Tandem refurb/upgrade

ejls2

Hi all,

A couple of months ago I was given an old Phillips Duo tandem that was in pretty good condition other than having both seatposts firmly stuck in their respective seat tubes with very little post showing at the top. This morning, I finally freed them both and have started work stripping the frame down for powder-coating.

I’m hoping to use it for general recreational road riding and some light off-road riding (think XC style trails at most but not racing). I have posted this in the road forum as I thought there would probably be more tandem experts here but some of my questions (re disc brakes etc) are more MTB oriented. The bike has 26” 36 spoke wheels, V brakes and a shimano nexave 3 x 7 drivetrain (with a bent rear axle). It also has a 1” threaded headset with a short quill stem.

I have a whole load of things that I’d like to change and I thought it would be best to put them all in one big thread. I don’t know whether they are all possible/sensible or how best to do some of them. If anyone has any advice I’d be very grateful!

1) Fitting rear disc brake mounts to frame:

I’ve got a pair of 180mm XT disc brakes which I’d like to fit. I know I’ll need a longer cable but I’m not sure whether it’s possible to get the IS mounts brazed onto the frame. I know you can get clamp on mounts but they don’t seem to get very good reviews. I imagine that for weak frames that aren’t designed to take the stress it wouldn’t be possible to fit them but it’s a pretty sturdy steel tandem frame so I hope it would be okay. Does anyone have any idea if there are any shops that can do this?

2) Headset/fork/stem:

The current fork is a rigid steel fork with v-brake mounts and the headset is a 1” threaded type. The headset is quite notchy and I don’t really know what my options are here. I’ve found a rigid fork with a 1” threadless steerer and disc brake mounts:

http://cgi.ebay.co.uk/eXotic-Carbon-Ste ... 2eac59a064

and there seem to be a few options for threadless 1” headsets but I’m not sure whether I can just replace the old headset with the new one. Looking at Sheldon’s website, the diameters should be the same but I’m not sure. Can anyone confirm this?

As for stems, very few 1” MTB stems seem to be available (unsurprisingly!) but people seem to use shims sometimes to use normal 11/8” stems. I probably wouldn’t trust these for racing but am tempted to try them for general riding. Has anyone got any experience of these?

3) Stoker bar stem shims:

The bars and stem the bike came with are quite industrial and seem like a good place to save some weight. Looking at some expensive tandems, it seems that people often use normal 11/8 inch stems with a shim. Again, has anyone got any good/bad experience with these? Does anyone know where you can get these in the UK?

4) Wheels:

I’ll be building these up myself. The rear is 135mm. Does anyone think that 36 spoke XT hubs with plain gauge spokes will be strong enough? Do you reckon I could get away with DT Swiss comp spokes? Any ideas for rims?

5) Seatpost

The stoker’s seatpost is narrower than the other one (27.2). I don’t have a micrometer so can’t measure it yet but it seems to be less than 2mm narrower. Does anyone know a good source of old, non-standard seatposts as I had to cut the top off the old one to get it out!


I think that should be everything for now! Sorry for the essay! Please let me know if you have any ideas re the above.

All the best,

Ed

desweller

I realise that this is technically requesting mechanical advice, but you might do better posting it in the Special Interests forum.

ejls2

I know, I was torn about posting it there. I may see how it goes here and then repost there if I haven't had many responses. Not an ideal solution I know but it does seem to fit into several areas (we may be commuting on it as well!)

Cheers,

Ed

teamtommy

I'm pretty much in the same position as you mate, I've just stripped down an old tandem and am about to have it powder coated before attempting to put it back together with (some) upgraded parts.

It looks like you'll be doing a rather more serious job of it than me, but I'll be very interested to hear how you get on. I think my biggest issue will be brakes.

I put a thread on special interest titled "pimp my tandem" which is still on the first page and got a bit back from it...

will3

ejls2 wrote:

1) Fitting rear disc brake mounts to frame:

You could, but TBH a decent set of v brakes should be sufficient unless you live somewhere particularly hilly.
I modded my Duo to fit a shimano roller brake (as an auxilliary brake) which requires no additional bosses. Works OK although it's not great on a 15% downhill with two heavy riders and camping gear.
The original v brakes suck tho'.

ejls2 wrote:

2) Headset/fork/stem:

The current fork is a rigid steel fork with v-brake mounts and the headset is a 1” threaded type. The headset is quite notchy and I don’t really know what my options are here. I’ve found a rigid fork with a 1” threadless steerer and disc brake mounts:

http://cgi.ebay.co.uk/eXotic-Carbon-Ste ... 2eac59a064

I really really wouldn't use a fork for a tandem that wasn't designed for it. And I really realyl wouldn't use a carbon steerer if it's not designed for the tandem

ejls2 wrote:

and there seem to be a few options for threadless 1” headsets but I’m not sure whether I can just replace the old headset with the new one. Looking at Sheldon’s website, the diameters should be the same but I’m not sure. Can anyone confirm this?

