Circe Helios tandem

Please be fair and thoughtful in your opinions. No rants please.
reohn2
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Circe Helios tandem

Postby reohn2 » 30 May 2016, 7:42pm

Image

We recently bought this for it's low step over design due to Mrs R2's on going health issues,and my arthritic hip,which proves difficult for me mounting a conventional tandem,a solo is OK as I can slip over the rear of the saddle but mounting a tandem needs considerable articulation of the hip joint which can be quite painful for me on a bad day.
The bike's compact design is also easier for transporting in the car.

The bike is proving a great success in those regards,and the ride is surprisingly good,handling though different to a large wheel machine isn't to it's detriment,the steering is slightly 'twitchier' at low speed which I can only put down to the small wheel's possible lack of gyroscopic effect(?) as the steering geometry isn't aggressive,that said we can manoeuvre quite easily at sub 2mph without any concerns.
This is our first small wheel bike and though initially we thought it looked slightly odd,we've warmed to it :) .
We bought the bike second hand but almost new with a claimed 20miles on it,which I've no reason to doubt,as it's immaculate still with moldings bits on the centre of the tyres.
It came as a standard 2014/5 bike with flat bars,V brakes,8sp rear cassette all Alivio drivetrain except for Sora 130BCD triple c/sets,straight through solo chainsets on external BB's running 52/39 final drive with the inner(third)ring 74BCD position being used as the timing chain.
This is standard equipment on dérailleur equipped Circe Helios tandems and works quite well as it gives a low/high gearing set for most terrain with a range from 23inch to 96inch with the 11-34 Megarange cassette.But for us was also weak point of the bike as it limits really low gearing range,and a pity as it has such other good features for disabled riders,small frame and wheel size means it fits into almost any car,low step over,and extremely versatile height range from the smallest possible size to 6ft plus riders.
IMO Circe are missing a trick not fitting a cross over chainset,though TBF to Circe they'll fit one as a special order.
Another criticism in the same area is the timing chain tension,the bike has a mid bottom run spring loaded tensioning device which would have been better taken care of with an eccentric front BB IMHO,the extra cost at manufacture wouldn't be more than £50 to £70 max and IMHO spoils the ship for a ha'worth of tar,that said the tensioner does it's job well enough though.
It rides and handles well on the standard 50mm Schwalbe Big Apple tyres @ 60psi f&r,with an all up weight of 175kgs(bike 20kgs as per photo,2kg of day bag,153kg riders)the bike itself weighs 20kg with rack mudguards bottle cages and a small bag with a inner tube inside as seen in the photo and all modifications mentioned below included,which IMHO ain't bad at all.

Modifications anticipated when buying and carried out shortly after purchase:-
Mrs R2's health problems have robbed her energy levels as I've mentioned above,so we need a much lower gear range which was impossible with the straight through chainsets fitted,so I replaced them with a Stronglight Impact tandem cross over chainset this is 110/74BCD and frees up the inner ring for final drive use,and Shimano UN55 BB's.This arrangement is fitted with 26/36/46 final drive rings and 38t timing rings.Trying not to get too techie but the chainset came with 39t timing rings but the chain tensioner couldn't cope,dropping them down one tooth to 38's(which I happened to have in 'the box') sorted it out.
The front mech was for the double already fitted,which coped in the stand but we couldn't get it to drop to the inner ring under pressure,so I fitted a triple which is a Tiagra road one.I had to use a road mech because the front mech is a braze on due to the unusual stoker seatube arrangement(see photo).
The 8sp Megarange cassette has some quantum :roll: leaps in it so I customised it into a 14-16-18-20-23-25-28-32 giving a more even spread across the range,with the 26/36/46 rings we now have a manageable(for us)range of 16inch to 67inch with an option to go lower with a 24t inner ring or higher with a 48/50 or bigger outer ring.
I changed the V's for BB7 MTN with 160mm discs as I was concerned about premature wear of the rims and because I like discs as some people may be aware of :) .The rear rack needed a leettle bending modification and a spacer on the left side to clear the caliper,no big deal and looks great.
Saddles were swapped for MRs R2's favoured Brooks Flyer S and her sus post off the Santana tandem.I've been riding the bike on a rather hard Squadra saddle so swapped it out for a Charge Spoon,I've been riding a Spoon on one of my Vaya's and I think I like it,fingers crossed.
Stokers 'bars were swapped for the ones fitted to the our Santana(since sold)and which Mrs R2 prefers to the one's fitted as standard.
I was going to keep it with some kind of straight 'bars on for me,but I had a pair of Richie 44cm wide compact drops that I bought some time ago from a forum member,so I fitted those with a pair of Kelly's I had,and 8sp DT levers,I even had bartape in stock :shock: .With a slightly longer stem(stock :shock: ) and Tektro RL520's(stock :shock: )to finished the the job :) .I think it's just about dialed in for trundling about the cyclepaths that it's intended for,plus everything's stopping,steering and changing gear all as it should,and I can see behind with my Cateye 'racing' :? RVM .Result! :)
This isn't an exhaustive test as we don't do enough tandem miles these days but we've been riding tandems long enough to know a gud 'un when we ride one and so I'd recommend it,nice versatile bike :D .

