Our first tandem build - advice appreciated!
Hello everyone! My first post here, what a great trove of info in this forum! I'm a life-long bike rider and enthusiast (and shop mechanic in a different life), though brand new to the tandem world. My family is based in Beijing, my wife is also an avid cyclist, and we love taking our kids on rad wild adventures. We've completed some great tours here in China, and our kids (3 and 6) have outgrown our current travelling setup. Our smallest is moving up to her brother's Weehoo trailer which my wife will tow behind her touring bike, so we need a solution for our boy that keeps him active, involved and safe... enter our tandem build!
We have a shop here that does custom bikes, including tandems. So, a custom titanium tandem frame has just been ordered with one pair of couplers. It follows in style and geometry to a tandem mountain bike to give us better standover for the captain and the wee stoker. I've designed, ridden and worked on enough bikes that the geometry is all set, so now it's on to components! Being new to tandems, the drive train is tripping me out. Suggestions and feedback are super appreciated! Here's our build brief by order of importance:
Thanks in advance for your suggestions and please let me know if I've neglected anything important! Cheers, Owen |
Your wheels seems a bit under engineered for tandem touring. Chinese courier service is very fast, reliable and cheap inside China but getting the right parts could be an issue in the backwoods of China.
For our touring tandem, I spec'ed 26" wheels with 48H rims. I wanted bombproof wheels. They are heavy but the 11S cogs are the heaviest part of the wheel. |
On the first iteration of our Ritchey I used some well respected wheels from the Mountain Bike world. The front survived just fine. The rear failed fairly suddenly and catastrophically. The wheels were 32 spoke and they looked beefy, but the rims cracked around the spoke holes. I would go with a wheel set designed for a tandem.
I would also go with a tandem specific fork. I know that House of Tandems has one and Wound Up Composites has one. Also, I had some trouble with build quality on the Archer units that I saw and abandoned the idea. I use a 1X 9 a Box 9 11-50 cassette to reduce the chain offset, but more gears did work, sort of with the Ritchey frame. If my budget allowed I would go with an SRAM Eagle AXS setup. I am running a left side timing chain with 41 tooth sprockets. I have thought of going to right side drive, and if I do I plan on using a belt drive in front. |
I'm in agreement with what the others have said above. I'm curious as to why you'd use only one pair of couplers? For airplane travel in particular, you may have a difficult time checking in a bike in two oversized packages, where as a bike that breaks down into three pieces (as opposed to two) allows two compartments to be packed much smaller and tighter. Of course, you may have a different idea for justifying only a pair of couplers, but I thought I'd ask just the same. Good luck with the build!
|
I don't know ... "(very) low speed climbing" ability AND a "high gear range" AND a "1x drivetrain", even a SRAM Eagle drivetrain, just seems like a bridge too far IMO. The insistence on a single side drivetrain also causes me to go hmmm. Can the o.p. say more about these druthers? Some seem mutually exclusive from my casual acquaintance with the technologies involved.
|
I agree with questioning the wisdom of a 1X tandem. Tandems require a bigger gear range than any half bike. Our current tandem has 26/36/50 chainrings and 11-36 cassette with 650B wheels, and we use the full range of gears. In fact the 50/11 top gear is too small. Our next tandem (on order from Curtlo) will have 46/30 chainrings with 10-42 cassette.
I don't have the new tandem yet, but the fork recommends by Doug Curtiss is the Co-Lab Cross fork, which is tandem rated. |
We have been running a 1X on our tandem from the start. Our working cadence is the key to this. We have a 30 tooth chainring in front and a 11-50 9 speed cluster in back. Our wheels are 700C and currently we are running a 700X32C Conti GP5000. I originally had a 9-50 SRAM11 speed in back, but I switched to the Box 9 speed because I felt that the chain line angle with the 11 speed was the source of poor shifting. The Box 9 speed does indeed shift much better
With the 11 tooth sprocket we have a top speed under pedal power of right around 30 MPH. We can run a fairly high cadence, With the 50 tooth sprocket we have a 3 MPH crawl speed that has taken us up some fairly steep ( more than 10%hills. With a long steep downhill and gravity to pull us we have seen a top speed of between 45 and 50 MPH. We consider this acceptable for a touring tandem. We are able to bridge the gaps in the gearing as our working cadence is from 75 - 105. We are both in our mid to late 60's and while we are in pretty good shape for people in the 65-70 year range we are not going to win any races. Our longest days on the bike have been in the 75 mile range and Mrs. Dan was ready to kill me at the end of those days. We have an agreement that no future tour will include such a day without approval of the Stoker. |
Firstly - huge thanks to everyone for your suggestions and questions. Super appreciated.
