dmnobrien

Just noticed that Bike Friday has a new Season Tikit, using the SRAM i-Motion 9-speed hub:
https://community.bikefriday.com/node/11312?styleId=1676

...and here's a blog entry about it from BF Walter, with pics:
https://bikefridaywalter.wordpress.co...or-a-new-ride/

One big plus for me is the gear range of the i-Motion - 101-30 gear inches [incorrect - see below], compared to the Nexus at 88-29 and the stock Tikit at 79-31. Wellington is hilly, and I'm doing some light touring, so I'd like both lower and higher gears than the stock model.

Couple of things I'm wondering about, if anyone has experience with these bikes (or these hubs):
- Does the i-Motion Tikit replace the Nexus-based one, or is it just another choice? I'll ask BF.
- How does the i-Motion compare to the Nexus in everyday use?
- Is it worth the extra $300 over the Nexus? ($1,925 vs. $1,615) Didn't notice any other differences in spec.

Any help appreciated.

ChiapasFixed

sweetness! can the i-motion 9 take disc brakes? i have a tikit with the Alfine hub and BB7's, the shifting is super smooth and the hub is completely silent, but does not have quite the range of the sram. in fact, the range is exactly the same as the nexus-8, although alot smoother, quieter, and more efficient (i have the nexus-8 on my Joey), and it can take disc brakes..

Joako

dmnobrien:

In order to get that gearing with the I-Motion 9, you will need a 62T chainring, which is rare and expensive.

I never used an I-Motion 9, but from the research I did when looking for an IGH for my wheel build, I found out that the I-Motion:

- have more evenly spaced gearing
- it is easier to remove the wheel than a Nexus/Alfine
- weights more than a Nexus/Alfine (about 2000g)
- only grip shift for now
- does not use silent clutch, so you will hear the tic sound as in most hubs
- 36 holes only

Now the Alfine/Nexus (I had the red band 8r36 with triple roller):

- Gears are not evenly spaced
- Super silent (no one will ever hear you coming)
- Shifts while pedaling
- grip shift, trigger shift, and thumb shift
- Wheel is harder to remove
- The Alfine is a hardcore hub and it has been tested by mountain bikers in some nasty terrain. Check the mtb forums.
- 36 and 32 holes plus black and silver finish

Is it worth the $300 difference? It depends on how you look at it. For me, I can build an imotion wheel for about $375. So I would rather spend an extra $75 for a new wheel, try both, and then sell the one I did not like, or keep it as a spare.

ChiapasFixed:


Yes, the I-Motion 9 accepts disc brake. ISO standard, not centerlock.

boston blackie

Price is over $400 for the hub and shifter here: https://www.sheldonbrown.com/harris/sram.html
Add the cost of wheel and building and that's a lot.

feijai

And which will not fit on a Tikit.

The largest chainring which will go on a Tikit is probably 61T.

chucky

How many gears do you really need?

Maintaining consistent speed is a more efficient use of energy. So you're better off grunting up hill in a higher gear and cruising down hill in a lower gear anyway.

invisiblehand

Is that with the smallest sprocket available?

invisiblehand

A 36-hole hub with small wheels is a royal pain in the @ss in my opinion. At least if you use all of the holes and use a crossing pattern.

invisiblehand

I just checked, it appears that an 18-tooth sprocket is the smallest available and yes ... one needs a 62-tooth chainring to reach the high gears discussed earlier.

tcs

A Sturmey-Archer XRK8(W) will give 96-30 G.I. @ 46/25T, ISO35x349mm. The Sturmey 8 is available with 28 spoke holes.

If it's high gears one desires on their tikit, a S-A 8(W) with the stock 53T chainwheel and a 19T cog would yield 146-45 G.I.

tcs

dmnobrien

Don't know the details of the components, but BF Walter listed the i-Motion as yielding 101-30 GI (he corrected himself later - see below), and I assume he meant on the Tikit that he has. Hmmm.

As far as gearing needs go, I'm no expert for sure, but I do know that:
- On my Mu P8, low gear is 33-ish, and I keep wishing I could go one lower on the hills here, especially if I had the extra weight of touring stuff.
- The Mu P8 tops out at 92-ish, and that's OK, but if I got an extra gear on top, I would definitely use it.