One point that I've found about small wheels,tyres are limited and lack some big supple high quality examples on the market,the BA's(but 50mm ones only measure 46mmx46mm :? ) OK but they're not Hypers,and Kojaks or Racers aren't big enough IMHO.
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Bonefishblues
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Re: Circe Helios tandem

Postby Bonefishblues » 30 May 2016, 7:59pm

That's very tidy, but you're right, it doesn't look "serious" at first glance.

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pjclinch
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Re: Circe Helios tandem

Postby pjclinch » 31 May 2016, 10:54am

reohn2 wrote:The bike is proving a great success in those regards,and the ride is surprisingly good,handling though different to a large wheel machine isn't to it's detriment,the steering is slightly 'twitchier' at low speed which I can only put down to the small wheel's possible lack of gyroscopic effect(?) as the steering geometry isn't aggressive,that said we can manoeuvre quite easily at sub 2mph without any concerns.


I'd guess relative lack of trail. It's certainly the case that my Brom and Moulton are more... "responsive" when riding no-handed, but as you suggest this is more a matter of getting used to it than being a problem.

reohn2 wrote:One point that I've found about small wheels,tyres are limited and lack some big supple high quality examples on the market,the BA's(but 50mm ones only measure 46mmx46mm :? ) OK but they're not Hypers,and Kojaks or Racers aren't big enough IMHO.


As long as you don't have close clearances (and it looks like you don't) there's actually a fair selection. Our touring 'bents run Schwalbe Marathons and there's a Marathon Racer in 40-406.

Bonefishblues wrote:That's very tidy, but you're right, it doesn't look "serious" at first glance.


Anyone that rides with wee wheels tends to get past this fairly soon. It's often the assumption that they must be slow, and you say, "like Mini Coopers are so much slower than JCB's, right?" and then the penny drops that The Miracle Of Gearing can get you past that particular issue. Rolling resistance is a little higher, aero resistance is a little lower, tyre selection is worse and your tyres wear out quicker. OTOH the wheels are stronger if all else is equal, and (again, if all else is equal) the bike tends to be more manoeuvrable and easier to manhandle.

Pete.
Often seen riding a bike around Dundee...

reohn2
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Re: Circe Helios tandem

Postby reohn2 » 31 May 2016, 2:15pm

I think you've made yer point :mrgreen:

I'd guess relative lack of trail. It's certainly the case that my Brom and Moulton are more... "responsive" when riding no-handed, but as you suggest this is more a matter of getting used to it than being a problem.


Less trail:- ie;quick(nervous)steering,isn't any worse(?) than the Santana(now sold) or our KHS childback both of which which need to be kept in check at <5mph manoeuvring,in fact better,especially the KHS as there's little weight on the back and it has 665mm flat bars.
I've just roughly measured the head angle with an adjustable spirit level(I did say rough),as there's no official figures,and it's about 72/73deg with a fork offset of 45mm,but the small wheels mean the fork ends are nearer to the ground,which makes for less trail(?) add to that the small wheel to steer it all adds up.
Our Cannodale Road tandem is much more relaxed than any of them at 73 deg H/A and 53mm fork offset.
All this isn't any problem at all over >5mph.
I've tried no hands at 15mph+ on the Circe and it tracked well for a short while but as we're only doing short rides on flat terrain I can't put it through any real exhaustive trials,and tandems don't lend themselves to no hands riding as you can steer them too well due to the long WB/all up weight.