Wheels - I'm trying to source as much as I can from within China just for access to spare parts and I don't want to abuse my friend's diplomatic post service. 48h rims and hubs seem to be completely unavailable here. I hear what you're saying though so maybe it's what's required. Food for thought, thank you. The reason for 1x is that with my son on the back I am both captain and stoker. Our first cycle tour as a family I had my 2x8 26" mountain bike with him in the weehoo towed behind. Me, him, bike, trailer, luggage, food, water, camping gear was about 260lbs. Since then I got my 29" touring bike which 1x11 and slightly heavier loads (he got bigger). Needing to switch through the gear range rapidly when riding rolling hills in particular on the 2x system required a huge amount of shifting and it was a PIA on long days. I've made it through some tough climbs with the touring bike and boy in tow with the 32-46 I have. My wife's bike (she tows similar weight with our daughter) has 2x9 and she regularly gets annoyed at the shifting between front rings. A 32-50 gives me 3.3mph at 60rmp, which would take some serious gradient to get me that low in cadence. At the other end 32-11 gives me 22.5mph at 90rmp, which with my most valuable cargo behind is plenty fast enough and I'm not killing the downhills anyway. I'm a strong rider and that gearing has worked for me a wide variety of trips so far. The 1 set of couplings is partly a budget, and partly because the second set is not necessary as we are travelling as a family and oversize baggage is how we've rolled for a long time now. Also, the airlines here run on a piece system, so 3 pieces of check-in can be problematic/expensive. Two oversize pieces don't worry me, but again thank you for the question and for making me think about it. Single-sided drive train. I want to use my ultegra cranks that have a power meter. I don't want to cut new pedal threads or loctite my pedals in to install in reverse (am I understanding that correctly?). My understanding was that to use that crankset I'd have to go single-side drive. If there's a way to use them with a two-sided system without damaging them or relying on loctite then I am open to suggestions! That's why I asked :) Thank you for the fork recommendations, I'll look into those! Thanks again everyone and follow up comments/questions really appreciated! |
Originally Posted by DangerousDanR
(Post 21996062)
On the first iteration of our Ritchey I used some well respected wheels from the Mountain Bike world. The front survived just fine. The rear failed fairly suddenly and catastrophically. The wheels were 32 spoke and they looked beefy, but the rims cracked around the spoke holes. I would go with a wheel set designed for a tandem.
Also, I had some trouble with build quality on the Archer units that I saw and abandoned the idea. I use a 1X 9 a Box 9 11-50 cassette to reduce the chain offset, but more gears did work, sort of with the Ritchey frame. If my budget allowed I would go with an SRAM Eagle AXS setup. I am running a left side timing chain with 41 tooth sprockets. I have thought of going to right side drive, and if I do I plan on using a belt drive in front. SRAM AXS was under consideration until sticker shock made me look elsewhere... it is super cool though. I checked out House of Tandem's wheelsets... 24 spoke rims! What am I missing here??? |
Originally Posted by odfid
(Post 22003745)
Firstly - huge thanks to everyone for your suggestions and questions. Super appreciated.
