Tiagra 4600 BB - BBS02...

[its_just_a_ride]

as title, this is my intention, I have a 2009 Genesis Vapour cyclocross that I've put MTB bars on, road wheels and moderately skinny slicks (although may go back to something fatter for comfort). I've used it as a light tourer, commuter, sportive and everything inbetween and am now planning to convert it.

I have a big hill Ill need to get over and back each day (all off road of course.....).

The bottom bracket I last installed was Shimano BB4600 Tiagra Bottom Bracket BC137 English Thread. From what I can gather the kit will work with the bikes BB based on what Ive currently got but seeking reassurance.

Second part is, hill is 1.5 miles and 715ft ascent (one of them there Pennines) on way out and 3 miles 600ft ascent on return. I'll be free wheeling all the rest obviously. Is my proposed kit likely to be the right kind of thing?

Other option is to continue on an do full journey which would be round trip of 46 miles with 3000ft total ascent..... is this achieveable on a regular basis? I can charge inbetween.

All comments and thoughts welcomed.

Ed

 

[Deleted member 4366]

The BB will be OK.

 

[tommie]

as d8 says,

46 miles??
just do not skimp on the battery, you`ll need a 52/48v 17.5aH at least.

 

[its_just_a_ride]

as d8 says,

46 miles??
just do not skimp on the battery, you`ll need a 52/48v 17.5aH at least.

The 46 miles is only an option. Option 1 is 5.3 miles each way to train station with the hill described. Option 2 is 46 miles and lots of hills. Realistically option 1 is what im aiming for until i get familiar with it.

Another question: Aiming for reliability and good speed up the hill, is there any caution necessary with over powering the motor and choice of motor?

Another question: What are recommended chain ring cassette combos, i planned on changing the 12/25 cassette i have at present as its hard work up the steeper bits of hill with current chain ring which i think the smallest is a 42 and i guess if motor or battery fails need some easier cogs....?

 

[Deleted member 4366]

Think about security if you plan to leave your bike at the station. You could come back to find the motor gone, which would mean that you wouldn't even be able to pedal it.

I know several people, who's Bafang mid-motor packed up after riding in heavy rain, so only leave it at the station under cover.

The standard chain-ring will be about right. if you want lower gearing, change the cassette to an 11T/32T or something like that. Don't forget that the motor will be pedalling with a force of four of you or more, so don't change anything until you've tried it; however, I'm pretty sure that you'll want a higher top gear.

 

[its_just_a_ride]

Hmmmm.... heavy rain is kind of the norm in these parts, I'd be stuck if I couldn't get it sodden wet 8 months of the year and frozen and salty the other 4.... are they generally bad in rain or just the odd one or two?

I was going to go 11/30 on rear as it was originally, standard chain ring doesn't seem to exist, it's all options options options!

I'm not that weak in the legs and have cycled the hill many times but I'll now need to do it 5 days a week. Twice. And in good time!

Since I literally only need to get up it and freewheel down I was going to go for a 42 or 44 up front. It's pretty steep on the way out.

Are any motors known for being more waterproof than others? I'm coming from a Ducati, that doesn't really like the wet either!

 

[topographer]

Ask around at the station for somewhere to leave your bike safely.

 

[anotherkiwi]

42:30 will get you up most anything, I use an 11-32 7 speed cassette and have 42 and 32 chainrings. The 32 is for Navarra, they do hills that stall motors over there... 32:32 in assistance level 5 will climb ramps, scary ramps!

 

[Woosh]

you would be better off with a lower power setup, a little less speed flying up the hill but longer range.
I'd suggest the XF08C kit with 17AH HL battery.

 

[its_just_a_ride]

Hmmmm. Is that a rear wheel kit woosh? I've got R500 wheels at present, no plans to change them. Crank kit seems the way forwards. I'm getting more tempted by doing the whole journey by bike, reliability is main concern as I'll be racking up huge miles if I go with that option though security then ceases to be an issue as we have a cage under the building I work in.

I've gone for a 12-27 cassette as the 12-25 I've got at the moment is only just too tough on the monster climb under my own steam, my small chainring is a 42 at present so will keep ratio the same at conversion. Still a bit concerned about rain and the likes. Trying to get a cheaper late nineties mtb to convert now as well which would let me keep my current as a spare in case of a breakdown.

 

[its_just_a_ride]

Here is route profile of whole journey. The neares rail station is at 5.3 miles... on the other side of the huge hill...

 

[topographer]

https://www.theguardian.com/cities/2016/sep/14/e-bikes-long-distance-commuting-speed-pedelec-electric-cycles