Author Topic: Tern up for the books  (Read 3421 times)

Si

Tern up for the books
« on: 31 July, 2021, 04:48:12 pm »
I've had my tern link p24 for at least seven years.  Not had that much use as it felt like riding through treacle.  A friend had the same model and felt the same.  So it just got used to for short trips around town that might be too hilly for the brommie.

Finally got around to having a tinker.  My friend thought it was the hub dynamo causing the drag...I wasn't convinced.  I removed the 3x8 dual drive hub and slapped in an old quando 7 SPD.  Then took it out again and respaced it so it fit.  Put an old 8 SPD cassette on with the little sprocket omitted.  Took it fr a ride, not expecting a lot.  Good heavens!  It's like a different bike....feels effortless to ride.  Having only used it a few times a year I'm now riding it several times a week!

Not quite as fast as my road bike but just feels so good.  Have even ridden into work on it (40 miles) a couple of times.

Problem now is the saddle.  I think the small wheels and frame, and fat seat post send a lot more vibration up through the saddle than a 700c bike.  Plus, being a small wheeler I ride out the saddle a little less.  Have tried putting my comfie touring saddles on it but still a pain after 20miles or so.  Thinking of a sprung saddle but the nice brooks are soooooooo expensive.  If I can solve the saddle issue then I will be off touring on it.  Might also need a bigger chain ring.

It may also explain why my experience of ridingna 'bent wasn't so convincing.....despite the aero advantage my 'bent was never any faster than my upright despite riding for a few 1000 miles to get my 'bent muscles.  Could it have all been down to the dual drive hub like on the Tern?  Might be time to try a bent again.

Re: Tern up for the books
« Reply #1 on: 31 July, 2021, 08:53:34 pm »
I've had my tern link p24 for at least seven years.  Not had that much use as it felt like riding through treacle.  A friend had the same model and felt the same.  So it just got used to for short trips around town that might be too hilly for the brommie.

Finally got around to having a tinker.  My friend thought it was the hub dynamo causing the drag...I wasn't convinced.  I removed the 3x8 dual drive hub and slapped in an old quando 7 SPD.  Then took it out again and respaced it so it fit.  Put an old 8 SPD cassette on with the little sprocket omitted.  Took it fr a ride, not expecting a lot.  Good heavens!  It's like a different bike....feels effortless to ride.  Having only used it a few times a year I'm now riding it several times a week!

Not quite as fast as my road bike but just feels so good.  Have even ridden into work on it (40 miles) a couple of times.

Problem now is the saddle.  I think the small wheels and frame, and fat seat post send a lot more vibration up through the saddle than a 700c bike.  Plus, being a small wheeler I ride out the saddle a little less.  Have tried putting my comfie touring saddles on it but still a pain after 20miles or so.  Thinking of a sprung saddle but the nice brooks are soooooooo expensive.  If I can solve the saddle issue then I will be off touring on it.  Might also need a bigger chain ring.

It may also explain why my experience of ridingna 'bent wasn't so convincing.....despite the aero advantage my 'bent was never any faster than my upright despite riding for a few 1000 miles to get my 'bent muscles.  Could it have all been down to the dual drive hub like on the Tern?  Might be time to try a bent again.

What size tyres do you have? I have 44x406 BMX tyres on my Montana (Tern clone) and they do take the buzz out of the road. My folder is very nearly as quick as my (fairly non-descript) road bikes (probably as quick or quicker on some rides, truth be known). Others on here would probably suggest Marathons but mine were cheaper and I don't need the puncture protection to the same extent as a big city rider. Big sections on those 20" wheels don't seem to make the bike slower, if anything I would say the opposite, and a lot more comfortable

StuAff

  • Folding not boring
Re: Tern up for the books
« Reply #2 on: 31 July, 2021, 09:38:16 pm »
Having owned two DualDrive equipped Dahons- and Chutney the Speed Pro TT in particular is most definitely Not Slow,  I'm not sure that the hub was the problem-though if you've got a regular derailleur setup on there, the bike's lost a kilo in weight, which will of course help a lot. Drag in 1:1 is practically non-existent and there's not much in high/low mode (YMMV). Possible it was faulty or just needed careful tweaking. I'd agree with mzio that tyre choice is crucial, I found 28mm on the TT too harsh- though fast- and like the Jetstream XP I previously had, went to 40mm (Marathons on the XP, Marathon Racer on the TT). Done up to 140 miles on the TT…

Would recommend staying on the saddle -if out then the long handlepost is not going to like the extra stress at all, and it certainly doesn't help stability.

LittleWheelsandBig

  • Whimsy Rider
Re: Tern up for the books
« Reply #3 on: 31 July, 2021, 09:51:40 pm »
Small wheels need fast tyres more than big wheels do. Wider tyres are more helpful for small wheels than big wheels.

As noted above, direct drive in a hub gear has virtually no additional drag. If that gear felt slow, the hub was badly adjusted.
Wheel meet again, don't know where, don't know when...

Re: Tern up for the books
« Reply #4 on: 01 August, 2021, 06:15:34 am »
My DAhon Speed TR came with a Thudbuster seat post that was so comfortable I fitted them on two other uprights.
Never knowingly under caffeinated

Si

Re: Tern up for the books
« Reply #5 on: 01 August, 2021, 04:48:58 pm »
I can only report as I find.  There is certainly a marked difference.....for one thing I'm cruising two sprockets smaller and in danger of running out of gears....something that rarely happened in middle ratio when hub gear was installed. 

It may be that there was an issue with this particular hub gear......although it was practically new when I had it and it was certainly set up right.

On the other hand, many years ago I had the same set up on a Birdy, and that didn't feel slow...back when I was much fitter.  Perhaps those who put out less power to start with feel the extra drag from running a derailer and hub setup together a bit more?

As for tyres, currently has fairly wide marathon Supremes....are these considered a good compromise of comfort, reliability and speed?

StuAff

  • Folding not boring
Re: Tern up for the books
« Reply #6 on: 01 August, 2021, 05:08:51 pm »
I can only report as I find.  There is certainly a marked difference.....for one thing I'm cruising two sprockets smaller and in danger of running out of gears....something that rarely happened in middle ratio when hub gear was installed. 

It may be that there was an issue with this particular hub gear......although it was practically new when I had it and it was certainly set up right.

On the other hand, many years ago I had the same set up on a Birdy, and that didn't feel slow...back when I was much fitter.  Perhaps those who put out less power to start with feel the extra drag from running a derailer and hub setup together a bit more?

As for tyres, currently has fairly wide marathon Supremes....are these considered a good compromise of comfort, reliability and speed?
I have bugger all power & don't notice the drag much!  :)
Marathon Supremes (now sadly discontinued in 406 size) are terrific- fast and comfy and tough. Might try G-Ones on the TT when my Racers are dead.