M-part make a 1" threadless headset. It's usually available from CRC or DH cyclesport.

ejls2 wrote:

4) Wheels:

I’ll be building these up myself. The rear is 135mm. Does anyone think that 36 spoke XT hubs with plain gauge spokes will be strong enough? Do you reckon I could get away with DT Swiss comp spokes? Any ideas for rims?

Yes they will be fine so long as you are a good builder.

ejls2 wrote:

5) Seatpost

The stoker’s seatpost is narrower than the other one (27.2). I don’t have a micrometer so can’t measure it yet but it seems to be less than 2mm narrower. Does anyone know a good source of old, non-standard seatposts as I had to cut the top off the old one to get it out!

IIRC the pilot seatpost isn't standard either. If I remember I'll have a look later.

Also IIRC, the rear is 25.4 Don't shoot me if I'm wrong.

I got a post moderne suspension seatpost for the back and a kalloy one for the front. Both were available in the sizes required.

ejls2

Thank you both very much!

Tommy - I'll go and have a look at your thread and may re-post/ask for mine to be moved to the same forum. Thanks!

Will - thank you very much for the detailed response. Going through your points in turn:

1) I agree to an extent. The V brakes that are on there are actually pretty good but I thought that as I was doing a thorough job and had a disc brake already it might make sense to do it at the same time. Bob Jackon cycles can apparently braze on a brace between the chain and seat stays and then fit the mount for not very much money. I may ask them if they could fit a few hose guides while they're at it.

Good idea re the roller brake though. Might be good for the stoker to use as an auxiliary! Was the modification difficult? Which hub did you use?

2) I had come to the same conclusion. I meant to post the one with the steel steerer but am still a bit concerned. Will keep looking for a steel disc brake fork in 1"

Thanks for the advice re the headset. That seems to be much better priced than the Chris King alternative ;-)

4) Brilliant, thanks!

5) Ah, thanks for the warning re the pilot's post. It looks very similar to the 27.2 post from my normal bike but I hadn't measured it. I did measure the stoker's though and it looked like it should be between 25 and 26 so 25.4 sounds spot on. If you do have a definitive answer though I'd loev to know for sure!

On a semi related note, do you know roughly when the Duos were made? Mine is in surprisingly good condition but the headet and odd seatpost sizes makes me wonder whether it is actually older than it looks!

All the best,

Ed

will3

ejls2 wrote:

Good idea re the roller brake though. Might be good for the stoker to use as an auxiliary! Was the modification difficult? Which hub did you use?

I used the nexave hub. It was actually 130 OLN, but a washer and that helped sort that one.
The main things with it are: it's not quick release and you have to detatch the reaction arm to take the wheel off
It's not really a good stopping brake, just a bit extra that helps keep it under control on the downhills. Mine is controlled using a bar end shifter on the stokers bars.
I broke the freehub on mine eventually, but that's par for the course with tandems I think

ejls2 wrote:

2) I had come to the same conclusion. I meant to post the one with the steel steerer but am still a bit concerned. Will keep looking for a steel disc brake fork in 1"

Thanks for the advice re the headset. That seems to be much better priced than the Chris King alternative ;-)

of course I'm not saying the M-part headset will last as long as the CK one, but..........

you also might want to check the fork rake. I'm not sure if it's meant to be or what, but you'll notice that the steering's pretty unstable on the Duo. I can't ride it hands off or even wheel it along holding the saddle only. I suspect there's not much caster, which may be dliberate.

ejls2 wrote:

On a semi related note, do you know roughly when the Duos were made? Mine is in surprisingly good condition but the headet and odd seatpost sizes makes me wonder whether it is actually older than it looks!

Not absolutely sure. I'd guess 5-8 years or so. Mine was not new either.
Have fun
Will

will3

Right, just went and had a shufty at my seatposts (and re-greased them at the same time :oops: )
mine is:
26.4 front
25.4 rear

YMMV, past performance is no guarantee of future performance, you home may be re..........


y'know,

Monty Dog

Definitely recommend have a brace fitted between the rear stays if having disc tabs fitted - see solo frames break

ejls2

Thanks both!

Will - still haven't managed to measure mine accurately but, using a variety of bodged methods, I think mine are 26-27 (front) and 25-26 (rear) so probably the same as yours. Thanks for measuring for me (and well done on regreasing!) and disclaimer duly noted That said, I've ordered a £9 seatpost for the stoker but they don't do a 26.4 so I may just use a shim and the same post again.

Monty - thanks I'm inclined to agree with you and it's what Bob Jackson cycles do as standard. The chainstays and seaststays, like the rest of the frame, are definitely on the chunky side even for a tandem but why take the risk.

I'll post up some pics once I've got it done. Should look good!

All the best,

Ed

will3

ejls2 wrote:

The chainstays and seaststays, like the rest of the frame, are definitely on the chunky side even for a tandem but why take the risk.

You'll be supprised how whippy it'll feel nontheless, particularly when riding it solo.
And when climbing with both out of the saddle