Wheels - I'm trying to source as much as I can from within China just for access to spare parts and I don't want to abuse my friend's diplomatic post service. 48h rims and hubs seem to be completely unavailable here. I hear what you're saying though so maybe it's what's required. Food for thought, thank you. The reason for 1x is that with my son on the back I am both captain and stoker. Our first cycle tour as a family I had my 2x8 26" mountain bike with him in the weehoo towed behind. Me, him, bike, trailer, luggage, food, water, camping gear was about 260lbs. Since then I got my 29" touring bike which 1x11 and slightly heavier loads (he got bigger). Needing to switch through the gear range rapidly when riding rolling hills in particular on the 2x system required a huge amount of shifting and it was a PIA on long days. I've made it through some tough climbs with the touring bike and boy in tow with the 32-46 I have. My wife's bike (she tows similar weight with our daughter) has 2x9 and she regularly gets annoyed at the shifting between front rings. A 32-50 gives me 3.3mph at 60rmp, which would take some serious gradient to get me that low in cadence. At the other end 32-11 gives me 22.5mph at 90rmp, which with my most valuable cargo behind is plenty fast enough and I'm not killing the downhills anyway. I'm a strong rider and that gearing has worked for me a wide variety of trips so far. The 1 set of couplings is partly a budget, and partly because the second set is not necessary as we are travelling as a family and oversize baggage is how we've rolled for a long time now. Also, the airlines here run on a piece system, so 3 pieces of check-in can be problematic/expensive. Two oversize pieces don't worry me, but again thank you for the question and for making me think about it. Single-sided drive train. I want to use my ultegra cranks that have a power meter. I don't want to cut new pedal threads or loctite my pedals in to install in reverse (am I understanding that correctly?). My understanding was that to use that crankset I'd have to go single-side drive. If there's a way to use them with a two-sided system without damaging them or relying on loctite then I am open to suggestions! That's why I asked :) As for one set of couplers, Chinese airlines (so far) seems to tolerate some pretty big luggage even in domestic flights for free. I've seen some pretty oversized parcels show up on the baggage carousels. The problem with only one set of couplers is mainly that of land transportation. Chinese taxis usually aren't that big. Other than Shenzhen, where there are lots of BYD hatchback EV taxis, most cities use sedans as taxis. Not sure even 1/2 of a tandem will fit into one of those. When we use to fly our tandem oversea for touring pre-COVID, we always end up with 4 pieces of check-in luggage. 2 S&S hard case for the bike and 2 soft bags for clothes and stuff. 2 half of a tandem will not reduce the number of pieces you need to fly with. |
Originally Posted by odfid
(Post 22003745)
The 1 set of couplings is partly a budget, and partly because the second set is not necessary as we are travelling as a family and oversize baggage is how we've rolled for a long time now. Also, the airlines here run on a piece system, so 3 pieces of check-in can be problematic/expensive. Two oversize pieces don't worry me, but again thank you for the question and for making me think about it.
https://i.postimg.cc/3NjBp2Jp/coupled-tandem.jpg ......can fit into two cases like this: https://i.postimg.cc/VsX43PB6/coupled-travel.jpg The case width and height are only a little larger than the diameter of a typical wheel. I guess my thought is if you're already running with one set of couplers, it only makes sense to run with another set for a more compact travel situation. |
Originally Posted by odfid
(Post 22003851)
When did you check out the Archer units? From recent reviews, it seems the latest version has made improvements on the previous. What build quality issues did you have?
SRAM AXS was under consideration until sticker shock made me look elsewhere... it is super cool though. I checked out House of Tandem's wheelsets... 24 spoke rims! What am I missing here??? The House of Tandems wheels use a polymer material for the spokes, and it is supposed to be 3X the strength of steel. No spoke or wheel bending issues. I did have a rim fracture on the next to the last day of our tour of Burgundy which was noted after we rode down the second road pictured below. HoT did honor their warranty in spite of the obvious abuse. I must note that Google Maps sent us down some "roads" that were single track mountain bike trails, and we always rode until Mrs. Dan, my stoker, said enough is enough and this in not fun anymore. That was always after we had ridden at least a mile of trail. Here are a couple of the worst examples: Should have known that a "no cars" sign was there because even my old Land Rover Defender would have had a hard time with the trail... https://goo.gl/maps/DwkikDdPfXQ4JvL26 and then there was a trail that turned into a dead end in a couple of ways... https://goo.gl/maps/R3r3Ed3QkhXM4YEV9 where their route is the rutted path that goes off to the left... |
Regarding your envisioned weight of 260lb I would not be too worried regarding the spoke count. There are many teams in this forum with 300- 350lb running 32- 36 hole wheels.
For hubs with 36 holes, there are also the Hope Pro4 and Dt Swiss 350 hybrid, which are supposed to be stout. The latter is even certified until 330lb total weight and for ASTM 4 riding, i.e. drops until 1.20m. Dt siwss also offers rims in their hybrid line-up, e.g. the hx491 which is certified to the same weight as the mentioned hub. They are considerably more expensive than xt though, which is probably be fine for your weight now. If your boy grows bigger, it might be worth investing into a stronger set of wheels already though. There are also some useful forum posts of heavier mtb riders (270-330lbs) discussing their wheel builds online, e.g. if you google 'mtb wheelset heavy rider': https://weightweenies.starbike.com/f...p?f=1&t=138902 |
Originally Posted by scycheng
(Post 22003958)
I've seen rental beach boardwalk tandems in Shenzhen with double side driven rear wheel. 48H wheels probably don't have enough volume for parts to be easily available inside China. 36H wheel with deep(er) dish rims you might be able to source in China if you can find a good bike shop. I still haven't found a good shop in Shenzhen. You may have to stockpile tandem-specific spare parts and ask a friend to mail them to you if you need anything on tour.
