Tandem Gear Woes

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Pete Cuthbert
Posts: 21
Joined: 8 Aug 2021, 9:26pm

Tandem Gear Woes

Post by Pete Cuthbert »

Hi Cycling Colleages

We run a Longstaff tandem trike with a 7 speed freewheel. The not very old bar shifter is a Shimano Revoshift while the chain is moved by a Shimano Altus. The only trouble is that after much work by our local bike expert the shifting is not good. It seems impossible to set it up to shift to both the top and bottom of the freewheel and these are not extreme sprockets. It is all very run of the mill (Sorry I forgot to do a tooth count but it is probably 14-28).

In years past the change was good and stayed that way between services. However the last two Revoshift sets have been poor performers.

I wondered if we should get rid of the Altus and fit a different changer that is meant for more than 7 sprockets. Perhaps it would have a more powerful spring and that would carry the chain all the way to the highest gear. The other possibility we wondered about is a non indexed shifter on the bars where we could go back to 'feeling' the change like I still do on my 1980s two wheeler.

Your advice would be welcome. Yes we are looking at alternative trikes but we need this one to work ASAP if we can.

Regards

Pete
PT1029
Posts: 1744
Joined: 16 Apr 2012, 9:20pm

Re: Tandem Gear Woes

Post by PT1029 »

I'll refrain from commenting on a George Longstaff being despoiled by Shimano Revoshift levers...!
I would replace the Revo twist grip lever, it is one of the few really duff things Shimano have made. I see quite a lot at work, they sort of feel ok but just don't index.This happens when the are/look/feel to be not that old.
Altus gears are reasonable unless the pivots and/or jockey wheels are worn.
Shimano rapid fire levers are more reliable (about £30 ish for 7 speed ones), you just need to ensure you get the correct brake lever version - "V" or cantilever - a few lever models have a plastic insert so you can adjust for either type of brake/cable pull.
If you still want twist grip, I'd go with Gripshift or Microshift, these are more durable and replacing the cable is straight forward.
Don't buy Sunrace, it is almost impossible to open them to replace a cable (I asked the distributor, who got back saying how to do it, saying it took 2 of them in the office a long time to do it....)
To check the gear shifting spring. Ensure the gear is correctly adjusted (H screw) for top gear (small cog), or even over adjusted (for test purposes only). With the bike stationary/rear wheel(s) off the ground), turn the pedals and pull on the gear cable (not lever) or just push the gear in by hand and then let go, see if the gear springs back into top gear or not. If not the spring might be weak and/or the pivots stiff - in which case spraying the pivots with thin oil/GT85 etc and working the gear back and forth (ie left and right) might free the pivots up.
I am assuming you chain is not worn (if worn shifting will be poor).
tatanab
Posts: 5033
Joined: 8 Feb 2007, 12:37pm

Re: Tandem Gear Woes

Post by tatanab »

Let me assume that you have a two wheel drive which uses Maillard freewheels. In this case the 7 sprockets are at a spacing of 5 mm which. The freewheel is actually for 8 speed but the last position is used to carry the drive to the left side, hence you have only 7 sprockets. This 5mm is the same as Campagnolo use at 8 speed. So Campagnolo levers and mechs work just fine. Shimano spacing is different so may work okish. A possible way around this is to use a Shiftmate 1 from St John St Cycles which allows for those small differences. Of course friction levers will work too. May I suggest you post a question on the Upright Tricycle Forum https://www.tapatalk.com/groups/on3wheels/ where most of the posters are Tricycle Association members, as am I.
Last edited by tatanab on 23 Apr 2022, 6:35pm, edited 1 time in total.
rjb
Posts: 7200
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Tandem Gear Woes

Post by rjb »

If you are shifting from the front captains position the long cable run dosent help due to frictional losses. Keeping cables well lubed and in good condition helps and ensure your cable run isn't subject to kinks, tight bends, or anything which could increase friction. Even the gear shifter needs some lub occasionally too.
A picture could help too. :wink:
As Tatanab has indicated if you have a tandem trike specific drive with non standard specs then you will have all kinds of issues until you know what exactly you have.
Last edited by rjb on 23 Apr 2022, 6:37pm, edited 1 time in total.
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
Geoffrey
Posts: 91
Joined: 1 May 2010, 5:29pm
Location: North Devon

Re: Tandem Gear Woes

Post by Geoffrey »

