had come up on R.B.T. and Andrew Muzi reminds us

"Sure. Use a friction front* and Shimano seven compatible
rear top shifters, about $19.95 with cables. You'll need a
slightly longer mounting screw. Get shifters with steel
clamps - the aluminum clamp models won't fit. "

I thing thumbies right next to the stem is fine.

I have a box full of stem shifters you might be interested in.

See if you can score a set of some Suntour Command-Shifters. It sounds like those are exactly what you're looking for. BTW, a long time ago, I mounted a pair of the original set of SRAM GripShifts to the end of my drops and they worked extremely well. I could easily shift from the drops and I liked them better than Bar-Cons.

I have a box full of stem shifters you might be interested in.

Uhhh....no