Barchettaman

I have converted my 7-speed Tern to 9-speed with a new wheelset from AliExpress. It’s been an excellent upgrade; the bike is however very slightly over geared, so I am considering a new crankset.

Have any of you upgraded or swapped out your crank and bottom bracket from the supplied square taper Tern one?

Are there any major pitfalls doing this? It all looks fairly standard, without weird proprietary standards.

AliExpress offer cheap and light cranksets. After the positive experience with the wheels I am considering getting the crank there too. Any recommendations?

In an ideal world I would also like a slightly lighter option, as the combined weight of bike plus bag (Dahon Airporter) means I can’t add as much luggage as I would like!

thanks all!

Simon

Barchettaman

Barchettaman

We all like photos of bikes, so here are a few of it post-wheelset upgrade. It’s a Link B7 I think

Ron Damon

Several years ago I swapped out the Square Taper BB on my Dahon Dash for a Hollowtech 2 one. Removing a ST BB requires a crank arm extraction tool and then a wrench for the BB shellb itself. If you are gonna do it yourself, you'll need those two tools. Hollowtech simply screws on the BB shell threads, but you'll need a HT 2 wrench to tighten. You'll want a HT2 BB for 68 BSA threads. I default to the Ultegra/105 level Shimano BBR60 which sells for under $20 in my locality




I've used Litepro HT2 cranks, chainrings and bolts since 2016 without any problems so I recommend those items. Go with the steel bolts rather than the ones from 7075 Al.


Litepro crank and chainring in continuous service since 2016 across two bikes and four countries

Jipe

You do not necessarily need a crank arm extraction tool, self extracting crank bolts for square taper also do the job.

seat_boy

I've used the Litepro crank on my Bike Friday for the last few years, no complaints here.

OK, one complaint: they advertised the ring as narrow wide, but it's not really. But the crank itself is OK, nothing fancy.

Ron Damon

Litepro offers both straight-narrow and normal chainrings. I should know for I've installed and used both types. I, myself, always buy the crankarms and the chainring separately, both of which are offered in a few different styles and specs.
.

Litepro chainring, wide-narrow sans chainguard
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Litepro chainring, normal with integrated chainguard
.

Oh yeah, make sure the bolts you purchase match the drive configuration. 1x bolts for 1x, 2x bolts for 2x.

tds101 

I love IitePro parts. The quality is better than most, and the pricing is excellent...even here in the USA.

seat_boy

Does Litepro make an actual NW ring with the integrated chainguard? I've grown to like the chainguard on mine, though I would probably like the NW ring more.


(I had the ring on backwards in the above picture, in an attempt to keep the chain from falling off every time I folded my BF. It didn't help, and I dropped the chain a few times every ride. This setup didn't last long, but I like the background in this picture )

Ron Damon

Not that I know of. The ones with the integrated chain guard are the original, classic chainrings. I still like their simple aesthetic the most.

jfouellette

I have four Litepro crankwheels. They have been reliable. Two are on square taper BB and two on hollowtec.

Barchettaman

50PlusCycling

I swapped out the square taper crank set on my Birdy, and bolted in a Shimano Dura Ace system with the Hollow Tech bottom bracket. No other mod I did helped so much to lighten the bike, the Hollow Tech parts weighed half as much as the original parts.

Ron Damon

Well, for example, the Goode ole' Shimano BB-UN55 ST BB weighs 300g while the BBR60 HT2 BB weighs about 80g so there's that. But, on the plus side, you gotta take into account the weight of the spline on the HT2 crank.

Jipe

Tourist in MSN

If you get one of these, make sure that the black rings that thread into the crankset are tight and you may consider using a thread locker to make sure they stay there.

I used those on my heavy touring bike several years ago for a month long tour. I have to remove both crank arms to fit my bike into the S&S case. But one of the black rings self extracted somewhere in the middle of Iceland. When I went to remove both crank arms, discovered one was missing. That meant I had to remove the other one to move to the other side of the crank when I lacked the proper tools to do that. Since then I now carry a real proper crank arm removal instead of the self extracting crank bolts.

Ron Damon

Do you mean to tell us that the self extracting bolt self extracted? 😆

To be fair, though, I've heard plenty of stories from folks with HT2 cranks whose non-drive side crank arm simply feel off while pedaling, enduring insufferable embarrassment, cuz the main bolt had unscrewed. Note that unlike pedal threads, the main HT2 crank arm bolt on the non-drive side, is threaded normally, meaning that it unscrews in the same direction as the pedaling motion.

Tourist in MSN

Yup, as I said: But one of the black rings self extracted somewhere in the middle of Iceland.