As for one set of couplers, Chinese airlines (so far) seems to tolerate some pretty big luggage even in domestic flights for free. I've seen some pretty oversized parcels show up on the baggage carousels. The problem with only one set of couplers is mainly that of land transportation. Chinese taxis usually aren't that big. Other than Shenzhen, where there are lots of BYD hatchback EV taxis, most cities use sedans as taxis. Not sure even 1/2 of a tandem will fit into one of those. When we use to fly our tandem oversea for touring pre-COVID, we always end up with 4 pieces of check-in luggage. 2 S&S hard case for the bike and 2 soft bags for clothes and stuff. 2 half of a tandem will not reduce the number of pieces you need to fly with. |
Originally Posted by DangerousDanR
(Post 22004374)
I had a couple of very early units from Archer. I had a switch failure that they attributed to our very cold weather here in Fargo (-20F) and one unit that just died at power up. I am happy with the Box 9 speed and with a 1X system a single coupled cable is not a big deal. I can store my Campagnolo EPS in my unheated garage with no issues.
The House of Tandems wheels use a polymer material for the spokes, and it is supposed to be 3X the strength of steel. No spoke or wheel bending issues. I did have a rim fracture on the next to the last day of our tour of Burgundy which was noted after we rode down the second road pictured below. HoT did honor their warranty in spite of the obvious abuse. I must note that Google Maps sent us down some "roads" that were single track mountain bike trails, and we always rode until Mrs. Dan, my stoker, said enough is enough and this in not fun anymore. That was always after we had ridden at least a mile of trail. Here are a couple of the worst examples: Should have known that a "no cars" sign was there because even my old Land Rover Defender would have had a hard time with the trail... and then there was a trail that turned into a dead end in a couple of ways... -where their route is the rutted path that goes off to the left... |
Originally Posted by rocknrollin
(Post 22004680)
Regarding your envisioned weight of 260lb I would not be too worried regarding the spoke count. There are many teams in this forum with 300- 350lb running 32- 36 hole wheels.
For hubs with 36 holes, there are also the Hope Pro4 and Dt Swiss 350 hybrid, which are supposed to be stout. The latter is even certified until 330lb total weight and for ASTM 4 riding, i.e. drops until 1.20m. Dt siwss also offers rims in their hybrid line-up, e.g. the hx491 which is certified to the same weight as the mentioned hub. They are considerably more expensive than xt though, which is probably be fine for your weight now. If your boy grows bigger, it might be worth investing into a stronger set of wheels already though. There are also some useful forum posts of heavier mtb riders (270-330lbs) discussing their wheel builds online, e.g. if you google 'mtb wheelset heavy rider': |
Originally Posted by odfid
(Post 22005409)
Cheers for the detailed reply mate. I saw your PM come up but can't read it until I reach 10 posts... such is the rules. We ship our bikes in advance and pick them up at our destination, easier than trying to fly with them. Once we get our bikes we just ride out of the city, though we can order a van through huolala if need be.
You can easily recover the cost of extra set of couplers after shipping a tandem a few times in North America. |
Originally Posted by scycheng
(Post 22005548)
Shipping cost for large parcels outside of China is not quite as economical if you ever want to take that tandem outside of China. 😀
You can easily recover the cost of extra set of couplers after shipping a tandem a few times in North America. BLAM! is what I'd expect! Tandems place unreal torque loads on rear hubs and the XT simply isn't designed for it. DT/Swiss 450 TANDEM hub, Chris King or Onyx would be my recommendations. Otherwise, it's just a matter of time for that freehub body to explode. (See the tandem hub failure discussion on this forum.) And yes, I'd spend the few extra dollars on 2-3 more couplers so you can pack your tandem in a suitcase. And just because you have the extra set of couplers doesn't mean you have to use them. But building a custom Ti tandem frame with couplers, but leaving half of them off seems rather short-sighted. I value future flexibility and anticipating unforeseen needs - something I'd really plan for with a tandem. Plus, resale value will be dinged when someone says, "So it has S&S couplers but won't actually pack up like an S&S coupled bike?" |
Hi everyone! Thank you for your suggestions. Been a little while so figured I'd pop an update here.