Hello Pete,
Great choice of machine. (George rightly persuaded me to buy a standard tandem, not trike (which I wanted but couldn't really afford), in 1993. What a gentleman. Greatly reduced his profit, but left me a delighted customer. I still have the tandem, and the girl I went on to marry. I digress...
I would recommend getting rid of the revoshift before changing the derailleur. They are often a little vague indexing and this is made worse on the long cable run of a tandem. There are cheap but effective trigger shifters still available for seven speed (Ebay: Shimano Altus m315 for £20) and others cheaper). I am assuming that the freewheel is of the modern Shimano HG design with ramps that greatly improve shifting (if so it is almost bound to be 14-28). Remember that friction shifting is wonderful in its simplicity and flexibility but has some downsides. Over the length of a tandem it is harder to hear how the chain is running and there is less feedback through the pedals as well. (I run a Higgins tandem trike on friction and my Longstaff tandem indexed, the difference is marked.)
If shifting is still poor and you need to change the derailleur remember that all Shimano derailleurs designed for indexing between 7 and 9 speeds are interchangeable. It is often easy to find used, but good quality, derailleurs of this age.
All of the above assumes that nothing has recently been changed on the bike that could cause issues or has worn(New cable routing; Degraded cables, inner or outer; Bent derailleur hanger, etc.)
Good luck in curing the fault. I find my trike the hardest machine to keep running sweetly but I think that is because it is what I have least experience with, and most mechanics have even less!
Jodel
Posts: 60
Joined: 27 Oct 2020, 8:19pm

Re: Tandem Gear Woes

Post by Jodel »

Just my 2p worth. I've found that the lower end Shimano components are not especially good performers, or particularly durable. The best 'bang-for-buck' I've found in the Shimano range is the Deore level parts. The first thing I did when I got a bike with a Revoshift changer was to swap it out for a Deore rapidfire plus changer - the difference was very marked.

I also have a tandem and I switched from a 'normal' 9 speed Deore rear derailleur to the 'shadow' type which has a slightly stronger spring. With the longer cable runs on a tandem, I found this made the shifting a bit better - not a huge difference, but enough to be noticeable. You can still find new 9-speed rear derailleurs on-line and radidfire plus shifters , so it may be worth a try?
Pete Cuthbert
Posts: 21
Joined: 8 Aug 2021, 9:26pm

Re: Tandem Gear Woes

Post by Pete Cuthbert »

Hi Everybody

Thank you all for your suggestions and advice. First here are some photos:
IMG_20220424_Trike 1.jpg
IMG_20220424_Trike 2.jpg
IMG_20220424_Trike 3.jpg
Glad to hear that tandems still feature in romance. Ours only arrived after some years of marriage. We have tested the spring and it seems to be OK. The cables and outers have been well lubricated and the cable runs are not bad. The bar bag is a bit of a cable compressor but is needed as it is home for the battery which, given our ages, is an important addition. However there are no awkward kinks.

The freewheel block is as originally listed and the sprockets appear to be 4.7mm apart (top surface to top surface). My gauge is too fat to measure the interval between them but it looks consistent by eye.

So I think the next step might be to swop out the twist grip for a trigger shifter. I have also spotted that SJS sell tandem gear cable in 1.2mm diameter rather than the more usual 1.1. It might be worth adding that as stretching might be somewhat less.

Regards

Pete
rjb
Posts: 7200
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Tandem Gear Woes

Post by rjb »

It looks like a standard 7 speed shimano freewheel. Single wheel drive on the left? It looks like the mech is almost at its limit implying that the freewheel is too far away. If its mounted on a carrier is there any possibility of it being moved closer to the mech. Possible by inserting a couple of 2mm washers (Sturmey archer washers) for instance between the freewheel and its carrier and/ or adding a washer to the carrier fitting bolted to the hexaganol axle so not sure how much room is available without risk of overdoing it and having insufficient security.
Have a look around the trike forum (https://www.tapatalk.com/groups/on3wheels/) for more information. :wink:
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
rjb
Posts: 7200
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Tandem Gear Woes

Post by rjb »

rjb wrote: 24 Apr 2022, 1:53pm It looks like a standard 7 speed shimano freewheel. Single wheel drive on the left? It looks like the mech is almost at its limit implying that the freewheel is too far away. If its mounted on a carrier is there any possibility of it being moved closer to the mech. Possible by inserting a couple of 2mm washers (Sturmey archer washers) for instance between the freewheel and its carrier and/ or adding a washer to the carrier fitting bolted to the hexaganol axle so not sure how much room is available without risk of overdoing it and having insufficient security.
Have a look around the trike forum (https://www.tapatalk.com/groups/on3wheels/) for more information. :wink:
The teeth on the top cog of your shifter look very worn as well. Possibly due to the b tension not being set correctly. That's not helping you either. There are some trike experts here who may offer more knowledge than I have.
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
tatanab
Posts: 5033
Joined: 8 Feb 2007, 12:37pm

Re: Tandem Gear Woes

Post by tatanab »

Ok, you can ignore my previous comment about sprocket spacing/Campag etc since thay applied to two wheel drive Maillard based units. This tandem trike is a Cyclon which George built as economy options to his fully custom frames. It is single wheel drive, and as others have said it is all Shimano parts so "should" work.