As I noted, using a threadlocker would probably prevent it from falling out. I did not suggest more detail, as the OP is in Germany and I do not know what brands of thread locker is sold there. But the removable (blue) would be best.

Not sure what an HT2 crank is.

Many years ago a friend was out for a bike ride, he later told me that as he was riding, he suddenly heard someone swearing loudly. He looked over and saw a bicyclist with a crank arm hanging down from his foot. That was in the toe clip era, before shoe cleats.

I have square taper cranks on most of my bikes, but my road bike that I bought as a complete bike has a Campy Power Torque. All the bikes I built up from parts, which is most of them, have square taper.

Ron Damon

Hollowtech 2 (HT2)


Replacement metal bolt

Duragrouch

I agree with others, and strongly recommend replacing a square taper bottom bracket, with a hollowtech II style crank (but NOT Shimano, there is a recall on many, come apart, a spider bonded (glued, or mashed together under pressure) to the chainring).

External bearings last longer, both because larger and/or more balls per side, and spaced further apart, but also because you can periodically readjust the bearing preload to take up slack; you can't do that with a cartridge square taper BB (you can with old style non-cartridge, but it's a pain), and once loose, wear accelerates; proper preload (zero slack) is key. The crank does not freeze up on the taper due to corrosion, or work its way loose due to putting anti-seize or grease on the taper. Very easy to remove the crank for cleaning.

My preference is retro 5 bolt on 110mm bolt circle diameter, with replaceable chainrings. I'm currently using a 50/34 that came complete with external bearings for about USD $75, equal or less cost than 2 chainrings alone. The bearing spline style is "ISO external", quite common. I'd recommend a bearing wrench that has the 4 most common styles, it's only slightly more expensive than a 2 or 3 way wrench, and you're set for life.

Barchettaman

I’ve gone with a Litepro 47t square taper crankset, for €33,50 it seemed like a decent deal.

I might convert the whole rig to drop bars too as I have the parts (drop bar with MTB clamp diameter, 9-speed Shimano STI shifter, a travel agent, a Tektro long pull drop bar lever) in the parts bin.

I just need to check that it’ll fit OK in the Dahon Airporter suitcase with the drop bars as I travel with this a lot.

Duragrouch

If the handlebar clamp opens up like a clamshell so drop bars easily removable, my guess is it should fit that way, if not fully assembled.

I have an early Dahon stem without a clamshell clamp, so would take an hour to pull apart and an hour to reassemble. I may have to upgrade that if I travel; no drop bars, but do have flat bar with bar-ends and clip-on aero bar, which makes for a bigger fold because that stem folds between the frame halves. But the telescoping stem is weaker. I'll look for a tall fixed stem with clamshell clamp.

Barchettaman

When I got the bike I found the reach at the bars too short and the handling very twitchy. I ended up with a stem extender from AliExpress which works superbly well:



I highly recommend this mod; it transforms the handling and comfort of the bike. I know there’s an Andros stem extender from Tern but it was incompatible with my handlebar post.

I need to check if the 25.4 drop bar has a wide enough clamp diameter for this extender, and if so, I will have a look at swapping them in.

Duragrouch

Yes, putting the bars further forward helps stability, both by putting that mass further forward of the steering axis, and your hand force causing a more "centering" feel; My handlebars are centered on the stempost but are still forward of the steering axis as the stempost is canted forward from the steering axis.

Yes, width of clamp diameter on bars can be a problem, both for that, and for typical clip-on aero bars that don't mount close to the stem clamp; clamping on the smaller diameter is possible with shims, but problematic if clamping in the transition (tapered) area between diameters. If aeros clamp close to the stem, then they prevent use of a stem extender like you have. I have aero clip-ons.

I saw some of those extenders on amazon, but most looked much less stout than the Tern part, which is expensive; The parts will be subjected to significant torsion loads when climbing, in addition to normal bending loads. Some looked like they were designed just to mount a short bar for accessories like lights and computer, but not transfer handlebar loads to the stem. But again, I can't use due to my aero bars. Also, my current reach is perfect.

What I would like to fit, and would be worth the cost, is one of those parallel-link suspension stems, which my current stempost will not accommodate, but even if I get one that does, I don't want the bars further forward, which that stem would do. A stempost more tilted back would correct that, but then is more likely to get hit with my knees when climbing.

Ron Damon

Another, perhaps simpler way to add reach is use a riser bar rotated forwards.

An advantage of this approach is that whereas stem of the sort above are kinda limited in size, riser handlebars come in a myriad of rises. You need 9cm of additional reach, no problem. Ridiculous, yes, but you can simply get a 9cm riser bar.