Linear Front Derailleur Mount Query.

a.twiddler

Senior Member
I have been pondering the possibilities of resuscitating the front derailleur on my Linear at some time in the future. It has the frame mounting block in place, but it is missing the short tube to which the front derailleur attaches On measuring the circular groove in the top of the block it seems to be about 1". Could some obliging Linear owner out there who has one fitted measure the diameter and length of their mounting tube and let me know? I could then find a suitable bit of tube and possibly hold it in place with a threadless steerer cap and bolt. Perhaps a photo of the existing set up could be helpful.

That would only leave me to find a Suntour X-1 front changer, or an equivalent, to match the Suntour 52-38-28 triple that is on it, and a cable stop. My bits box is heaving with odd shifters and spare cables.

I don't actually need 63 gears, but sometimes it could be convenient to jump onto the small ring to get up an unexpectedly steep or long climb. Also by occasionally shifting chainrings it could help to even out wear on the rear cassette. I have a feeling that in the lowest of the low gears available it's not possible to actually ride that slow without falling over, and similarly it's a bit ambitious to expect these legs to push the immense top gear available. Still, if you have got the potential facilities, why not make them work? Normal business would continue between the Sachs hub gear and the 7 speed cassette. but it's nice to have something in reserve. Also, I just can't leave things alone, and like to experiment.
 

Mr Magoo

Veteran
The box section "I" beam on the Linear is wider than the norm ? If the bottom bracket is none original (Linear OEM is extra wide) . You may have issues fine tuning the mech to allow all three rings to function . The control cable run has quite tortuous routing ...so always buy high quality inner and outer cables . If you still need images ....ping me a message with your Email address .
 

404 Not Found Anywhere

Well-Known Member
Could you use one of the MTB front mechs that are secured by the bottom bracket shell, ie original Shimano e-type? At least it would be in the right place relative to the chainrings. For example:

https://www.hargrovescycles.co.uk/c...MIx4Gz2fTk7QIVENnVCh3mnQmoEAQYAyABEgLydvD_BwE

although this is top of the range they made them all the way down to Altus models. You would only have to think about cabling and stops. Probably you are going to need smaller rings, but with a 3 speed hub at the back you’re unlikely to need a 52T ring unless you regularly ride down vertical drop offs or have massive thighs...
 
Only 56 gears here on my ICE Sprint ....... :sad:

I've found that having ultra high gears means I don't spin out going downhill before I decide if I need to freewheel.
Keeping my most efficient cadence downhill as well as on the flat/uphill saves me energy in the long run.
Being more efficient means it's easier to go for longer.
Plus I love the ability to pedal slowly downhill at 40 mph ........ :whistle:

YMMV .......... ^_^
 
OP
a.twiddler

a.twiddler

Senior Member
The reason I mentioned the Sun Tour X-1 front derailleur is that is what's on the photos I've seen of Iowa Linears with the corresponding X-1 triple chainset which is on mine, which could reduce the likelihood of incompatibility. As @Mr Magoo suggests, the BB is wide, but then as @recumbentpanda observed, the mounting point on the derailleur block is well offset to the right.

From searches on the net it seems that X-1 FDs come with clamps to fit 31.8 or 28.6mm tubing, maybe others too. If the mounting point on the derailleur block can be persuaded to take a 28.6mm tube then a section of seat pin of that diameter would do the job. The suggestion for using a Shimano e-type FD would give a neat solution but it would be nice to stick with the original chainset, as it's not very worn, and a used or NOS X-1 FD won't break the bank. Suggestions for alternative triple FDs which can cope with the 28-52 would be welcome. Perhaps even top pull FDs which could allow a more generous curve of cable run from above, making the routing less tortuous (though I imagine that Linear used the bottom pull set up for a reason).

It ought to be possible to make the triple changer work without too much difficulty. If there are any alignment issues which can't be simply overcome, it isn't the end of the world to revert to manually changing the chain on to another chainring as it is now, though less convenient.
 
OP
a.twiddler

a.twiddler

Senior Member
Update.
I got the bits together and had a go at setting up the triple on the front. After a lot of experimentation I have a feeling that my "refurbished" X-1 may be a little distorted as it will change OK when set up on small-medium or medium-large but not on all 3. The changer does not have any issues with the frame width or reach. I don't have another X-1 to compare it with. On reflection, did I need such a large chainring?

I don’t see me using a 150 inch gear any time soon, and the middle ring gives 111” with the hub gear. Initially I tried to set it up without using the big ring via the limit stops but it “just” needed the changer to overlap the big ring, causing some rubbing. I got some washers out of my nuts and bolts box and just took the big ring off. I noticed that it had “Stronglight” embossed on it. Using the washers I was able to just use the smaller rings and also fit the changer lower down. It now changes easily and it can be trimmed to run silently. Due to the long chain all the gears are usable without pulling the chain across at an angle. I could shorten the chain to reduce the sag but as it is practically running as it was before I will give it a few good runs before I decide what to do about it. Once it’s shortened it will not be easy to go back to the original set up. It may be that the convenience of having 42 easily available gears will outweigh the potential of having 63 manual ones at hand.

Further update.
Following a 26 mile test run I can confirm that the new set up works really well, far better than I had expected. The gear range is now from around 20" to around 111", previously around 28" to 111" which is a useful improvement and very noticeable. I include a photo if anyone might be able to suggest any obvious adjustments.

575358
 
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