"PAUL'S" thumbies / "KELLY" take-offs for skinflints

[slowster]

Apologies for reviving an old thread, but this photograph of a Spa steel tourer in their ex-demo clearance bikes section here caught my eye. Spa state that the photograph is for illustrative purposes only, but even so it looks like they have built a bike with some form of shifter mount similar to 531Colin's. Which makes me wonder if this is an option which Spa do actually offer for their builds, and if so what exactly is the mount?

[531colin]

That's a one-off. I made some very simple mounts to take thumbshifters; basically a bit of 22mm tube and a "doughnut" to fix the tube at the proper angle to the handlebar, attached by a drop=bar brake lever type band.
The mounts were a success, but the same couldn't be said for the (Sun Race?) thumbies.
If anybody knows of good thumbies that don't cost a fortune, then it could still be a working system.

The original mounts to fit D/T levers to handlebar brackets which this thread is about fell down because Shimano make too many types of D/T levers. 9 speed D/T levers are different to 7/8 sp D/T levers, and I never got as far as looking at 10 sp. (its the distance of the cable from the downtube that varies, meaning re-tooling for 9 vs. 8 speed...I didn't think it was commercial. Bar end levers all fit the same, but they are expensive and I didn't think that was commercial either.

The D/T lever mount I made here https://forum.cyclinguk.org/viewtopic.php?f=5&t=113772&hilit=bullbars is easy to adjust for different cable to downtube distance, but I'm not going to make them. Its a fairly straightforward bit of shed work, but my hands are arthritic and I don't want the job.

[Brucey]

That's a one-off. I made some very simple mounts to take thumbshifters; basically a bit of 22mm tube and a "doughnut" to fix the tube at the proper angle to the handlebar, attached by a drop=bar brake lever type band.
The mounts were a success, but the same couldn't be said for the (Sun Race?) thumbies.
If anybody knows of good thumbies that don't cost a fortune, then it could still be a working system.
.

The indexed RH sun race thumbshift levers are built the same way internally as the SA branded ones that are meant to control their hub gears. This means they are problematic (sticky and with backlash) to start with and they only get worse with time. It is possible to rebuild them (for hub gear use) but it is neither easy nor quick to do so. For derailleur gears the spring/cable tension is higher and the shifters are liable to be used more often as well, making rebuilds less easy and less effective too.

Ironically the sun race LH shift levers have a quite good 'power ratchet' mechanism inside them. I have built this mechanism into a RH shifter (*) and put the remaining parts into a LH shifter but this leaves you with a LH shifter that is an oddball one. This isn't so bad if you start with a three speed SA RH shifter and a LH sun race shifter; you end up with a RH power ratchet shifter and a LH three speed shifter. The latter can be mounted upside down on the RH side of the bar and is probably all the better for it too.

(*) NB with some combinations of RD and cassette it gives a 'semi-indexed' shift, whereby two clicks of the power ratchet makes for a perfect downshift.

cheers

[willp01908]

This was my solution to getting a flat bar shifter to work on my drop bar hack bike. Basically chopped up an old stem to make a bracket and mounted the shifter using the screw that held it to it``s original one. Had to file a notch for the brake cable and the gear cable only just clears the stem clamp, but works quite well.

[niggle]

I used an 'accessory bar' to mount a SRAM P5 trigger shifter on my drop bar ebike, the bar and clamps are all aluminium alloy so rigidity is adequate:



It functions quite well, the accessory bar is standard flat bar thickness and I think flat bar rapid fire pods might work even better.

[Brucey]

SL-S500 Alfine 8s shifter (rapidfire type, bottom normal), mounted using special bracket which attaches to stem nosebolt.

In the photo, the forefinger is on the downshift paddle (releases cable), thumb on the upshift paddle (pulls cable).

More photos here https://forum.cyclinguk.org/viewtopic.php?f=5&t=115182

cheers

[John biggles]

Thanks for this thread, it's prompted me to try moving some down tube shifters from the top tube (the bike is a mountain bike with drop bars and the derailleurs are cabled from the top, so using down tube shifters would require re making the cable runs and replacing the front derailleur) to the handle bars. Just at the trial stage at the moment, first trial is adding thumb shifters directly to the handle bars, second trial is a mock up of mounting down tube shifters cantilevered from the bars. Only involved cutting and drilling metal so relatively straightforward.

[Greystoke]

Top one allows your thumbs to fit between the hoods and the gear shifter, bottom one doesn't appear to.

[John biggles]

Yes, the lack of room for the thumb to rest and possibly interfering with brake usage is why I'm currently pursuing two lines of attack. It'll be a little while before I get ready for a road trial, but fingers crossed that one or the other (both?) are workable?

[John biggles]

The Mk1 is now on the bike, though the gear shifters are not cabled up, but I want to see how the thumbies feel and how much they impede the brake levers before going any further with them.

Meanwhile the Mk2s are now Mk2.2 with a bit of tidying up, and looking more promising I think!

[Brucey]

you need a lot less scaffolding once you accept that a RH shifter can be used on the LH side of the bike and vice-versa





from upthread
https://forum.cyclinguk.org/viewtopic.php?f=5&t=57027&start=180

when the levers are well forwards they don't get in the way of your thumbs on the hoods BTW

cheers

[531colin]

Theres less "scaffolding" in this second type of mount I made..https://forum.cyclinguk.org/viewtopic.php?f=5&t=113772&hilit=bullbars
I made them for bullbars, but they would work equally for drops, to get the gear lever next to the hoods. There is no adjustment for the angle of the lever in these.

[John biggles]

Update on the road tests. The Mk 1 (thumbies attached directly to drop bars) proved quite uncomfortable in use, with lever and cable obstructing braking.

But the Mk 2.2 proved to be excellent! They may look ugly, but I really enjoyed using them on a little test ride involving plenty of gear changes both front and rear.

I'm contemplating trying Brucey's attachment of DT shifters below the stem, perhaps on my other drop bar mountain bike which currently uses DT shifters, and which I'm very happy with so far (so not much inventive to change!) Thanks for all the ideas on here and on other threads, they've been very helpful!

Cheers

[John biggles]

I have continued with my mounting of shifters by the brake levers, and the latest is my neatest so far, I used bar end shifters and some wide bars which allows an altura Arran bar bag to fit within the gear shifters

[John biggles]

PS I've added DT shifters via home made mounts and have a total of 4 set up so far, 3 with DT shifters for the right/rear shifting and cheap Shimano thumbies for the left/front changing, all friction. 2 of these are for Shimano derailleurs, but one uses a SRAM 1:1 actuation derailleur combined with an old Huret DT shifter, which, following the removal of the small tab that prevents rotation beyond 180 degrees now operates through 270 degrees in order to pull enough cable. I couldn't have done that with the shifter mounted on the downtube but can on the bars. So thanks for this thread, it's been an inspiration!

I've also investigated various accessory mounts which work but have a couple of potential drawbacks, firstly they are fixed length and orientation, and secondly some are a little flimsy, they are after all not designed to resist much force.