Chain line - I'm hoping I can find a short enough isis spline for the rear crankset to try and get a decent chain line. I'm planning to install the front crankset and then experiment from there, I feel like I need the frame to experiment with what fits as I'm not sure about the clearance at the chainstays with different spindle lengths. Put the bottom bracket in and then go from there. Unless anyone has a better suggestion? Cheers, Owen |
Update
Hey odfid,
I was curious if you have an update! I’m working on bottom bracket spacing dilemmas myself. Thanks! |
We ride a fullsuspenion tandem with Shimano EP8 motor.
Fork choice is relied with total drivers weight(al gear included) Ours is 155. The only fork that can handle this weight is the Rock Shox Lyrik.(up to 170kg) Other forks have problems because the max pressure is limited to 125 PSI. Consequence : oo much sag, u get seesick and the fork dives too much. U can change the travel of the Lyrik between 100 and 180 mm. Fork is stiff enough. Theres enough rebound damping.(I run the fork 3 clicks from closed) The RCT3 version has my preference: lock out when driving onroad. RC2 is relatively quiet when climbing or speeding up standing on the pedals if u close the high speed compression and the low speed compression. Offroad I keep the low speed compression closed and the high speed half closed (2 of 4 turns) U lose a bit of comfort on samll bumps. The fork b-never bottomed out with 2 tokens(4 advised). But pressure is very high so I think 2 is enough. I use 13.5 cm of the 14cm of travel. 140 mm is about right for a tandem because the higher fork raises the rear bottom bracket. With 10 or 12 cm forks the stokers pedals hav tooo much ground contact. Th other forks i tried were Suntour Aion 35, Fox EMTB34 and fox 36. All failed. Wheels : go for boost wheels with 32 spokes for EMTB's : the DT hybrid series (up to 150KG max weight) and Mavic(up to 180kg). We ride DT Swiss H1900 for 3000 km without problems. Price is also OK. U can change to the ratchet freeweheelbody. Drivetrain everything on the right also. Reason : cheaper, bigger choice and EP 8 motor. Important is that there is a differnce between timing chain wheels and driving chain wheel. eg 34/32/30 teeth an 38 teeth. This helps avoiding chain jam. Because the pedal of the stoker hit the ground very hard a few times wit low forks the eccentric in the bottom bracket moved which overtrensioned the chain 2 times and one time jammed the 2 chains. When the chains jammed one chain broke. Everything fixed on the trail. Since 14 cm fork this problem not happened again. Brakes : magura MT5 with 18 to 22 cm rotors depending on the terrain we ride. In the back the 22 cm rotor handels the heat very well. |
Originally Posted by DangerousDanR
(Post 22000897)
We have been running a 1X on our tandem from the start. Our working cadence is the key to this. We have a 30 tooth chainring in front and a 11-50 9 speed cluster in back. Our wheels are 700C and currently we are running a 700X32C Conti GP5000. I originally had a 9-50 SRAM11 speed in back, but I switched to the Box 9 speed because I felt that the chain line angle with the 11 speed was the source of poor shifting. The Box 9 speed does indeed shift much better
With the 11 tooth sprocket we have a top speed under pedal power of right around 30 MPH. We can run a fairly high cadence, With the 50 tooth sprocket we have a 3 MPH crawl speed that has taken us up some fairly steep ( more than 10%hills. With a long steep downhill and gravity to pull us we have seen a top speed of between 45 and 50 MPH. We consider this acceptable for a touring tandem. We are able to bridge the gaps in the gearing as our working cadence is from 75 - 105. We are both in our mid to late 60's and while we are in pretty good shape for people in the 65-70 year range we are not going to win any races. Our longest days on the bike have been in the 75 mile range and Mrs. Dan was ready to kill me at the end of those days. We have an agreement that no future tour will include such a day without approval of the Stoker. I’m not sure that math quite works. With 32mm tires, 105 RPM in the 30/11 yields 23 mph according to gear calculator.com |
... our working cadence is from 75 - 105. ... |
All times are GMT -6. The time now is 08:30 AM. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.