My main problem with the stock Tikit is the top end of 79 GI. For my intended routes, that's just too low. And I like the idea of a low-maintenance drivetrain and clean chainline, hence my interest in an IGH.

I think the low end of the Capreo is 39 (?), and so that wouldn't work for me either. I figure if I'm spending this kind of dough on a bike, I can afford to be picky.

invisiblehand

Well ... what is the smallest cog that you can put on an Alfine or Nexus? You can always use a double crank in the front to get the extra range you want. Similarly, you can do the same with the Capreo hub. a 56/39 double in the front mated with the Capreo hub would provide appropriate gearing.

Joako

Alfine/Nexus = 16T

tcs

IIRC a SRAM P7 will fit a 14T sprocket. I could be wrong.

tcs

K6-III

It can even go down to 13t!

tcs

With the stock tikit 53T chainwheel an S7 with a 13T cog would yield 114-37 G.I.

tcs

invisiblehand

Then if you are looking for high gears, one would need really big chainrings like 60t.

dmnobrien

Just asked BF Walter about the gear range of the SRAM iMotion 9 (originally reported as 101-30), and he corrected the numbers as follows:

"The stock configuration comes with a 20 tooth cog, yielding 80.5-23.7
...the highest cog I know to be available is an 18 giving 89.5-26.3.
...You could put a 54 on there with the 18 and get 91.2-26.8
...or go 56 and get 94.5-27.8."

I think the Nexus is something like 86-28, so it looks like the iMotion gives a higher top end for a given low gear (28 GI is good for my purposes).

The other difference I'm pondering is the handy cable release on the SRAM. Is the Nexus a pain to deal with if I get a rear flat?

Joako

Yep, better practice a few times and carry a solid object to help you push the lever. There is another solution, which I used to do with my 08 Curve SL; just keep the shifter housing long enough in order to have enough clearance to pull the wheel off the dropouts.

badmother

NO, the Nexus is not difficult to remowe. where did this come from? Nexus is super easy, just pactice a few times at home so you know what t is like and what tools you need.

ChiapasFixed

super easy to remove the nexus cable IF you have a very thin allen key to slip into the special hole and move the spring loaded cam... doing it this way literally takes 1 second.
otherwise it is hard on the fingers, and you will be cussing and swearing.

dmnobrien

Thanks for the replies on removing the Nexus hub. Sounds like even I can handle it.

For my purposes, I don't think the iMotion9 is worth the extra $300 over the Nexus. So I'll probably go with the Nexus Season Tikit.

Besides, I just learned that the Season Tikit price ($1615) doesn't include the hyperfold - that's a $226 option on all custom Tikits - ouch!

vik 

I've got a Season Tikit [on long term loan to a friend] a regular Tikit, a NWT with an Nexus 8 and a Surly Pugsley with an Alfine. FWIW I also have two Rohloff equipped bikes.

I can definitely say the Season Tikit is a worthwhile upgrade on the standard Tikit if your budget allows for it. If I had to replace my Tikit I'd get one with a Shimano Alfine hub for sure.

Every time I have added a new IGH hub to the fleet I looked at the SRAM offerings. They do have some good points, but the quality of the shifting and ride of the Nexus 8 and the Alfine have kept me loyal to Shimano's IGHs. The shifting is the nicest of any bikes I've owned.

I have also abused an Alfine in beach sand, saltwater, desert sand/dust, snow/salt/grit, +40 deg C to -40 deg C, offroad/dirt road fully loaded touring, corrosive dust for a week at Burning Man - and this Alfine hasn't even noticed. It just keeps pedaling and shifting like it was business as usual.

dmnobrien

Vik, thanks for your IGH wisdom. Your blog was the first place I saw a Season Tikit.

From the BF page, it looks like they're offering the Red Band Nexus 8. Not sure if they offer the Alfine. How would you compare the Red Band to the Alfine?

vik 

Well on paper the Alfine is a superior hub, but I'm not sure if I could tell the difference from the saddle. All the bikes I have Nexus 8 or Alfine hubs in are quite different so it's hard to compare.

I'd probably hold out for the Alfine. I'd be surprised if BF wouldn't build you a Season Tikit with an Alfine if you asked nicely.