Cube Acid 400 chainring upgrade

[TobyAnscombe]

Just a quick sanity check before I click the order button!

I've a Cube Acid 400 that I use on trails and on my commute. Commute is relatively flat, maybe 100m elevation change over a 6km route. I'm finding that with the default 38t and 11-34 that I'm constantly on the bottom 3 sprockets and I'm spinning out on some gradients when I get close to 35-40km.

Logic says that increasing the front sprocket should solve this and allow me to use more range on the rear (fringe benefit of upping my speed if I can keep up!) so looking around it seems that
https://www.bike-discount.de/en/buy/fsa-bosch-gen3-e-bike-w0120-50.5mm-chainring-40t-846256 will fit as a like for like replacement. Its only a 2 tooth increase so I'm hoping I get some of the benefits without radically altering the current feel... opinions welcome!

In terms of other stuff - will I need anything more than:
https://www.bike-discount.de/en/buy/radon-puller-for-bosch-and-brose-e-bike-lock-ring-locking-ring-779929 to undo the lock ring and https://www.bike-discount.de/en/buy/bosch-lockring-incl.-o-ring-for-mounting-chainring-active-performance-504996 to keep in reserve just in case? Anything else worth doing on the bike? I've only done about 400 miles so far so its probably too early for anything else...

 

[Andy McNish]

"I've a Cube Acid 400 that I use on trails and on my commute. Commute is relatively flat, maybe 100m elevation change over a 6km route. I'm finding that with the default 38t and 11-34 that I'm constantly on the bottom 3 sprockets and I'm spinning out on some gradients when I get close to 35-40km"

That's quite a quick pace for a Cube (which is a pretty heavy bike) that cuts off at 25kph.
I speak as someone who uses a similar bike on a flattish 20km each way commute.
Is it dongled or are you pushing it to 40kph on the flat under your own power?

If the latter you might be better off just buying a budget road bike (or if there are some off road surfaces involved a gravel bike) for the short commute as, if you are that fit, you'll probably find it faster and easier to use.

 

[TobyAnscombe]

;-)

Big bike + big rider means gravity is your friend (at least going down hill...) I'm averaging around 26km on the whole journey and can keep it around that pace on the flats/gentle gradients with no problem. I've not got the strength or conditioning to pull off the bottom sprocket on anything other than hills but on the 9speed that comes with the bike I am almost always in 7,8 or 9 unless there is a bloody big headwind!

My speeds are 25-27km on the flats and 35-45km on the hills - the battery is there to help me back up the hills on the reverse journey. You can see my profile on Strava https://www.strava.com/athletes/1085593 and FWIW I'm normally in Sport mode and the battery lasts me about a week..

Its only on the downhills that I want an extra cog - bit of effort from me will see me coast much further up the other side but I can't make the cadence work for me. If I was pulling that on the flat then I'd be off to Decathlon for a cheap road bike to abuse on the commute but I'm not quite there yet...

 

[Artstu]

2 teeth more isn't much, I'd run a few options through a gear calculator first, I'd have thought you need at least 45 teeth.

There are plenty of options for 104 mm BCD chainrings, here is just one example, good choice of sizes too in 3/32" width.
Gebhardt Singlespeed MTB or Road 3/32" 104mm BCD Chainring

VeloSolo Shop - Chainsets, Chainrings, Chainring Bolts

VeloSolo Fixed Wheel & Singlespeed Bike Shop - Chainsets, Chainrings, Chainring Bolts

www.velosolo.co.uk

 

[Andy McNish]

Oh, downhill! I see.

I just coast downhill if I'm already doing 30kph+ to be honest. Never really thought about pushing faster.
I suspect that I have the same 9 speed default set up as you (I have a Cube Touring Hybrid). so I'd be interested in seeing what you come up with as a solution.

 

[Artstu]

You can see my profile on Strava https://www.strava.com/athletes/1085593 and FWIW I'm normally in Sport mode and the battery lasts me about a week..

Nice to see a Cube used as they were intended to be used, the only thing I'd say is you should really be listing your rides as E-Bike when you're on your e-bike

 

[Artstu]

I did a time trial on my bike the other night, came last of course but I was interested to see how I'd get on on my 23kg plus hybrid with hub gears and the power off, pretty happy with 15.7 mph average on the TT to be honest. https://www.strava.com/activities/2367787337

 

[TobyAnscombe]

@Artstu - good effort!

 

[Andy McNish]

I just did the 100km Tour de MAnc Sportiv on mine. weight more like 30kg with panniers on.
I unexpectedly found myself doing it with an old work colleague on her 9kg aero-bike!

The hills were fine but the flat sections almost killed me trying to keep up! Unlike every other rider I was praying for red lights

 

[TobyAnscombe]

Just a heads-up for anyone who's following.

I ordered a new 46t sprocket from VeloSolo without checking the clearances and its too big to fit in the same position as the current sprocket. Will try to fit it "in reverse" (aka rather than behind the spider, in front of the spider) as it looks like that should give enough clearance to the frame.

 

[mark_north]

@TobyAnscombe Did you manage to find a sprocket that fitted. ive also got an acid 400, and also have the same issue going downhill..and never need the lowest gears for going uphill.
Would be great to know if you got it sorted.

 

[TobyAnscombe]

It’s in progress. It turns out that there are two sizes of Bosch spider locknuts and I bought the wrong one!!

 

[mark_north]

It’s in progress. It turns out that there are two sizes of Bosch spider locknuts and I bought the wrong one!!

nightmare !! i wouldnt have known any better either so its good to learn from your experience....good luck getting it all sorted

 

[TobyAnscombe]

Yeah, imagine how happy I was when it turned up and didn't fit. https://www.amazon.co.uk/gp/product/B07CRB4X98/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1 is not the spider you are looking for.....

What I am trying is I've bought some longer chainring bolts and will space out the chainring so that it clears the frame - the engineer in me isn't happy but if its only spaced out by a couple of mm then it *should* be ok and allow a quick reset back to hill-climb mode for the weekends..

 

[TobyAnscombe]

Yeah, even my 2nd spider is the wrong size. Out with the screwdriver and hammer..

Anyone want a cheap spider that doesn’t fit a Gen3 ALP?

 

[TobyAnscombe]

New sprocket mounted on the outside of the old spider.

Might need a longer chain ;-)

You can get a rizla paper between the sprocket and the frame...

A quick spin out round the village and it felt about 4-5km faster and a gear maybe two higher for a given cadence. Will try my commute tomorrow and see what Strava says...

 

[xena]

Anyone want a cheap spider that doesn’t fit a Gen3 ALP?

I'm in the market for one for the CX...? Do you think that's what you've got? Ta

 

[TobyAnscombe]

PM me your address and I'll post you one to try ;-)

 

[Gringo]

View attachment 30761View attachment 30762View attachment 30763

New sprocket mounted on the outside of the old spider.

Might need a longer chain ;-)

You can get a rizla paper between the sprocket and the frame...

A quick spin out round the village and it felt about 4-5km faster and a gear maybe two higher for a given cadence. Will try my commute tomorrow and see what Strava says...

Did you consider leaving the small ring in place ? Best of both worlds, just lift the chain off one ring and drop it onto the other when ever you have the need

 

[TobyAnscombe]

Yah. Only coz I don’t have any longer chainring bolts.. it will do for a trial but it’s pissing it down today!