I think I would change the rear mech since you say that Revoshift did work but not the recent couple you have tried. Then I would put a spacer behind the freewheel block. But since it all worked at some time in the past, then something is past its best, be it the Revoshift or the rear mech.
Pete Cuthbert
Posts: 21
Joined: 8 Aug 2021, 9:26pm

Re: Tandem Gear Woes

Post by Pete Cuthbert »

Hi Everybody

Thanks for all the earlier advice. I have homed in on some of it and started by purchasing a Shimano SL-M315 Shift Lever Rapidfire Plus 7-speed device. That was a great improvement over the Revoshift but did not actually sort out the problem. The mech we were using at that time was a Shimano Altus RD M310 which is a 7 speed unit. Our bike man had a Shimano RD 5701, which I have discovered is a 10 speed, and we ran that for a bit with no obvious improvement.

I started a conversation with Dr Booker about possible upgrades and he suggested that what I needed with the SL-M315 was a Shimano Acera SGS RD M360 which is 7-8 speed. That I have now purchased and tried to fit today. Unfortunately it will only give me 5 gears whatever I do with the limit screws. However, alterted by RJB about the freewheel possibly being too far away I looked at the cable when the changer was in the lowest gear it would pull. At that point the mech seems to have run out of cable (See photo)
IMG_20220818_No More Cable.jpg
It looks as if a spacer behind the freewheel is going to be necessary.

By way of a check, I measured the distance from the face of the smallest sprocket to the face of the hanger bracket to which the mech is screwed. That came to 16.6mm. We also have a handcycle in the house so I measured the same components on that and came up with 12.2mm. Thus I think it safe to conclude that I need to move the freewheel by about 5mm if we are to use the RD M360.

That brings me to a final question; how on earth does one remove a screwed on 7 speed freewheel from a Longstaff axle? (I have signed up to the On3Wheels forum so will probably post this question there too.)

Thanks for showing your interest.

Pete
Jdsk
Posts: 24635
Joined: 5 Mar 2019, 5:42pm

Re: Tandem Gear Woes

Post by Jdsk »

Pete Cuthbert wrote: 18 Aug 2022, 8:59pmThat brings me to a final question; how on earth does one remove a screwed on 7 speed freewheel from a Longstaff axle?
Is that anything like the one discussed here?
viewtopic.php?p=1699423#p1699423

Jonathan
Pete Cuthbert
Posts: 21
Joined: 8 Aug 2021, 9:26pm

Re: Tandem Gear Woes

Post by Pete Cuthbert »

Thanks Jonathan

That is the task. I had better make notes in the morning...

Regards

Pete
rjb
Posts: 7200
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Tandem Gear Woes

Post by rjb »

I see you have some advice on th 3 wheels trike forum. I would just add that if you remove the Allen bolt from the centre of the freewheel and the circlips holding the axle in situ you may be able to insert a standard freeweel remover and holding it with a spanner spin the drive wheel forwards to release the freewheel. :wink:

If you need to take the axle out completely and have a vice, hold the freewheel remover In the vice and use the axle with the wheel as a capstan to release the freewheel from the alloy carrier. There's not a great deal of meat on the carrier to enable it to be gripped securely in a vice. You can see a photo of the carrier in the link I posted referenced by Jonathan above. :wink:
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
Pete Cuthbert
Posts: 21
Joined: 8 Aug 2021, 9:26pm

Re: Tandem Gear Woes

Post by Pete Cuthbert »

Many thanks RJB

I think the job will need to be held over until Saturday. We have a garden contractor in at the moment who I have been helping shift several tunny bags of soil to replace the builders shame. I have also to pop into town on the Brompton for some shopping this afternoon which has been postponed rather too long.

I put the old mech back on this morning so we were able to go out for the daily ride. It is just a pity that trikes are so awkward to work on when balanced on axle stands. There must be a better way than lying on one's back on the floor...

Regards

Pete
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