As long as you don't have close clearances (and it looks like you don't) there's actually a fair selection. Our touring 'bents run Schwalbe Marathons and there's a Marathon Racer in 40-406.

I find racers harsh,and the present standard Marathons worse still,spoiled by Hypers :mrgreen: .
Casting about there was only Kojaks that looked anywhere near,but Schwalbe only do them in small widths in 406's,they claim 35mm but who believes any of Schwalbe's tyre width ratings? :? The Big Apples fitted are 406x50mm but measure 46x46mm on the 19mm Alex rims.
Concerned about finding a tyre if we trashed one away from home(we're caravaners so the Circe comes along too)I did a spares/better tyres search and came to the conclusion we won't better the BA's already fitted,unless we're riding on billiard table tarmac(fat chance),I found SJS selling them for £10 each,so I bought two :)
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hercule
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Re: Circe Helios tandem

Postby hercule » 31 May 2016, 8:50pm

If you want a bigger, tougher version of the BA then have a look at the Schwalbe Big Ben. Similar style, deeper tread, 20x2.15" size. It feels a bit more sluggish than the BA but the BikeE mine is fitted to isn't exactly a speed machine anyway!

reohn2
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Re: Circe Helios tandem

Postby reohn2 » 31 May 2016, 9:55pm

hercule wrote:If you want a bigger, tougher version of the BA then have a look at the Schwalbe Big Ben. Similar style, deeper tread, 20x2.15" size. It feels a bit more sluggish than the BA but the BikeE mine is fitted to isn't exactly a speed machine anyway!


Thanks for the recommendation but I think the BA's are about as good as it's going to get.
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squeaker
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Re: Circe Helios tandem

Postby squeaker » 1 Jun 2016, 11:37am

reohn2 wrote:Thanks for the recommendation but I think the BA's are about as good as it's going to get.

BMX market is competitive ;)
Schwalbe's Shredda has a reputation as a fast 406 tyre amongst the velomobile crowd. (Light and folds ;) )
"42"

reohn2
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Re: Circe Helios tandem

Postby reohn2 » 1 Jun 2016, 5:55pm

squeaker wrote:
reohn2 wrote:Thanks for the recommendation but I think the BA's are about as good as it's going to get.

BMX market is competitive ;)
Schwalbe's Shredda has a reputation as a fast 406 tyre amongst the velomobile crowd. (Light and folds ;) )


Thanks for the heads up,on paper that looks the business,high 127 TPI casing,folding bead,and the 406x50mm ones have a respectable load rating for tandems @ 85kg. :)
I never gave BMX tyres a serious coat of staring at,as I didn't think their load rating would be anywhere near enough for tandem weights

These tyres in 40 or 44mm sizes may be just the job for MickF's and Deliquium's Moultons.
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squeaker
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Re: Circe Helios tandem

Postby squeaker » 1 Jun 2016, 6:12pm

reohn2 wrote:Thanks for the heads up,on paper that looks the business,high 127 TPI casing,folding bead,and the 406x50mm ones have a respectable load rating for tandems @ 85kg. :)

Some of the base data is shown in this table, taken from Wim Schermer's blog. (The upper data is on a rough-ish asphalt, as compared with an unrealistically smooth floor.)
"42"

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RickH
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Re: Circe Helios tandem

Postby RickH » 1 Jun 2016, 11:29pm

I found I the sidewalls of BAs showed sign of coming apart quite rapidly on the back. The 55mm version also struggled with clearance with the Pletscher stand I have fitted (useful when trying to get a child in a seat on the back & makes parking generally easier - I've made it into an impromptu bike stand with other folk's bikes leaned against each side on a group ride :-)). The front one was fine so I ran it with a 50mm BA on the front & the OEM 47mm Marathon on the back.

Earlier this year I fitted a pair of the new model Marathons & haven't found them a shock to the system.

An alternative I'd wondered about is Conti Contact IIs as they are available in 47-406. I'd seen the Shreddas but didn't know anything much about them apart from noting that Schwalbe only give them a 2 out of 5 for durability.

Apart from ruminations about tyres I really like mine - my regular sight impaired stoker & I passed our 4000 mile mark this week (in 23 months) so it does work as a "serious" machine as well as being a good grandchildren transporter & load lugger. :-D

Rick